Abstract
Casein phosphopeptides were prepared from 12% trichloroacetic acid-soluble fractions of raw and different kinds of pasteurized cow's milks digested with porcine trypsin by ethanol precipitation. The yield of casein phosphopeptide preparation reduced by approximately 25% at maximum when cow's milk had been pasteurized at higher than 80℃. However, the elution profile of all casein phosphopeptide preparations from the pasteurized milks was very similar to that of casein phosphopeptide preparation from raw milk, and sequences 59–79 of αs1-casein, 1-32 of αs2-casein and 1-25 of β-casein were identified as major peptides in the casein phosphopeptide preparations. Moreover, all CPP preparations from the pasteurized milks had mitogenic effects on mouse spleen cells and enhanced proliferative responses of mouse spleen cells stimulated by lipopolysaccharide and concanavalin A.
