Optimization of Enzymatic Hydrolysis of Peanut Protein and Molecular Weight Distribution of Hydrolysates

Peanut polypeptides were prepared from peanut protein by enzymatic hydrolysis. The effects of five factors such as enzyme kind, protease dose, hydrolysis time, hydrolysis temperature and pH value on degree of hydrolysis (DH) of peanut protein were investigated as well as the molecular weight distribution of hydrolysates. Quadratic regression rotational combina- tion design was employed to optimize three key factors influencing hydrolysis of peanut protein. Results indicated that the optimum ranges for hydrolysis temperature, pH value and hydrolysis time were 44.9 to 47.6 ℃, 7.93 to 8.15 and 2.46 to 2.76 h, respectively. These optimized conditions resulted in the high DH of 19.61%. The peptides with molecular weight of below 1000 D accounted for over 84.73% of the obtained hydrolysates.