Proteinase activities for Alcalases 2.4L (EC 3.4.21.62), Flavourzymes (EC 3.4.11.1), Protease A (EC 3.4.24.39) and Protease N (IUB 3.4.24.28) were determined using 2% whey protein isolate (WPI) and 2% casein. The optimum substrate and enzyme concentrations and temperature were determined by the pH-stat method. Residual enzyme activity, hydrolysate molecular weight and free amino acid (FAA) content were determined. ProteaseNand Alcalases 2.4L had the highest proteinase activities on casein and WPI, respectively. Alcalases 2.4L was more stable in the presence of WPI while Protease N was inhibited by hydrolysates, and like Protease A which released high FAAs, they produced shorter peptides. Flavourzymes hydrolysed WPI poorly and released the highest FAAs. Short peptides were removed by 5% trichloroacetic acid (TCA) and 3.5% 5-sulphosalicylic acid before FAA analysis by reversed phase high-performance liquid chromatography (RP-HPLC) of Flavourzymes and Protease A hydrolysates, but were detected in Alcalases 2.4L and Protease N hydrolysates. The enzyme activities for WPI hydrolysis in an enzymatic membrane reactor were FlavourzymesoProtease AoAlcalases 2.4LpProtease N.     «

Proteinase activities for Alcalases 2.4L (EC 3.4.21.62), Flavourzymes (EC 3.4.11.1), Protease A (EC 3.4.24.39) and Protease N (IUB 3.4.24.28) were determined using 2% whey protein isolate (WPI) and 2% casein. The optimum substrate and enzyme concentrations and temperature were determined by the pH-stat method. Residual enzyme activity, hydrolysate molecular weight and free amino acid (FAA) content were determined. ProteaseNand Alcalases 2.4L had the highest proteinase activities on casein and WP...     »