The effect of ultrasound pretreatment on the antioxidant properties of hydrolyzed protein from flaxseed meal using alcalase and pancreatin enzymes by response surface methodology

In recent years, researchers have identified and extracted bioactive peptides with acceptable antioxidant properties from different protein sources. Flaxseed meal, which is the main by-product of the linseed oil extraction process, contains a large amount of protein, which can be obtained by enzymatic hydrolysis to peptides with antioxidant properties. In this research, the effect of hydrolysis conditions (enzyme concentration 2.7-1% and time 30-183.64 minutes), type of protease (pancreatin and alcalase) and ultrasound pretreatment on the degree of hydrolysis and antioxidant properties (DPPH free radical inhibition, Total antioxidant activity, and iron ion chelation) of hydrolyzed protein obtained from flaxseed meal were evaluated using the response surface method. The optimal conditions for the production of hydrolyzed protein with the most antioxidant properties with alcalase enzyme with and without pretreatment and pancreatin enzyme with and without pretreatment, respectively, were hydrolysis time 79, 146.79, 111.77 and 97.21 minutes and enzyme concentration 2.29%, 1.46%, 2.26% and 1.38%; According to the obtained results, by examining the degree of hydrolysis and antioxidant properties of the hydrolyzed proteins of flaxseed meal, hydrolyzed protein with pancreatin enzyme was suggested as the optimal treatment. Hydrolyzed protein with pancreatin enzyme with ultrasound pretreatment was reported to have 75.66% DPPH free radical inhibition, 70.39% iron ion chelating activity, total antioxidant activity with absorbance of 0.86 nm and 80.69% hydrolysis degree. Therefore, it can be stated that the hydrolyzed protein of flax seed meal with strong antioxidant capacity is a bioactive compound for use in food formulations and the production of beneficial products.