Casein desirable properties

Casein is used to improve the desired properties of such diverse products as high protein chocolate [77], synthetic caviar [78], imitation cheese [79], macaroni [80], yoghurt [81], effervescent lemonade powders [82], ice cream, instant puddings and desserts [82] and simulated meat [83]. 

Reclaimed mbber, which is widely used in dry mbber, has Htde use in latex compounding. A dispersion or artificial latex of the red aim must be made by a rather expensive process of milling in dispersing agents, eg, soaps and casein, and water. Some reclaim dispersions are used in latex compounds for such things as spread mbber goods and adhesives and fiber binders to reduce cost. However, for most latex compounds, it is not desirable because of the poor physical properties it imparts and the resultant darkening of the compound. 

Casein may be coagulated and recovered as rennet casein by treatment of milk with selected proteinases (rennets). However, one of the caseins, K-casein, is hydrolysed during renneting and therefore the properties of rennet casein differ fundamentally from those of acid casein. Rennet casein, which contains the colloidal calcium phosphate of milk, is insoluble in water at pH 7 but can be dissolved by adding calcium sequestering agents, usually citrates or polyphosphates. It has desirable functional properties for certain food applications, e.g. in the production of cheese analogues. 

Homogenization of cream results inevitably in the formation of a secondary fat globule membrane, consisting predominantly of micellar casein and (denatured) whey proteins (Walstra et al., 1999). To obtain desirable product properties, the formation of larger, thermally induced... 

In general, high protein content and solubility are desirable casein properties. Fat, lactose, moisture, ash, bacteria, and odor are expected to be low. Light-colored material is also preferred. The viscosity and particle size sought depend on the compounding practices and intended use of the adhesive. 

Changes in the Body and Texture of Cheese as a Result of Aging. Alterations in the physical (functional) properties of the caseins occur during the development of the desirable smooth texture of cheese from the rubbery, elastic curd as a result of aging. The development of desirable textural characteristics of aged cheese is the result of very complex biochemical processes which are incompletely understood at this time. 

Soy proteins are accepted in many applications because they provide desirable functionalities (performance properties) in fabricated foods at less cost than animal-source alternatives such as dried milk solids, casein, egg yolks, egg whites, or gelatin. Mimicking more expensive animal proteins has long been an objective of processing soy proteins. Reviews on soy protein functionality, modifications, and applications were prepared by Kinsella (1979), Kinsella and coworkers (Kinsella Soucie, 1989 BCin-sella et al., 1985), Cherry (1981), Rhee (1989), and Lusas Rhee (1986). 

With a typical size ranging from nanometric (<100 nm) to submicrometric (<1 pm), biopolymeric particles and nanoparticles, made of proteins or polysaccharides, thanks to their excellent compatibility with foods, are able to efficiently encapsulate, protect and deliver bioactive compounds, forming different structures, such as random coils, sheets, or rods around the bioactive molecules. The most suitable biopolymers for the incorporation into foods include (1) proteins, such as whey proteins, casein, gelatin, soy protein, zein, and (2) polysaccharides, such as starch, cellulose, and other hydrocolloids, with the particle formulation depending on the desired particle functionality (size, morphology, charge, permeability, environmental stability), on end product compatibility and in general in product behavior, as well as on release properties and in body behavior. 

Casein plastics can be fabricated in the same manner as cast plastics. The hardening operation, which is considered to be a condensation reaction between the aldehyde and the amino group of the casein molecule, transforms the material from a thermoplastic to a thermosetting condition. Casein plastics are nonflammable and extremely tough. These properties along with its availability in all colors have given casein its widest use in the manufacture of buttons, buckles, etc. The usefulness of the material is somewhat limited by its odor, but more importantly by its absorption of water (7-14% after 24-h water immersion). Because of this hygroscopic nature, casein plastics are not suitable where dimensional stability is desired. Casein plastics are not widely nsed today. 

The BT/KPVS complex is not soluble over a wide range of pH It also exhibits considerable enzymatic activities towards BAN A and casein (Figs. 18.9 and 18.11). Thus, the complex can be expected to function as an immobilized enzyme. However, several difficulties arise in handling the complexed enzyme, because it is in the form of an amorphous precipitate. It seems desirable to modify its morphological properties through an appropriate method such as gel entrapment. 

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