Present sources of raw material 



Each of the many industrial applications may require proteins of 

 different composition and with specific characteristics. Protein hy- 

 drolysates have been successfully prepared from such widely divergent 

 materials as yeast, blood fibrin, casein and lactalbumin from milk, and 

 residue from tuna and mackerel cannei*y operations. Most infant and 

 special dietary foods use milk proteins as the basic part of their formulae. 

 Proteins from several sources have been used as the raw material for the 

 preparation of amino acids. For example, glutamic acid, and its salt, 

 mono-sodium glutamate, the form in which it is widely used as a food 

 flavoring, can be prepared from the gluten of wheat and is also being pro- 

 duced on a large scale frx)m "oteffens waste" which is recovered as a by- 

 product during the refining of beet sugar. 



Methods of manufacture 



Some proteins must be highly purified before they can be used for 

 certain industrial applications, while other processes do not require such 

 purity or specificity and can utilize the protein in its natural form 

 without separation from such impurities as carbohydrates, fats, lipids, 

 and mineral salts. The two most important proteins in milk, casein and 

 lactalbumin, are prepared in various degrees of purity depending upon the 

 use for which they are intended. The protein is precipitated chemically 

 and further purified by removal of fat and ash. Specifications for semi- 

 purified proteins require a nitrogen content above 12.0 percent; fat, 4.0 

 percent maximum; and ash, 3.5 percent or less. Moisture should be held be- 

 low 5.0 percent. Proteins intended for the subsequent manufacture of 

 protein hydrolysates should be as free as possible from carbohydrate sub- 

 stances since these latter are converted to "humin", which in undue amounts 

 is undesirable and also causes greater difficulty in preparing the finished 

 product . 



Economics of manufacture 



Purified and semi-purified animal proteins are at present in great 

 demand and command a good market price. For example, the milk proteins 

 are being quoted at the price of 55 cents a pound for casein (purified — 

 for food use) and 72 cents a pound for lactalbumin. Although production 

 of these two proteins is very large, it could be increased by installation 

 of additional processing equipment because large quantities of skim milk 

 and whey are not being fully utilized. Egg albumin is also produced in 

 large quantity and its market price has at times gone above 5f2.00 a pound. 



When casein and lactalbumin are used directly in preparing infant 

 and special dietary foods, the cost of the basic ingredients is a very 

 important item in determining the price of the finished product. How- 

 ever, when extensive chemical testing, biological evaluation and clinical 

 investigation are required before final marketing of a product such as a 

 protein hydrolysate, then the cost of the basic ingredients do not repre- 

 sent a major item in the selling price. It can, therefore, be readily 

 seen that in attempting to enter any given market with a competitive pro- 

 tein product, the cost of the raw or basic material is not the only factor 

 to be condidered. 



