Enzymatic hydrolysis of whey protein concentrate: effect of enzyme type and enzyme:substrate ratio on peptide profile

Enzymatic hydrolysis of whey protein concentrate was used to prepare hydrolysates with appropriate peptide profiles for use in the development of dietary supplements. Effects of the type of enzyme (pancreatin and proteases from Bacillus licheniformis, Aspergillus oryzae and Aspergillus sojae) and enzyme:substrate ratio (0.5:100, 1:100, 2:100, 3:100, 4:100 and 8:100) were evaluated. Twenty-four hydrolysates were prepared, and their peptide profiles were characterized by chain length using size exclusion liquid chromatography fractionation, followed by a rapid Correct Fraction Area method for quantifying the peptide and amino acid contents. The use of a protease from Bacillus licheniformis (E:S 8:100) and a pancreatin (E:S 2:100, 3:100, 4:100 and 8:100) yielded preparations of hydrolysates with the highest sums of di- and tripeptide and free amino acid contents (9.99 and 11.28 % for the protease from Bacillus licheniformis and pancreatin, respectively) as well as the lowest amount of large peptides (44.61 and 44.13 %, respectively).