Optimizing the production of hydrolyzed protein with antioxidant properties from Tarem rice bran by alcalase enzyme

Peptides obtained from protein hydrolysis have many bioactive properties and have strong antioxidant activity against free radicals and prevent oxidation processes that cause damage to biological macromolecules and degradation and loss of food quality. Due to the large amount of rice production in the world, a large amount of rice bran is produced and available. As a suitable and cheap protein source, rice bran can be used for the production of plant-derived peptides. Optimizing conditions of enzymatic hydrolysis of rice bran protein by alcalase enzyme was done with the aim of achieving maximum antioxidant properties. In order to check the antioxidant activity of the obtained peptides, iron 3 reduction power tests and DPPH free radical inhibitory activity and total antioxidant activity were used. In order to optimize the process, Design Expert software and response surface method were used with three independent variables: enzyme concentration to substrate 1-3%, temperature 40-55 degrees Celsius and hydrolysis time 30-210 minutes. The optimal treatment was obtained under the determined conditions including temperature of 51.5 degrees Celsius, time of 131.5 minutes and concentration of enzyme to substrate of 3%, which has maximum DPPH free radical inhibition of 37.172%, total antioxidant activity of 1.109% and reductiveness of 2.084%. The obtained results showed that the hydrolysis process of rice bran protein by alkalase enzyme has led to the production of peptides with high and significant antioxidant properties that can be used in the production of useful foods and pharmaceutical industries and can also replace synthetic antioxidants.