Antioxidant Properties of Fenugreek Bioactive Peptides Prepared with Pancreatin Enzyme

In this research, the optimization of protein hydrolysis process with the pancreatin enzyme was performed to evaluate the effect of time (30-270 min), temperature (20-60°C) and enzyme concentration (0.25-3.25%) on DPPH radical scavenging activity and Fe2+ chelating activity by using the response surface methodology. Optimum conditions to achieve the highest DPPH radical scavenging activity (42.77%) and Fe2+ chelating activity (78.57%), were obtained at time of 141.1 min, temperature of 41.93 °C and enzyme concentrations of 2.14%. Under these conditions, the degree of hydrolysis was 36.8 ± 0.35. Comparing the antioxidant power of the hydrolyzed protein and the intact protein showed that the hydrolysis increased the antioxidant activity of the fenugreek protein, significantly. Then, the antioxidant properties of optimum treatment were investigated at concentrations of 10-50 (mg/ml). The highest DPPH radical scavenging activity (50.65%) and total antioxidant capacity (absorbance 1.65 at wavelength of 695 nm), hydroxyl radical scavenging activity (69.03%) and Fe2+ chelating activity (79.72%) were achieved at concentration of 50 (mg/ml) and reducing power (absorption 0.8 at wavelength of 700 nm) were achieved at concentration of 40 (mg/ml). The results showed that the hydrolysis of fenugreek protein with the pancreatin enzyme is an effective way to produce antioxidant peptides. So, the bioactive peptides, with significant antioxidant properties, can be used as potential substitute of synthetic antioxidants and as a protein supplement in food formulation to produce functional products with health promotion properties.