Preparation and Antioxidant Activity Analysis of Hydrolyzed Peptides from Eucommia ulmoides Seed Meal

Eucommia ulmoides seed meal protein prepared by alkali extraction and acid precipitation was utilized as raw material. On the basis of single factor experiment, the total evaluation value of the hydrolysis degree and total antioxidant capacity (T-AOC) as response value was used to optimize the addition of enzyme, hydrolysis time and substrate concentration. And the Box-Behnken method was used for three factors and three levels response surface test design to determine the best enzymatic preparation process of hydrolyzed peptides from Eucommia ulmoides seed meal. The antioxidant activity of the obtained hydrolyzed peptides was determined in vitro. The results showed that neutral protease was the best protease, and the best enzymatic hydrolysis condition were enzyme was 10000 U/g, hydrolysis time 1.50 h and substrate concentration 20 g/L. Under these conditions, the degree of hydrolysis and T-AOC of hydrolyzed peptides were 47.45%±1.50% and 30.62±0.59 μmol/g, separately; the IC50 for DPPH free radical, superoxide anion radical and ABTS free radical scavenging rates were 0.731, 4.258 and 0.407 mg/mL, respectively. The Eucommia ulmoides seed meal peptides prepared under these conditions had great antioxidant capacity and provided a theoretical basis for the high-value utilization of Eucommia ulmoides seed meal and the development of antioxidant peptide functional products.