Preparation and analysis of hydrolysates from whey protein concentrate using the proteases from Bacillus licheniformis and Aspergillus oryzae

The action of proteases from Bacillus licheniformis and Aspergillus oryzae was studied with the aim of preparing hydrolysates from whey protein concentrate with nutritionally appropriate peptide profile. Various enzyme/substrate ratios were used, and the peptides were fractionated by size-exclusion HPLC followed by their quantification using the rapid method of correct fraction area (CFA). The protease from B. licheniformis (E:S of 8:100) produced the best peptide with a much lower amount of large peptides (44.61%), greater of di- and tripeptides (8.79%) and higher sum of the di- and tripeptides with free amino acids (9.99%) than the other hydrolysates. The advantage of using a lower E:S ratio to obtain a nutritionally adequate peptide profile was observed for the protease of A. oryzae when it passed from 3:100 to 2:100.