Effect of Enzyme Type and Hydrolysis Time on Antioxidant Properties of Hydrolyzed Turkmen Melon Seed Protein

Enzymatic hydrolysis of protein sources is a common method in food processing. Hydrolyzed protein is a mixture of peptides and amino acids that have many health properties including anti-hypertensive, anti-cholesterol and antioxidant. Turkmen melon seed is one of the fruit by-product which can be a cost-effective source for the production of bioactive peptides. In this study, enzymatic hydrolysis of Turkmen melon seed protein with pancreatin and trypsin enzymes in enzyme to substrate ratio of 1% and time intervals of 20-200 minutes was performed. The degree of hydrolysis and antioxidant properties (DPPH radical scavenging activity, Fe3+ reducing power, total antioxidant activity and hydroxyl radical scavenging activity) of the obtained hydrolysates were investigated. The results showed that with increasing the hydrolysis time up to 180 minutes, the degree of hydrolysis increased significantly and after that no significant differences was observed in this factor. The maximum DPPH scavenging activity, Fe3+ reducing power and hydroxyl radical scavenging activity were obtained by hydrolysis with pancreatin enzyme and after 180 minutes of hydrolysis and were 72.49%, 0.55 (adsorption at 700 nm) and 59%, respectively. The maximum total antioxidant activity of pancreatin and trypsin hydrolysates was obtained after hydrolysis at 180 minutes and there was no significant difference between them. According to the results, compared to trypsin, pancreatin enzyme showed a better performance in the production of protein hydrolysate with maximum antioxidant properties. As a result, the resulting hydrolysates, can be used in food formulation as a natural preservative and the production of functional products.