Whey protein hydrolysis with free and immobilized Alcalase®: effects of operating parameters on the modulation of peptide profiles obtained

Abstract

In this work, the effects of operating parameters on the modulation of peptide profiles obtained during enzymatic hydrolysis of whey protein concentrates (WPC) with a commercial enzyme (Alcalase 2.4L AF) were analyzed. Hydrolyzates of WPC were obtained working with free and immobilized enzyme and evaluating different operating conditions (initial substrate concentrations, time, temperature and pH). Characteristics of hydrolyzates obtained were evaluated by the hydrolysis degree obtained (DH) and the peptide profile by RP-HPLC. Moreover, a quantitative descriptive sensory analysis was performed to compare different preparations of commercial desserts prepared using as ingredients milk, WPC and WPC hydrolyzates. The DH values increased very quickly during the first 10 min. followed by a slow increase up to 25 min. For the range of conditions tested, we proposed to operate at temperatures close to 50˚C, pH between 8 and 9 and initial substrate concentration from 7% as good reactions conditions. Finally, whey protein hydrolyzates obtained with Alcalase showed very interesting sensorial characteristics to be incorporated in desserts commercial preparations.