Abstract:The optimal protease for preparing bitter almond kernel gliadin-based α-glycosidase inhibitory hydrolysates (AGIH) was determined according to the inhibition rate and degree of hydrolysis. Based on the α-glycosidase inhibition rate, optimal process parameters for AGIH preparation, including the substrate concentration required, amounts of enzymes added, pH, temperature, and duration, were examined in single-factor and response surface experiments. The physical stability (against pH and temperature) and gastrointestinal stability of the resulting AGIH were characterized. Papain was found to be the optimal protease; the optimal conditions were as follows: substrate concentration of 4.0% (m/V), enzyme addition of 6000 U/g, initial pH of 7.0, hydrolysis temperature of 55 ℃, and reaction time of 6 h. AGIH prepared under these conditions showed an α-glucosidase inhibition rate of 18.10% and IC50 value of 17.66 mg/mL, and was stable under relatively high temperature, extreme pH, and gastrointestinal digestion conditions. This study provides a foundation for developing bitter almond kernel gliadin-based bioactive hydrolysates.
