Protein Hydrolysate from Brewer’s Spent Grain and its Inhibitory Ability of α-Glucosidase

Brewer’s spent grain (BSG) rich in proteins is the main by-products in brewery. BSC proteins were extracted and hydrolyzed by Alcalase. The effects of hydrolysis time, temperature, pH and amount of enzyme added on the peptide yield were investigated. Inhibition of BSG protein hydrolysate against α-glucosidase was evaluated in vitro. BSG protein hydrolysate at 4.0 mg/mL showed the inhibition of 21.42% against α-glucosidase. The BSG protein hydrolysate after ultrafiltration purification exhibited much higher inhibition than that without ultrafiltration purification. The inhibition of BSC protein hydrolysate fraction with molecular weight fraction less than 5 kDa was 56.41%.