SKIMMILK SOLIDS AS SUBSTRATE FOR THE PREPARATION OF CASEIN ENZYMATIC HYDROLYSATES

The time-course hydrolysis curves of low-heat (LH) and high-heat (HH) skimmilk powders (SMP) by trypsin or chymotrypsin were compared to tha t of sodium caseinate (SC). Rates of hydrolysis, shown to be different (P < 0.05), were SC > LH-SMP > HH-SMP. A two-step ultrafiltration pro cess was applied to hydrolyzed LH-SMP and to hydrolyzed SC, and result s were compared. Protein and lactose composition differences between L H-SMP and SC were accentuated by ultrafiltration. The hydrolysis profi le (molecular weight distribution of peptides, amino acid content) of LH-SMP tryptic hydrolysate showed a greater proportion of shea peptide s (<2000 Daltons) and a lower content in GLU, PRO, VAL and TYR, compar ed to that of SC.