摘要: Casein, the principal protein in cow’s milk, has been extracted commercially for most of twentieth century. The casein content whole milk varies according to breed cow, stage lactation and time milking, but is generally range 24–29 gl-1 (Jenness Patton, 1959a; Fox, 1989). skim-milk produced from separation a 40 per cent fat cream (the first manufacture casein) consequently contains 25–31 1959b; McDowall, 1971), which accounts 75-80 nitrogen (Dolby et al., 1969; Gordon Kalan, 1974; With 0.7-0.9 phosphorus, covalently bound by serine ester linkage, as phosphoprotein member relatively rare class proteins (Gordon 1974). amino-acid well established includes high proportions all amino-acids essential man 1974) with possible exception cysteine.