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Due to concerns about the safety and long-term health of synthetic antioxidants such as BHT and BHA, the use of natural compounds with antioxidant properties, such as bioactive peptides, has attracted the attention of many researchers. The aim of this study was to determine the optimum hydrolysis time of edible mushroom protein ( Agaricus bisporus) with alcalase enzyme to produce protein hydrolyzate with high antioxidant properties. For this study, first edible mushrooms were converted into powder and then was hydrolyzed in different times of 200, 150, 100, 50 and 250 minutes with an enzyme to substrate of 2% at temperature of 50 °C and then appropriate treatment based on antioxidant properties of the produced sample was determined. The results showed that hydrolysis time 200 minutes is suitable to achieve maximum antioxidant properties. Next, the effect of different concentrations (10 to 50 mg/ml) of hydrolyzed protein prepared under optimal conditions on the antioxidant properties of the product compared to ascorbic acid (50 mg/ml) was investigated. In all the tests, the product showed a concentration-dependent behavior and with increasing concentration, the DPPH free radical scavenging, iron ion reduction power and total antioxidant power increased and in concentrations of 40 and 50 mg/ml the antioxidant power was similar to ascorbic acid (50 mg/ml). The results showed that the hydrolyzed protein produced has the potential to be used as a functional ingredient and as an alternative to synthetic antioxidants in food formulations. [ABSTRACT FROM AUTHOR]

Bioactive peptides are actually specific protein parts that, in addition to nutritional value, have positive effects on body function and conditions that lead to health effects. The combined use of pretreatment and enzymatic hydrolysis causes changes in the physical and chemical properties of hydrolyzed proteins. Microwave pretreatment is a well-known strategy to increase the accessibility of hydrolysis-sensitive bonds, facilitating enzyme cleavage sites and exposure to proteases. The aim of this research was to investigate the effect of hydrolysis time and also the effect of microwave pretreatment on enzymatic hydrolysis of edible mushroom (Agaricus bisporus) protein by trypsin enzyme to produce antioxidant peptides. To conduct this research, first, edible mushrooms were turned into powder after purchase from the market and conducting related processes. In this research, hydrolyzed edible mushroom was produced using trypsin enzyme without pretreatment and with microwave pretreatment at different powers of 120, 200, and 280W and time intervals of 30, 60, 90, 120, 150, 180 and 210 minutes. The antioxidant properties of the hydrolysed samples (DPPH radical scavenging activity, iron chelating power, iron ion reduction power and total antioxidant activity) were evaluated and compared. The results showed that in most of the experiments, pretreatment with microwaves decreased the time of obtaining and increased the antioxidant capacity of the samples, so that the samples pretreated with microwave power of 120W showed higher antioxidant power compared to the other treated samples. In all antioxidant tests, the sample pre-treated with microwave with power 120W and hydrolysed at 90minutes showed higher antioxidant performance, and therefore it is considered as suitable treatment. [ABSTRACT FROM AUTHOR]

Background and Objectives: 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. Materials and Methods: 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. Results: 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). Conclusions: 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. [ABSTRACT FROM AUTHOR]