**Bioactive Compounds in Goat Milk and Cheese: The Role of Feeding System and Breed Role of Feeding System and Breed**

**Bioactive Compounds in Goat Milk and Cheese: The** 

DOI: 10.5772/intechopen.70083

Salvatore Claps, Roberta Rossi, Adriana Di Trana, Maria Antonietta di Napoli, Daniela Giorgio and Lucia Sepe Trana, Maria Antonietta di Napoli, Daniela Giorgio and Lucia Sepe Additional information is available at the end of the chapter

Additional information is available at the end of the chapter

Salvatore Claps, Roberta Rossi, Adriana Di

http://dx.doi.org/10.5772/intechopen.70083

#### **Abstract**

[183] Lara-Villoslada F, Debras E, Nieto A, Concha A, Gálvez J, López-Huertas E, et al. Oligosaccharides isolated from goat milk reduce intestinal inflammation in a rat model

of dextran sodium sulfate-induced colitis. Clinical Nutrition. 2006;**25**(3):477-488 [184] Daddaoua A, Puerta V, Requena P, Martínez-Férez A, Guadix E, Medina de FS, et al. Goat milk oligosaccharides are anti-inflammatory in rats with hapten-induced colitis.

[185] Kunz C, Rudloff S. Health promoting aspects of milk oligosaccharides. International

Journal of Nutrition. 2006;**136**(3):672-676

Dairy Journal. 2006;**16**(11):1341-1346

232 Goat Science

This chapter provides an introductory overview of some bioactive compounds in goat milk, presenting a selection of key results from literature. The aim of the chapter is to review the effects of the feeding system and of the breed on goat milk and cheese fine quality in order to identify management options aimed at improving the nutraceutical characteristics of milk and dairy products. We will discuss a series of case studies focused on the assessment of the effects of feeding system and breed and their interaction on specific health-promoting bioactive compounds: (i) fatty acid (FA) profile, (ii) antioxidant compounds and (iii) oligosaccharides (OS). Experimental data will be discussed highlighting the potential role of local Mediterranean breeds for the production of functional dairy products.

**Keywords:** bioactive compounds, feeding system, goat, Mediterranean breeds, fatty acids, antioxidants, oligosaccharides, milk, cheese

#### **1. Introduction: overview on the main bioactive compounds of goat milk**

Bioactive compound, according to the National Cancer Institute (USA), is "one type of chemical food in small amounts in plants and certain foods (such as fruits, vegetables, nuts, oils, and whole grains). Bioactive compounds have actions in the body that may promote good health. They are being studied in the prevention of cancer, heart disease, and other diseases". By [1], a bioactive compound is "a compound which has the capability and the ability to interact with one or more component(s) of the living tissue by presenting a wide range of probable effects". The origin of these substances can be natural—terrestrial or aquatic, a plant, animal or other

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. © 2018 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.

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons

source (e.g., microorganisms)—or synthetic. The term "bioactive compound" is not attributed to the nutrient contained in food or, more broadly, to the nutrients that are essential for a living organism, such as primary metabolites.

The amount of these biologically active molecules in milk and cheese fat from ruminants is affected by animal diets [8]. There have been studies about grazing based on shrub and woody lands affecting CLA and VA content in milk and cheese from sheep and goats [9] also with regard to specific forage species in the pasture [10]. Nevertheless, our knowledge on the effects of common Mediterranean forage species, agronomic management, forage conserva-

Bioactive Compounds in Goat Milk and Cheese: The Role of Feeding System and Breed

http://dx.doi.org/10.5772/intechopen.70083

235

Recently, another topic of interest has been the antioxidant content in milk and cheeses. In milk there are several antioxidant compounds which can be classified as enzymatic antioxidant and non-enzymatic antioxidant. Among antioxidant enzymes, superoxide dismutase, catalase and glutathione peroxidases have been demonstrated in milk. Non-enzymatic antioxidants, lactoferrin, vitamin C (ascorbic acid), vitamin E (tocopherols and tocotrienols), carotenoids and polyphenols can be formed in the animal body or need to be supplied in the feed as essential nutrients [11, 12]. Several non-enzymatic antioxidants act as radical scavengers in the lipid phase, such as vitamin E, carotenoids and ubiquinol, whereas vitamin C acts in the water phase. Others can react in both the lipid and the water phase, such as some polyphenols (flavonoids), which operate both as radical scavengers and metal ion binders [12]. The parameters that are taken more into consideration are the beta-carotene and α-tocopherol content and the level of protective antioxidants. A molecule is recognised as an antioxidant when it is able to slow down, or hinder, oxidising processes against certain substances. A synthetic index of this capability is represented by the degree of antioxidant protection (DAP) [13]. The DAP is calculated as ratio between the amount antioxidant element (e.g., α-tocopherol) and the element to be protected against oxidation (cholesterol). Increasing α-tocopherol in milk is important not only to enhance its nutritive value but also to prevent lipid oxidation which leads to rancidity of milk and dairy products; vitamin E supplementation is a standard practice in most farming systems. Milk tocopherol content depends on several factors such as breed, feed and stage of lactation; large differences exist

Very little is known on the effect of diet on the content of non-volatile phenolic compounds in milk or cheese. The results of a few recent studies demonstrate the accumulation of various phenolic compounds in the milk of grazing goats [14, 15]. High content of phenols in milk has shown to improve the quality of milk, such as its oxidative stability of the process' efficiency

The interest towards drinking goat milk is increasing, due to the recognised nutritional properties of this milk in comparison with cow milk [17, 18]. A class of bioactive compounds recently rose to major interest, namely, the oligosaccharides [19], due to their beneficial effects on human health as intestinal inflammation [20] and on brain development and immunity in infants [21]. The content of goat oligosaccharides (OS) compared to other domestic ruminants milk is about 4–5 times higher than cow milk and up 10 times than sheep milk [22]. The scarce availability of those from human milk encouraged to deepen studies on these bio-compounds. The studies showed OS content and profile in goat milk most similar to breast milk in comparison to other farm mammalians, in particular as far as fucosylated and sialylated OS to human milk oligosaccharides [23], as to suggest, by several authors, the use

in the production of products for human nutrition, such as infant formulae.

tion and breed on goat milk bioactive fractions is still limited.

among ruminant species and within species.

and quality of dairy products [16].

Controversies over except the essential elements of the definition of bioactive compounds arise for food (or source of nutrition in general), where food constituents include water, carbohydrate, proteins, lipids and fatty acids, fibres, vitamins, minerals and oligo-elements. Ref. [2] consider that bioactive peptides, many vitamins, fatty acids, flavonoids and phytosterol and the soluble and insoluble fibres are bioactive compounds. Examples of bioactive compound include lycopene, resveratrol, lignan, tannins and indoles.

In recent years, functional foods and bioactive components in foods have drawn a lot of attention and interest among food scientists, nutritionists, health professionals and general consumers. A functional food may be similar in appearance to a conventional food; it is consumed as a part of normal diet but has various physiological benefits and can reduce the risk of chronic diseases beyond basic nutritional functions.

Goat milk (GM) when compared to cow milk in terms of fatty acid (FA) profile shows a larger content of medium-chain fatty acids (MCFA) such as caproic (C6:0), caprylic (C8:0) and capric (C10:0), which can be considered bioactive compounds [3]. These three fatty acids that alone represent up to 15–18% of total FA in goat milk and not more than 9% in cow milk, due to their great energy giving facility, play a key dietary role in improving lipid metabolism, especially in patients suffering from various forms of malabsorption syndromes, typically developed after intestine resection, in rehabilitating premature and undernourished infants [4]. Dietary GM improves iron bioavailability favouring the recovery of haematological parameters [5]. GM contributes to restore bone demineralisation associated to anaemia by increasing the digestive and metabolic utilisation of calcium and phosphorus. Its consumption has beneficial effects on nutritive utilisation of iron and copper [6].

The role of polyunsaturated fatty acid (PUFA), and in particular conjugated linoleic acid (CLA), alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA) and the docosahexaenoic acid (DHA), has received much attention of nutritionists in the last 10 years. The n-3 fatty acids (i) reduce total cholesterol and low-density lipoprotein cholesterol (LDL) levels but increase high-density lipoprotein (HDL) cholesterol, (ii) counteract hypertension, (iii) play a role in the regulation of hormonal secretion and (iv) are beneficial in the care of skin pathologies and are also useful in the therapy of arthritis and other inflammatory problems.

The acronym CLA is used to express the mixture of isomers of the linoleic fatty acid with double conjugated bonds, located, above all, on the atoms of carbons 9 and 11. Biological activity is mainly attributed to rumenic acid (C18:2 cis 9, trans 11), which represent about 90% of the total isomers present in the fat of ruminants [7]. The CLA in milk has two origins: from the rumen biohydrogenation of unsaturated fatty acids, present in substantial quantities in fresh forage, and from the synthesis in animal tissue, mainly the mammary gland and adipose tissue, starting with the vaccenic acids (VA) through the action of the delta 9-desaturase enzyme.

The amount of these biologically active molecules in milk and cheese fat from ruminants is affected by animal diets [8]. There have been studies about grazing based on shrub and woody lands affecting CLA and VA content in milk and cheese from sheep and goats [9] also with regard to specific forage species in the pasture [10]. Nevertheless, our knowledge on the effects of common Mediterranean forage species, agronomic management, forage conservation and breed on goat milk bioactive fractions is still limited.

source (e.g., microorganisms)—or synthetic. The term "bioactive compound" is not attributed to the nutrient contained in food or, more broadly, to the nutrients that are essential for a liv-

Controversies over except the essential elements of the definition of bioactive compounds arise for food (or source of nutrition in general), where food constituents include water, carbohydrate, proteins, lipids and fatty acids, fibres, vitamins, minerals and oligo-elements. Ref. [2] consider that bioactive peptides, many vitamins, fatty acids, flavonoids and phytosterol and the soluble and insoluble fibres are bioactive compounds. Examples of bioactive compound

In recent years, functional foods and bioactive components in foods have drawn a lot of attention and interest among food scientists, nutritionists, health professionals and general consumers. A functional food may be similar in appearance to a conventional food; it is consumed as a part of normal diet but has various physiological benefits and can reduce the risk of

Goat milk (GM) when compared to cow milk in terms of fatty acid (FA) profile shows a larger content of medium-chain fatty acids (MCFA) such as caproic (C6:0), caprylic (C8:0) and capric (C10:0), which can be considered bioactive compounds [3]. These three fatty acids that alone represent up to 15–18% of total FA in goat milk and not more than 9% in cow milk, due to their great energy giving facility, play a key dietary role in improving lipid metabolism, especially in patients suffering from various forms of malabsorption syndromes, typically developed after intestine resection, in rehabilitating premature and undernourished infants [4]. Dietary GM improves iron bioavailability favouring the recovery of haematological parameters [5]. GM contributes to restore bone demineralisation associated to anaemia by increasing the digestive and metabolic utilisation of calcium and phosphorus. Its consumption has beneficial effects on nutritive utilisation of iron and

The role of polyunsaturated fatty acid (PUFA), and in particular conjugated linoleic acid (CLA), alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA) and the docosahexaenoic acid (DHA), has received much attention of nutritionists in the last 10 years. The n-3 fatty acids (i) reduce total cholesterol and low-density lipoprotein cholesterol (LDL) levels but increase high-density lipoprotein (HDL) cholesterol, (ii) counteract hypertension, (iii) play a role in the regulation of hormonal secretion and (iv) are beneficial in the care of skin pathologies and are also useful in the therapy of arthritis and other inflammatory

The acronym CLA is used to express the mixture of isomers of the linoleic fatty acid with double conjugated bonds, located, above all, on the atoms of carbons 9 and 11. Biological activity is mainly attributed to rumenic acid (C18:2 cis 9, trans 11), which represent about 90% of the total isomers present in the fat of ruminants [7]. The CLA in milk has two origins: from the rumen biohydrogenation of unsaturated fatty acids, present in substantial quantities in fresh forage, and from the synthesis in animal tissue, mainly the mammary gland and adipose tissue, starting with the vaccenic acids (VA) through the action of the delta 9-desaturase enzyme.

ing organism, such as primary metabolites.

include lycopene, resveratrol, lignan, tannins and indoles.

chronic diseases beyond basic nutritional functions.

copper [6].

234 Goat Science

problems.

Recently, another topic of interest has been the antioxidant content in milk and cheeses. In milk there are several antioxidant compounds which can be classified as enzymatic antioxidant and non-enzymatic antioxidant. Among antioxidant enzymes, superoxide dismutase, catalase and glutathione peroxidases have been demonstrated in milk. Non-enzymatic antioxidants, lactoferrin, vitamin C (ascorbic acid), vitamin E (tocopherols and tocotrienols), carotenoids and polyphenols can be formed in the animal body or need to be supplied in the feed as essential nutrients [11, 12]. Several non-enzymatic antioxidants act as radical scavengers in the lipid phase, such as vitamin E, carotenoids and ubiquinol, whereas vitamin C acts in the water phase. Others can react in both the lipid and the water phase, such as some polyphenols (flavonoids), which operate both as radical scavengers and metal ion binders [12]. The parameters that are taken more into consideration are the beta-carotene and α-tocopherol content and the level of protective antioxidants. A molecule is recognised as an antioxidant when it is able to slow down, or hinder, oxidising processes against certain substances. A synthetic index of this capability is represented by the degree of antioxidant protection (DAP) [13]. The DAP is calculated as ratio between the amount antioxidant element (e.g., α-tocopherol) and the element to be protected against oxidation (cholesterol).

Increasing α-tocopherol in milk is important not only to enhance its nutritive value but also to prevent lipid oxidation which leads to rancidity of milk and dairy products; vitamin E supplementation is a standard practice in most farming systems. Milk tocopherol content depends on several factors such as breed, feed and stage of lactation; large differences exist among ruminant species and within species.

Very little is known on the effect of diet on the content of non-volatile phenolic compounds in milk or cheese. The results of a few recent studies demonstrate the accumulation of various phenolic compounds in the milk of grazing goats [14, 15]. High content of phenols in milk has shown to improve the quality of milk, such as its oxidative stability of the process' efficiency and quality of dairy products [16].

The interest towards drinking goat milk is increasing, due to the recognised nutritional properties of this milk in comparison with cow milk [17, 18]. A class of bioactive compounds recently rose to major interest, namely, the oligosaccharides [19], due to their beneficial effects on human health as intestinal inflammation [20] and on brain development and immunity in infants [21]. The content of goat oligosaccharides (OS) compared to other domestic ruminants milk is about 4–5 times higher than cow milk and up 10 times than sheep milk [22]. The scarce availability of those from human milk encouraged to deepen studies on these bio-compounds. The studies showed OS content and profile in goat milk most similar to breast milk in comparison to other farm mammalians, in particular as far as fucosylated and sialylated OS to human milk oligosaccharides [23], as to suggest, by several authors, the use in the production of products for human nutrition, such as infant formulae.

This chapter provides an overview of the main bioactive compounds in milk and goat cheese (fatty acids, antioxidant and oligosaccharides) conveying data from significant case studies carried out at the experimental farm of Council for Agricultural Research-Unit for Extensive Husbandry (CREA-ZOE), located in Bella (Muro Lucano, Potenza), Basilicata region (Southern Italy).

at flowering were contributing to a higher concentration of linoleic and ALA in ewe's milk and a lower ω6/ω3 ratio. Refs. [32, 33] showed that red clover silage, which contained levels of ALA similar to that of grass silage, improved milk PUFA due to a high proportion of red clover ALA passing through the rumen. Polyphenol oxidase (PPO), which is the enzyme involved in the browning reaction of red clover leaves when cut or crushed and exposed to air, has been found

Bioactive Compounds in Goat Milk and Cheese: The Role of Feeding System and Breed

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Overall, this brief overview on the role of feeding regimen in modulating goat milk fatty acid profile shows that both farm-grown forages including legumes, as well as native pastures, can be considered an effective low-cost way to improve goat milk FA composition without compromising yield and opening new alleys towards a sustainable intensification of the extensive

In this section we report a study carried out at the experimental farm of Council for Agricultural Research and Economics-Research Unit for the Extensive Animal Husbandry (CREA-ZOE) located in Bella (Basilicata region, Southern Italy) during winter, spring and summer seasons. In order to examine changes in milk FA profile under the effect of different feeding regimes, typical of Mediterranean extensive and semi-extensive goat production systems, four groups of Mediterranean Red goats were formed and allocated to different feeding systems: (G) grazing on a native pasture (8 h/day) without supplementation, (GS1) grazing supplemented with 550 g/d of maize and broad beans (CP 14% and NDF 18%, slowly degradable), (GS2) grazing supplemented with 550 g/d of barley and chickpeas (CP 14% and NDF 18%, rapidly degradable) and (H) housing and fed with hay produced with the grass from the same pasture plus 550 g/d of mixed grains (CP 15% and NDF 18%) [35–38]. Regarding lipid extraction method,

and centrifuged (500 × g, 10 min). After removing the upper layer, the lower layer was filtered

SO<sup>4</sup>

using a rotary evaporator at 30°C. The residue was stored at −80°C for lipid determination. Lipid extract was methylated adding hexane (1 ml) and 2 N methanolic KOH (0.05 ml). Gas chromatograph analysis was performed on a Varian model 3800 GC instrument fitted with an automatic sampler (CP 8410) for a multiple injection. Fatty acid methyl esters (FAME) were separated through a cyanopropyl polysiloxane (DB 23, J & W) fused silica capillary column (60 m × 0.25 mm i.d.). Operating conditions were a helium flow rate of 1.2 ml/min, a FID detector at 250°C and a split-splitless injector at 230°C with a split ratio 1:100. The column temperature was held at 60°C for 5 min after sample injection (1 μl), increased at 14°C/min to 165°C and at 2°C/min to 225°C and held at 225°C for 20 min. The individual fatty acid peaks were identified with reference to the retention times of standard of CLA isomers (cis-9, trans-11 97% and trans-10, cis-12 3%; Larodan, Malmö, Sweden) and a known mixture of standards (FAME,

Milk produced by goat groups showed a wide variability in its FA composition linked to the characteristics of the ingested feed in each type of feeding system (**Figure 1**). In particular,

, rinsed with CHCl<sup>3</sup>

and MeOH mixture (2/1, v/v)

(30 ml) and concentrated

(30 ml) and then again filtered. The chloroform-

to reduce protein and lipid degradations in vitro and potentially in the rumen [34].

*2.1.1. Case study: feeding and season on milk fatty acid profile*

briefly milk sample (10 ml) was homogenised (2 min) with CHCl<sup>3</sup>

Sigma). Fatty acids were expressed as percentage of total FAME.

through a Buchner funnel, rinsed with CHCl<sup>3</sup>

lipid extract was dried over anhydrous Na<sup>2</sup>

dairy goat system.
