Fractionation of Whey by Membrane Operations
Reference work entry
Whey is a coproduct of cheese-making and casein manufacture in the dairy industry; it is the liquid drained from the curd obtained after addition of rennet (chymosin) or mineral/organic, or the permeate obtained during skimmed milk microfiltration (MF) in view of casein concentration. Whey contains many classes of different-size components (salts, lactose, soluble proteins (mainly β-lactoglobulin and α-lactalbumin), residual casein, microorganisms, etc. (see Table 1)), but its composition depends on the cheese-making process. The addition of enzyme or rennet milk leads to sweet whey (pH 6.2–6.4), whereas acid whey (pH 4.6–5) is obtained after acidic coagulation of milk. Considered as waste for years, whey is now widely used as food ingredients in many goods and infant and dietetic foods. Owing to chromatographic, electrodialytic, and membrane techniques which permit whey fractionation, it is possible to prepare valuable proteins and peptides with high nutritional qualities (high...
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