Determination of Optimum Conditions for the Production of Peptides with Antioxidant and Nitric-Oxide Inhibition Properties from Protein Hydrolysis of Pumpkin Seed Meals Using Pepsin Enzyme

In this study, hydrolysis condition optimization of the pumpkin (Cucurbita pepo) seed proteins was carried out achieve maximum DPPH radical scavenging and nitric-oxide inhibition properties using Design Expert Software and response surface methodology.

In general, 1–3% concentrations of pepsin enzyme, 30–40 °C temperature and 120–100 min time were selected as the independent variables.

Results showed that the optimum conditions for achieving maximum DPPH radical scavenging and nitric-oxide inhibition activities included temperature of 32 °C, time of 161.5 min and an enzyme-substrate ratio of 3% with antioxidant and nitric-oxide inhibitory activities of 54.63 and 89.09%, respectively. These results were largely similar to the results suggested by the software (56.03 and 91.92%, respectively).

Based on the results, hydrolyzed proteins of the pumpkin seeds include good antioxidant and nitric-oxide inhibitory activities and can therefore be used as natural compounds for replacing synthetic preservatives in food products.