This study examined the production of protein hydrolysates with controlled
composition from cheese whey proteins. Cheese whey was characterized and se
veral hydrolysis experiments were made using whey proteins and purified bet
a -lactoglobulin, as substrates, and trypsin and a-chymotrypsin, as catalys
ts, at two temperatures and several enzyme concentrations. Maximum degrees
of hydrolysis obtained experimentally were compared to the theoretical valu
es and peptide compositions were calculated. For trypsin, 100% of yield was
achieved; for alpha -chymotrypsin, hydrolysis seemed to be dependent on th
e oligopeptide size. The results showed that the two proteases could hydrol
yze beta -lactoglobulin. Trypsin and alpha -chymotrypsin were stable at 40
degreesC, but a sharp decrease in the protease activity was observed at 55
degreesC.