Optimization of production of hydrolyzed protein with antioxidant properties from edible mushroom (Agaricus bisporus)

Free radicals and hydroperoxides originate from oxidation reactions could reduce food quality and also promote incidence of various diseases such as cancer. In this regard, the use of natural compounds with antioxidant properties, such as bioactive peptides, is of interest to many researchers. Demand for natural and safe antioxidants such as bioactive peptides has increased dramatically due to concerns about the safety and long-term health implications of synthetic antioxidants such as BHT and BHA. Bioactive peptides are defined as hydrolyzed proteins that, after entering the body, show potential ability to stimulate desirable and health promoting activities.

The aim of this study was to optimize the hydrolysis conditions of edible mushroom (Agaricus bisporus) powder protein with alcalase enzyme in order to produce hydrolyzed protein with potential antioxidant properties. To conduct this research, first, edible mushrooms were turned into powder after purchase from the market and conducting related processes. Then, in order to optimize the production of hydrolyzed proteins with maximum antioxidant activity using response surface methodology, the independent variables selected as time, temperature and ratio of enzyme to substrate and dependent variables was selected as the antioxidant capacity of the hydrolyzed sample (using DPPH free radical scavenging methods, iron ion reduction power and total antioxidant capacity). The temperatures used were in the range of 40-55 °C, the hydrolysis time between 30 to 210 minutes and the enzyme to substrate ratio 1 to 3%, which was optimized by the surface response methodology. In this research, Design Expert statistical software was used to apply the response level of statistical design. The statistical design was prepared with a central composite design with 20 experimental treatments that included a central point with six replications.

The obtained results showed that all the studied parameters (enzyme concentration, temperature and time of hydrolysis) had a significant effect on the antioxidant activity of the hydrolyzed product. The results showed that for the production of hydrolyzed protein of edible mushroom with high antioxidant activity (DPPH free radical scavenging methods, reducing power of Fe3+ and total antioxidant capacity) by the alcalase enzyme, the optimal conditions include temperature of 47.5 ° C, the hydrolysis time of 197 minutes and the enzyme-to-substrate ratio 2.1%, which with desirability of 100% was equal to DPPH free radical scavenging of 10.661%, reducing power of Fe3+ equal to 2.45 (absorption at 700 nm) and the total antioxidant capacity of 1.224 (absorption at 695 nm).

The results showed that by hydrolysis of protein of edible mushroom under optimal conditions a product with suitable antioxidant capacity can be obtained, which can be used as natural and functional additives in food formulations.