Casein composition

Barry, J. G. and Donnelly, W. J. 1980. Casein compositional studies. 1. The composition of casein from Friesian herd milk. J. Dairy Res. 47, 71-82. 

Average Casein Composition in Bulk Milk Samples ... 

Britten, M., Giroux, H.J., and Rodrigue N. (1991). Emulsifying properties of whey protein and casein composite blends. IDF Special Issue 9303,368 374. 

W. S. Murray, Moldable Casein Composition, Patent Number 2115316, 1938. 

Casein. Milk contains proteins and essential amino acids lacking in many other foods. Casein is the principal protein in the skimmed milk (nonfat) portion of milk (3—4% of the weight). After it is removed from the Hquid portion of milk, whey remains. Whey can be denatured by heat treatment of 85°C for 15 minutes. Various protein fractions are identified as a-, P-, and y-casein, and 5-lactoglobulin and blood—semm albumin, each having specific characteristics for various uses. Table 21 gives the concentration and composition of milk proteins. 

Milk. Imitation milks fall into three broad categories filled products based on skim milk, buttermilk, whey, or combinations of these synthetic milks based on soybean products and toned milk based on the combination of soy or groundnut (peanut) protein with animal milk. Few caseinate-based products have been marketed (1,22,23). Milk is the one area where nutrition is of primary concern, especially in the diets of the young. Substitute milks are being made for human and animal markets. In the latter area, the emphasis is for products to serve as milk replacers for calves. The composition of milk and filled-milk products based on skim milk can be found in Table 10. Table 15 gives the composition of a whey /huttermilk-solids-hased calf-milk replacer, which contains carboxymethyl cellulose (CMC) for proper viscosity of the product. 

Seven diets were constructed from purified natural ingredients obtained from either C3 (beet sugar, rice starch, cottonseed oil, wood cellulose, Australian Cohuna brand casein, soy protein or wheat gluten for protein) or C4 foodwebs (cane sugar, corn starch, com oil, processed corn bran for fiber, Kenya casein for protein) supplemented with appropriate amounts of vitamins and minerals (Ambrose and Norr 1993 Table 3a). The amino acid compositions of wheat gluten and soy protein differ significantly from that of casein (Ambrose and Norr 1993). 

Colorant containing annatto and Ca caseinate as carrier mixed with water to be added directly to cheese milk yielding uniform colored cheese mass Water-dispersible beadlet of p-carotene is mixed with oil to attein composition that remains stable even in presence of polyphosphates and with antioxidant action even in absence of ascorbic acid Blending carotenoid pigment and soybean fiber (wifii tomato juice) as effective ingredient for dispersion stability... 

Four reconstituted milks were prepared by blending hydrated skim milk powder (35g/L) with four different emulsions (35g/L) differing by composition of the fat-water interface. Whole reconstituted milks were coded MP (milk proteins), BCAS ( 6-casein), and BLG5 (j6-lactoglobulin 5 g/L). 

The precipitation of casein in its uncombincd form by the addition to milk of one or another acid, forms the basis of all methods of preparation. These differ widely, however, in the subsequent purification. In the method of Hammarsten,4 just enough alkali is added to dissolve this casein completely. The alkalinity reached in this process somewhat modifies its physical properties but probably not its composition. In the method of Van Slyke and Bosworth 5 the last trace of calcium is removed by adding oxalate to an ammoniacal solution of the casein, but... 

But we must appreciate how the phosphate group acts much like the anion from a weak acid (see Chapter 6), so its exact composition will depend on the pH of solution. The pH of cow s or human milk is about 7 (see Table 6.4). If the pH decreases much below about 6 (e.g. by adding an acid in the form of orange juice), the phosphates become protonated. The emulsifying properties of casein cease as soon as its structure changes, causing the milk to separate. 

All of the studies were conducted with weanling, male albino rats of the Sprague-Dawley strain (Holtzman company). The basal diet used for these studies consisted of casein, starch, vegetable oil, vitamin and mineral mixtures, and cellulose. The Wesson Modification of the Osborne-Mendel mineral mixture was used in all studies. This mineral mixture contained no zinc, but it was adequate in the other minerals required by the rat. Most of the non-zinc-supplemented diets used in the various experiments contained approximately 7 ppm zinc. The level of mineral mixture used in the basal diets was 4%, and based on the chemical composition of the mixture, the basal diets contained approximately 0.57% calcium and 0.41% phosphorus ... 

The protein efficiency ratio (PER) of field pea flours is considerably less than that of casein (1.46 vs. 2.50), and somewhat less than that of soy flour (1.81). However, composites of wheat flour and pea or rice and pea (50% of the protein from each source) had PER s of 2 or more (22). Thus, supplementation of cereals with pea flour results in improvement of protein quality. 

Example number 1. Medium for fermentation. The goal of this experiment was to develop a defined fermention medium that was usable for the manufacture of ImuVert The objectives were to evaluate the effect of replacing citrate with a phosphate buffer, yeast extract with vitamins and minerals, casamino acids with casein peptone and high or low O2 levels on the final yield and composition of ImuVert. 

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