Preface

The dairy industry has faced several challenges that impact dairy food quality and consumer acceptability. As a response to these challenges, this book presents a different approach to address these issues facing the dairy industry and includes seven chapters dealing with dairy processing, probiotic characteristics, and current issues related to consumers. The book is divided into four sections and begins with an introductory section that describes the background and history of dairy science along with recent developments. The second section is related to dairy processing technology and covers drying processes and by-product utilization. The third section of the book consists of two chapters that address dairy supply chain risks and issues related to consumer decisions about dairy products. Finally, the last section deals with dairy foods as functional food products and the probiotic characterization of yogurt starter culture.

**Salam A. Ibrahim, PhD, Tahl Zimmerman, PhD, and Rabin Gyawali, PhD** North Carolina A&T State University, Greensboro, North Carolina, USA

**II**

**Section 4**

Functional Dairy Food Products **79**

**Chapter 6 81**

**Chapter 7 101**

Development of Functional Cheeses with Fructooligosaccharides

*María L. Castells, Noemi Zaritzky and Mercedes E. Campderrós*

Probiotic Characteristics and Health Benefits of the Yogurt

*by Ayowole Oyeniran, Rabin Gyawali, Sulaiman O. Aljaloud,* 

*by Diana Palatnik, Noelia Rinaldoni, Diego Corrales, María L. Rolon, Haydée Montero, Germán Aranibar,* 

Bacterium *Lactobacillus delbrueckii* sp. *bulgaricus*

*Albert Krastanov and Salam A. Ibrahim*

**1**

Section 1

Introduction

Section 1 Introduction

**3**

world [4].

fermented milks [6].

**Chapter 1**

Technology

**1. Introduction**

Introductory Chapter: Overview

of Trends in Dairy Science and

*Tahl Zimmerman, Rabin Gyawali and Salam A. Ibrahim*

Dairy science and technology is a field that encompasses the production and manufacturing of all dairy products as well as the machinery and methods used in the dairy industry. The largest part of the food supply chain is, by far, the dairy industry. This industry is an integral part of our food economy that not only supplies consumers with many ready-to-eat products such as milk, butter, and cheese but also produces many of the ingredients like milk powder and condensed milk that are found in processed foods. Milk itself has also become a key ingredient for the deployment of probiotics and the development of functional food products designed to improve consumer health. As such, dairy products have become an area of accelerated research and innovation, particularly in the areas of processing,

Milk has been a source of sustenance for newborn offspring since the emergence of mammals: all species of which produce milk to sustain their young [1]. Meanwhile, the practice of domesticating other mammalian species for milk production and consumption is so ancient; it predates written records [2]. In fact, prehistoric baby bottles have recently been uncovered in Bavaria, Germany, indicating that animal milk was used as far back as the Bronze Age to feed infants [3]. The discovery of animal milk as a food source was an important achievement because a sustainable food source that could meet human physiological needs for energy, water, and nutrients was then available [2]. All of the animal species originally exploited for milk, including cows, buffaloes, camels, sheep, yaks, goats, horses, and camels, are still used today for that purpose as milk and milk products continue to be a diet staple in many cultures around the

The role of milk in traditional diets varies according to climate. For example, milk does not play a role in the diet of many tropical cultures as much as in temperate Northern Europe, where far higher volumes of milk and milk products are produced and consumed [5]. This is most likely simply due to the fact that, with a lack of refrigeration, warmer climates make milk refractory to long-term storage [5]. In these warmer climate cultures, milk has traditionally been consumed immediately or otherwise preserved by boiling or processing into more stable products such as

sustainability, and health, and marketing strategy.

**2. Historical reviews and developments**

#### **Chapter 1**

## Introductory Chapter: Overview of Trends in Dairy Science and Technology

*Tahl Zimmerman, Rabin Gyawali and Salam A. Ibrahim*

#### **1. Introduction**

Dairy science and technology is a field that encompasses the production and manufacturing of all dairy products as well as the machinery and methods used in the dairy industry. The largest part of the food supply chain is, by far, the dairy industry. This industry is an integral part of our food economy that not only supplies consumers with many ready-to-eat products such as milk, butter, and cheese but also produces many of the ingredients like milk powder and condensed milk that are found in processed foods. Milk itself has also become a key ingredient for the deployment of probiotics and the development of functional food products designed to improve consumer health. As such, dairy products have become an area of accelerated research and innovation, particularly in the areas of processing, sustainability, and health, and marketing strategy.

#### **2. Historical reviews and developments**

Milk has been a source of sustenance for newborn offspring since the emergence of mammals: all species of which produce milk to sustain their young [1]. Meanwhile, the practice of domesticating other mammalian species for milk production and consumption is so ancient; it predates written records [2]. In fact, prehistoric baby bottles have recently been uncovered in Bavaria, Germany, indicating that animal milk was used as far back as the Bronze Age to feed infants [3]. The discovery of animal milk as a food source was an important achievement because a sustainable food source that could meet human physiological needs for energy, water, and nutrients was then available [2]. All of the animal species originally exploited for milk, including cows, buffaloes, camels, sheep, yaks, goats, horses, and camels, are still used today for that purpose as milk and milk products continue to be a diet staple in many cultures around the world [4].

The role of milk in traditional diets varies according to climate. For example, milk does not play a role in the diet of many tropical cultures as much as in temperate Northern Europe, where far higher volumes of milk and milk products are produced and consumed [5]. This is most likely simply due to the fact that, with a lack of refrigeration, warmer climates make milk refractory to long-term storage [5]. In these warmer climate cultures, milk has traditionally been consumed immediately or otherwise preserved by boiling or processing into more stable products such as fermented milks [6].

Advances in the technology of milk production have occurred only relatively recently. The milk homogenizer was patented in 1899. This device was designed to break up milk globules in order to give milk the consistency that we take for granted today [7]. Automated milking systems appeared nearly a century later [8]. Milk production and biotechnology intersected in the 1990s with the advent of recombinant bovine growth hormones that were used to provoke an increase in milk production per cow [9] and the approval by the FDA of cloned animals for milk production in 2008 [10]. Recently, automated cell counters have emerged which can be used for the early detection of bovine mastitis [11].

Dairy product safety is an important issue because milk, being nutrient dense, not only serves as a medium that supports the growth of beneficial fermentative microflora [12] but is also a medium in which pathogenic species can proliferate [13]. The first dairy safety technologies included the invention of the process of pasteurization in the nineteenth century by Louis Pasteur, a technique adopted universally in the USA in 1917 [14]. The first milk safety packaging was glass milk delivery bottles invented by Henry Thatcher [15]. Milk tankers appeared in 1914 [16], and milk cartons became ubiquitous by 1974 [17]. In very recent years, cold pressure processing has been developed as an alternative to pasteurization [18]. Pulse electric field [19], ultra-sonication [20], and irradiation [21] have also been explored as alternatives. Meanwhile, dairy supply chains have become more centralized, leading to emerging issues in dairy safety. Hazard analysis and critical control point (HACCP) management programs have been developed to help neutralize biological, physical, and chemical hazards. HACCP mandates risk assessments at different points in the production process [22]. These programs demand continuous monitoring of the microbiota of both the dairy products and the production environment which has led to a new demand for rapid methods of microbiological detection and identification. As a result, novel rapid and high-precision techniques such as qPCR [23] and enzyme immunoassays [24] have been developed to identify milk pathogens such as *Campylobacter* and *Escherichia coli* O157:H7.

Another key achievement of mankind in the area of nutrition was the accidental discovery of bacterially fermented products from the milk of the domesticated species mentioned above [25]. Instead of being considered spoiled, these products entered the human diet as nutritional food products. Long before refrigeration existed and microbes were discovered, fermentation was adopted as an ancient method of preserving milk. As such, traditional fermented milk products are found in many cultures. These products include dadiah, the traditional fermented buffalo milk from West Sumatra; filmjölk, from Scandinavia; and the eastern European kefir.

Yogurt is the fermented milk product most widely distributed in the West and is thought to have been invented in 5000 B.C. Yogurt has also been known to be a health food for a long time: its health benefits are mentioned in the Vedas and in the Old Testament [26]. The type of yogurt we know today originated from the Balkans and is produced using a culture of *Lactobacillus delbrueckii* subsp. *bulgaricus* and *Streptococcus thermophilus* bacteria. Yogurt was popularized in Europe and the USA in the first decade of the twentieth century by the scientist Élie Metchnikoff [27]. Metchnikoff believed that this fermented milk product promoted good health and ultimately longevity by supporting a balance of beneficial bacterial microflora in the gut [28]. The original hypotheses and observations regarding the first "probiotic" and the effects it had on health have since led to the proliferation of probiotic food products, supplements, and functional foods that we see on the market today. The number of these products has increased with the discovery of novel beneficial species of gut bacteria and the development technologies that can support the delivery of viable bacteria to the consumer [29]. However, there is some controversy

**5**

modulation [39].

innovative solutions.

*Introductory Chapter: Overview of Trends in Dairy Science and Technology*

[36] and finding methods to speed up the curd drying process [37].

The functional properties associated with cheese include the following: flavor/ aroma, which is a result, in part, of protein and fat content; viscosity, which is determined by the liquid phase of the milkfat; texture/mouthfeel, stretch, which depends on pH, relative fractions of colloidal calcium phosphate, and the proportion of casein proteins that remain intact; browning during baking, which occurs due to a reaction between lactose and proteins; and freezing ability, which is the ability to be frozen and retain physical properties. Research in the area of functional properties of cheeses is ongoing as new products are created in response to demands by the end user. For example, due to some of the negative health effects of saturated fats, low-fat alternatives have been developed. However, additives are needed to compensate for the lack of fats so that the properties of the cheese do not change with respect to normal fat cheese [38]. Another aspect of functionality is associated with the health benefits that the components of cheese provide. For example, beneficial bioactive peptides, oligosaccharides, and fatty acids are found in cheeses such as Parmesan and Gouda. The health benefits of these bioactives can include a reduction in hypertension and blood sugar as well as immune system

Modern industrial production of soft cheeses and Greek yogurt generates large quantities of liquid acid whey byproducts, which are environmentally unfriendly and costly to transport and dispose of [40]. One solution that has been attempted is to transfer liquid whey to farmers for use as a crop fertilizer [41]. However, transportation costs for high volumes are high. In addition, limited amounts of acid whey can be disposed of in this fashion because runoff can lead to acidification of nearby water supplies. Such additional contamination in water can lead to algal blooms and a resultant drop in dissolved oxygen which is lethal for aquatic animal species [42]. For this reason, a method for converting the liquid whey by-product into a usable product in other processed food products or to limit the production of whey [43] are active areas of research. Some possible solutions that have been proposed are to process the lactose found in this by-product for use as a sweetener [44] or to use microfiltration technologies to separate out specific proteins that can be used as functional ingredients in other food products [45]. However, the vast quantities of acid whey produced by the dairy industry remain an ongoing problem in search of

over whether or not the species of bacteria found in the original Balkan product can

Cheese was similarly discovered in ancient times when fermented milk was found to fractionate into a liquid and a coagulated solid that was protein rich. The liquid, known as whey, was drained, leaving a solid curd to be stacked and dried during an aging process to produce cheese [30]. Cheeses, particularly hard cheeses, maintain their nutritional value for long periods of time. In addition, because it contains little lactose, cheese can command an advantage over milk for consumers who are lactose intolerant [31]. In a later discovery, rennet, an enzyme found in the stomach lining of cows, was found to quicken the coagulation process. Medieval clergymen later tinkered with the aging processes and the use of rennet to give us the hard cheeses like Parmesan, Gruyère, Roquefort, and Munster [32]. Modern technologies have focused on standardizing milk inputs, such as by diafiltration [33], and creating cheeses with the functional properties taste, color, melt, and mouth feel that are considered desirable by the end user [34], such as by adding adjunct species during the fermentation process [35]. In addition, there are areas of intensive research with the aim of reducing production time. These include developing strategies for preventing bacteriophage infections that might slow the acidification process during fermentation by exploiting host bacteriophage resistance and defense mechanisms

*DOI: http://dx.doi.org/10.5772/intechopen.91050*

be considered a probiotic.

#### *Introductory Chapter: Overview of Trends in Dairy Science and Technology DOI: http://dx.doi.org/10.5772/intechopen.91050*

*Current Issues and Challenges in the Dairy Industry*

be used for the early detection of bovine mastitis [11].

milk pathogens such as *Campylobacter* and *Escherichia coli* O157:H7.

Another key achievement of mankind in the area of nutrition was the accidental discovery of bacterially fermented products from the milk of the domesticated species mentioned above [25]. Instead of being considered spoiled, these products entered the human diet as nutritional food products. Long before refrigeration existed and microbes were discovered, fermentation was adopted as an ancient method of preserving milk. As such, traditional fermented milk products are found in many cultures. These products include dadiah, the traditional fermented buffalo milk from West Sumatra; filmjölk, from Scandinavia; and the eastern

Yogurt is the fermented milk product most widely distributed in the West and is thought to have been invented in 5000 B.C. Yogurt has also been known to be a health food for a long time: its health benefits are mentioned in the Vedas and in the Old Testament [26]. The type of yogurt we know today originated from the Balkans and is produced using a culture of *Lactobacillus delbrueckii* subsp. *bulgaricus* and *Streptococcus thermophilus* bacteria. Yogurt was popularized in Europe and the USA in the first decade of the twentieth century by the scientist Élie Metchnikoff [27]. Metchnikoff believed that this fermented milk product promoted good health and ultimately longevity by supporting a balance of beneficial bacterial microflora in the gut [28]. The original hypotheses and observations regarding the first "probiotic" and the effects it had on health have since led to the proliferation of probiotic food products, supplements, and functional foods that we see on the market today. The number of these products has increased with the discovery of novel beneficial species of gut bacteria and the development technologies that can support the delivery of viable bacteria to the consumer [29]. However, there is some controversy

Advances in the technology of milk production have occurred only relatively recently. The milk homogenizer was patented in 1899. This device was designed to break up milk globules in order to give milk the consistency that we take for granted today [7]. Automated milking systems appeared nearly a century later [8]. Milk production and biotechnology intersected in the 1990s with the advent of recombinant bovine growth hormones that were used to provoke an increase in milk production per cow [9] and the approval by the FDA of cloned animals for milk production in 2008 [10]. Recently, automated cell counters have emerged which can

Dairy product safety is an important issue because milk, being nutrient dense, not only serves as a medium that supports the growth of beneficial fermentative microflora [12] but is also a medium in which pathogenic species can proliferate [13]. The first dairy safety technologies included the invention of the process of pasteurization in the nineteenth century by Louis Pasteur, a technique adopted universally in the USA in 1917 [14]. The first milk safety packaging was glass milk delivery bottles invented by Henry Thatcher [15]. Milk tankers appeared in 1914 [16], and milk cartons became ubiquitous by 1974 [17]. In very recent years, cold pressure processing has been developed as an alternative to pasteurization [18]. Pulse electric field [19], ultra-sonication [20], and irradiation [21] have also been explored as alternatives. Meanwhile, dairy supply chains have become more centralized, leading to emerging issues in dairy safety. Hazard analysis and critical control point (HACCP) management programs have been developed to help neutralize biological, physical, and chemical hazards. HACCP mandates risk assessments at different points in the production process [22]. These programs demand continuous monitoring of the microbiota of both the dairy products and the production environment which has led to a new demand for rapid methods of microbiological detection and identification. As a result, novel rapid and high-precision techniques such as qPCR [23] and enzyme immunoassays [24] have been developed to identify

**4**

European kefir.

over whether or not the species of bacteria found in the original Balkan product can be considered a probiotic.

Cheese was similarly discovered in ancient times when fermented milk was found to fractionate into a liquid and a coagulated solid that was protein rich. The liquid, known as whey, was drained, leaving a solid curd to be stacked and dried during an aging process to produce cheese [30]. Cheeses, particularly hard cheeses, maintain their nutritional value for long periods of time. In addition, because it contains little lactose, cheese can command an advantage over milk for consumers who are lactose intolerant [31]. In a later discovery, rennet, an enzyme found in the stomach lining of cows, was found to quicken the coagulation process. Medieval clergymen later tinkered with the aging processes and the use of rennet to give us the hard cheeses like Parmesan, Gruyère, Roquefort, and Munster [32]. Modern technologies have focused on standardizing milk inputs, such as by diafiltration [33], and creating cheeses with the functional properties taste, color, melt, and mouth feel that are considered desirable by the end user [34], such as by adding adjunct species during the fermentation process [35]. In addition, there are areas of intensive research with the aim of reducing production time. These include developing strategies for preventing bacteriophage infections that might slow the acidification process during fermentation by exploiting host bacteriophage resistance and defense mechanisms [36] and finding methods to speed up the curd drying process [37].

The functional properties associated with cheese include the following: flavor/ aroma, which is a result, in part, of protein and fat content; viscosity, which is determined by the liquid phase of the milkfat; texture/mouthfeel, stretch, which depends on pH, relative fractions of colloidal calcium phosphate, and the proportion of casein proteins that remain intact; browning during baking, which occurs due to a reaction between lactose and proteins; and freezing ability, which is the ability to be frozen and retain physical properties. Research in the area of functional properties of cheeses is ongoing as new products are created in response to demands by the end user. For example, due to some of the negative health effects of saturated fats, low-fat alternatives have been developed. However, additives are needed to compensate for the lack of fats so that the properties of the cheese do not change with respect to normal fat cheese [38]. Another aspect of functionality is associated with the health benefits that the components of cheese provide. For example, beneficial bioactive peptides, oligosaccharides, and fatty acids are found in cheeses such as Parmesan and Gouda. The health benefits of these bioactives can include a reduction in hypertension and blood sugar as well as immune system modulation [39].

Modern industrial production of soft cheeses and Greek yogurt generates large quantities of liquid acid whey byproducts, which are environmentally unfriendly and costly to transport and dispose of [40]. One solution that has been attempted is to transfer liquid whey to farmers for use as a crop fertilizer [41]. However, transportation costs for high volumes are high. In addition, limited amounts of acid whey can be disposed of in this fashion because runoff can lead to acidification of nearby water supplies. Such additional contamination in water can lead to algal blooms and a resultant drop in dissolved oxygen which is lethal for aquatic animal species [42]. For this reason, a method for converting the liquid whey by-product into a usable product in other processed food products or to limit the production of whey [43] are active areas of research. Some possible solutions that have been proposed are to process the lactose found in this by-product for use as a sweetener [44] or to use microfiltration technologies to separate out specific proteins that can be used as functional ingredients in other food products [45]. However, the vast quantities of acid whey produced by the dairy industry remain an ongoing problem in search of innovative solutions.

#### **3. Dairy foods in human nutrition**

Recognizing the importance of milk in the human diet, the USDA has promoted the consumption of milk since at least the mid-twentieth century. For example, the National School Lunch Act of 1946 mandated that milk be included in subsidized school lunches. Meanwhile, the Child Nutrition Act of 1966 and the Special Milk Program led to the provision of free milk to schools that did not participate in other nutrition programs. In 1990, the Fluid Milk Promotion Act was passed in order to authorize the USDA to conduct campaigns to increase consumer purchases of liquid milk. Since then, the "Got Milk" campaign began in 1993 as a way to counter the rise in the consumption of sugary soft drinks as a primary beverage. This campaign was replaced by the "Milk Life" campaign in 2014 that emphasized lifestyle choices. In 2004, the "3-A-Day" advertising campaign was introduced which promoted a link between milk products and the health benefit of weight loss (this campaign was later discontinued in 2007 to due complaints to the Federal Trade Commission of the lack of evidence for this claim). Private initiatives were also carried out, such as the formation of Dairy Management, Inc. to promote the sale of milk. Beginning in 2015, the issue of low milk sales took particular prominence due to the drop in sales of dairy products vs. non-milk plant-based products. Since then, research into how best to promote the sale of liquid milk has been welcomed [46]. Another recent development in human nutrition is related to the establishment of "my plate." It replaced the USDA's MyPyramid guide on June 2, 2011, ending 19 years of USDA food pyramid diagrams. This clearly demonstrated that dairy foods become part of modern healthy diet.

The primary purpose of this book is thus to explore a cross section of current trends in dairy science with respect to safety, sustainability, processing, health, and marketing. Food safety risks in the dairy supply chain will be explored as well as systematic discovery of marketing messages designed to appeal to the dairy consumer. We will look at some of the technology improvements in manufacturing processes, the exploitation of waste products, and new frontiers in the production of functional cheese products. In addition, we also reopen the issue, originally proposed by Metchnikoff, that the species of bacteria found in yogurt is the reason for yogurt's health benefits, with an emphasis on the particular properties and benefits of *L. bulgaricus*, one of two primary species used in the fermentation of yogurt products. Other trends left unexplored are the search for antimicrobial targets that can be exploited in food safety applications [47, 48] and gaining a better understanding of the process of autolysis, which is fundamental to cheese making and probiotic stability [49], and the role of prebiotics in health promotion [50].

#### **Acknowledgements**

This publication was made possible by grant number NC.X-267-5-12-170-1 from the National Institute of Food and Agriculture (NIFA), by Jarrow Formulas, USA. The content herein is solely the responsibility of the authors and does not necessarily represent the official view of NIFA.

**7**

**Author details**

Tahl Zimmerman\*, Rabin Gyawali and Salam A. Ibrahim

\*Address all correspondence to: tzimmerman@ncat.edu

Technical State University, Greensboro, NC, USA

provided the original work is properly cited.

Food Microbiology and Biotechnology Laboratory, North Carolina Agricultural and

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

*Introductory Chapter: Overview of Trends in Dairy Science and Technology*

*DOI: http://dx.doi.org/10.5772/intechopen.91050*

*Introductory Chapter: Overview of Trends in Dairy Science and Technology DOI: http://dx.doi.org/10.5772/intechopen.91050*

### **Author details**

*Current Issues and Challenges in the Dairy Industry*

Recognizing the importance of milk in the human diet, the USDA has promoted the consumption of milk since at least the mid-twentieth century. For example, the National School Lunch Act of 1946 mandated that milk be included in subsidized school lunches. Meanwhile, the Child Nutrition Act of 1966 and the Special Milk Program led to the provision of free milk to schools that did not participate in other nutrition programs. In 1990, the Fluid Milk Promotion Act was passed in order to authorize the USDA to conduct campaigns to increase consumer purchases of liquid milk. Since then, the "Got Milk" campaign began in 1993 as a way to counter the rise in the consumption of sugary soft drinks as a primary beverage. This campaign was replaced by the "Milk Life" campaign in 2014 that emphasized lifestyle choices. In 2004, the "3-A-Day" advertising campaign was introduced which promoted a link between milk products and the health benefit of weight loss (this campaign was later discontinued in 2007 to due complaints to the Federal Trade Commission of the lack of evidence for this claim). Private initiatives were also carried out, such as the formation of Dairy Management, Inc. to promote the sale of milk. Beginning in 2015, the issue of low milk sales took particular prominence due to the drop in sales of dairy products vs. non-milk plant-based products. Since then, research into how best to promote the sale of liquid milk has been welcomed [46]. Another recent development in human nutrition is related to the establishment of "my plate." It replaced the USDA's MyPyramid guide on June 2, 2011, ending 19 years of USDA food pyramid diagrams. This clearly demonstrated that dairy foods become part of

The primary purpose of this book is thus to explore a cross section of current trends in dairy science with respect to safety, sustainability, processing, health, and marketing. Food safety risks in the dairy supply chain will be explored as well as systematic discovery of marketing messages designed to appeal to the dairy consumer. We will look at some of the technology improvements in manufacturing processes, the exploitation of waste products, and new frontiers in the production of functional cheese products. In addition, we also reopen the issue, originally proposed by Metchnikoff, that the species of bacteria found in yogurt is the reason for yogurt's health benefits, with an emphasis on the particular properties and benefits of *L. bulgaricus*, one of two primary species used in the fermentation of yogurt products. Other trends left unexplored are the search for antimicrobial targets that can be exploited in food safety applications [47, 48] and gaining a better understanding of the process of autolysis, which is fundamental to cheese making and probiotic stability [49], and the role of prebiotics in health promotion [50].

This publication was made possible by grant number NC.X-267-5-12-170-1 from the National Institute of Food and Agriculture (NIFA), by Jarrow Formulas, USA. The content herein is solely the responsibility of the authors and does not

**3. Dairy foods in human nutrition**

modern healthy diet.

**Acknowledgements**

necessarily represent the official view of NIFA.

**6**

Tahl Zimmerman\*, Rabin Gyawali and Salam A. Ibrahim Food Microbiology and Biotechnology Laboratory, North Carolina Agricultural and Technical State University, Greensboro, NC, USA

\*Address all correspondence to: tzimmerman@ncat.edu

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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[21] Odueke OB, Farag KW, Baines RN, Chadd SA. Irradiation applications in dairy products: A review. Food and Bioprocess Technology. 2016;**9**(5):751-767

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[23] Zhou B, Liang T, Zhan Z, Liu R, Li F, Xu H. Rapid and simultaneous quantification of viable *Escherichia coli* O157:H7 and Salmonella spp. in milk through multiplex real-time PCR. Journal of Dairy Science. 2017;**100**(11):8804-8813

[24] Law JW-F, Ab Mutalib N-S, Chan K-G, Lee L-H. Rapid methods for the detection of foodborne bacterial pathogens: Principles, applications, advantages and limitations. Frontiers in Microbiology. 2015;**5**:770

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[26] Shah NP. Yogurt in Health and Disease Prevention. London: Academic Press, an imprint of Elsevier; 2017. p. xxviii, 542 p

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[30] Button JE, Dutton RJ. Cheese microbes. Current Biology. 2012;**22**(15):R587-R589

[31] Gross M. On the origins of cheese. Current Biology. 2018;**28**(20):R1171-R1173

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Evershed RP. Milk of ruminants in ceramic baby bottles from prehistoric child graves. Nature.

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[8] Castro A, Pereira JM, Amiama C, Bueno J. Estimating efficiency in automatic milking systems. Journal of Dairy Science. 2012;**95**(2):929-936

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[37] Fagan CC, Castillo M, Payne FA, O'Donnell CP, O'Callaghan DJ. Effect of cutting time, temperature, and calcium on curd moisture, whey fat losses, and curd yield by response surface methodology. Journal of Dairy Science. 2007;**90**(10):4499-4512

[38] Ardö Y. Flavour and texture in low-fat cheese. In: Law BA, editor. Microbiology and Biochemistry of Cheese and Fermented Milk. Boston, MA: Springer; 1997

[39] Santiago-López L, Aguilar-Toalá JE, Hernández-Mendoza A, Vallejo-Cordoba B, Liceaga AM, González-Córdova AF. Invited review: Bioactive compounds produced during cheese ripening and health effects associated with aged cheese consumption. Journal of Dairy Science. 2018;**101**(5):3742-3757

[40] Gyawali R, Ibrahim SA. Addition of pectin and whey protein concentrate minimises the generation of acid whey in Greek-style yogurt. Journal of Dairy Research. 2018;**85**(2):238-242

[41] Finaru AL, Gavrila L, Grosu L, Fernandez B, Grigoras CG, Patriciu OI, et al. Valorization of whey from dairy industry for agricultural use as fertiliser: Effects on plant germination and growth. Environmental Engineering and Management Journal. 2012;**11**(12):2203-2210

[42] Kavaz D, Öztoprak H. Environmental awareness of university students on white cheese waste water. Eurasia Journal of Mathematics, Science and Technology Education. 2017;**13**(12):8003-8015

[43] Gyawali R, Ibrahim SA. Effects of hydrocolloids and processing conditions on acid whey production with reference to Greek yogurt. Trends in Food Science and Technology. 2016;**56**:61-76

[44] Lindsay MJ, Walker TW, Dumesic JA, Rankin SA, Huber GW. Production of monosaccharides and whey protein from acid whey waste streams in the dairy industry. Green Chemistry. 2018;**20**(8):1824-1834

[45] Kavaz D, Öztoprak H. Environmental Awareness of University Students on Woodhead Publishing Series in Food Science, Technology and Nutrition. 2018:93-126

[46] Finnell KJ, John R. A social marketing approach to 1% milk use: Resonance is the key. Health Promotion Practice. 2017;**19**(3):437-444

Section 2

Dairy Food Processing

Technology

**11**

[47] Zimmerman T, Ibrahim S. Choline kinase, a novel drug target for the inhibition of *Streptococcus pneumoniae*. Antibiotics (Basel). 2017;**6**(4):20. DOI: 10.3390/antibiotics6040020

[48] Zimmerman T, Lacal Sanjuan JC, Ibrahim SA. Choline kinase emerges as a promising drug target in gram-positive bacteria. Frontiers in Microbiology. 2019;**6**

[49] Zimmerman T, Gyawali R, Ibrahim S. Autolyse the cell in order to save it? Inducing, then blocking, autolysis as a strategy for delaying cell death in the probiotic *Lactobacillus reuteri*. Biotechnology Letters. 2017;**39**:1547-1551

[50] Gyawali R, Nwamaioha N, Fiagbor R, Zimmerman T, Newman RH, Ibrahim SA. The Role of Prebiotics in Disease Prevention and Health Promotion. Dietary Interventions in Gastrointestinal Diseases: Foods, Nutrients, and Dietary Supplements. 2019. pp. 151-167

Section 2

## Dairy Food Processing Technology

*Current Issues and Challenges in the Dairy Industry*

[43] Gyawali R, Ibrahim SA. Effects of hydrocolloids and processing conditions on acid whey production with reference to Greek yogurt. Trends in Food Science

[44] Lindsay MJ, Walker TW, Dumesic JA, Rankin SA, Huber GW. Production of monosaccharides and whey protein from acid whey waste streams in the dairy industry. Green Chemistry.

[45] Kavaz D, Öztoprak H. Environmental Awareness of University Students on Woodhead Publishing Series in Food Science, Technology and

[46] Finnell KJ, John R. A social marketing approach to 1% milk use: Resonance is the key. Health Promotion

Practice. 2017;**19**(3):437-444

10.3390/antibiotics6040020

[49] Zimmerman T, Gyawali R, Ibrahim S. Autolyse the cell in order to save it? Inducing, then blocking, autolysis as a strategy for delaying cell death in the probiotic *Lactobacillus reuteri*. Biotechnology Letters.

[50] Gyawali R, Nwamaioha N,

Fiagbor R, Zimmerman T, Newman RH, Ibrahim SA. The Role of Prebiotics in Disease Prevention and Health Promotion. Dietary Interventions in Gastrointestinal Diseases: Foods, Nutrients, and Dietary Supplements.

2017;**39**:1547-1551

2019. pp. 151-167

2019;**6**

[47] Zimmerman T, Ibrahim S. Choline kinase, a novel drug target for the inhibition of *Streptococcus pneumoniae*. Antibiotics (Basel). 2017;**6**(4):20. DOI:

[48] Zimmerman T, Lacal Sanjuan JC, Ibrahim SA. Choline kinase emerges as a promising drug target in gram-positive bacteria. Frontiers in Microbiology.

and Technology. 2016;**56**:61-76

2018;**20**(8):1824-1834

Nutrition. 2018:93-126

Seventh Symposium on Lactic Acid Bacteria: Genetics, Metabolism and Applications; 1-5 September 2002; Egmond aan Zee, The Netherlands. Antonie Van Leeuwenhoek International Journal of General and Molecular.

[37] Fagan CC, Castillo M, Payne FA, O'Donnell CP, O'Callaghan DJ. Effect of cutting time, temperature, and calcium on curd moisture, whey fat losses, and curd yield by response surface methodology. Journal of Dairy Science.

[38] Ardö Y. Flavour and texture in low-fat cheese. In: Law BA, editor. Microbiology and Biochemistry of Cheese and Fermented Milk. Boston,

[39] Santiago-López L, Aguilar-Toalá JE, Hernández-Mendoza A, Vallejo-Cordoba B, Liceaga AM, González-Córdova AF. Invited review: Bioactive compounds produced during cheese ripening and health effects associated with aged cheese consumption. Journal of Dairy Science.

2002;**82**(1-4):1-1

2007;**90**(10):4499-4512

MA: Springer; 1997

2018;**101**(5):3742-3757

[40] Gyawali R, Ibrahim SA. Addition of pectin and whey protein concentrate minimises the generation of acid whey in Greek-style yogurt. Journal of Dairy

Research. 2018;**85**(2):238-242

[41] Finaru AL, Gavrila L, Grosu L, Fernandez B, Grigoras CG, Patriciu OI, et al. Valorization of whey from dairy industry for agricultural use as fertiliser:

Effects on plant germination and growth. Environmental Engineering

Environmental awareness of university students on white cheese waste water. Eurasia Journal of Mathematics, Science and Technology Education.

and Management Journal. 2012;**11**(12):2203-2210

[42] Kavaz D, Öztoprak H.

2017;**13**(12):8003-8015

**10**

**Chapter 2**

**Abstract**

Cheeses

*Vladimir Ermolaev*

Study of the Kinetics of Vacuum

The chapter considers cheeses as an object of drying process. It describes the changes occurring in the cheese during the drying process. The results of experimental studies of cheese vacuum drying are presented as well. The kinetics of cheese vacuum drying is investigated. Such important indicator as the shrinkage losses of cheeses in the process of vacuum drying was studied. It has been established that cheese vacuum drying proceeds in two steps: at constant drying speed and at falling one. By graphic differentiation, the curves of the speed of cheese drying were constructed. It was determined by an analytical method that the moisture content of polymolecular adsorption for cheeses is 4–9%. The values of equilibrium moisture for cheese vacuum drying were established. The dependences of the coefficients of cheese shrinkage on the thickness of the drying layer, the shape, and size of grinding were obtained. When the thickness of the drying layer is from 10 to 30 mm, the coefficient of cheese shrinkage, depending on the shape and size of grinding, is from 3 to 14%. With an increase in the mass fraction of moisture

**Keywords:** kinetics, vacuum drying, cheeses, temperature, shrinkage, moisture,

Considering cheese as an object of drying, it should be noted that the change in the cheese properties during the drying process depends on both the physicochemical properties, the structure, the binding forms of moisture in the material, and the thermophysical characteristics that take into account the features of mass and

The main structural elements of the cheese are the macrograins, the interlayer between the macrograins, the microvoids, and the micrograins. The basis of each macrograin structure is a protein network, in the cells of which numerous

micrograins are interspersed in the form of fat drops, lipoid drops, and crystalline

The transition of fat from milk to cheese depends on many factors. Most of the fat balls are transferred (under all other conditions) to medium-sized fat and then to small and large fat [1, 2]. Milk fat is considered to be the most valuable component of milk, although in terms of the nutrition physiology, milk proteins are

in cheeses, the shrinkage coefficient increases as well.

drying the adjusted, heat, drying curves

**1. Introduction**

energy transfer.

formations.

**13**

Drying of Hard and Semihard

#### **Chapter 2**

## Study of the Kinetics of Vacuum Drying of Hard and Semihard Cheeses

*Vladimir Ermolaev*

#### **Abstract**

The chapter considers cheeses as an object of drying process. It describes the changes occurring in the cheese during the drying process. The results of experimental studies of cheese vacuum drying are presented as well. The kinetics of cheese vacuum drying is investigated. Such important indicator as the shrinkage losses of cheeses in the process of vacuum drying was studied. It has been established that cheese vacuum drying proceeds in two steps: at constant drying speed and at falling one. By graphic differentiation, the curves of the speed of cheese drying were constructed. It was determined by an analytical method that the moisture content of polymolecular adsorption for cheeses is 4–9%. The values of equilibrium moisture for cheese vacuum drying were established. The dependences of the coefficients of cheese shrinkage on the thickness of the drying layer, the shape, and size of grinding were obtained. When the thickness of the drying layer is from 10 to 30 mm, the coefficient of cheese shrinkage, depending on the shape and size of grinding, is from 3 to 14%. With an increase in the mass fraction of moisture in cheeses, the shrinkage coefficient increases as well.

**Keywords:** kinetics, vacuum drying, cheeses, temperature, shrinkage, moisture, drying the adjusted, heat, drying curves

#### **1. Introduction**

Considering cheese as an object of drying, it should be noted that the change in the cheese properties during the drying process depends on both the physicochemical properties, the structure, the binding forms of moisture in the material, and the thermophysical characteristics that take into account the features of mass and energy transfer.

The main structural elements of the cheese are the macrograins, the interlayer between the macrograins, the microvoids, and the micrograins. The basis of each macrograin structure is a protein network, in the cells of which numerous micrograins are interspersed in the form of fat drops, lipoid drops, and crystalline formations.

The transition of fat from milk to cheese depends on many factors. Most of the fat balls are transferred (under all other conditions) to medium-sized fat and then to small and large fat [1, 2]. Milk fat is considered to be the most valuable component of milk, although in terms of the nutrition physiology, milk proteins are

superior in value to milk fat. Four factors determine the special significance of milk fat in milk and dairy products: economic value, nutritional value, taste, and physical properties of fat-containing dairy products caused by the presence of fat [2].

**2. Materials and methods**

*DOI: http://dx.doi.org/10.5772/intechopen.85276*

which is shown in **Figure 1**.

measurement system.

**Figure 1.**

**15**

The objects of research were cheeses of the following brands: Soviet, Swiss, Altai, Gorny, Moscow, Holland, Kostroma, Poshekhonskiy, and Yaroslavskiy. For the experimental studies on the drying unit that was used, the scheme of

of plant and animal origin. The drying unit consists of a drying chamber, a desublimator, a vacuum pump, a cooling machine, and a regulation and

sufficient to ensure uniform heating of the dried product.

*Study of the Kinetics of Vacuum Drying of Hard and Semihard Cheeses*

the product in the process of vacuum drying.

to increase the amount of radiant flux incident on the product.

The product is heated by pulses of infrared radiation to the desired temperature. Characteristic features of infrared lamps are low thermal inertia. This characteristic allows you to accurately maintain the required temperature of

In the lower part of the chamber, there is a pipeline connecting the drying chamber with the desublimator. The desublimator is a shell-coil heat exchanger with in-line boiling of the refrigerant, which is the evaporator of the refrigerating machine. Desublimator is designed to remove water vapor from the vacuum chamber formed during the drying process. At the bottom of the desublimator,

*The scheme of the experimental setup: (1) vacuum pump, (2) chamber vacuum, (3) compressor, (4) capacitor, (5) liquid separator, (6) desublimator, (7) receiver, (8) vacuum gauge, and (9) thermostatic valve.*

This drying unit is universal and can be used for drying almost any raw material

Two infrared lamps of the KGT 220 brand were used as sources of heat in the installation. Since the chamber volume is relatively small (36 liters), two sources are

The design of the vacuum chamber provides for the possibility of changing the distance between the heaters and the tray on which the product is located during the drying process. Cylindrical walls of the vacuum chamber itself serve as screens

During maturation, all components of the cheese mass are exposed with profound changes; as a result of which, the proper consistency and drawing of this type of cheese are acquired [3].

Cheese humidity depends on the technological mode of production, temperature and duration of rennet clotting, temperature of the second heating stage, partial salting of the curd mass in the grain, and adding water during the second heating stage, as well as on the duration of the cheese grain processing. With a decrease in the clotting temperature and the temperature of the second heating stage, the moisture capacity of the curd and the water content in the finished product increase. As the temperature rises, the moisture content in the cheese decreases. Loss of moisture occurs at the stage of salting (osmotic transfer of water) and during the period of maturation (evaporation). The intensity of the microbiological and biochemical processes occurring in it depends on the value of the initial moisture content of the cheese (after pressing) [4].

According to the GOST (the RF standards and regulations) 7616-85, GOST 11041-88, and GOST R 52686-2003, the following dependence characterizes cheese: with an increase in the moisture mass fraction, the mass fraction of fat decreases. The mass fraction of fat and moisture of all objects of the current research is presented in **Table 1**.

For most solid and semihard cheeses, the mass fraction of fat in the dry matter is 45–50%, and the mass fraction of moisture is 40–44%.

The fat in the cheese is in the form of micrograins with a diameter of 10–15 microns. There are also larger inclusions of fat, the so-called fat drops, which are allocated evenly throughout the thickness of the cheese. Fat drops and lipid micrograins in cheese are milk fat destabilized in the process of cheese making and ripening. This judgment is justified, since at temperatures above 20°C, the fat in the cheese can be melted out of the cheese mass, which is the main obstacle in the thermal dehydration of the cheese.


#### **Table 1.**

*Mass fraction of fat and moisture of the research objects.*

#### **2. Materials and methods**

superior in value to milk fat. Four factors determine the special significance of milk fat in milk and dairy products: economic value, nutritional value, taste, and physical properties of fat-containing dairy products caused by the presence of fat [2]. During maturation, all components of the cheese mass are exposed with profound changes; as a result of which, the proper consistency and drawing of

Cheese humidity depends on the technological mode of production, temperature and duration of rennet clotting, temperature of the second heating stage, partial salting of the curd mass in the grain, and adding water during the second heating stage, as well as on the duration of the cheese grain processing. With a decrease in the clotting temperature and the temperature of the second heating stage, the moisture capacity of the curd and the water content in the finished product increase. As the temperature rises, the moisture content in the cheese decreases. Loss of moisture occurs at the stage of salting (osmotic transfer of water) and during the period of maturation (evaporation). The intensity of the microbiological and biochemical processes occurring in it depends on the value of the initial mois-

According to the GOST (the RF standards and regulations) 7616-85, GOST 11041-88, and GOST R 52686-2003, the following dependence characterizes cheese: with an increase in the moisture mass fraction, the mass fraction of fat decreases. The mass fraction of fat and moisture of all objects of the current research is

For most solid and semihard cheeses, the mass fraction of fat in the dry matter is

The fat in the cheese is in the form of micrograins with a diameter of 10–15 microns. There are also larger inclusions of fat, the so-called fat drops, which are allocated evenly throughout the thickness of the cheese. Fat drops and lipid

micrograins in cheese are milk fat destabilized in the process of cheese making and ripening. This judgment is justified, since at temperatures above 20°C, the fat in the cheese can be melted out of the cheese mass, which is the main obstacle in the

**Fat in the dry matter (no less than) Moisture (no more than)**

this type of cheese are acquired [3].

*Current Issues and Challenges in the Dairy Industry*

ture content of the cheese (after pressing) [4].

45–50%, and the mass fraction of moisture is 40–44%.

**Product name Mass fraction (%)**

Sovetskiy 50 42 Swedish 50 42 Altaiskiy 50 42 Gornyiy 50 40 Moscowskiy 50 42

Dutch 45–50 43–44 Kostromskoy 45 44 Poshekhonskiy 45 42 Yaroslavskiy 45 44

**Hard cheeses with a high temperature of the second heat stage**

**Semihard cheeses with a low temperature of the second heat stage**

*Mass fraction of fat and moisture of the research objects.*

presented in **Table 1**.

**Table 1.**

**14**

thermal dehydration of the cheese.

The objects of research were cheeses of the following brands: Soviet, Swiss, Altai, Gorny, Moscow, Holland, Kostroma, Poshekhonskiy, and Yaroslavskiy.

For the experimental studies on the drying unit that was used, the scheme of which is shown in **Figure 1**.

This drying unit is universal and can be used for drying almost any raw material of plant and animal origin. The drying unit consists of a drying chamber, a desublimator, a vacuum pump, a cooling machine, and a regulation and measurement system.

Two infrared lamps of the KGT 220 brand were used as sources of heat in the installation. Since the chamber volume is relatively small (36 liters), two sources are sufficient to ensure uniform heating of the dried product.

The design of the vacuum chamber provides for the possibility of changing the distance between the heaters and the tray on which the product is located during the drying process. Cylindrical walls of the vacuum chamber itself serve as screens to increase the amount of radiant flux incident on the product.

The product is heated by pulses of infrared radiation to the desired temperature. Characteristic features of infrared lamps are low thermal inertia. This characteristic allows you to accurately maintain the required temperature of the product in the process of vacuum drying.

In the lower part of the chamber, there is a pipeline connecting the drying chamber with the desublimator. The desublimator is a shell-coil heat exchanger with in-line boiling of the refrigerant, which is the evaporator of the refrigerating machine. Desublimator is designed to remove water vapor from the vacuum chamber formed during the drying process. At the bottom of the desublimator,

#### **Figure 1.**

*The scheme of the experimental setup: (1) vacuum pump, (2) chamber vacuum, (3) compressor, (4) capacitor, (5) liquid separator, (6) desublimator, (7) receiver, (8) vacuum gauge, and (9) thermostatic valve.*

there is a valve for depressurizing the system and removing the moisture frozen on the evaporator upon completion of the drying process.

The vacuum in the system is maintained using a two-stage vacuum pump brand 2TW-1C. Evaporation of evaporated moisture and non-condensable gases occurs as follows: evaporated moisture from the product enters the desublimator through the pipeline, where it passes through the evaporator and freezes on its surface that portion of water vapor that is not frozen and the non-condensable gases are pumped out with a vacuum pump into the environment.

The content of the mass fraction of moisture in the cheeses before and after drying was determined by an accelerated method on a Chizhova device, by drying the weight of the product according to GOST 3626-73.

The content of the fat mass fraction in the cheeses before and after drying was determined by the Gerber acid method according to GOST 5867-90. The method is based on the separation of fat from milk and dairy products under the action of concentrated sulfuric acid and isoamyl alcohol, followed by centrifugation and measuring the amount of released fat in the graduated part of the fat meter.

the amount of bound moisture in cheese: the longer the ripening process is, the more bound moisture is contained in the cheese. This dependence is quite aligned

*, J/kg.*

**Form of the moisture binding with the matter Types of cheese**

*Study of the Kinetics of Vacuum Drying of Hard and Semihard Cheeses*

Monomolecular adsorption 4.20–2.70 3.90–2.50 3.40–2.50 Polymolecular adsorption 2.20–0.50 2,30–0,70 2.20–0.70 Osmotically bound 0.45–0.12 0.65–0.10 0.60–0.10

Microcapillary 0.45–0.12 0.65–0.10 0.60–0.10 Wetting and macrocapillary <0.10 <0.10 <0.10

**Sovetskiy Dutch Ozernyiy**

Studies have shown that the energy characteristic of the bound moisture is different; when moving from free moisture (wetting and macrocapillaries) to bound moisture (mono- and polymolecular adsorption), the binding energy of moisture to the dry matter of the cheese increases significantly. Binding energy (10<sup>5</sup> J/kg) for wetting and macrocapillary moisture, it is <0.10, for osmotically bound moisture and moisture of microcapillaries 0.45–0.12, for polymolecular adsorption moisture 2.30–0.50, and for moisture monomolecular adsorption 4.20– 2.50. Consequently, the moisture of the monomolecular and polymolecular adsorption due to the highest binding energy is the most strongly bounded. In this regard, it can be said that the moisture of monomolecular adsorption is the main hydration indicator of the product constituent parts and is important for the food restoration

It is known that while storage, dry food products absorb moisture from the ambient air until an equilibrium state occurs. The works of R.I. Ramanauskas are devoted to the study of the equilibrium moisture content of dairy products [6, 7]. We have conducted studies of the cheese hygroscopic characteristics (**Table 4**). When the air relative humidity decreases, the equilibrium moisture of the product decreases too, while the binding energy of moisture with the dry part of the

**Table 5** shows data on the thermal characteristics of cheese. To determine the mode of drying for any product, including cheese, it is necessary to know both physicochemical parameters and thermophysical characteristics. The latter characteristics are necessary in the determination of regime parameters and technological ones as well. When choosing regime parameters (temperature, heat flux density, and residual pressure), it is important to take into account the product's heat capacity and thermal diffusivity in order to calculate the temperature distribution over the layer thickness and the rate of its change. In determining the technological parameters (thickness of the drying layer and the degree of grinding), the thermal conductivity should be observed, since the thickness of the layer of dried material

To determine the effect of moisture content in cheese on its cryoscopic temperature, samples of "Dutch," "Kostromskoy," and "Poshekhonskiy" cheese with a pH of 5.7 and a moisture content of 38–45% were used. **Figure 2** shows the dependences of the change in the cryoscopic temperature of semihard cheeses with a low

second heating temperature on the mass fraction of moisture.

with our results.

**Table 3.**

**Physicochemical bound**

*DOI: http://dx.doi.org/10.5772/intechopen.85276*

**Physicomechanical bound**

*Binding energy of moisture in cheese<sup>10</sup><sup>5</sup>*

after drying.

product increases.

depends on its size.

**17**

Experiments on the study of the forms and the energy of the binding of moisture in semihard cheeses were carried out using non-isothermal analysis using a derivatograph. In the course of heating the sample of the samples under study, the change in mass, the rate of change in mass, and the rate of change in temperature of the product, obtained by thermogravimetry, were determined.

Thermophysical characteristics of cheeses were determined by the first buffer method of two temperature-time intervals.

#### **3. Results of experimental studies**

Moisture is one of the most important cheese components. The moisture content of cheeses affects the ripening process, the cheese structure, and its thermophysical properties. The quantitative content of various forms and the binding energy of moisture in cheeses were determined (**Tables 2** and **3**).

It should be clarified that the mass fraction of moisture in the cheese was, for Sovetskiy, 40%; Dutch, 44%; and Ozernyiy, 48%. In the "Soviet" cheese, the highest content of bound moisture is set at 18.0%, "Dutch," 13.0%; and "Ozernyiy," 10.0%. The Sovetskiy cheese shows the smallest amount of total moisture from the three considered cheeses, while it contains the greatest amount of bound moisture. The content of energy-intensive bonds in cheeses depends on the technology of their production and the duration of the ripening process. P.F. Krasheninin and V.P. Tabachnikov established a general increase in the waterholding capacity along with the cheese maturation [5]. That is, the duration of ripening can be taken into account as a first approximation as a factor affecting


**Table 2.**

*Quantitative content of various forms of moisture binding in cheese (%).*


**Table 3.**

there is a valve for depressurizing the system and removing the moisture frozen

The vacuum in the system is maintained using a two-stage vacuum pump brand 2TW-1C. Evaporation of evaporated moisture and non-condensable gases occurs as follows: evaporated moisture from the product enters the desublimator through the pipeline, where it passes through the evaporator and freezes on its surface that portion of water vapor that is not frozen and the non-condensable gases

The content of the mass fraction of moisture in the cheeses before and after drying was determined by an accelerated method on a Chizhova device, by drying

The content of the fat mass fraction in the cheeses before and after drying was determined by the Gerber acid method according to GOST 5867-90. The method is based on the separation of fat from milk and dairy products under the action of concentrated sulfuric acid and isoamyl alcohol, followed by centrifugation and measuring the amount of released fat in the graduated part of the fat meter.

Experiments on the study of the forms and the energy of the binding of moisture

Moisture is one of the most important cheese components. The moisture content of cheeses affects the ripening process, the cheese structure, and its thermophysical properties. The quantitative content of various forms and the binding energy of

It should be clarified that the mass fraction of moisture in the cheese was, for Sovetskiy, 40%; Dutch, 44%; and Ozernyiy, 48%. In the "Soviet" cheese, the highest content of bound moisture is set at 18.0%, "Dutch," 13.0%; and "Ozernyiy," 10.0%. The Sovetskiy cheese shows the smallest amount of total moisture from the three considered cheeses, while it contains the greatest amount of bound moisture. The content of energy-intensive bonds in cheeses depends on the technology of their production and the duration of the ripening process. P.F. Krasheninin and V.P. Tabachnikov established a general increase in the waterholding capacity along with the cheese maturation [5]. That is, the duration of ripening can be taken into account as a first approximation as a factor affecting

**Physicochemical bond Physicomechanical bond**

**moisture Monomolecular polymolecular**

**moisture and microcapillary moisture** **Wetting moisture and macrocapillary**

**Adsorption-bound moisture Osmotically bound**

*Quantitative content of various forms of moisture binding in cheese (%).*

Sovetskiy 7.0 11.0 12.0 10.0 Dutch 5.0 8.0 19.0 12.0 Ozernyiy 4.0 6.0 21.0 17.0

in semihard cheeses were carried out using non-isothermal analysis using a derivatograph. In the course of heating the sample of the samples under study, the change in mass, the rate of change in mass, and the rate of change in temperature of the product, obtained by thermogravimetry, were determined. Thermophysical characteristics of cheeses were determined by the first buffer

on the evaporator upon completion of the drying process.

*Current Issues and Challenges in the Dairy Industry*

are pumped out with a vacuum pump into the environment.

the weight of the product according to GOST 3626-73.

method of two temperature-time intervals.

moisture in cheeses were determined (**Tables 2** and **3**).

**3. Results of experimental studies**

**Types of cheese**

**Table 2.**

**16**

*Binding energy of moisture in cheese<sup>10</sup><sup>5</sup> , J/kg.*

the amount of bound moisture in cheese: the longer the ripening process is, the more bound moisture is contained in the cheese. This dependence is quite aligned with our results.

Studies have shown that the energy characteristic of the bound moisture is different; when moving from free moisture (wetting and macrocapillaries) to bound moisture (mono- and polymolecular adsorption), the binding energy of moisture to the dry matter of the cheese increases significantly. Binding energy (10<sup>5</sup> J/kg) for wetting and macrocapillary moisture, it is <0.10, for osmotically bound moisture and moisture of microcapillaries 0.45–0.12, for polymolecular adsorption moisture 2.30–0.50, and for moisture monomolecular adsorption 4.20– 2.50. Consequently, the moisture of the monomolecular and polymolecular adsorption due to the highest binding energy is the most strongly bounded. In this regard, it can be said that the moisture of monomolecular adsorption is the main hydration indicator of the product constituent parts and is important for the food restoration after drying.

It is known that while storage, dry food products absorb moisture from the ambient air until an equilibrium state occurs. The works of R.I. Ramanauskas are devoted to the study of the equilibrium moisture content of dairy products [6, 7].

We have conducted studies of the cheese hygroscopic characteristics (**Table 4**).

When the air relative humidity decreases, the equilibrium moisture of the product decreases too, while the binding energy of moisture with the dry part of the product increases.

**Table 5** shows data on the thermal characteristics of cheese. To determine the mode of drying for any product, including cheese, it is necessary to know both physicochemical parameters and thermophysical characteristics. The latter characteristics are necessary in the determination of regime parameters and technological ones as well. When choosing regime parameters (temperature, heat flux density, and residual pressure), it is important to take into account the product's heat capacity and thermal diffusivity in order to calculate the temperature distribution over the layer thickness and the rate of its change. In determining the technological parameters (thickness of the drying layer and the degree of grinding), the thermal conductivity should be observed, since the thickness of the layer of dried material depends on its size.

To determine the effect of moisture content in cheese on its cryoscopic temperature, samples of "Dutch," "Kostromskoy," and "Poshekhonskiy" cheese with a pH of 5.7 and a moisture content of 38–45% were used. **Figure 2** shows the dependences of the change in the cryoscopic temperature of semihard cheeses with a low second heating temperature on the mass fraction of moisture.


"Poshekhonskiy" cheese:

*DOI: http://dx.doi.org/10.5772/intechopen.85276*

material over time ð Þ *φ* � *τ* —drying curves.

**Figure 3.**

*thickness.*

**19**

*mode: t = 60°C, q = 5.52 kW/m<sup>2</sup>*

where *B<sup>с</sup>* is the mass fraction of moisture in the cheese.

*Study of the Kinetics of Vacuum Drying of Hard and Semihard Cheeses*

According to **Figure 2** and Eqs. (1)–(3), it follows that a change in moisture of 1% leads to a change in the cryoscopic temperature of the studied cheeses by 0.25°C. The kinetics of the drying process is usually understood as a change in the average volume of the dried material humidity *φ<sup>с</sup>* and temperature *t* over time *τ*. The nature of the drying process is most accurately described by the drying curves (in the coordinates of the moisture mass fraction-time), the curves of the drying speed (in the coordinates of the drying speed-the moisture mass fraction), and temperature curves (in the coordinates of the material temperature-the humidity of the material). The work of drying units of different performances cannot be compared by changing the mass of material in the drying process. To do this, it is rational to use graphic figures of the change in moisture mass fraction of the

The data for constructing the curves is usually obtained in the laboratory when the mass (weight) of the material sample and its temperature are recorded during the drying process. Drying is usually done with heated air at a constant rate. For vacuum drying, the constant mode is the material temperature, the residual pressure value. Naturally, the transfer of laboratory research data to production conditions (where drying is usually carried out under variable conditions) requires special adjustments. The change in the average volume moisture mass fraction over time *φ<sup>с</sup>* ¼ *f*ð Þ*τ* is graphically represented by a curve called the drying curve. In the general, the drying curve consists of several sections corresponding to different periods of drying [6]. **Figure 3** shows the curves of vacuum drying (heat load-time,

temperature–time, mass fraction of moisture-time) for the "Swiss" cheese.

*Drying curves for "Swiss" cheese. (a) Heat load. (b) Temperature on the surface and throughout the thickness:*

*, Р = 2–3 kPa, and h = 10 mm. (1) On the surface. (2) Throughout the*

*tкр* ¼ 0*,*12 � *Bc* � 8*,*38 (3)

#### **Table 4.**

*Hygroscopic characteristics of cheeses.*


#### **Table 5.**

*Cheese thermophysical characteristics.*

#### **Figure 2.**

*Dependence of the cryoscopic temperature of cheeses on the mass fraction of moisture: (1) "Dutch," (2) Kostromskoy, and (3) "Poshekhonskiy."*

As a result of the research, the dependences between the cryoscopic temperature *tкр* and the moisture content in hard cheeses with a low second heating temperature were revealed for:

"Dutch" cheese:

$$t\_{\rm kp} = \mathbf{0}, \mathbf{1} \mathbf{5} \mathbf{9} \mathbf{5} \cdot B\_{\rm c} - \mathbf{9}, \mathbf{6} \mathbf{7} \tag{1}$$

"Kostromskoy" cheese:

$$t\_{\rm \kappa p} = 0, 14\mathbf{\tilde{64}} \cdot B\_{\rm c} - 9, 28 \tag{2}$$

*Study of the Kinetics of Vacuum Drying of Hard and Semihard Cheeses DOI: http://dx.doi.org/10.5772/intechopen.85276*

"Poshekhonskiy" cheese:

$$t\_{\kappa p} = 0, \mathbf{12} \cdot B\_t - 8, \mathbf{38} \tag{3}$$

where *B<sup>с</sup>* is the mass fraction of moisture in the cheese.

According to **Figure 2** and Eqs. (1)–(3), it follows that a change in moisture of 1% leads to a change in the cryoscopic temperature of the studied cheeses by 0.25°C.

The kinetics of the drying process is usually understood as a change in the average volume of the dried material humidity *φ<sup>с</sup>* and temperature *t* over time *τ*. The nature of the drying process is most accurately described by the drying curves (in the coordinates of the moisture mass fraction-time), the curves of the drying speed (in the coordinates of the drying speed-the moisture mass fraction), and temperature curves (in the coordinates of the material temperature-the humidity of the material). The work of drying units of different performances cannot be compared by changing the mass of material in the drying process. To do this, it is rational to use graphic figures of the change in moisture mass fraction of the material over time ð Þ *φ* � *τ* —drying curves.

The data for constructing the curves is usually obtained in the laboratory when the mass (weight) of the material sample and its temperature are recorded during the drying process. Drying is usually done with heated air at a constant rate. For vacuum drying, the constant mode is the material temperature, the residual pressure value. Naturally, the transfer of laboratory research data to production conditions (where drying is usually carried out under variable conditions) requires special adjustments. The change in the average volume moisture mass fraction over time *φ<sup>с</sup>* ¼ *f*ð Þ*τ* is graphically represented by a curve called the drying curve. In the general, the drying curve consists of several sections corresponding to different periods of drying [6]. **Figure 3** shows the curves of vacuum drying (heat load-time, temperature–time, mass fraction of moisture-time) for the "Swiss" cheese.

#### **Figure 3.**

*Drying curves for "Swiss" cheese. (a) Heat load. (b) Temperature on the surface and throughout the thickness: mode: t = 60°C, q = 5.52 kW/m<sup>2</sup> , Р = 2–3 kPa, and h = 10 mm. (1) On the surface. (2) Throughout the thickness.*

As a result of the research, the dependences between the cryoscopic

*Dependence of the cryoscopic temperature of cheeses on the mass fraction of moisture: (1) "Dutch," (2)*

temperature were revealed for:

*Kostromskoy, and (3) "Poshekhonskiy."*

"Kostromskoy" cheese:

"Dutch" cheese:

**Sovetskiy cheese**

**Dutch cheese**

**Ozernyiy cheese**

*Hygroscopic characteristics of cheeses.*

*Cheese thermophysical characteristics.*

**Density (kg/m<sup>3</sup> )**

*Current Issues and Challenges in the Dairy Industry*

**Table 4.**

**Table 5.**

**Figure 2.**

**18**

**Types of cheese**

temperature *tкр* and the moisture content in hard cheeses with a low second heating

Relative air humidity (%) 10 20 30 40 50 60 70 80 90

Equilibrium humidity (%) 7.0 10.0 11.5 13.5 15.5 17.5 19.5 22.0 26.5

Equilibrium humidity (%) 5.0 6.5 8.0 9.5 11.0 13.0 17.0 25.0 33.0

Equilibrium humidity (%) 4.0 5.0 6.0 7.0 8.0 10.0 15.0 22.0 31.0

**Thermal conductivity (W/(m**�**K))**

Sovetskiy 1070 0.34 2570 0.135 Dutch 1060 0.35 2530 0.133 Ozernyiy 1040 0.35 2540 0.132

**Thermophysical characteristics**

**Heat capacity (J/(kg**�**K))**

**Thermal diffusivity (10**�**<sup>6</sup> m<sup>2</sup> /с)**

*tкр* ¼ 0*,*1595 � *Bc* � 9*,*67 (1)

*tкр* ¼ 0*,*1464 � *Bc* � 9*,*28 (2)

Within 9–15 min, until the drying unit reached the required mode by residual pressure (2–3 kPa), heat is not supplied from the heaters (**Figure 3**), and the cheese temperature decreases from 17 to 15 to 12–10°С.

The first derivative of the function *φ<sup>с</sup>* ¼ *f*ð Þ*τ* calculates the drying rate, under which we understand the change in the material moisture content per unit time ð Þ *dφс=dτ;* %*=*мин . Curves of drying rates were drawn by the method of graphical differentiation according to drying curves (curves of change in the mass fraction of moisture): the drying rate at a given time is determined as the tangent of the tangent angle, drawn through the drying curve point that corresponds to a specific

*tg<sup>ψ</sup>* <sup>¼</sup> *<sup>d</sup><sup>φ</sup>*

Maximum drying rate *N* during the period of constant drying rate:

*МАКС*

By the end of the process at equilibrium moisture, the drying rate is *<sup>d</sup><sup>φ</sup>*

During the constant period of drying, moisture is removed from the cheeses: "Swiss," 18%; "Dutch," 17%; "Kostromskoy," 22%; "Poshekhonskiy," 28%;

At the beginning of the drying process, the unit goes to the desired mode for the residual pressure, and the drying rate increases from zero to the maximum value. The maximum value of the cheese drying rate for "Swiss" is 0.62%/min; "Dutch," 0.71%/min; "Kostromskoy," 0.88%/min; "Poshekhonskiy," 0.78%/min; "Rizhskiy,"

In the period of constant drying rate, the drying rate is equal to the maximum.

Starting from the first critical point, a decrease in the drying rate begins. The nature of the curves in the period of the falling drying rate corresponds to colloidal

Critical humidity corresponds to the humidity limit when the mechanism of moisture movement in the material changes. This point marks the beginning of

polymolecular adsorption. That is, the mass fraction of moisture of polymolecular

Temperature curves *t* ¼ *f φ<sup>с</sup>* ð Þ are very informative. Temperature curves for the first were introduced by A.V. Lykov; now, they are important for the analysis of the drying process. **Figure 4** shows the temperature curves characteristic of

At the beginning of the drying process, the cheese temperature decreases as the heat from the heaters is not supplied. At the beginning of the first drying period, when the heaters are turned on, the surface temperature of the material rises, reaching the temperature of the wet-bulb thermometer. During this period, the most intense moisture return occurs, and practically all the heat imparted to the material is spent on the moisture evaporation. The temperature over the thicker

point and the mass fraction of moisture of dry cheeses is the moisture of

layer of cheese is equalized by the end of the first drying period.

Starting from the first critical point, the rate of moisture evaporation decreases. When the humidity of the cheeses reaches the value of the equilibrium moisture, the drying process is completed. The equilibrium moisture content for

The second critical point corresponds to the following mass fraction of moisture of cheese: "Swiss," 10%; "Dutch," 10%; "Kostromskoy," 13%; "Poshekhonskiy," 8%; "Rizhskiy," 10%; and "Russian," 9%. Moisture mass fraction of dry cheeses is 4–5%. The difference between the mass fraction of moisture at the second critical

*tg<sup>ψ</sup>* <sup>¼</sup> *<sup>d</sup><sup>φ</sup> dτ* 

*Study of the Kinetics of Vacuum Drying of Hard and Semihard Cheeses*

*DOI: http://dx.doi.org/10.5772/intechopen.85276*

0.92%/min; and "Russian," 0.75%/min.

"Rizhskiy," 48%; and "Russian," 32%.

moisture removal by polymolecular adsorption.

capillary-porous bodies.

adsorption for cheeses is 4–9%.

vacuum drying of Swiss cheese.

**21**

*<sup>d</sup><sup>τ</sup> :* (4)

¼ *N,* %*=*чили%*=*мин*:* (5)

*<sup>d</sup><sup>τ</sup>* ¼ 0.

moisture mass fraction:

The temperature lowers due to the intense evaporation of moisture from the surface of the cheese. The decrease in the mass fraction of moisture while the unit is set to operate is 2–3%. Segment A–B corresponds to the time required for the unit to reach the required mode by residual pressure (2–3 kPa). Then comes the first drying period—a period of constant drying rate, a segment B–K1 on the curve of change in the mass fraction of moisture. The first period is characterized by a constant rate of decrease in the mass fraction of moisture (for equal periods of time, the same amount of moisture is removed).

The temperature of the cheese increases due to the supply of heat from the heaters. The cheese temperature during the first period reaches the desired value and is maintained at a predetermined level (**Figure 3**). By the end of the first period, the temperature leveling along the thicker layer of the dried cheese is observed. At the beginning of the first period, the heat load is equal to the maximum allowable value. When the cheese reaches the desired drying temperature, the heat load is reduced. Reducing the heat load is necessary to prevent the drying temperature of the cheese from exceeding the required value.

During the first period, the greatest amount of moisture is removed. In the first drying period, the moisture mass fraction of the "Swiss" cheese decreased by 24%; "Dutch," 23%; and "Poshekhonskiy," 34%. The duration of the first drying period is, for the "Swiss" cheese, 74 min; "Dutch," 83 min; "Kostromskoy," 92 min; and "Poshekhonskiy," 80 min. The period of constant drying speed continues until the first critical moisture content reaches.

During the period of constant drying rate, the intensity of the process is determined only by the parameters of the drying agent and does not depend on the moisture content (mass fraction of moisture) and the physicochemical properties of the material. At a certain value of the moisture mass fraction, the rate of the moisture removal begins to decrease and the second period starts—the period of falling drying rate. The beginning of the second period corresponds to the critical moisture content of the material. During the second period, the moisture that is the most strongly bound to the product is removed. The evaporation rate decreases, the drying rate slows down, and the temperature levels throughout the product thicken.

In the period of the falling drying rate, the drying rate decreases with decreasing moisture content of the material. During this period, the bound moisture is removed, and a gradual decrease in the drying rate is explained by an increase in the binding energy of moisture with the material.

In the period of falling speed of drying, the mass fraction of moisture of the "Swiss" cheese decreases by 12%; "Dutch," 15%; "Kostromskoy," 24%; and "Poshekhonskiy," 12%. The duration of the period of the falling speed of drying "Swiss" cheese is 108 min; "Dutch," 100 min; "Kostromskoy," 17 min; and "Poshekhonskiy," 100 min.

Duration of the period of the falling drying speed can be divided into some segments corresponding to the first and second phases. By the second critical moment, the evaporation zone reaches the deep layers of the product. At this moment, movement of moisture occurs only in the form of steam, and mainly adsorption moisture evaporates.

At the end of the drying process, the drying curve (the curve of change in the mass fraction of moisture) asymptotically approaches the equilibrium moisture, and the equilibrium moisture value corresponds to this drying mode. When equilibrium moisture occurs, the drying process stops—the drying rate equals zero.

#### *Study of the Kinetics of Vacuum Drying of Hard and Semihard Cheeses DOI: http://dx.doi.org/10.5772/intechopen.85276*

The first derivative of the function *φ<sup>с</sup>* ¼ *f*ð Þ*τ* calculates the drying rate, under which we understand the change in the material moisture content per unit time ð Þ *dφс=dτ;* %*=*мин . Curves of drying rates were drawn by the method of graphical differentiation according to drying curves (curves of change in the mass fraction of moisture): the drying rate at a given time is determined as the tangent of the tangent angle, drawn through the drying curve point that corresponds to a specific moisture mass fraction:

$$\text{tg}\varphi = \frac{d\varphi}{d\tau}.\tag{4}$$

Maximum drying rate *N* during the period of constant drying rate:

$$\text{tg}\varphi = \left(\frac{d\rho}{d\tau}\right)\_{\text{MAKC}} = \text{N, } \text{\textyen} / \text{\textquotedbl{}u\textquotedbl{}u\textquotedbl{}} \text{\textquotedbl{}M\textquotedbl{}H\textquotedbl{}}.\tag{5}$$

By the end of the process at equilibrium moisture, the drying rate is *<sup>d</sup><sup>φ</sup> <sup>d</sup><sup>τ</sup>* ¼ 0.

At the beginning of the drying process, the unit goes to the desired mode for the residual pressure, and the drying rate increases from zero to the maximum value. The maximum value of the cheese drying rate for "Swiss" is 0.62%/min; "Dutch," 0.71%/min; "Kostromskoy," 0.88%/min; "Poshekhonskiy," 0.78%/min; "Rizhskiy," 0.92%/min; and "Russian," 0.75%/min.

In the period of constant drying rate, the drying rate is equal to the maximum. During the constant period of drying, moisture is removed from the cheeses: "Swiss," 18%; "Dutch," 17%; "Kostromskoy," 22%; "Poshekhonskiy," 28%; "Rizhskiy," 48%; and "Russian," 32%.

Starting from the first critical point, a decrease in the drying rate begins. The nature of the curves in the period of the falling drying rate corresponds to colloidal capillary-porous bodies.

Critical humidity corresponds to the humidity limit when the mechanism of moisture movement in the material changes. This point marks the beginning of moisture removal by polymolecular adsorption.

The second critical point corresponds to the following mass fraction of moisture of cheese: "Swiss," 10%; "Dutch," 10%; "Kostromskoy," 13%; "Poshekhonskiy," 8%; "Rizhskiy," 10%; and "Russian," 9%. Moisture mass fraction of dry cheeses is 4–5%. The difference between the mass fraction of moisture at the second critical point and the mass fraction of moisture of dry cheeses is the moisture of polymolecular adsorption. That is, the mass fraction of moisture of polymolecular adsorption for cheeses is 4–9%.

Temperature curves *t* ¼ *f φ<sup>с</sup>* ð Þ are very informative. Temperature curves for the first were introduced by A.V. Lykov; now, they are important for the analysis of the drying process. **Figure 4** shows the temperature curves characteristic of vacuum drying of Swiss cheese.

At the beginning of the drying process, the cheese temperature decreases as the heat from the heaters is not supplied. At the beginning of the first drying period, when the heaters are turned on, the surface temperature of the material rises, reaching the temperature of the wet-bulb thermometer. During this period, the most intense moisture return occurs, and practically all the heat imparted to the material is spent on the moisture evaporation. The temperature over the thicker layer of cheese is equalized by the end of the first drying period.

Starting from the first critical point, the rate of moisture evaporation decreases. When the humidity of the cheeses reaches the value of the equilibrium moisture, the drying process is completed. The equilibrium moisture content for

Within 9–15 min, until the drying unit reached the required mode by residual pressure (2–3 kPa), heat is not supplied from the heaters (**Figure 3**), and the cheese

The temperature lowers due to the intense evaporation of moisture from the surface of the cheese. The decrease in the mass fraction of moisture while the unit is set to operate is 2–3%. Segment A–B corresponds to the time required for the unit to reach the required mode by residual pressure (2–3 kPa). Then comes the first drying period—a period of constant drying rate, a segment B–K1 on the curve of change in the mass fraction of moisture. The first period is characterized by a constant rate of decrease in the mass fraction of moisture (for equal periods of time,

The temperature of the cheese increases due to the supply of heat from the heaters. The cheese temperature during the first period reaches the desired value and is maintained at a predetermined level (**Figure 3**). By the end of the first period, the temperature leveling along the thicker layer of the dried cheese is observed. At the beginning of the first period, the heat load is equal to the maximum allowable value. When the cheese reaches the desired drying temperature, the heat load is reduced. Reducing the heat load is necessary to prevent the drying

During the first period, the greatest amount of moisture is removed. In the first drying period, the moisture mass fraction of the "Swiss" cheese decreased by 24%; "Dutch," 23%; and "Poshekhonskiy," 34%. The duration of the first drying period is, for the "Swiss" cheese, 74 min; "Dutch," 83 min; "Kostromskoy," 92 min; and "Poshekhonskiy," 80 min. The period of constant drying speed continues until the

During the period of constant drying rate, the intensity of the process is determined only by the parameters of the drying agent and does not depend on the moisture content (mass fraction of moisture) and the physicochemical properties of the material. At a certain value of the moisture mass fraction, the rate of the moisture removal begins to decrease and the second period starts—the period of falling drying rate. The beginning of the second period corresponds to the critical moisture content of the material. During the second period, the moisture that is the most strongly bound to the product is removed. The evaporation rate decreases, the drying rate slows down, and the temperature levels throughout the product thicken. In the period of the falling drying rate, the drying rate decreases with decreasing

moisture content of the material. During this period, the bound moisture is

removed, and a gradual decrease in the drying rate is explained by an increase in the

In the period of falling speed of drying, the mass fraction of moisture of the "Swiss" cheese decreases by 12%; "Dutch," 15%; "Kostromskoy," 24%; and "Poshekhonskiy," 12%. The duration of the period of the falling speed of drying "Swiss" cheese is 108 min; "Dutch," 100 min; "Kostromskoy," 17 min; and

Duration of the period of the falling drying speed can be divided into some segments corresponding to the first and second phases. By the second critical moment, the evaporation zone reaches the deep layers of the product. At this moment, movement of moisture occurs only in the form of steam, and mainly

At the end of the drying process, the drying curve (the curve of change in the mass fraction of moisture) asymptotically approaches the equilibrium moisture, and the equilibrium moisture value corresponds to this drying mode. When equilibrium moisture occurs, the drying process stops—the drying

temperature of the cheese from exceeding the required value.

temperature decreases from 17 to 15 to 12–10°С.

*Current Issues and Challenges in the Dairy Industry*

the same amount of moisture is removed).

first critical moisture content reaches.

binding energy of moisture with the material.

"Poshekhonskiy," 100 min.

adsorption moisture evaporates.

rate equals zero.

**20**

**Figure 4.** *Temperature curves of vacuum drying of Swiss cheese: (1) on the surface and (2) in the thickness.*

cheeses is, for "Swiss," 5.21%; "Dutch," 4.46%; "Kostromskoy," 5.46%; and "Poshekhonskiy," 4.26%.

It has been established that vacuum drying of cheeses proceeds in two periods: constant and falling drying rates. The drying curves of various types of cheeses in the coordinates were obtained and investigated (heat load-time, temperature–time, mass fraction of moisture-time). By graphic differentiation, the curves of drying rate of cheeses are constructed. By the analytical method, it was determined that the amount of moisture of polymolecular adsorption for cheeses is 4–9%. The temperature curves of the cheeses in the coordinates (temperature-mass fraction of moisture) were investigated. The values of equilibrium moisture for vacuum drying of cheeses are established.

**Figure 6** shows the dependence of the shrinkage factor on the initial mass fraction of the cheese moisture in the drying process. According to the curves presented in **Figure 5**, the following dependence is established: with an increase in the mass fraction of cheese moisture, the shrinkage rate increases. A similar dependence follows from the analysis of the curves presented in **Figure 6**. Shrinkage of cheeses in both periods of vacuum drying occurs evenly.

If the linear size of the material (length, width, height) is denoted with *l*,

*β<sup>l</sup>* is a coefficient of linear shrinkage, characterizing shrinkage rate of 1%, i.e.,

Formula (6) is valid for relatively small gradients of moisture content inside

the material will shrink faster than the average ones. **Table 6** shows the moisture content of the "Sovietskiy" and "Dutch" cheese in a layer thickness of 20 mm.

The moisture content data on the thickness of the cheese layer was obtained at the required temperatures, thermal loads, and residual pressure of the vacuum drying of the cheeses. As the temperature increases, the heat load on the surface of the cheese

the material. With a large moisture content gradient, the surface layers of

*The dependence of shrinkage coefficients of cheeses on the initial mass fraction of moisture.*

*l* ¼ *l*<sup>0</sup> � 1 þ *β<sup>l</sup>* ð Þ � *W* (6)

when the mass fraction of moisture is *W*, then it can be written as [13]

where *l*<sup>0</sup> is the linear size of the absolutely dry material;

*The dependence of coefficients of cheeses shrinkage on the mass fraction of moisture.*

*Study of the Kinetics of Vacuum Drying of Hard and Semihard Cheeses*

*DOI: http://dx.doi.org/10.5772/intechopen.85276*

*<sup>β</sup><sup>l</sup>* <sup>¼</sup> <sup>1</sup> *<sup>l</sup>*<sup>0</sup> � *dl dW*.

**Figure 6.**

**23**

**Figure 5.**

The size and volume of most materials are reduced during the drying process. This phenomenon is called material shrinkage [8–10]. For example, in convective drying, such materials as vegetables, fruits, and cereals shrink significantly, decreasing in volume by three to four times [11].

Most materials (peat, grain, leather, dough, bread, etc.) shrink throughout the drying process. However, a number of materials (clay, ceramic masses, and some other materials) shrink during a period of constant drying rate. In this case, the shrinkage is stopped at approximately critical moisture content, if the moisture content gradient inside the material is small. Other materials (wood, coal) shrink only in the period of falling drying rate, it begins approximately at a point of critical moisture content [12].

The least shrinkage results are shown by cheeses produced with a residual pressure of 2–3 kPa. It is established that an increase in the size of grinding and thickness of the drying layer of the "Dutch," "Kostromskoy," and "Poshekhonskiy" cheeses leads to an increase in shrinkage factors. At the drying material thickness from 10 to 30 mm, the shrinkage ratio is from 3 to 14%. When the thickness of the drying layer is 40 mm, the coefficient of shrinkage increases up to 15–24%. Drying the cheeses with the required operating and technological parameters causes minimal drops in the mass fraction of moisture, while particle shrinkage is minimal and takes place with preservation of shape.

**Figure 5** shows the dependence of the coefficient of cheese shrinkage on the initial mass fraction of moisture.

With an increase in the mass fraction of the cheese moisture, the shrinkage factors increase. The greatest increase in the coefficient of cheese shrinkage is observed when the mass fraction of moisture is more than 50%. With a change in the mass fraction of the cheese moisture from 40 to 50%, the shrinkage rate increases by 2.5%; from 50 to 60%—by 6.5%.

*Study of the Kinetics of Vacuum Drying of Hard and Semihard Cheeses DOI: http://dx.doi.org/10.5772/intechopen.85276*

**Figure 5.** *The dependence of coefficients of cheeses shrinkage on the mass fraction of moisture.*

**Figure 6** shows the dependence of the shrinkage factor on the initial mass fraction of the cheese moisture in the drying process. According to the curves presented in **Figure 5**, the following dependence is established: with an increase in the mass fraction of cheese moisture, the shrinkage rate increases. A similar dependence follows from the analysis of the curves presented in **Figure 6**. Shrinkage of cheeses in both periods of vacuum drying occurs evenly.

If the linear size of the material (length, width, height) is denoted with *l*, when the mass fraction of moisture is *W*, then it can be written as [13]

$$l = l\_0 \cdot (\mathbf{1} + \beta\_l \cdot \mathbf{W}) \tag{6}$$

where *l*<sup>0</sup> is the linear size of the absolutely dry material;

*β<sup>l</sup>* is a coefficient of linear shrinkage, characterizing shrinkage rate of 1%, i.e., *<sup>β</sup><sup>l</sup>* <sup>¼</sup> <sup>1</sup> *<sup>l</sup>*<sup>0</sup> � *dl dW*.

Formula (6) is valid for relatively small gradients of moisture content inside the material. With a large moisture content gradient, the surface layers of the material will shrink faster than the average ones. **Table 6** shows the moisture content of the "Sovietskiy" and "Dutch" cheese in a layer thickness of 20 mm.

The moisture content data on the thickness of the cheese layer was obtained at the required temperatures, thermal loads, and residual pressure of the vacuum drying of the cheeses. As the temperature increases, the heat load on the surface of the cheese

**Figure 6.** *The dependence of shrinkage coefficients of cheeses on the initial mass fraction of moisture.*

cheeses is, for "Swiss," 5.21%; "Dutch," 4.46%; "Kostromskoy," 5.46%; and

*Temperature curves of vacuum drying of Swiss cheese: (1) on the surface and (2) in the thickness.*

It has been established that vacuum drying of cheeses proceeds in two periods: constant and falling drying rates. The drying curves of various types of cheeses in the coordinates were obtained and investigated (heat load-time, temperature–time, mass fraction of moisture-time). By graphic differentiation, the curves of drying rate of cheeses are constructed. By the analytical method, it was determined that the amount of moisture of polymolecular adsorption for cheeses is 4–9%. The temperature curves of the cheeses in the coordinates (temperature-mass fraction of moisture) were investigated. The values of equilibrium moisture for vacuum drying of

The size and volume of most materials are reduced during the drying process. This phenomenon is called material shrinkage [8–10]. For example, in convective drying, such materials as vegetables, fruits, and cereals shrink significantly,

Most materials (peat, grain, leather, dough, bread, etc.) shrink throughout the drying process. However, a number of materials (clay, ceramic masses, and some other materials) shrink during a period of constant drying rate. In this case, the shrinkage is stopped at approximately critical moisture content, if the moisture content gradient inside the material is small. Other materials (wood, coal) shrink only in the period of falling drying rate, it begins approximately at a point of critical

The least shrinkage results are shown by cheeses produced with a residual pressure of 2–3 kPa. It is established that an increase in the size of grinding and thickness of the drying layer of the "Dutch," "Kostromskoy," and "Poshekhonskiy" cheeses leads to an increase in shrinkage factors. At the drying material thickness from 10 to 30 mm, the shrinkage ratio is from 3 to 14%. When the thickness of the

drying layer is 40 mm, the coefficient of shrinkage increases up to 15–24%. Drying the cheeses with the required operating and technological parameters causes minimal drops in the mass fraction of moisture, while particle shrinkage is

**Figure 5** shows the dependence of the coefficient of cheese shrinkage on the

With an increase in the mass fraction of the cheese moisture, the shrinkage factors increase. The greatest increase in the coefficient of cheese shrinkage is observed when the mass fraction of moisture is more than 50%. With a change in the mass fraction of the cheese moisture from 40 to 50%, the shrinkage rate

"Poshekhonskiy," 4.26%.

*Current Issues and Challenges in the Dairy Industry*

**Figure 4.**

cheeses are established.

moisture content [12].

decreasing in volume by three to four times [11].

minimal and takes place with preservation of shape.

increases by 2.5%; from 50 to 60%—by 6.5%.

initial mass fraction of moisture.

**22**

moisture content decreases rapidly, while in the thickness layers, it changes more slowly. Surface layers, which affect the size of the material, tend to decrease not in proportion to the average moisture content, but approximately in proportion to the moisture content on the surface. Therefore, starting from a certain moisture content (mass fraction of moisture), shrinkage is hardly observed (**Figure 7**).

Thus, formula (6) is valid only with a small gradient of moisture content (mass fraction of moisture), when the mass fraction of moisture *u* at any point of the cheese is approximately equal to the average mass fraction of moisture *W u*ð Þ � *W* . A more rigorous writing of the formula (4.6) was proposed by

*Study of the Kinetics of Vacuum Drying of Hard and Semihard Cheeses*

*DOI: http://dx.doi.org/10.5772/intechopen.85276*

For most materials, the dependence between the volume of the body and its

*β<sup>V</sup>* is the coefficient of volumetric shrinkage, equal to the relative decrease in

A.V. Lykov proposed to determine the coefficient *β<sup>V</sup>* by two values *V*<sup>1</sup> and *V*<sup>2</sup> for the mass fraction of moisture and, for example, before and after drying.

*V*<sup>0</sup> and *β<sup>V</sup>* can be determined by these equations. Denoting relative shrinkage

*<sup>δ</sup>* <sup>¼</sup> *<sup>V</sup>*<sup>1</sup> � *<sup>V</sup>*<sup>2</sup> *V*1 *,* (11) then

The area of the sample material is equal to the product of the length *l* by the

*<sup>S</sup>* <sup>¼</sup> *<sup>l</sup>* � *<sup>L</sup>* <sup>¼</sup> *<sup>l</sup>*<sup>0</sup> � *<sup>L</sup>*<sup>0</sup> � <sup>1</sup> <sup>þ</sup> *<sup>β</sup><sup>l</sup>* ð Þ � *<sup>W</sup>* <sup>2</sup> <sup>¼</sup> *<sup>S</sup>*<sup>0</sup> � <sup>1</sup> <sup>þ</sup> *<sup>β</sup><sup>l</sup>* ð Þ � *<sup>W</sup>* <sup>2</sup>

**Cheese Coefficient of volumetric shrinkage (***βV***)**

Sovietskiy 0.017–0.004 Dutch 0.006–0.003

ð Þ� *W*<sup>1</sup> � *W*<sup>2</sup> *δ* � *W*<sup>1</sup>

*<sup>β</sup><sup>V</sup>* <sup>¼</sup> *<sup>δ</sup>*

**Table 7** shows the coefficients of volumetric shrinkage of cheeses. If the linear sizes of the cheeses vary from the mass fraction of moisture according to the ratio (7), a simple relationship can be found between *β<sup>V</sup>* and *βl*, as

where *S*<sup>0</sup> ¼ *l*<sup>0</sup> � *L*<sup>0</sup> is the area of absolutely dry material.

volume when moisture content changes on 1%, *<sup>β</sup><sup>V</sup>* <sup>¼</sup> *dV*

*V*<sup>0</sup> is the volume of absolutely dry matter.

(with respect to the original volume) with *δ*, it is as

*l* ¼ *l*<sup>0</sup> � 1 þ *β<sup>l</sup>* ð Þ � *W :* (7)

*V* ¼ *V*<sup>0</sup> � ð Þ 1 þ *β<sup>V</sup>* � *W ,* (8)

*<sup>V</sup>*0�*dW*.

*V*<sup>1</sup> ¼ *V*<sup>0</sup> � ð Þ 1 þ *β<sup>V</sup>* � *W*<sup>1</sup> *,* (9)

*V*<sup>2</sup> ¼ *V*<sup>0</sup> � ð Þ 1 þ *β<sup>V</sup>* � *W*<sup>2</sup> *:* (10)

*:* (12)

*,* (13)

A.V. Lykov [14, 15]:

where

Consequently:

moisture content is linear:

well as between *β<sup>l</sup>* and *βS*.

*The coefficients of volumetric shrinkage of cheeses.*

width *L*, that is:

**Table 7.**

**25**

The shrinkage curves of the cheeses, "Sovietskiy" (1) and "Dutch" (3), were obtained at the required drying temperature of 60°C. Shrinkage curves 2 and 4 were obtained at a temperature higher than the required one (80°C). When the drying temperature is high, the surface layers dry quickly. The central layers have an increased mass fraction of moisture. Shrinkage at elevated temperatures is less, but dry cheese has a large mass fraction of moisture.

With an increase in the drying temperature, the shrinkage coefficient decreases; this is explained by an increase in the gradient of the mass fraction of moisture inside the material. In the presence of a gradient of the mass fraction of moisture, the surface layers tend to shrink more compared to internal ones. However, the reduction of the surface layers is impeded by internal ones, the mass fraction of which is more moisture than the surface layers. As a result, the shrinkage of the surface layers is less than that which should correspond to the moisture removed from them. Consequently, an increase in the difference in the mass fraction of moisture between the inner and surface layers is accompanied by an increase in the difference between the actual shrinkage and the possible shrinkage corresponding to the amount of liquid to be removed.


#### **Table 6.**

*Moisture content of cheeses at the layer thickness of 20 mm.*

#### **Figure 7.**

*Shrinkage curves of cheeses "Sovietskiy" (1 and 2) and "Dutch" (3 and 4): (1) t = 60°С; q = 5.52 kW/m<sup>2</sup> ; Р = 2–3 kPa; (2) t = 80°С; q = 5.52 kW/m2 ; Р = 2–3 kPa; (3) t = 60°С; q = 7.36 kW/m<sup>2</sup> ; Р = 2–3 kPa; (4) t = 80°С; q = 7.36 kW/m<sup>2</sup> ; Р = 2–3 kPa.*

*Study of the Kinetics of Vacuum Drying of Hard and Semihard Cheeses DOI: http://dx.doi.org/10.5772/intechopen.85276*

Thus, formula (6) is valid only with a small gradient of moisture content (mass fraction of moisture), when the mass fraction of moisture *u* at any point of the cheese is approximately equal to the average mass fraction of moisture *W u*ð Þ � *W* . A more rigorous writing of the formula (4.6) was proposed by A.V. Lykov [14, 15]:

$$l = l\_0 \cdot (\mathbf{1} + \beta\_l \cdot \mathbf{W}).\tag{7}$$

For most materials, the dependence between the volume of the body and its moisture content is linear:

$$V = V\_0 \cdot (\mathbf{1} + \beta\_V \cdot W),\tag{8}$$

where

moisture content decreases rapidly, while in the thickness layers, it changes more slowly. Surface layers, which affect the size of the material, tend to decrease not in proportion to the average moisture content, but approximately in proportion to the moisture content on the surface. Therefore, starting from a certain moisture content

The shrinkage curves of the cheeses, "Sovietskiy" (1) and "Dutch" (3), were obtained at the required drying temperature of 60°C. Shrinkage curves 2 and 4 were obtained at a temperature higher than the required one (80°C). When the drying temperature is high, the surface layers dry quickly. The central layers have an increased mass fraction of moisture. Shrinkage at elevated temperatures is less, but

With an increase in the drying temperature, the shrinkage coefficient decreases;

**At the first critical point At the second critical point Surface layers Thickness layer Surface layers Thickness layer**

this is explained by an increase in the gradient of the mass fraction of moisture inside the material. In the presence of a gradient of the mass fraction of moisture, the surface layers tend to shrink more compared to internal ones. However, the reduction of the surface layers is impeded by internal ones, the mass fraction of which is more moisture than the surface layers. As a result, the shrinkage of the surface layers is less than that which should correspond to the moisture removed from them. Consequently, an increase in the difference in the mass fraction of moisture between the inner and surface layers is accompanied by an increase in the difference between the actual shrinkage and the possible shrinkage corresponding

(mass fraction of moisture), shrinkage is hardly observed (**Figure 7**).

**Cheese Moisture content (wet/dry material)**

Sovietskiy 6–9 20–24 4–5 9–17 Dutch 6–8 19–22 4–5 7–12

*Shrinkage curves of cheeses "Sovietskiy" (1 and 2) and "Dutch" (3 and 4): (1) t = 60°С; q = 5.52 kW/m<sup>2</sup>*

*; Р = 2–3 kPa.*

*; Р = 2–3 kPa; (3) t = 60°С; q = 7.36 kW/m<sup>2</sup>*

*;*

*; Р = 2–3 kPa;*

dry cheese has a large mass fraction of moisture.

*Current Issues and Challenges in the Dairy Industry*

to the amount of liquid to be removed.

*Moisture content of cheeses at the layer thickness of 20 mm.*

**Table 6.**

**Figure 7.**

**24**

*Р = 2–3 kPa; (2) t = 80°С; q = 5.52 kW/m2*

*(4) t = 80°С; q = 7.36 kW/m<sup>2</sup>*

*β<sup>V</sup>* is the coefficient of volumetric shrinkage, equal to the relative decrease in volume when moisture content changes on 1%, *<sup>β</sup><sup>V</sup>* <sup>¼</sup> *dV <sup>V</sup>*0�*dW*.

*V*<sup>0</sup> is the volume of absolutely dry matter.

A.V. Lykov proposed to determine the coefficient *β<sup>V</sup>* by two values *V*<sup>1</sup> and *V*<sup>2</sup> for the mass fraction of moisture and, for example, before and after drying. Consequently:

$$V\_1 = V\_0 \cdot (\mathbf{1} + \beta\_V \cdot W\_1),\tag{9}$$

$$V\_2 = V\_0 \cdot (\mathbf{1} + \beta\_V \cdot W\_2). \tag{10}$$

*V*<sup>0</sup> and *β<sup>V</sup>* can be determined by these equations. Denoting relative shrinkage (with respect to the original volume) with *δ*, it is as

$$\text{then} \tag{11}$$

$$\delta = \frac{V\_1 - V\_2}{V\_1}, \tag{11}$$

$$\beta\_V = \frac{\delta}{(W\_1 - W\_2) - \delta \cdot W\_1}.\tag{12}$$

**Table 7** shows the coefficients of volumetric shrinkage of cheeses.

If the linear sizes of the cheeses vary from the mass fraction of moisture according to the ratio (7), a simple relationship can be found between *β<sup>V</sup>* and *βl*, as well as between *β<sup>l</sup>* and *βS*.

The area of the sample material is equal to the product of the length *l* by the width *L*, that is:

$$\mathbf{S} = l \cdot L = l\_0 \cdot L\_0 \cdot \left(\mathbf{1} + \boldsymbol{\beta}\_l \cdot \mathbf{W}\right)^2 = \mathbf{S}\_0 \cdot \left(\mathbf{1} + \boldsymbol{\beta}\_l \cdot \mathbf{W}\right)^2,\tag{13}$$

where *S*<sup>0</sup> ¼ *l*<sup>0</sup> � *L*<sup>0</sup> is the area of absolutely dry material.


**Table 7.**

*The coefficients of volumetric shrinkage of cheeses.*

In deriving Eq. (13), it is assumed that the material is isotropic and shrinkage along the length and width is the same. If 1 <sup>þ</sup> *<sup>β</sup><sup>l</sup>* ð Þ � *<sup>W</sup>* <sup>2</sup> expanded in a row, the value of *β*<sup>2</sup> *<sup>l</sup>* � *<sup>W</sup>*<sup>2</sup> is small compared to 2 � *<sup>β</sup><sup>l</sup>* � *<sup>W</sup>*; then, it can be written as

$$\mathcal{S} = \mathcal{S}\_0 \cdot (\mathbf{1} + \mathbf{2} \cdot \boldsymbol{\beta}\_l \cdot \mathbf{W}) = \mathcal{S}\_0 \cdot (\mathbf{1} + \boldsymbol{\beta}\_{\mathcal{S}} \cdot \mathbf{W}),\tag{14}$$

It follows that the uneven distribution of moisture content (moisture content field) is the main characteristic of the volume-stressed state of a moist body when it is dried. A similar picture occurs when studying thermal stresses. The phenomenological approach consists in the fact that the body-stressed state of the body at heating is uniquely determined by an uneven temperature distribution (temperature field). The main cause of cracking in the drying process is the presence of moisture content

A.V. Lykov considered drying the material in the form of a plate. Evaporation occurs from two opposite sides (the remaining surfaces have moisture insulation, that is, the moisture content surface is one-dimensional), and the temperature is the same everywhere and constant (isothermal drying conditions in the first period). It has been determined that the maximum compressive stresses occur in the central plane ð Þ *u<sup>ц</sup>* ¼ *uмакс* and the maximum tensile stresses appear on the surface ð Þ *u<sup>п</sup>* ¼ *uмин* < *u* when the linear strain modulus *E* remains unchanged. During the period of constant drying rate, the moisture content is distributed according to the law of a parabola. This distribution does not occur immediately, but after a certain period of time. Then, the difference between the average moisture content *u* and the moisture content on the surface *u<sup>п</sup>* equals to

<sup>3</sup> � <sup>Δ</sup>*<sup>u</sup>* ¼ � *<sup>R</sup>*

where Δ*u<sup>п</sup>* ¼ *u<sup>ц</sup>* � *u<sup>п</sup>* is the moisture content difference between the central

According to the formula, it follows that, if the value is Δ*u<sup>п</sup>* ¼ *u<sup>ц</sup>* � *uп*, the cracking of the drying material occurs when its strength is less than the value of *Рп*. Experiments on vacuum drying of raw materials confirm that cracking occurs at a

Dry cheeses are an indispensable product for diet food, supply of remote areas, army, and expeditions. In addition, the product is necessary for the production of modern nutrient mixtures for a given purpose (dry breakfasts, mixtures of medical nutrition). Dry cheese can be used as a base for various foods and sauces. Cheesebased sauces can be used instead of mayonnaise, which can significantly expand the possibilities of their use in cooking. After reconstitution, the dry cheese is vacuum

The obtained research results can be successfully applied in the food industry not only to cheeses but also to other products. They are of theoretical and practical value and can be used by technologists, researchers, and food industry workers in

3 � ð Þ� 1 � *μ* 1 þ *β<sup>l</sup>* ð Þ � *u<sup>п</sup>*

<sup>3</sup> � ð Þ <sup>∀</sup>*<sup>u</sup> <sup>п</sup>,* (18)

� ð Þ ∀*u <sup>п</sup>:* (19)

and temperature fields with a significant difference in these values.

*Study of the Kinetics of Vacuum Drying of Hard and Semihard Cheeses*

*DOI: http://dx.doi.org/10.5772/intechopen.85276*

*<sup>u</sup>* � *<sup>u</sup><sup>п</sup>* <sup>¼</sup> <sup>2</sup>

ð Þ ∀*u <sup>п</sup>* is the moisture content gradient on the plate surface.

<sup>1</sup> <sup>þ</sup> *<sup>β</sup><sup>l</sup>* ð Þ� � *<sup>u</sup><sup>п</sup>* ð Þ <sup>1</sup> � *<sup>μ</sup>* <sup>¼</sup> *<sup>β</sup><sup>l</sup>* � *<sup>E</sup>* � *<sup>R</sup>*

The tensile stress on the surface of the plate is [18]

<sup>3</sup> � *<sup>β</sup><sup>l</sup>* � *<sup>E</sup>* � <sup>Δ</sup>*<sup>u</sup>*

dried and has the consistency of melted cheese.

the development of relevant technological processes.

layers and surface.

*Рп* ¼ � <sup>2</sup>

certain value of ð Þ Δ*u макс*.

**27**

2 � *R* is the plate thickness.

where *β<sup>S</sup>* ¼ 2 � *β<sup>l</sup>* is the coefficient of shrinkage on the area; it equals to twice the linear shrinkage coefficient.

The coefficient of shrinkage on the area can be determined by the formula:

$$\beta\_{\rm S} = \frac{\delta\_{\rm S}}{(W\_1 - W\_2) - \delta\_{\rm S} \cdot W\_1},\tag{15}$$

where *<sup>δ</sup><sup>S</sup>* <sup>¼</sup> ð Þ *<sup>S</sup>*2�*S*<sup>1</sup> *<sup>S</sup>*<sup>1</sup> is the relative shrinkage on the area.

The dependence between the volume of the material and the moisture content is written as

$$V = V\_0 \cdot (\mathbf{1} + \beta\_V \cdot \mathbf{W})^3. \tag{16}$$

Thus, an approximate formula can be derived:

$$V = V\_0 \cdot (\mathbf{1} + \mathbf{3} \cdot \boldsymbol{\beta}\_V \cdot \mathbf{W}) = V\_0 \cdot (\mathbf{1} + \boldsymbol{\beta}\_V \cdot \mathbf{W}),\tag{17}$$

where *β<sup>V</sup>* ¼ 3 � *β<sup>l</sup>* is the coefficient of volumetric shrinkage, equal to triple linear shrinkage coefficient.

Thus, the dependences of the coefficients of cheese shrinkage on the thickness of the drying layer and the shape and size of grinding are obtained. When the thickness of the drying layer is from 10 to 30 mm, the coefficient of cheese shrinkage is from 3 to 14%, depending on the shape and size of the grinding. With an increase in the mass fraction of the moisture of the cheeses, the shrinkage coefficient increases. It was determined that the shrinkage of cheeses in both periods of vacuum drying occurs uniformly. When the drying temperature rises above the required shrinkage ratio decrease, this is explained by the increase in the gradient of the mass fraction of moisture inside the material.

Shrinking of wet material with a uniform distribution of moisture content and temperature is a physical property of the material, when fluid is removed from it and does not cause any dangerous stresses. Only shrinkage of the material with an uneven distribution of moisture content causes a stress state, which can lead to the appearance of cracks and the complete destruction of the body structure. Therefore, the main obstacle to the rapid drying of many materials is their cracking. The cause of the cracking appearance (local destruction), as well as complete destruction (loss of the integrity of the structure), is the development of the volume-stressed state of the material being dried beyond the maximum allowable, due to the strength of the material.

This stress state is created by unacceptable shrinkage, which, in turn, appears as a result of an uneven distribution of moisture content and temperature inside the material [16, 17].

The method of studying shrinkage stresses does not exclude a phenomenological approach to the phenomenon of shrinkage of wet material under study. It is important to note that the capillary and wedging pressures of the liquid phase in a solid body are functions of moisture content. Therefore, the field of capillary contractions under isothermal conditions will be similar to the field of moisture content.

#### *Study of the Kinetics of Vacuum Drying of Hard and Semihard Cheeses DOI: http://dx.doi.org/10.5772/intechopen.85276*

It follows that the uneven distribution of moisture content (moisture content field) is the main characteristic of the volume-stressed state of a moist body when it is dried.

A similar picture occurs when studying thermal stresses. The phenomenological approach consists in the fact that the body-stressed state of the body at heating is uniquely determined by an uneven temperature distribution (temperature field). The main cause of cracking in the drying process is the presence of moisture content and temperature fields with a significant difference in these values.

A.V. Lykov considered drying the material in the form of a plate. Evaporation occurs from two opposite sides (the remaining surfaces have moisture insulation, that is, the moisture content surface is one-dimensional), and the temperature is the same everywhere and constant (isothermal drying conditions in the first period). It has been determined that the maximum compressive stresses occur in the central plane ð Þ *u<sup>ц</sup>* ¼ *uмакс* and the maximum tensile stresses appear on the surface ð Þ *u<sup>п</sup>* ¼ *uмин* < *u* when the linear strain modulus *E* remains unchanged.

During the period of constant drying rate, the moisture content is distributed according to the law of a parabola. This distribution does not occur immediately, but after a certain period of time. Then, the difference between the average moisture content *u* and the moisture content on the surface *u<sup>п</sup>* equals to

$$
\overline{u} - u\_n = \frac{2}{3} \cdot \Delta u = -\frac{R}{3} \cdot (\forall u)\_{n'} \tag{18}
$$

where Δ*u<sup>п</sup>* ¼ *u<sup>ц</sup>* � *u<sup>п</sup>* is the moisture content difference between the central layers and surface.

ð Þ ∀*u <sup>п</sup>* is the moisture content gradient on the plate surface.

2 � *R* is the plate thickness.

In deriving Eq. (13), it is assumed that the material is isotropic and shrinkage along the length and width is the same. If 1 <sup>þ</sup> *<sup>β</sup><sup>l</sup>* ð Þ � *<sup>W</sup>* <sup>2</sup> expanded in a row, the value

where *β<sup>S</sup>* ¼ 2 � *β<sup>l</sup>* is the coefficient of shrinkage on the area; it equals to twice the

ð Þ� *W*<sup>1</sup> � *W*<sup>2</sup> *δ<sup>S</sup>* � *W*<sup>1</sup>

The dependence between the volume of the material and the moisture content is

where *β<sup>V</sup>* ¼ 3 � *β<sup>l</sup>* is the coefficient of volumetric shrinkage, equal to triple linear

Thus, the dependences of the coefficients of cheese shrinkage on the thickness of the drying layer and the shape and size of grinding are obtained. When the thickness of the drying layer is from 10 to 30 mm, the coefficient of cheese shrinkage is from 3 to 14%, depending on the shape and size of the grinding. With an increase in the mass fraction of the moisture of the cheeses, the shrinkage coefficient increases. It was determined that the shrinkage of cheeses in both periods of vacuum drying occurs uniformly. When the drying temperature rises above the required shrinkage ratio decrease, this is explained by the increase in the gradient of the mass fraction

Shrinking of wet material with a uniform distribution of moisture content and temperature is a physical property of the material, when fluid is removed from it and does not cause any dangerous stresses. Only shrinkage of the material with an uneven distribution of moisture content causes a stress state, which can lead to the appearance of cracks and the complete destruction of the body structure. Therefore, the main obstacle to the rapid drying of many materials is their cracking. The cause of the cracking appearance (local destruction), as well as complete destruction (loss of the integrity of the structure), is the development of the volume-stressed state of the material being dried beyond the maximum allowable, due to the strength of the

This stress state is created by unacceptable shrinkage, which, in turn, appears as a result of an uneven distribution of moisture content and temperature inside the

The method of studying shrinkage stresses does not exclude a phenomenological

approach to the phenomenon of shrinkage of wet material under study. It is important to note that the capillary and wedging pressures of the liquid phase in a solid body are functions of moisture content. Therefore, the field of capillary contractions under isothermal conditions will be similar to the field of moisture content.

*<sup>V</sup>* <sup>¼</sup> *<sup>V</sup>*<sup>0</sup> � ð Þ <sup>1</sup> <sup>þ</sup> *<sup>β</sup><sup>V</sup>* � *<sup>W</sup>* <sup>3</sup>

The coefficient of shrinkage on the area can be determined by the formula:

*S* ¼ *S*<sup>0</sup> � 1 þ 2 � *β<sup>l</sup>* ð � *W*Þ ¼ *S*<sup>0</sup> � 1 þ *β<sup>S</sup>* ð Þ � *W ,* (14)

*V* ¼ *V*<sup>0</sup> � ð1 þ 3 � *β<sup>V</sup>* � *W*Þ ¼ *V*<sup>0</sup> � ð Þ 1 þ *β<sup>V</sup>* � *W ,* (17)

*,* (15)

*:* (16)

*<sup>l</sup>* � *<sup>W</sup>*<sup>2</sup> is small compared to 2 � *<sup>β</sup><sup>l</sup>* � *<sup>W</sup>*; then, it can be written as

*<sup>β</sup><sup>S</sup>* <sup>¼</sup> *<sup>δ</sup><sup>S</sup>*

*<sup>S</sup>*<sup>1</sup> is the relative shrinkage on the area.

Thus, an approximate formula can be derived:

of *β*<sup>2</sup>

linear shrinkage coefficient.

*Current Issues and Challenges in the Dairy Industry*

where *<sup>δ</sup><sup>S</sup>* <sup>¼</sup> ð Þ *<sup>S</sup>*2�*S*<sup>1</sup>

shrinkage coefficient.

of moisture inside the material.

written as

material.

**26**

material [16, 17].

The tensile stress on the surface of the plate is [18]

$$P\_n = -\frac{2}{3} \cdot \frac{\beta\_l \cdot E \cdot \Delta u}{(1 + \beta\_l \cdot u\_n) \cdot (1 - \mu)} = \frac{\beta\_l \cdot E \cdot R}{3 \cdot (1 - \mu) \cdot (1 + \beta\_l \cdot u\_n)} \cdot (\forall u)\_n. \tag{19}$$

According to the formula, it follows that, if the value is Δ*u<sup>п</sup>* ¼ *u<sup>ц</sup>* � *uп*, the cracking of the drying material occurs when its strength is less than the value of *Рп*. Experiments on vacuum drying of raw materials confirm that cracking occurs at a certain value of ð Þ Δ*u макс*.

Dry cheeses are an indispensable product for diet food, supply of remote areas, army, and expeditions. In addition, the product is necessary for the production of modern nutrient mixtures for a given purpose (dry breakfasts, mixtures of medical nutrition). Dry cheese can be used as a base for various foods and sauces. Cheesebased sauces can be used instead of mayonnaise, which can significantly expand the possibilities of their use in cooking. After reconstitution, the dry cheese is vacuum dried and has the consistency of melted cheese.

The obtained research results can be successfully applied in the food industry not only to cheeses but also to other products. They are of theoretical and practical value and can be used by technologists, researchers, and food industry workers in the development of relevant technological processes.

*Current Issues and Challenges in the Dairy Industry*

**References**

[1] King V, Zall R. Controlled lowtemperature vacuum dehydration—A new approach for low-temperature and low-pressure food drying. Journal of Food Science. 1989;**54**(6):1573-1579

*DOI: http://dx.doi.org/10.5772/intechopen.85276*

*Study of the Kinetics of Vacuum Drying of Hard and Semihard Cheeses*

[8] Rubinskienė M, Viškelis P, Dambrauskienė E, Viškelis J,

**102**(2):223-228

Karklelienė R. Effect of drying methods of the chemical composition and colour of peppermint (*Mentha piperita* L.) leaves. Zemdirbyste-Agriculture. 2015;

[9] Zdravko M, Aleksandra N, Stela D, Radomir V. Optimization of frozen wild blueberry vacuum drying process. Hemijska Industrija. 2015;**69**(1):77-84

[10] Wojdylo A, Figiel A, Lech K, Nowicka P, Oszmianski J. Effects of convective and vacuum- microwave drying on the bioactive compounds, color, and antioxidant capacity of sour

cherries. Food and Bioprocess Technology. 2014;**7**:829-841

2013;**6**(3):80-87

2017;**317**:430-437

**2**(1):11-16

[11] Yanqiu M, Xinhuai Z, Bingxin L, Chenghai L, Zheng X. Influences of microwave vacuum puffing conditions on anthocyanin content of raspberry snack. International Journal of

Agricultural and Biological Engineering.

[12] Horszwald A, Julien H, Andlauer W. Characterisation of *Aronia* powders obtained by different drying processes. Food Chemistry. 2013;**141**(3):2858-2863

[13] Li Y-h, Qi Y-r, Wu Z-f, Wang Y-q, Wang X-c, Wang F, et al. Comparative study of microwave-vacuum and vacuum drying on the drying characteristics, dissolution, physicochemical properties, and antioxidant capacity of *Scutellaria* extract powder. Powder Technology.

[14] Ermolaev VA. Effect of vacuum drying on microstructure of semi-solid cheese. Foods and Raw Materials. 2014;

[15] Nile S, Park S. Edible berries: Bioactive components and their effect

[2] Ermolaev VA. Development of technology of vacuum drying of fat-free

cottage cheese[Ph.D. thesis in Engineering Science]. Kemerovo Technological Institute of Food Industry. Разработка технологии вакуумной сушки обезжиренного творога: диссертация кандидата технических наук. Кемеровский технологический институт пищевой промышленности. 168; 2008

[3] Devahastin S, Suvarnakuta P, Soponronnarit S, Mujumdar A. Comparative study of low-pressure superheated steam and vacuum drying of a heat-sensitive material. Drying Technology. 2004;**22**:1845-1867

[4] Ermolaev VA. Kinetics of the vacuum drying of cheeses. Foods and Raw Materials. 2014;**2**(2):130-139

2017;**40**(6):e12569

**44**(2):275-280

**29**

[5] Lope J, Vega-Galvez A, Bilbao-Sainz C, Bor-Sen C, Uribe E, Quispe-Fuentes I. Influence of vacuum drying temperature on: Physico-chemical composition and antioxidant properties of murta berries. Journal of Food Process Engineering.

[6] Xie L, Mujumdar AS, Xiao-Ming F, Jun W, Jian-Wu D, Zhi-Long D, et al. Far-infrared radiation heating assisted pulsed vacuum drying (FIR-PVD) of wolfberry (*Lycium barbarum* L.): Effects

[7] Rabeta M, Lin S. Effects of different drying methods on the antioxidant activities of leaves and berries of

*Cayratia trifolia*. Sains Malaysiana. 2015;

on drying kinetics and quality attributes. Food and Bioproducts Processing. 2017;**102**:320-331

### **Author details**

Vladimir Ermolaev T.F. Gorbachev Kuzbass State Technical University (KuzSTU), Russia

\*Address all correspondence to: ermolaevvla@rambler.ru

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

*Study of the Kinetics of Vacuum Drying of Hard and Semihard Cheeses DOI: http://dx.doi.org/10.5772/intechopen.85276*

#### **References**

[1] King V, Zall R. Controlled lowtemperature vacuum dehydration—A new approach for low-temperature and low-pressure food drying. Journal of Food Science. 1989;**54**(6):1573-1579

[2] Ermolaev VA. Development of technology of vacuum drying of fat-free cottage cheese[Ph.D. thesis in Engineering Science]. Kemerovo Technological Institute of Food Industry. Разработка технологии вакуумной сушки обезжиренного творога: диссертация кандидата технических наук. Кемеровский технологический институт пищевой промышленности. 168; 2008

[3] Devahastin S, Suvarnakuta P, Soponronnarit S, Mujumdar A. Comparative study of low-pressure superheated steam and vacuum drying of a heat-sensitive material. Drying Technology. 2004;**22**:1845-1867

[4] Ermolaev VA. Kinetics of the vacuum drying of cheeses. Foods and Raw Materials. 2014;**2**(2):130-139

[5] Lope J, Vega-Galvez A, Bilbao-Sainz C, Bor-Sen C, Uribe E, Quispe-Fuentes I. Influence of vacuum drying temperature on: Physico-chemical composition and antioxidant properties of murta berries. Journal of Food Process Engineering. 2017;**40**(6):e12569

[6] Xie L, Mujumdar AS, Xiao-Ming F, Jun W, Jian-Wu D, Zhi-Long D, et al. Far-infrared radiation heating assisted pulsed vacuum drying (FIR-PVD) of wolfberry (*Lycium barbarum* L.): Effects on drying kinetics and quality attributes. Food and Bioproducts Processing. 2017;**102**:320-331

[7] Rabeta M, Lin S. Effects of different drying methods on the antioxidant activities of leaves and berries of *Cayratia trifolia*. Sains Malaysiana. 2015; **44**(2):275-280

[8] Rubinskienė M, Viškelis P, Dambrauskienė E, Viškelis J, Karklelienė R. Effect of drying methods of the chemical composition and colour of peppermint (*Mentha piperita* L.) leaves. Zemdirbyste-Agriculture. 2015; **102**(2):223-228

[9] Zdravko M, Aleksandra N, Stela D, Radomir V. Optimization of frozen wild blueberry vacuum drying process. Hemijska Industrija. 2015;**69**(1):77-84

[10] Wojdylo A, Figiel A, Lech K, Nowicka P, Oszmianski J. Effects of convective and vacuum- microwave drying on the bioactive compounds, color, and antioxidant capacity of sour cherries. Food and Bioprocess Technology. 2014;**7**:829-841

[11] Yanqiu M, Xinhuai Z, Bingxin L, Chenghai L, Zheng X. Influences of microwave vacuum puffing conditions on anthocyanin content of raspberry snack. International Journal of Agricultural and Biological Engineering. 2013;**6**(3):80-87

[12] Horszwald A, Julien H, Andlauer W. Characterisation of *Aronia* powders obtained by different drying processes. Food Chemistry. 2013;**141**(3):2858-2863

[13] Li Y-h, Qi Y-r, Wu Z-f, Wang Y-q, Wang X-c, Wang F, et al. Comparative study of microwave-vacuum and vacuum drying on the drying characteristics, dissolution, physicochemical properties, and antioxidant capacity of *Scutellaria* extract powder. Powder Technology. 2017;**317**:430-437

[14] Ermolaev VA. Effect of vacuum drying on microstructure of semi-solid cheese. Foods and Raw Materials. 2014; **2**(1):11-16

[15] Nile S, Park S. Edible berries: Bioactive components and their effect

**Author details**

Vladimir Ermolaev

**28**

T.F. Gorbachev Kuzbass State Technical University (KuzSTU), Russia

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

\*Address all correspondence to: ermolaevvla@rambler.ru

provided the original work is properly cited.

*Current Issues and Challenges in the Dairy Industry*

on human health. Nutrition. 2014;**30**(2): 134-144

[16] Kellogg J, Wang J, Flint C, Lila M, Ribnicky D, Kuhn P, et al. Alaskan wild berry resources and human health under the cloud of climate change. Journal of Agricultural and Food Chemistry. 2010; **58**(7):3884-3900

[17] Bowen-Forbes C, Nair M, Zhang Y. Anthocyanin content, antioxidant, antiinflammatory and anticancer properties of blackberry and raspberry fruits. Journal of Food Composition and Analysis. 2010;**23**(6):554-560

[18] Afrin S, Gasparrini M, Forbes-Hernandez T, Reboredo-Rodriguez P, Giampieri F, Battino M, et al. Promising health benefits of the strawberry: A focus on clinical studies. Journal of Agricultural and Food Chemistry. 2016; **64**(22):4435-4449

**31**

tions in many food products.

**Chapter 3**

**Abstract**

as packaging films.

**1. Introduction**

Milk By-Products Utilization

The dairy industry processes raw milk into an array of products including butter, cheese, cream, yogurt, ghee, condensed milk, dried milk, ice cream, etc. and produces various by-products including buttermilk, whey, ghee, and skim milk. These dairy by-products have high nutritive value and have found applications in many food industries as well as nonfood applications. Buttermilk which is a by-product of butter-making is used both in liquid form (fermented to produce a beverage *chaas*) and dried to be used as an ingredient. Whey, a by-product of cheese and paneer manufacture with high nutritive value, has been utilized in the preparation of products like sports drinks and beverages. Whey is also used in the preparation of certain types of cheese like ricotta. Skim milk which is a by-product of cream manufacture has been used to produce flavored milks and certain type of cheeses like cottage and quark cheese. Ghee residue from ghee manufacture has been used in the preparation of sweets, cookies, and chocolates. Casein and casein derivates are mainly used in bakery and confectionary. In addition to these food applications, whey proteins (WP) and caseins have found applications

A number of by-products like whey, buttermilk, skim milk, and ghee residue (GR) and derived by-products like caseins, caseinates, lactose, whey proteins (WP), etc. are produced by the dairy industry. Attempts have been made globally to utilize these by-products because of their high nutritive value. Dairy plants in India are still confronted with the problem of by-product utilization because of lack of adequate technology and high cost of new technologies. However the Indian dairy industry is making advancement in this direction. Whey is the major by-product of the dairy industry. It is a useful resource of nutrients containing about 50% of the solids of milk [1]. Whey production is steadily growing, and its high organic content is an important environmental and health issue. Therefore, suitable management of this by-product is required. Like milk, whey may have different origins (e.g., goat, sheep, and buffalo), but the most relevant in terms of production volume and economical value is that obtained from cow milk processing. Skim milk is a by-product obtained from cream manufacture. It is rich in SNF content and has high nutritional value and has been utilized in the manufacture of a number of dairy products or in powder form. Buttermilk, a by-product of butter manufacture, has been used as such or in dried form. Ghee residue from ghee manufacture has also found applica-

*Syed Mansha Rafiq and Syed Insha Rafiq*

**Keywords:** buttermilk, whey, ghee residue, skim milk, caseins

## **Chapter 3** Milk By-Products Utilization

*Syed Mansha Rafiq and Syed Insha Rafiq*

### **Abstract**

on human health. Nutrition. 2014;**30**(2):

*Current Issues and Challenges in the Dairy Industry*

[16] Kellogg J, Wang J, Flint C, Lila M, Ribnicky D, Kuhn P, et al. Alaskan wild berry resources and human health under the cloud of climate change. Journal of Agricultural and Food Chemistry. 2010;

[17] Bowen-Forbes C, Nair M, Zhang Y. Anthocyanin content, antioxidant, antiinflammatory and anticancer properties of blackberry and raspberry fruits. Journal of Food Composition and Analysis. 2010;**23**(6):554-560

[18] Afrin S, Gasparrini M, Forbes-Hernandez T, Reboredo-Rodriguez P, Giampieri F, Battino M, et al. Promising health benefits of the strawberry: A focus on clinical studies. Journal of Agricultural and Food Chemistry. 2016;

134-144

**58**(7):3884-3900

**64**(22):4435-4449

**30**

The dairy industry processes raw milk into an array of products including butter, cheese, cream, yogurt, ghee, condensed milk, dried milk, ice cream, etc. and produces various by-products including buttermilk, whey, ghee, and skim milk. These dairy by-products have high nutritive value and have found applications in many food industries as well as nonfood applications. Buttermilk which is a by-product of butter-making is used both in liquid form (fermented to produce a beverage *chaas*) and dried to be used as an ingredient. Whey, a by-product of cheese and paneer manufacture with high nutritive value, has been utilized in the preparation of products like sports drinks and beverages. Whey is also used in the preparation of certain types of cheese like ricotta. Skim milk which is a by-product of cream manufacture has been used to produce flavored milks and certain type of cheeses like cottage and quark cheese. Ghee residue from ghee manufacture has been used in the preparation of sweets, cookies, and chocolates. Casein and casein derivates are mainly used in bakery and confectionary. In addition to these food applications, whey proteins (WP) and caseins have found applications as packaging films.

**Keywords:** buttermilk, whey, ghee residue, skim milk, caseins

#### **1. Introduction**

A number of by-products like whey, buttermilk, skim milk, and ghee residue (GR) and derived by-products like caseins, caseinates, lactose, whey proteins (WP), etc. are produced by the dairy industry. Attempts have been made globally to utilize these by-products because of their high nutritive value. Dairy plants in India are still confronted with the problem of by-product utilization because of lack of adequate technology and high cost of new technologies. However the Indian dairy industry is making advancement in this direction. Whey is the major by-product of the dairy industry. It is a useful resource of nutrients containing about 50% of the solids of milk [1]. Whey production is steadily growing, and its high organic content is an important environmental and health issue. Therefore, suitable management of this by-product is required. Like milk, whey may have different origins (e.g., goat, sheep, and buffalo), but the most relevant in terms of production volume and economical value is that obtained from cow milk processing. Skim milk is a by-product obtained from cream manufacture. It is rich in SNF content and has high nutritional value and has been utilized in the manufacture of a number of dairy products or in powder form. Buttermilk, a by-product of butter manufacture, has been used as such or in dried form. Ghee residue from ghee manufacture has also found applications in many food products.

#### **2. Whey utilization**

Whey, a by-product of cheese manufacturing, contains approximately 7% dry matter of which 13% is proteins. It generally represents a volume fraction of 90% in milk and is being classified into sweet and acid whey. The sweet whey originates from cheese manufacturing or from industrial casein production where the casein is coagulated by rennet, at pH of 6.0–6.5, while the acid whey (pH < 5.0), resulting from processes in which casein is coagulated by fermentation or addition of organic or mineral acids, as in the processing of fresh, acid-coagulated cheeses (e.g., cottage cheese or quark) or strained yogurt (e.g., Greek-style yogurt). The main components for both types of wheys are given in **Table 1**. Water constitutes approximately 93% of the whey, while the total solid fraction contains lactose (70–72%), minerals (12–15%), and whey proteins (8–10%). The main difference between both wheys is the mineral content, the acidity, and the composition of the whey protein fraction. Acid whey has higher calcium content as, at this low pH, the colloidal calcium contained in the casein micelles in normal milk solubilized and partitioned into the whey [2]. Composition of whey protein fraction is different as sweet whey contains glycomacropeptide, a fragment of the κ-casein molecule produced by rennet clotting, constituting 20% of the whey protein fraction of sweet, rennet-based wheys [2]. Acid whey has a large potential to be used as the main component of beverages because of its nutritional composition. The utilization of liquid acid whey offers an interesting approach as there is no need for using complex technology other than pasteurization.

Up until very recently, whey resulting from the curd during manufacture of cheese was regarded as a polluting effluent from the dairy industry. Nowadays, the potential of a vast range of whey proteins and their peptides with great potential health benefits is well known. Recently, whey gained interest as a food ingredient, coming into use as a technological agent particularly through whey proteins, achieving a unique blend between nutritional and functional properties with applications both in food and health. Whey components are being separated by isolation and fractionation on selective porous membranes. Extensive investigations focused on the exploitation of techno functional, biological, and nutritional properties of the whey [3]. By far, membrane technology enabled the breakthrough of whey processing into several derivatives favoring their incorporation as ingredients into different foods. These whey proteins are separated and purified from the liquid whey in an efficient membrane filtration process and subsequent spray drying to obtain either whey protein concentrate (WPC) (65–80% protein in dry matter) or whey protein isolate (WPI) (90% protein in dry matter). Ultrafiltration (UF) techniques have been used for cheese milk to retain whey proteins to increase the yield of the


**33**

*Milk By-Products Utilization*

*DOI: http://dx.doi.org/10.5772/intechopen.85533*

new avenues for progress in cheese-making.

end product. Moreover, whey proteins have been added into cheese to boost its nutritional profile. Different pre-treatments of cheese milk have been developed to incorporate native or denatured WP in the cheese matrix. These options opened

Although these whey proteins are used as additives in the agro-food industry, such as the athletic drinks, still, 40% of whey remains unprocessed, which makes it an interesting resource in view of its excellent oxygen barrier properties [4, 5]. Whey protein films have excellent oxygen, aroma, and oil barrier properties. They have excellent mechanical properties that provide durability when used as coatings on food products, films separating layers of heterogeneous foods, or films formed into pouches

for food ingredients. These films do not significantly compromise the desirable primary barrier and mechanical properties as packaging films and hence add value for ultimate commercial applications [6, 7]. Whey-based formulations are processed for packaging applications and edible coatings through extrusion as well as compression molding. Incorporation of plasticizing agents is necessary to overcome the intrinsic brittleness. Whey protein isolate films are fully transparent. Whey coatings with a barrier layer and an active layer have been developed. The barrier layer contains whey protein isolates supplemented with plasticizers, and the active layer contains antimicrobials or antioxidants to extend the shelf life of the packaged food. Whey-based films may improve the sensory attributes of the coated goods while providing some health benefits to the consumers. These proteins have been used as a coating on paper as well as on plastics, polypropylene (PP), polyvinylchloride (PVC), and low-density polyethylene (LDPE), which demonstrated excellent visual properties, such as excellent gloss

The incorporation of whey proteins into the cheese matrix has been made possible with a number of new technologies. Whey protein addition enhances the nutritional and functional properties as well as the economic effectiveness of cheese production. Addition of whey proteins increases the yield but may result in a slightly poor flavor and texture [8]. Whey protein concentrate and whey protein powder addition has been reported in a variety of cheeses that include cream cheese, cheese spreads, Cheddar cheese, Gouda cheese, processed cheese, Domiati cheese, etc. Addition of WPC was found to increase the yields in all cheeses with softer texture in camembert and Iranian white cheese. The influence of whey protein incorporation in processed cheese on its functional and sensory properties has been extensively studied. It has been found that whey proteins can be used to replace caseins up to 2% in processed cheese [9]. Whey protein concentrates are used as fat replacers in processed cheese, and they reduce the hardness of the cheese [10]. Addition of whey proteins/carboxymethyl cellulose complex recovered from whey, corresponding to 25–75% of cheese milk weight in Domiati cheese, increased cheese yield, reduced loss of weight during pickling, and enhanced the body of cheese. Flavor intensity was not affected by the addition of whey proteins [11]. Replacement of rennet casein in part with WPC in mozzarella cheese analogue resulted in greater firmness and meltability, lower

Membrane separation techniques have been largely explored by dairy industries for their effective and economic implementation. These techniques work on

and high transparency, as well as good mechanical properties.

**3. Technologies to include whey proteins in cheese**

cohesiveness and fat leakage, and moderate chewiness [12].

**4. Membrane separation processes**

**Table 1.** *Typical composition of sweet and acid whey.*

#### *Milk By-Products Utilization DOI: http://dx.doi.org/10.5772/intechopen.85533*

*Current Issues and Challenges in the Dairy Industry*

Whey, a by-product of cheese manufacturing, contains approximately 7% dry matter of which 13% is proteins. It generally represents a volume fraction of 90% in milk and is being classified into sweet and acid whey. The sweet whey originates from cheese manufacturing or from industrial casein production where the casein is coagulated by rennet, at pH of 6.0–6.5, while the acid whey (pH < 5.0), resulting from processes in which casein is coagulated by fermentation or addition of organic or mineral acids, as in the processing of fresh, acid-coagulated cheeses (e.g., cottage cheese or quark) or strained yogurt (e.g., Greek-style yogurt). The main components for both types of wheys are given in **Table 1**. Water constitutes approximately 93% of the whey, while the total solid fraction contains lactose (70–72%), minerals (12–15%), and whey proteins (8–10%). The main difference between both wheys is the mineral content, the acidity, and the composition of the whey protein fraction. Acid whey has higher calcium content as, at this low pH, the colloidal calcium contained in the casein micelles in normal milk solubilized and partitioned into the whey [2]. Composition of whey protein fraction is different as sweet whey contains glycomacropeptide, a fragment of the κ-casein molecule produced by rennet clotting, constituting 20% of the whey protein fraction of sweet, rennet-based wheys [2]. Acid whey has a large potential to be used as the main component of beverages because of its nutritional composition. The utilization of liquid acid whey offers an interesting approach as there

is no need for using complex technology other than pasteurization.

Up until very recently, whey resulting from the curd during manufacture of cheese was regarded as a polluting effluent from the dairy industry. Nowadays, the potential of a vast range of whey proteins and their peptides with great potential health benefits is well known. Recently, whey gained interest as a food ingredient, coming into use as a technological agent particularly through whey proteins, achieving a unique blend between nutritional and functional properties with applications both in food and health. Whey components are being separated by isolation and fractionation on selective porous membranes. Extensive investigations focused on the exploitation of techno functional, biological, and nutritional properties of the whey [3]. By far, membrane technology enabled the breakthrough of whey processing into several derivatives favoring their incorporation as ingredients into different foods. These whey proteins are separated and purified from the liquid whey in an efficient membrane filtration process and subsequent spray drying to obtain either whey protein concentrate (WPC) (65–80% protein in dry matter) or whey protein isolate (WPI) (90% protein in dry matter). Ultrafiltration (UF) techniques have been used for cheese milk to retain whey proteins to increase the yield of the

**Component Sweet whey (g/L) Acid whey (g/L)** Total solids 63.0–70.0 63.0–70.0 Lactose 46.0–52.0 44.0–46.0 Protein 6.0–10.0 6.0–8.0 Calcium 0.4–0.6 1.2–1.6 Phosphate 1.0–3.0 2.0–4.5 Lactate 2 6.4 Chloride 1.1 1.1

**2. Whey utilization**

**32**

*Source: [2].*

*Typical composition of sweet and acid whey.*

**Table 1.**

end product. Moreover, whey proteins have been added into cheese to boost its nutritional profile. Different pre-treatments of cheese milk have been developed to incorporate native or denatured WP in the cheese matrix. These options opened new avenues for progress in cheese-making.

Although these whey proteins are used as additives in the agro-food industry, such as the athletic drinks, still, 40% of whey remains unprocessed, which makes it an interesting resource in view of its excellent oxygen barrier properties [4, 5]. Whey protein films have excellent oxygen, aroma, and oil barrier properties. They have excellent mechanical properties that provide durability when used as coatings on food products, films separating layers of heterogeneous foods, or films formed into pouches for food ingredients. These films do not significantly compromise the desirable primary barrier and mechanical properties as packaging films and hence add value for ultimate commercial applications [6, 7]. Whey-based formulations are processed for packaging applications and edible coatings through extrusion as well as compression molding. Incorporation of plasticizing agents is necessary to overcome the intrinsic brittleness. Whey protein isolate films are fully transparent. Whey coatings with a barrier layer and an active layer have been developed. The barrier layer contains whey protein isolates supplemented with plasticizers, and the active layer contains antimicrobials or antioxidants to extend the shelf life of the packaged food. Whey-based films may improve the sensory attributes of the coated goods while providing some health benefits to the consumers. These proteins have been used as a coating on paper as well as on plastics, polypropylene (PP), polyvinylchloride (PVC), and low-density polyethylene (LDPE), which demonstrated excellent visual properties, such as excellent gloss and high transparency, as well as good mechanical properties.

#### **3. Technologies to include whey proteins in cheese**

The incorporation of whey proteins into the cheese matrix has been made possible with a number of new technologies. Whey protein addition enhances the nutritional and functional properties as well as the economic effectiveness of cheese production. Addition of whey proteins increases the yield but may result in a slightly poor flavor and texture [8]. Whey protein concentrate and whey protein powder addition has been reported in a variety of cheeses that include cream cheese, cheese spreads, Cheddar cheese, Gouda cheese, processed cheese, Domiati cheese, etc. Addition of WPC was found to increase the yields in all cheeses with softer texture in camembert and Iranian white cheese. The influence of whey protein incorporation in processed cheese on its functional and sensory properties has been extensively studied. It has been found that whey proteins can be used to replace caseins up to 2% in processed cheese [9]. Whey protein concentrates are used as fat replacers in processed cheese, and they reduce the hardness of the cheese [10]. Addition of whey proteins/carboxymethyl cellulose complex recovered from whey, corresponding to 25–75% of cheese milk weight in Domiati cheese, increased cheese yield, reduced loss of weight during pickling, and enhanced the body of cheese. Flavor intensity was not affected by the addition of whey proteins [11]. Replacement of rennet casein in part with WPC in mozzarella cheese analogue resulted in greater firmness and meltability, lower cohesiveness and fat leakage, and moderate chewiness [12].

#### **4. Membrane separation processes**

Membrane separation techniques have been largely explored by dairy industries for their effective and economic implementation. These techniques work on the basis of size and shape of molecules as well as on charge and affinity for the membrane. Among these techniques UF was the first to be exploited for cheese enrichment with WP [1, 13]. Whey proteins, which remain entrapped in the curd matrix, contribute to the enhanced yield of cheese. Rennet-curd cheeses, such as mozzarella, cottage, and Cheddar, can be manufactured by this technique [14]. The implementation of spray drying has reduced the thermal degradation of whey components, as well as the cost associated with its concentration. Membrane filtration technique employs semipermeable surfaces (membranes) with specific pore sizes, where the permeate flows through, while the retentate is blocked based on size/molecular weight. Throughout the combination of successive filtrations steps, it is possible to produce protein fractions with different compositions and degrees of purity. This technology leads to a selective concentration of proteins, which after drying is called whey protein concentrate containing about 35–80% of protein. Further purification, often conjugating other techniques as ion-exchange chromatography, allows the achievement of higher degrees of purity with residual or no lactose content and higher desalination, resulting in whey protein isolate containing at least 90% of protein. With the application of more advanced techniques, such as chromatography, partial hydrolyses, and selective precipitation combined with centrifugation and dialysis, it is yet possible to obtain pure whey protein fractions. WPI and WPC can be widely used for food applications because of higher protein and amino acid contents; low calorie, fat, and sodium contents; absence of pathogens and toxic compounds; biocompatibility and generally recognized as safe status; ready availability; and inexpensive products.

#### **5. Ghee residue utilization**

Ghee is an important constituent of Indian meal prepared using different methods. It is clarified milk fat with incomparable organoleptic properties, which make it an important ingredient in a wide variety of food applications [15]. About 30–35% of the milk produced in India (112 million tons in 2009–2010) is converted into ghee [16]. A blackish brown residue mainly the SNF part of cream was coagulated out during ghee preparation as a by-product when cream is heated is known as ghee residue. It is obtained as moist brownish sediment after molten ghee has been strained out [17]. The amount of ghee residue was found to depend upon the method of preparation of ghee. This was due to the variation of nonfatty serum constituents of the different raw materials used for the preparation of ghee. Ghee yield was higher from creamery butter method in comparison to direct cream method, whereas ghee residue content was higher in direct cream method in comparison to creamery butter method. The average yield of ghee residue was maximum (12%) in direct creamery (DC) method followed by almost the same yield in creamery butter (CB) and desi butter (DB) methods, that is, 3.7%. Ripening of cream prior to clarification reduces the yield of ghee residue [18, 19]. It is one of the largest by-products of the dairy industry and consists mainly of milk proteins and small quantity of lactose and minerals. The ghee residue has been used in food industries for making sweets, bakery products, and as a flavor enhancer [20]. An appreciable amount of GR is produced in the country which is a nutritionally rich source of proteins and nitrogenous compounds. Ghee residue has been utilized for preparing burfi by mixing it with skim milk powder (SMP), khoa, chocolate, and sugar [21]. It can be utilized for preparing coconut burfi, candies, toffees, pinni, etc. after mixing with other ingredients. The nutritious by-product should be utilized as a food supplement in a variety of foods, food spreads, soups, etc. [22]. The utilization of this by-product in the preparation of some type of candies, toffees, edible pastes, etc. was suggested

**35**

the control [33].

**7. Skim milk**

*Milk By-Products Utilization*

phospholipids from GR.

**6. Buttermilk utilization**

*DOI: http://dx.doi.org/10.5772/intechopen.85533*

about two decades ago but was not adopted commercially by the industry due to lack of awareness about its nutritive value. In general, the residue contains appreciable amounts of nutrients of milk. Ghee residue has been used in the preparation

The phospholipids of milk occur in a complex form with proteins in the fat globule membrane. When butter is heated to 120°C and above, the phospholipids are liberated from the phospholipid-protein complex and transferred to the oil phase. When the ghee-making process is kept much below 120°C, phospholipids, which remain in a complex form with proteins, will not enter ghee and, therefore, will be retained by GR. GR is a rich source of phospholipids from which phospholipids can be recovered and added to ghee. Pruthi et al. [23] described a heat-processing method for the extraction and fortification of ghee with GR phospholipids. The fortification of ghee with phospholipids at 0.1% level showed that the oxidative stability of ghee can be increased by increasing its phospholipid content either through heat treatment of GR with ghee or by the addition of solvent-extracted

Buttermilk is a by-product of butter-making. It contains components derived both from fragments of milk fat globule membrane (MFGM), mainly consisting of proteins and neutral as well as polar lipids and all water-soluble components of cream [24]. Fortification with buttermilk is done to increase the yield provided cheese quality is unchanged. Buttermilk has high phospholipid content that has a significant function as emulsifiers in food systems and makes this dairy ingredient interesting for use as a functional ingredient [25] in an array of food products like chocolate, cheese seasonings, margarine, bread, ice cream mixes, or yogurt [26–28]. The buttermilk concentrate (BMC) rich in phospholipids has been utilized in processed cheese spread to improve its organoleptic, rheological, and functional properties [29]. The use of BMC in processed cheese spreads makes this dairy product useful as a functional food. This perspective could also bring economical income by enhancing the product yield or using low-value by-products from the dairy industry, such as buttermilk. Sweet buttermilk, condensed by heat and vacuum, supplemented at levels of 4 or 6% in regard to cheese milk improved the yield of pizza cheese with the contribution of denatured WP [30]. Kumari et al. [31] verified the effect of buttermilk as an ingredient in buffalo milk-derived chhana, an Indianstyle soft cottage cheese analogue. Substitution of milk with variable proportions of sweet buttermilk (from 0 to 50%) was technologically tested in cream cheese [32]. The authors revealed that the progressive increase of buttermilk percentage was followed by increase in moisture and yield. Buttermilk has been added to reducedfat cheese up to 40% and was found to improve the sensory scores in comparison to

Skim milk powder for cheese-making requires adequate reconstitution and recombination techniques compared to whole milk powders, and at places where modern equipment and processing facilities for the reconstitution and recombination are not available, the use of whole milk powders could be advantageous. Addition of skim milk powder has been reported in Karish cheese, Domiati cheese, and processed cheese. Skim milk along with milk protein and stabilizers were used

of candy, chocolate, burfi-type sweet, and bakery products.

#### *Milk By-Products Utilization DOI: http://dx.doi.org/10.5772/intechopen.85533*

*Current Issues and Challenges in the Dairy Industry*

ready availability; and inexpensive products.

**5. Ghee residue utilization**

the basis of size and shape of molecules as well as on charge and affinity for the membrane. Among these techniques UF was the first to be exploited for cheese enrichment with WP [1, 13]. Whey proteins, which remain entrapped in the curd matrix, contribute to the enhanced yield of cheese. Rennet-curd cheeses, such as mozzarella, cottage, and Cheddar, can be manufactured by this technique [14]. The implementation of spray drying has reduced the thermal degradation of whey components, as well as the cost associated with its concentration. Membrane filtration technique employs semipermeable surfaces (membranes) with specific pore sizes, where the permeate flows through, while the retentate is blocked based on size/molecular weight. Throughout the combination of successive filtrations steps, it is possible to produce protein fractions with different compositions and degrees of purity. This technology leads to a selective concentration of proteins, which after drying is called whey protein concentrate containing about 35–80% of protein. Further purification, often conjugating other techniques as ion-exchange chromatography, allows the achievement of higher degrees of purity with residual or no lactose content and higher desalination, resulting in whey protein isolate containing at least 90% of protein. With the application of more advanced techniques, such as chromatography, partial hydrolyses, and selective precipitation combined with centrifugation and dialysis, it is yet possible to obtain pure whey protein fractions. WPI and WPC can be widely used for food applications because of higher protein and amino acid contents; low calorie, fat, and sodium contents; absence of pathogens and toxic compounds; biocompatibility and generally recognized as safe status;

Ghee is an important constituent of Indian meal prepared using different methods. It is clarified milk fat with incomparable organoleptic properties, which make it an important ingredient in a wide variety of food applications [15]. About 30–35% of the milk produced in India (112 million tons in 2009–2010) is converted into ghee [16]. A blackish brown residue mainly the SNF part of cream was coagulated out during ghee preparation as a by-product when cream is heated is known as ghee residue. It is obtained as moist brownish sediment after molten ghee has been strained out [17]. The amount of ghee residue was found to depend upon the method of preparation of ghee. This was due to the variation of nonfatty serum constituents of the different raw materials used for the preparation of ghee. Ghee yield was higher from creamery butter method in comparison to direct cream method, whereas ghee residue content was higher in direct cream method in comparison to creamery butter method. The average yield of ghee residue was maximum (12%) in direct creamery (DC) method followed by almost the same yield in creamery butter (CB) and desi butter (DB) methods, that is, 3.7%. Ripening of cream prior to clarification reduces the yield of ghee residue [18, 19]. It is one of the largest by-products of the dairy industry and consists mainly of milk proteins and small quantity of lactose and minerals. The ghee residue has been used in food industries for making sweets, bakery products, and as a flavor enhancer [20]. An appreciable amount of GR is produced in the country which is a nutritionally rich source of proteins and nitrogenous compounds. Ghee residue has been utilized for preparing burfi by mixing it with skim milk powder (SMP), khoa, chocolate, and sugar [21]. It can be utilized for preparing coconut burfi, candies, toffees, pinni, etc. after mixing with other ingredients. The nutritious by-product should be utilized as a food supplement in a variety of foods, food spreads, soups, etc. [22]. The utilization of this by-product in the preparation of some type of candies, toffees, edible pastes, etc. was suggested

**34**

about two decades ago but was not adopted commercially by the industry due to lack of awareness about its nutritive value. In general, the residue contains appreciable amounts of nutrients of milk. Ghee residue has been used in the preparation of candy, chocolate, burfi-type sweet, and bakery products.

The phospholipids of milk occur in a complex form with proteins in the fat globule membrane. When butter is heated to 120°C and above, the phospholipids are liberated from the phospholipid-protein complex and transferred to the oil phase. When the ghee-making process is kept much below 120°C, phospholipids, which remain in a complex form with proteins, will not enter ghee and, therefore, will be retained by GR. GR is a rich source of phospholipids from which phospholipids can be recovered and added to ghee. Pruthi et al. [23] described a heat-processing method for the extraction and fortification of ghee with GR phospholipids. The fortification of ghee with phospholipids at 0.1% level showed that the oxidative stability of ghee can be increased by increasing its phospholipid content either through heat treatment of GR with ghee or by the addition of solvent-extracted phospholipids from GR.

#### **6. Buttermilk utilization**

Buttermilk is a by-product of butter-making. It contains components derived both from fragments of milk fat globule membrane (MFGM), mainly consisting of proteins and neutral as well as polar lipids and all water-soluble components of cream [24]. Fortification with buttermilk is done to increase the yield provided cheese quality is unchanged. Buttermilk has high phospholipid content that has a significant function as emulsifiers in food systems and makes this dairy ingredient interesting for use as a functional ingredient [25] in an array of food products like chocolate, cheese seasonings, margarine, bread, ice cream mixes, or yogurt [26–28]. The buttermilk concentrate (BMC) rich in phospholipids has been utilized in processed cheese spread to improve its organoleptic, rheological, and functional properties [29]. The use of BMC in processed cheese spreads makes this dairy product useful as a functional food. This perspective could also bring economical income by enhancing the product yield or using low-value by-products from the dairy industry, such as buttermilk. Sweet buttermilk, condensed by heat and vacuum, supplemented at levels of 4 or 6% in regard to cheese milk improved the yield of pizza cheese with the contribution of denatured WP [30]. Kumari et al. [31] verified the effect of buttermilk as an ingredient in buffalo milk-derived chhana, an Indianstyle soft cottage cheese analogue. Substitution of milk with variable proportions of sweet buttermilk (from 0 to 50%) was technologically tested in cream cheese [32]. The authors revealed that the progressive increase of buttermilk percentage was followed by increase in moisture and yield. Buttermilk has been added to reducedfat cheese up to 40% and was found to improve the sensory scores in comparison to the control [33].

#### **7. Skim milk**

Skim milk powder for cheese-making requires adequate reconstitution and recombination techniques compared to whole milk powders, and at places where modern equipment and processing facilities for the reconstitution and recombination are not available, the use of whole milk powders could be advantageous. Addition of skim milk powder has been reported in Karish cheese, Domiati cheese, and processed cheese. Skim milk along with milk protein and stabilizers were used

to produce high-quality and acceptable Karish cheese with increased yield. Domiati cheese production was attempted earlier by an Egypt-based company, but the cheese obtained was inferior to that made from fresh milk. The recombined Domiati cheese had a firm texture and developed weak flavor even after the normal maturation period. Later attempts were made to improve the quality of recombined Domiati cheese, and direct addition of skim milk powder to buffalo or cow milk up to 35% total solids and coagulating the concentrated milk covered with brine resulted in acceptable taste and flavor after a month of storage. The FDA recommends the use of nonfat dry milk in processed cheese foods and processed cheese spreads. However, processed cheese made using cheese base produced from reconstituted skim milk powder results in markedly firmer cheese than the control. Skim milk powder has been reported for fortification of nontraditional white soft cheese in Egypt.

#### **8. Conclusions**

Utilization of whey proteins in cheese through either the adoption of techniques favoring WP retention in the cheese network or the direct addition of dairy-based ingredients or their combination is a challenging area in dairy sector. Some techniques have been implemented and emerged in industrial processes. In addition, ultrafiltration process can be used to restrain and recover whey proteins from drained whey that can later be added to the cheese milk. Utilizing whey protein into cheese preparation puts whey to good use. Whey protein-based edible films are a viable alternative packaging process for food and improvement of shelf life. Ghee residue is a good source of proteins, and about 100,000 tonnes of proteins can be recovered annually from GR only, and this can help in combating severe problem of protein-energy malnutrition. Potential uses of either crude or purified caseins include the production of plastics, adhesives, gels, composites, and films.

#### **Author details**

Syed Mansha Rafiq1 \* and Syed Insha Rafiq2

1 National Institute of Food Technology Entrepreneurship and Management, Sonipat, Haryana, India

2 National Dairy Research Institute, Karnal, Haryana, India

\*Address all correspondence to: mansharafiq@gmail.com

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

**37**

*Milk By-Products Utilization*

2017. pp. 533-542

**References**

2015;**33**:756-774

Blackwell; 2008

2012;**52**(6):533-552

Journal. 2001;**11**:495-503

*DOI: http://dx.doi.org/10.5772/intechopen.85533*

processed cheese analogs containing whey proteins. Milchwissenschaft.

[10] Suzuki M, Asano Y, Fujita H, Inoue N, Abe T, Ochi H, et al. Effect of whey protein concentrate addition on the physical properties of low fat processed cheese. Journal of the Japanese Society for Food Science and Technology.

[11] Ashour MM, Baky AA, El Neshawy

AA, Salem OM. Improving the quality of Domiati cheese made from recombined milk. Food Chemistry.

[12] Dhanraj P, Jana A, Modha H, Aparnathi KD. Influence of using a blend of rennet casein and whey protein concentrate as protein source on the quality of Mozzarella cheese analogue. Journal of Food Science and Technology.

2017;**54**(3):822. DOI: 10.1007/

Pre-treatment of cheese milk: Principles and developments. Dairy Science and Technology. 2008;**88**:

[13] Kelly AL, Huppertz T, Sheehan JJ.

[14] Lipnizki F. Cross-flow membrane applications in the food industry. In: Membrane Technology for Food Applications. Vol. 3. Weinheim: Wiley-

[15] Pawar N, Gandhi K, Purohit A, Arora S, Singh RRB. Effect of added herb extracts on oxidative stability of ghee (butter oil) during accelerated oxidation condition. Journal of Food Science and Technology. 2012. DOI:

10.1007/s13197-012-0781-1

[16] Gandhi K, Arora S, Pawar N, Kumar N. Effect of vidarikand (extracts) on oxidative stability of ghee: A comparative study.

2000;**55**:513-516

2012;**59**(3):122-126

1986;**20**(2):85-96

s13197-017-2528-5

549-572

VCH; 2010

[1] Fox PF, Guinee TP, Cogan TM, McSweeney PLH. Factors that affect cheese quality. In: Fundamentals of Cheese Science. New York: Springer;

[2] Jelen P. Utilization and products. Whey processing. Encyclopedia of Dairy Sciences. 2011:731-738

[3] Yadav JSS, Yan S, Pilli S, Kumar L, Tyagi RD, Surampalli LY. Cheese whey: A potential resource to

transform into bioprotein, functional/ nutritional proteins and bioactive peptides. Biotechnology Advances.

[4] Bugnicourt E, Schmid M, Nerney OM, Wild F. Wheylayer: The barrier coating of the future. Coating International. 2010;**43**(11):7-10

[5] Onwulata CHP. Whey processing, functionality and health benefits. In: IFT Press Series; Variation: IFT Press Series. Ames, Iowa, USA: Wiley

[6] Ramos ÓL, Pereira JO, Silva SI, Fernandes JC, Franco MI, Lopesda-Silva JA, et al. Evaluation of antimicrobial edible coatings from a whey protein isolate base to improve the shelf life of cheese. Journal of Dairy

Science. 2012;**95**(11):6282-6292

[7] Ramos OL, Fernandes JC, Silva SI, et al. Edible films and coatings from whey proteins: A review on formulation, and on mechanical and bioactive properties. Critical Reviews in Food Science and Nutrition.

[8] Hinrichs J. Incorporation of whey proteins in cheese. International Dairy

[9] Mleko S, Foegeding EA. Physical properties of rennet casein gels and

### **References**

*Current Issues and Challenges in the Dairy Industry*

**8. Conclusions**

**Author details**

Syed Mansha Rafiq1

Sonipat, Haryana, India

to produce high-quality and acceptable Karish cheese with increased yield. Domiati cheese production was attempted earlier by an Egypt-based company, but the cheese obtained was inferior to that made from fresh milk. The recombined Domiati cheese had a firm texture and developed weak flavor even after the normal maturation period. Later attempts were made to improve the quality of recombined Domiati cheese, and direct addition of skim milk powder to buffalo or cow milk up to 35% total solids and coagulating the concentrated milk covered with brine resulted in acceptable taste and flavor after a month of storage. The FDA recommends the use of nonfat dry milk in processed cheese foods and processed cheese spreads. However, processed cheese made using cheese base produced from reconstituted skim milk powder results in markedly firmer cheese than the control. Skim milk powder has been reported for fortification of nontraditional white soft cheese in Egypt.

Utilization of whey proteins in cheese through either the adoption of techniques favoring WP retention in the cheese network or the direct addition of dairy-based ingredients or their combination is a challenging area in dairy sector. Some techniques have been implemented and emerged in industrial processes. In addition, ultrafiltration process can be used to restrain and recover whey proteins from drained whey that can later be added to the cheese milk. Utilizing whey protein into cheese preparation puts whey to good use. Whey protein-based edible films are a viable alternative packaging process for food and improvement of shelf life. Ghee residue is a good source of proteins, and about 100,000 tonnes of proteins can be recovered annually from GR only, and this can help in combating severe problem of protein-energy malnutrition. Potential uses of either crude or purified caseins

include the production of plastics, adhesives, gels, composites, and films.

\* and Syed Insha Rafiq2

2 National Dairy Research Institute, Karnal, Haryana, India

\*Address all correspondence to: mansharafiq@gmail.com

provided the original work is properly cited.

1 National Institute of Food Technology Entrepreneurship and Management,

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

**36**

[1] Fox PF, Guinee TP, Cogan TM, McSweeney PLH. Factors that affect cheese quality. In: Fundamentals of Cheese Science. New York: Springer; 2017. pp. 533-542

[2] Jelen P. Utilization and products. Whey processing. Encyclopedia of Dairy Sciences. 2011:731-738

[3] Yadav JSS, Yan S, Pilli S, Kumar L, Tyagi RD, Surampalli LY. Cheese whey: A potential resource to transform into bioprotein, functional/ nutritional proteins and bioactive peptides. Biotechnology Advances. 2015;**33**:756-774

[4] Bugnicourt E, Schmid M, Nerney OM, Wild F. Wheylayer: The barrier coating of the future. Coating International. 2010;**43**(11):7-10

[5] Onwulata CHP. Whey processing, functionality and health benefits. In: IFT Press Series; Variation: IFT Press Series. Ames, Iowa, USA: Wiley Blackwell; 2008

[6] Ramos ÓL, Pereira JO, Silva SI, Fernandes JC, Franco MI, Lopesda-Silva JA, et al. Evaluation of antimicrobial edible coatings from a whey protein isolate base to improve the shelf life of cheese. Journal of Dairy Science. 2012;**95**(11):6282-6292

[7] Ramos OL, Fernandes JC, Silva SI, et al. Edible films and coatings from whey proteins: A review on formulation, and on mechanical and bioactive properties. Critical Reviews in Food Science and Nutrition. 2012;**52**(6):533-552

[8] Hinrichs J. Incorporation of whey proteins in cheese. International Dairy Journal. 2001;**11**:495-503

[9] Mleko S, Foegeding EA. Physical properties of rennet casein gels and

processed cheese analogs containing whey proteins. Milchwissenschaft. 2000;**55**:513-516

[10] Suzuki M, Asano Y, Fujita H, Inoue N, Abe T, Ochi H, et al. Effect of whey protein concentrate addition on the physical properties of low fat processed cheese. Journal of the Japanese Society for Food Science and Technology. 2012;**59**(3):122-126

[11] Ashour MM, Baky AA, El Neshawy AA, Salem OM. Improving the quality of Domiati cheese made from recombined milk. Food Chemistry. 1986;**20**(2):85-96

[12] Dhanraj P, Jana A, Modha H, Aparnathi KD. Influence of using a blend of rennet casein and whey protein concentrate as protein source on the quality of Mozzarella cheese analogue. Journal of Food Science and Technology. 2017;**54**(3):822. DOI: 10.1007/ s13197-017-2528-5

[13] Kelly AL, Huppertz T, Sheehan JJ. Pre-treatment of cheese milk: Principles and developments. Dairy Science and Technology. 2008;**88**: 549-572

[14] Lipnizki F. Cross-flow membrane applications in the food industry. In: Membrane Technology for Food Applications. Vol. 3. Weinheim: Wiley-VCH; 2010

[15] Pawar N, Gandhi K, Purohit A, Arora S, Singh RRB. Effect of added herb extracts on oxidative stability of ghee (butter oil) during accelerated oxidation condition. Journal of Food Science and Technology. 2012. DOI: 10.1007/s13197-012-0781-1

[16] Gandhi K, Arora S, Pawar N, Kumar N. Effect of vidarikand (extracts) on oxidative stability of ghee: A comparative study.

Research & Reviews: Journal of Dairy Science and Technology. 2013;**2**(1):1-11

[17] Dairy India. Milk movements, utilization and trade. 1985;**1981**(82): 20-24

[18] Santha IM, Narayanan KM. Composition of ghee-residue. Journal of Food Science and Technology. 1978:24-27

[19] Santha IM, Narayanan KM. Composition of ghee-residue lipids. Indian Journal of Dairy Science. 1978:365-369

[20] Tamine AY. Dairy Fats and related Products. Blackwell Publishing Ltd; 2009

[21] Verma BB, De S. Preparation of chocsi due burfi from ghee residue. Indian Journal of Dairy Science. 1978:370-374

[22] Galhotra KK, Wadhwa BK. Chemistry of ghee-residue, its significance and utilization—A review. Indian Journal of Dairy Science. 1993:142-146

[23] Pruthi TD, Narayanan KM, Bhalerao VR. Indian Journal of Dairy Science. 1971;**24**:185

[24] Vanderghem C, Bodson P, Danthine S, Paquot M, Deroanne C, Blecker C. Milk fat globule membrane and buttermilks: From composition to valorization. Biotechnology, Agronomy, Society and Environment. 2010;**14**:485-500

[25] Sodini I, Morin P, Olabi A, Jime'nezflores R. Compositional and functional properties of buttermilk: A comparison between sweet, sour, and whey buttermilk. Journal of Dairy Science. 2006;**89**:525-536

[26] Dewettinck K, Rombaut R, Thienpont N, Le TT, Messens K, Van Camp J. Nutritional and technological aspects of milk fat globule membrane material. International Dairy Journal. 2008;**18**:436-457

[27] Rombaut R, Camp JV, Dewettinck K. Phospho- and sphingolipid distribution during processing of milk, butter and whey. International Journal of Food Science and Technology. 2006;**41**: 435-443

[28] Tamime AY, Robinson RK. Yoghurt: Science and Technology. Cambridge, UK: Woodhead Publishing Ltd.; 1999

[29] Sayed MME, Askar AA, Hamzawi LF, Fatma FA, Mohamed AG, El Sayed SM, et al. Utilization of buttermilk concentrate in the manufacture of functional processed cheese spread. Journal of American Science. 2010;**6**(9)

[30] Govindasamy-Lucey S, Lin T, Jaeggi JJ, Johnson ME, Lucey JA. Influence of condensed sweet cream buttermilk on the manufacture, yield, and functionality of pizza cheese. Journal of Dairy Science. 2006;**89**:454-467

[31] Kumari J, Kumar S, Gupta VK, Kumar B. The influence of mixing sweet cream buttermilk to buffalo milk on quality of Chhana production. Milchwissenschaft. 2012;**67**:57-60

[32] Bahrami M, Ahmadi D, Beigmohammadi F, Hosseini F. Mixing sweet cream buttermilk with whole milk to produce cream cheese. Irish Journal of Agricultural and Food Research. 2015;**54**:73-78

[33] Suneeta P, Bhatt JD, Prajapati JP. Evaluation of selected emulsifiers and buttermilk in the manufacture of reduced-fat Paneer. Basic Research Journal of Food Science and Technology. 2014;**1**(4):1-14

**39**

Section 3

Supply Chains and

Consumers

Section 3
