Abstract:In order to study the antioxidative stability of wheat peptide in the processing of manufacturing and gastrointestinal digestion, effects of temperature, pH value, food raw materials and adjuncts, metal ions and simulated gastrointestinal digestion on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, superoxide radical anion (O-2·) scavenging activity and hydroxyl radical (·OH) scavenging activity of wheat peptide were determined. The results showed that antioxidant activity of wheat peptide exhibited better thermal stability, while its antioxidant activity was significantly declined under the alkaline condition;NaCl, glucose and citric acid were beneficial to improve the antioxidant activity of wheat peptide and the synergistic effects were increased obviously with higher concentrations, while sucrose, potassium sorbate and sodium benzoate had little effect on antioxidant activity of wheat peptide;K+, Ca2+ and Mg2+ had no obvious effect on antioxidant activity of wheat peptide, while Zn2+ and Cu2+ could play certain enhancement role in the antioxidant activity of wheat peptide;artificial gastric juice digesting solely was helpful to improve antioxidant activity of wheat peptide, while artificial intestinal juice digesting solely resulted in the obvious decline of antioxidant activity of wheat peptide, moreover, artificial gastric juice and artificial intestinal juice digesting step by step caused certain decline of antioxidant activity of wheat peptide. However, wheat peptide could still maintain high antioxidant activity. It indicated that antioxidant activity of wheat peptide was affected by the manufacturing and gastrointestinal digestion of wheat peptide. Therefore, reasonable optimized processing conditions were critical for maintenance of the antioxidative stability of wheat peptide.
