**1. Introduction**

16 Food Industrial Processes – Methods and Equipment

Freire, J.L.O.; Cavalcante, L.F.; Rebequi, A.M.; Dias, T.J.; Nunes, J.C. & Cavalcante, I.L.C.

Mahmud, T.M.M.; Al Eryani-Raqeeb, A.; Syed Omar, S.R.; Mohamed Zaki, A.R. & Al Eryani,

Marschner, H. (2005). *Mineral Nutrition of Higher Plants*. (6th edition). UK: Academic Press,

Meletti, L.M.M.; Soares Scott, M.D.; Bernacci, L.C. & Azevedo, F.J.A. (2002). Desempenho

Mesquita, E.F.; Cavalcante, L.F.; Goldim, A.C.; Cavalcante, I.H.L.; Araújo, F.A.R. &

Nascimento, V.E.; Martins, A.B. & Hojo, R.H. (2008). Caracterização Física e Química de

Paull, R.E. & Duarte O. (2011). *Tropical Fruits*, (2nd edition), ISBN 978-1-84593-672-3,

Rodrigues, A.C.; Cavalcante, L.F.; Dantas, T.A.G.; Campos, V.B. & Diniz, A.A. (2008).

Rodrigues, A.C.; Cavalcante, L.F.; Oliveira, A.P.; Sousa, J.T. & Mesquita, F.O. (2009).

Silva Júnior, G.B.; Rocha, L.F.; Amaral, H.C.; Andrade, M.L.; Neto, R.F. & Cavalcante, I.H.L.

Silva, R.A.da; Cavalcante, L.F.; Holanda, J.S.de; Pereira, W.E.; Moura, M.F. & Ferreira Neto,

*Ambiental*, Vol. 13, N°. 2, pp. 117-123, ISSN 1807-1929

*Agrária*, Vol. 31, N°. 3, pp. 557-562, ISSN 1679-0359

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*Maracujazeiro*, Vol. 3, pp. 196-197

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London, Great Britain

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0102-5333

ISBN: 978-0-12-384905-2, London, Great Britain

ISSN 1557-4989

e Potássio na Fertirrigação. *Revista Brasileira de Engenharia Agrícola e Ambiental*, Vol.

(2010). Atributos Qualitativos do Maracujá Amarelo Produzido com Água Salina, Biofertilizante e Cobertura Morta no Solo. *Revista Brasileira de Ciências Agrárias*, Vol.

Abdul-R. (2008). Effects of Different Concentrations and Applications of Calcium on Storage Life and Physicochemical Characteristics of Papaya (*Carica Papaya* L.). *American Journal of Agricultural and Biological Sciences*, Vol. 3, N°. 3, pp. 526-533,

das Cultivares IAC-273 e IAC-277 de Maracujazeiro-Amarelo (*Passiflora edulis* f*. flavicarpa* Deg.) em Pomares Comerciais. In: *Reunião Técnica de Pesquisa em*

Cavalcante, M.Z.B. (2007). Produtividade e Qualidade de Frutos do Mamoeiro em Função de Tipos e Doses de Biofertilizantes. *Semina: Ciência Agrárias*, Vol. 28, N°. 4,

Frutos de Mamey. *Revista Brasileira de Fruticultura Brasileira*, Vol. 30, N°. 4, pp. 953-

Caracterização de Frutos de Maracujazeiro-Amarelo em Solo Tratado com Biofertilizante Supermagro e Potássio. *Magistra*, Vol. 20, N°. 3, pp. 264-272, ISSN

Produção e Nutrição Mineral do Maracujazeiro-Amarelo em Solo com Biofertilizantes Supermagro e Potássio. *Revista Brasileira de Engenharia Agrícola e*

(2010). Laranja-da-Terra: Fruta Cítrica Potencial Para o Piauí. *Semina: Ciência* 

M. (2006). Qualidade de Frutos do Coqueiro-Anão Verde Fertirrigado com Nitrogênio e Potássio. *Revista Brasileira de Fruticultura, Jaboticabal*, Vol. 28, N°. 2, pp. Hydrocolloids or gums are a diverse group of long chain polymers characterized by their property of forming viscous dispersions and/or gels when dispersed in water. These materials were first found in exudates from trees or bushes, extracts from plants or seaweeds, flours from seeds or grains, gummy slimes from fermentation processes, and many other natural products. Occurrence of a large number of hydroxyl groups noticeably increases their affinity for binding water molecules rendering them hydrophilic compounds. Further, they produce a dispersion, which is intermediate between a true solution and a suspension, and exhibits the properties of a colloid. Considering these two properties, they are appropriately termed as 'hydrophilic colloids' or 'hydrocolloids'.

Hydrocolloids have a wide array of functional properties in foods including; thickening, gelling, emulsifying, stabilization, coating and etc. Hydrocolloids have a profound impact on food properties when used at levels ranging from a few parts per million for carrageenan in heat-treated dairy products to high levels of acacia gum, starch or gelatin in jelly confectionery. The primary reason behind the ample use of hydrocolloids in foods is their ability to modify the rheology of food systems. This includes two basic properties of food systems that is, flow behavior (viscosity) and mechanical solid property (texture). The modification of texture and/or viscosity of food systems helps modify its sensory properties, therefore hydrocolloids are used as significant food additives to perform specific purposes. It is evident that several hydrocolloids belong to the category of permitted food additive in many countries throughout the world. Various food formulations such as soups, gravies, salad dressings, sauces and toppings use hydrocolloids as additives to achieve the preferred viscosity and mouth feel. They are also used in many food products like icecreams, jams, jellies, gelled desserts, cakes and candies, to create the desired texture.

In addition to the functional attributes, future acceptance and, possibly, positive endorsement may derive from the recognition that fibers contribute many physiological benefits to the natural function and well-being of the body.

The aim of this chapter of the book is to highlight the importance of the hydrocolloids in food industry.

### **2. Functional properties**

#### **2.1 Viscosity enhancing or thickening properties**

The foremost reason behind the ample use of hydrocolloids in foods is their ability to modify the rheology of food system. The modification of texture and/or viscosity of food

Hydrocolloids in Food Industry 19

hydrocolloid that proved significant surface activity. Gum arabic is the only gum adsorbing onto oil-water interfaces and imparting steric stabilization. Other gums such as galactomannans, xanthan, pectin, etc. have been known to reduce surface and interfacial tensions, to adsorb onto solid surfaces and to improve stability of oil-in-water emulsions. Micro crystalline cellulose (MCC) is an example of a hydrocolloid with no solubility in

It well documented that gum arabic, a natural polysaccharide, has excellent emulsification properties for oil-in-water emulsions. An excellent example of its use is in cloudy emulsions, as opacity builders for citrus beverages (Connolly et al. 1988). Related the significance of protein components presenting in gum arabic to its emulsifying properties. It seems that the protein-hybrid in gum arabic meets all the necessary requirements in a capacity similar to emulsifying proteins (such as casein, or soy protein) via its numerous adsorption sites, flexibility, conformational change at the interface and the entropy gain (solvent depletion). Gum arabic works by reducing the oil-water interfacial tension, thereby facilitating the disruption of emulsion droplets during homogenization. The peptides are hydrophobic and strongly adsorb on to the surface of oil droplets, whilst the polysaccharide chains are hydrophilic and extend out into the solution, preventing droplet flocculation and

Microcrystalline cellulose is also able to stabilize the oil-in-water emulsions. Its strong affinity for both the oil and the water results in precipitation and some orientation of the solid particles at the oil-in-water interface (Philips et al., 1984). It was proposed that the colloidal network of the free MCC thickens the water phase between the oil globules preventing their close approach and subsequent coalescence. Therefore, the MCC provides

As the galactomannans structure gives no suggestion of the presence of any significant proportion of hydrophobic groups, it is generally assumed that this type of hydrocolloid functions by modifying the rheological properties of the aqueous phase between the dispersed particles or droplets. It has been suggested that these gums stabilize emulsions by forming liquid crystalline layers around the droplets. It should be noted that this putative adsorption of the gum to the oil-water interface is reportedly rather weak and reversible. That is, the associated emulsion stability is lost on diluting the aqueous phase of the

Pectin is another class of hydrocolloid whose emulsifying character has attracted attention in recent years. While citrus and apple pectin is normally used as low-pH gelling or thickening agents (are not effective as emulsifying agents), sugar beet pectin does not form gels with calcium ions or at high sugar concentrations. Due to its higher protein content, sugar beet pectin is considerably more surface-active than gum arabic, and it is very effective in stabilizing fine emulsions based on orange oil or triglyceride oil at a pectin/oil

An edible film is defined as a thin layer, which can be consumed, coated on a food or placed as barrier between the food and the surrounding environment. The most familiar example of edible packaging is sausage meat in casing that is not removed for cooking and eating. Hydrocolloids are used to produce edible films on food surfaces and between food components. Such films serve as inhibitors of moisture, gas, aroma and lipid migration. Many gums and derivatives have been used for coating proposes. They include alginate,

water that adsorbs mechanically at the interface.

coalescence through electrostatic and steric repulsion forces.

long term stability (Philips et al., 1990).

emulsion with water (Dickinson, 2003).

ratio of 1:10 (Williams et al., 2005).

**2.4 Hydrocolloids as edible films and coatings** 

system helps to modify its sensory properties, and hence, hydrocolloids are used as important food additives to perform specific purposes. The process of thickening involves nonspecific entanglement of conformationally disordered polymer chains; it is essentially polymer-solvent interaction (Philips et al., 1986). Hydrocolloids that have been used as thickening agents are shown in Table 1. The thickening effect of produced by the hydrocolloids depends on the type of hydrocolloid used, its concentration, the food system in which it is used and also the pH of the food system and temperature. Ketchup is one of the most common food items where the hydrocolloid thickeners are used to influence its viscosity (Sahin & Ozdemir, 2004).

The question that arises is how hydrocolloids thicken solution. In dilute dispersion, the individual molecules of hydrocolloids can move freely and do not exhibit thickening. In concentrated system, these molecules begin to come into contact with one another; thus, the movement of molecules becomes restricted. The transition from free moving molecules to an entangled network is the process of thickening.

The viscosity of polymer solutions is influenced significantly by the polymer molecular mass. In addition to molecular mass effects, the hydrodynamic size of polymer molecules in solution is significantly influenced by molecular structure. Linear, stiff molecules have a larger hydrodynamic size than highly branched, highly flexible polymers of the same molecular mass and hence give rise to a much higher viscosity.

#### **2.2 Gelling properties**

Swollen particulate forms of gelled hydrocolloids are particularly useful as they combine macroscopic structure formation with an ability to flow and often have an attractive soft solid texture, which is especially sought in food applications, all at high water contents (*>*95%). There is a potential opportunity for particulate hydrocolloid systems to replace chemically cross-linked starches based on appropriate structuring, processing, and molecular release properties without the need for chemical treatment.

The characteristics of gel particles, and the application for which they are used, will depend on the type of hydrocolloid, the network formation mechanism and the processing method used for particle formation (Burey et al., 2008).

Hydrocolloid gel networks form through entwining and cross-linking of polymer chains to form a three-dimensional network. The mechanism by which this interchain linking occurs can vary (Djabourov, 1991).

Hydrocolloid gelation can involve a hierarchy of structures, the most common of which is the aggregation of primary interchain linkages into "junction zones" which form the basis for the three-dimensional network characteristic of a gel.

Various parameters such as temperature, the presence of ions, and the inherent structure of the hydrocolloid can affect the physical arrangement of junction zones within the network.

#### **2.3 Surface activity and emulsifying properties**

The functionality of hydrocolloids as emulsifiers and/or emulsion stabilizers correlates to phenomena such as: retardation of precipitation of dispersed solid particles, decreased creaming rates of oil droplets and foams, prevention of aggregation of dispersed particles, prevention of syneresis of gelled systems containing oils and retardation of coalescence of oil droplets. It is believed that gums will adsorb (onto solid or liquid surfaces) very slowly, weakly and with very limited surface load if at all. The hydrocolloids were classified according to their activity at the interface. Gum Arabic is probably the most studied

system helps to modify its sensory properties, and hence, hydrocolloids are used as important food additives to perform specific purposes. The process of thickening involves nonspecific entanglement of conformationally disordered polymer chains; it is essentially polymer-solvent interaction (Philips et al., 1986). Hydrocolloids that have been used as thickening agents are shown in Table 1. The thickening effect of produced by the hydrocolloids depends on the type of hydrocolloid used, its concentration, the food system in which it is used and also the pH of the food system and temperature. Ketchup is one of the most common food items where the hydrocolloid thickeners are used to influence its

The question that arises is how hydrocolloids thicken solution. In dilute dispersion, the individual molecules of hydrocolloids can move freely and do not exhibit thickening. In concentrated system, these molecules begin to come into contact with one another; thus, the movement of molecules becomes restricted. The transition from free moving molecules to an

The viscosity of polymer solutions is influenced significantly by the polymer molecular mass. In addition to molecular mass effects, the hydrodynamic size of polymer molecules in solution is significantly influenced by molecular structure. Linear, stiff molecules have a larger hydrodynamic size than highly branched, highly flexible polymers of the same

Swollen particulate forms of gelled hydrocolloids are particularly useful as they combine macroscopic structure formation with an ability to flow and often have an attractive soft solid texture, which is especially sought in food applications, all at high water contents (*>*95%). There is a potential opportunity for particulate hydrocolloid systems to replace chemically cross-linked starches based on appropriate structuring, processing, and

The characteristics of gel particles, and the application for which they are used, will depend on the type of hydrocolloid, the network formation mechanism and the processing method

Hydrocolloid gel networks form through entwining and cross-linking of polymer chains to form a three-dimensional network. The mechanism by which this interchain linking occurs

Hydrocolloid gelation can involve a hierarchy of structures, the most common of which is the aggregation of primary interchain linkages into "junction zones" which form the basis

Various parameters such as temperature, the presence of ions, and the inherent structure of the hydrocolloid can affect the physical arrangement of junction zones within the network.

The functionality of hydrocolloids as emulsifiers and/or emulsion stabilizers correlates to phenomena such as: retardation of precipitation of dispersed solid particles, decreased creaming rates of oil droplets and foams, prevention of aggregation of dispersed particles, prevention of syneresis of gelled systems containing oils and retardation of coalescence of oil droplets. It is believed that gums will adsorb (onto solid or liquid surfaces) very slowly, weakly and with very limited surface load if at all. The hydrocolloids were classified according to their activity at the interface. Gum Arabic is probably the most studied

viscosity (Sahin & Ozdemir, 2004).

**2.2 Gelling properties** 

can vary (Djabourov, 1991).

entangled network is the process of thickening.

used for particle formation (Burey et al., 2008).

for the three-dimensional network characteristic of a gel.

**2.3 Surface activity and emulsifying properties** 

molecular mass and hence give rise to a much higher viscosity.

molecular release properties without the need for chemical treatment.

hydrocolloid that proved significant surface activity. Gum arabic is the only gum adsorbing onto oil-water interfaces and imparting steric stabilization. Other gums such as galactomannans, xanthan, pectin, etc. have been known to reduce surface and interfacial tensions, to adsorb onto solid surfaces and to improve stability of oil-in-water emulsions. Micro crystalline cellulose (MCC) is an example of a hydrocolloid with no solubility in water that adsorbs mechanically at the interface.

It well documented that gum arabic, a natural polysaccharide, has excellent emulsification properties for oil-in-water emulsions. An excellent example of its use is in cloudy emulsions, as opacity builders for citrus beverages (Connolly et al. 1988). Related the significance of protein components presenting in gum arabic to its emulsifying properties. It seems that the protein-hybrid in gum arabic meets all the necessary requirements in a capacity similar to emulsifying proteins (such as casein, or soy protein) via its numerous adsorption sites, flexibility, conformational change at the interface and the entropy gain (solvent depletion). Gum arabic works by reducing the oil-water interfacial tension, thereby facilitating the disruption of emulsion droplets during homogenization. The peptides are hydrophobic and strongly adsorb on to the surface of oil droplets, whilst the polysaccharide chains are hydrophilic and extend out into the solution, preventing droplet flocculation and coalescence through electrostatic and steric repulsion forces.

Microcrystalline cellulose is also able to stabilize the oil-in-water emulsions. Its strong affinity for both the oil and the water results in precipitation and some orientation of the solid particles at the oil-in-water interface (Philips et al., 1984). It was proposed that the colloidal network of the free MCC thickens the water phase between the oil globules preventing their close approach and subsequent coalescence. Therefore, the MCC provides long term stability (Philips et al., 1990).

As the galactomannans structure gives no suggestion of the presence of any significant proportion of hydrophobic groups, it is generally assumed that this type of hydrocolloid functions by modifying the rheological properties of the aqueous phase between the dispersed particles or droplets. It has been suggested that these gums stabilize emulsions by forming liquid crystalline layers around the droplets. It should be noted that this putative adsorption of the gum to the oil-water interface is reportedly rather weak and reversible. That is, the associated emulsion stability is lost on diluting the aqueous phase of the emulsion with water (Dickinson, 2003).

Pectin is another class of hydrocolloid whose emulsifying character has attracted attention in recent years. While citrus and apple pectin is normally used as low-pH gelling or thickening agents (are not effective as emulsifying agents), sugar beet pectin does not form gels with calcium ions or at high sugar concentrations. Due to its higher protein content, sugar beet pectin is considerably more surface-active than gum arabic, and it is very effective in stabilizing fine emulsions based on orange oil or triglyceride oil at a pectin/oil ratio of 1:10 (Williams et al., 2005).

#### **2.4 Hydrocolloids as edible films and coatings**

An edible film is defined as a thin layer, which can be consumed, coated on a food or placed as barrier between the food and the surrounding environment. The most familiar example of edible packaging is sausage meat in casing that is not removed for cooking and eating. Hydrocolloids are used to produce edible films on food surfaces and between food components. Such films serve as inhibitors of moisture, gas, aroma and lipid migration. Many gums and derivatives have been used for coating proposes. They include alginate,

Hydrocolloids in Food Industry 21

The traditional approach is the partial replacement of fat using starches which, when dissolved in water, create stable thermo-reversible gels. Soft, fat-like gels can be created by conversion modifications to the degree necessary to produce thermo-reversible, spreadable gels. Typically, 25–30% solids, i.e. starch in water, form an optimal stable structure for fat replacement. New generation fat replacers are tailored to mimic more closely the many and complex properties of fats or oils in a particular application. These are referred to as fat mimetics. Maximising the synergies of functional ingredients such as hydrocolloids generally in combination with specific starch fat mimetics can mean that 100% fat reduction

Based on the particle gel characteristics of inulin, it can be concluded that inulin functions as a fat replacer but only in water-based systems. When concentrations exceed 15%, insulin has the ability to form a gel or cream, showing an excellent fat-like texture. This inulin gel is a perfect fat replacer offering various opportunities in a wide range of foods. Each inulin particle dispersed in the water phase of any food system will contribute to the creaminess of the finished food. Inulin is also destined to be used as a fat replacer in frozen desserts, as it processes easily to provide a fatty mouth-feel, excellent melting properties, as well as

Cellulose is the most abundant naturally occurring polysaccharide on earth. It is the major structural polysaccharide in the cell walls of higher plants. It is also the major component of cotton boll (100%), flax (80%), jute (60 to 70%), and wood (40 to 50%). Cellulose can be found in the cell walls of green algae and membranes of fungi. Acetobacter xylinum and related species can synthesize cellulose. Cellulose can also be obtained from many agricultural byproducts such as rye, barley, wheat, oat straw, corn stalks, and sugarcane. Cellulose is a high molecular weight polymer of (14)-linked -D-glucopyranose residues. The -(14) linkages give this polymer an extended ribbon-like conformation. The tertiary structure of cellulose, stabilized by numerous intermolecular H-bonds and van der Waals forces, produces three-dimensional fibrous crystalline bundles. Cellulose is highly insoluble and impermeable to water. Only physically and chemically modified cellulose finds applications

Microcrystalline cellulose (MCC) is purified cellulose, produced by converting fibrous cellulose to a redispersible gel or aggregate of crystalline cellulose using acid hydrolysis. Microcrystalline cellulose is prepared by treating natural cellulose with hydrochloric acid to partially dissolve and remove the less organized amorphous regions of this polysaccharide. The end product consists primarily of crystallite aggregates. MCC is available in powder form after drying the acid hydrolysates. Dispersible MCC is produced by mixing a hydrophilic carrier (e.g., guar or xanthan gum) with microcrystals obtained through wet mechanical disintegration of the crystallite aggregates (Cui, 2005). These colloidal dispersions are unique when compared to other soluble food hydrocolloids. They exhibit a variety of desirable characteristics including suspension of solids, heat stability, ice crystal control, emulsion stabilization, foam stability, texture modification and fat replacement

is achievable (Phillips & Willians, 2000).

freeze–thaw stability, without any unwanted off-flavor.

**3. Origins and structures of hydrocolloids** 

**3.1 Plant hydrocolloids** 

**3.1.1 Cellulose and derivatives** 

in various foodstuffs (Cui, 2005). **3.1.1.1 Microcrystalline cellulose** 

(Imeson, 2010).

carrageenan, cellulose and its derivatives, pectin, starch and its derivatives, among others. Since these hydrocolloids are hydrophilic, the coatings they produce have nature limited moisture barrier properties. However, if they are used in a gel form, they can retard moisture loss during short term storage when the gel acts as sacrificing agent rather than a barrier to moisture transmission. In addition, since in some cases an inverse relationship between water vapor and oxygen permeability has been observed, such films can provide effective protection against the oxidation of lipid and other susceptible food ingredient. The hydrocolloid edible films are classified into two categories taking into account the nature of their components: proteins, polysaccharides or alginates. Hydrocolloidal materials, i.e. proteins and polysaccharides, used extensively for the formation of edible films and coatings are presented in Table 1 (Hollingworth, 2010).


Table 1. Hydrocolloidal materials that have been studied extensively for the formation of edible films and coatings in foods.

#### **2.5 Hydrocolloids as fat replacers**

The changes in modern lifestyle, the growing awareness of the link between diet and health and new processing technologies have led to a rapid rise in the consumption of ready-made meals, novelty foods and the development of high fiber and low-fat food products. Caloriedense materials such as fats and oils may be replaced with 'structured water' to give healthy, reduced-calorie foods with excellent eating quality. In particular, numerous hydrocolloid products have been developed specifically for use as fat replacers in food. This has consequently led to an increased demand for hydrocolloids. As an example, the Italian dressing includes xanthan gum as a thickener and the 'Light' mayonnaise contains guar gum and xanthan gum as fat replacers to enhance viscosity.

carrageenan, cellulose and its derivatives, pectin, starch and its derivatives, among others. Since these hydrocolloids are hydrophilic, the coatings they produce have nature limited moisture barrier properties. However, if they are used in a gel form, they can retard moisture loss during short term storage when the gel acts as sacrificing agent rather than a barrier to moisture transmission. In addition, since in some cases an inverse relationship between water vapor and oxygen permeability has been observed, such films can provide effective protection against the oxidation of lipid and other susceptible food ingredient. The hydrocolloid edible films are classified into two categories taking into account the nature of their components: proteins, polysaccharides or alginates. Hydrocolloidal materials, i.e. proteins and polysaccharides, used extensively for the formation of edible films and

> Film forming material Principal function Agar Gelling agent Alginate Gelling agent Carrageenan Gelling agent

Chitosan Gelling agent

Pectin Gelling agent

Bovine gelatin Fish gelatin Pig gelatin

gum and xanthan gum as fat replacers to enhance viscosity.

Starches Thickener and gelling agent

Table 1. Hydrocolloidal materials that have been studied extensively for the formation of

The changes in modern lifestyle, the growing awareness of the link between diet and health and new processing technologies have led to a rapid rise in the consumption of ready-made meals, novelty foods and the development of high fiber and low-fat food products. Caloriedense materials such as fats and oils may be replaced with 'structured water' to give healthy, reduced-calorie foods with excellent eating quality. In particular, numerous hydrocolloid products have been developed specifically for use as fat replacers in food. This has consequently led to an increased demand for hydrocolloids. As an example, the Italian dressing includes xanthan gum as a thickener and the 'Light' mayonnaise contains guar

Arabic gum Guar gum Xanthan gum Thickener

Thickener

Emulsifier Thickener Thickener

Antimicrobials

Gelling agent Gelling agent Gelling agent

Thickener and emulsifier

Thickener, emulsifier and gelling agent

coatings are presented in Table 1 (Hollingworth, 2010).

CMC HPC HPMC MC

Polysaccharide

protein

Cellulose derivatives

Gum

Gelatin

edible films and coatings in foods.

**2.5 Hydrocolloids as fat replacers** 

The traditional approach is the partial replacement of fat using starches which, when dissolved in water, create stable thermo-reversible gels. Soft, fat-like gels can be created by conversion modifications to the degree necessary to produce thermo-reversible, spreadable gels. Typically, 25–30% solids, i.e. starch in water, form an optimal stable structure for fat replacement. New generation fat replacers are tailored to mimic more closely the many and complex properties of fats or oils in a particular application. These are referred to as fat mimetics. Maximising the synergies of functional ingredients such as hydrocolloids generally in combination with specific starch fat mimetics can mean that 100% fat reduction is achievable (Phillips & Willians, 2000).

Based on the particle gel characteristics of inulin, it can be concluded that inulin functions as a fat replacer but only in water-based systems. When concentrations exceed 15%, insulin has the ability to form a gel or cream, showing an excellent fat-like texture. This inulin gel is a perfect fat replacer offering various opportunities in a wide range of foods. Each inulin particle dispersed in the water phase of any food system will contribute to the creaminess of the finished food. Inulin is also destined to be used as a fat replacer in frozen desserts, as it processes easily to provide a fatty mouth-feel, excellent melting properties, as well as freeze–thaw stability, without any unwanted off-flavor.
