Preparation of chickpea peptide-calcium chelates with antioxidant activity

Chelation of antioxidant chickpea peptides with calcium can improve the absorption rate of calcium in human intestinal tract. In the present work, the optimum enzymatic hydrolysis scheme was determined by a single-factor test with an orthogonal experimental design with the following conditions: material-liquid ratio, 1:15; enzymatic hydrolysis time, 10 min; enzyme-substrate ratio, 1:20 (papain protease); and enzymatic hydrolysis temperature, 60°C. The protein hydrolysate obtained under these conditions had high antioxidant activity. The free radical scavenging rates of •OH, O2-•, DPPH•, and H2O2 were 49.44, 63.64, 66.57, and 57.64%, respectively. The reducing power was 0.75. The optimum conditions for the preparation of calcium chelate from chickpea peptides were determined by an orthogonal optimisation test: the peptide-calcium ratio, 7:1; the chelation temperature, 50°C; the initial pH of the reaction solution, 7.0; the chelation time, 40 min; and the chelation rate, 39.95%. Antioxidant chickpea peptide-calcium chelates could have the potential to induce synergistic physiological effects.