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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]

The edible mushroom mosquito Lycoriella auripila (Dip.: Sciaridae) causes quantitative and qualitative reductions in crop yield worldwide, that is, Iran. The present study was conducted to estimate the efficacy of the entomopathogenic nematode Steinernema feltiae and the bacterium Bacillus thuringiensis, separately and simultaneously, in controlling this mushroom mosquito. In the laboratory study, the efficacies of different concentrations of S. feltiae (Sf), B. thuringiensis subsp. israelensis (Bti) and Dichlorvos pesticide were investigated. Then, nine treatments, including the interaction between Sf and Bti, were performed in addition to the laboratory treatments in the field test. The mushroom production yields in the control and treatment groups were compared. Statistical analysis of data was done based on the number of whole insects caught in sticky yellow card traps and larvae attracted to potato slices. In the conducted tests, the reductions in the insect population in the treatments compared with the control were calculated. The laboratory experiments showed positive effects of all treatments on pest control. The concentrations of 1×106 IJ/m² Sf and 2/1000 Bti had the highest mortality rate of pest larvae with 81.6 and 77.4% mean mortality, respectively. Nematode Sf at this concentratration acted better than Dichlorvos for the control of this pest. In the field measurements, the highest population decreases were recorded in Bti with 75.7% control efficacy based on yellow sticky cards and in treatments of Dichlorvos and half-dose of two-biocontrol agent based on potato slices data with 75.3 and 74.8%, respectively. No significant difference was observed between Dichlorvos and Sf treatment for the control of this pest based on yellow sticky card data in field study. The obtained results recommend using these two biological control agents to control the L. auripila mosquito in edible mushroom cultivation halls. [ABSTRACT FROM AUTHOR]

Due to the length of the time required for protein hydrolysis, ultrasound, as a cheap technology, can be used as a pre-treatment in protein hydrolysis to shorten the time. The aim of this study was to investigate the effect of hydrolysis time and ultrasonic pretreatment on enzymatic hydrolysis of edible mushroom proteins by pancreatin enzyme to produce short chain peptides with high antioxidant capacity. In this research first edible mushrooms were turned into powder then hydrolysed during 30-210 min with enzyme to substrate ratio of 1% and at temperature of 40 °C without pretreatment, and with pretreatment by 80 and 40% ultrasound power. Increasing the power of ultrasonic treatment increased the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity and total antioxidant capacity at shorter hydrolysis time. The highest DPPH free radical scavenging activity in untreated and treated samples with 40 and 80% ultrasound power were 39.96, 42.91 and 47.76, respectively. The highest total antioxidant capacity for untreated and treated samples with 40 and 80% ultrasound power was 1.64, 1.73 and 1.98 (absorption at 695 nm), respectively. The results showed that the highest reducing power of Fe3+ in untreated and treated samples with 40 and 80% ultrasound power were 2.61, 2.84 and 2.90 (absorption at 700 nm), respectively. These results showed that pre-treated samples with 80% ultrasound compared to samples without pretreatment and pre-treated with 40% ultrasound had the highest antioxidant properties. Therefore, the use of high power ultrasonic pretreatment shortens the hydrolysis time to achieve peptides with higher antioxidant capacity.

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]

Nowadays the edible mushroom has got a great consideration as a high protein and low calorie food source and also its medicinal consumption. As the production of edible mushrooms increases, it is necessary to notice on its storability, waste decreasing and usage of dried mushrooms. For this reason drying of this crop as a practical way has been considered. Nowadays advantages of artificial neural network are noticeable for simulation and prediction of necessary parameters in drying processes. The objective of this study is moisture content prediction of edible mushroom with arithmetic neural network during drying process. In this study the thin layers of edible mushroom were dried by hot air dryer in three temperature levels: 40, 50, 60°C and three air flow speed levels: 0.5, 0.7, 1 m/s until the moisture content reached to 10% (d.b.). Regression models and feed forward neural network with Levenberg--Marquardt learning algorithms were used to estimate and predict the moisture content of mushroom thin layers. The results showed that the quadratic degree regression model with determination coefficient of 97.0 and the error sum of the squares of 0.071 and also the neural network with 3-20-18-1 structure with sigmoid threshold and logarithmic function in comparison with other topologies had better results to predict the moisture content of mushroom thin layer during drying. [ABSTRACT FROM AUTHOR]

Background and purpose: Mushrooms are highly nutritive, since they are low in calories and contain significant amounts of vegetative proteins, vitamins, minerals, amino acid, and fiber. Mushrooms might be contaminated by heavy metals such as lead, cadmium, chromium, etc. This contamination depends on type of mushrooms, their physiology, and ecosystem. The present study aimed at determining the amount of lead, cadmium and chromium in edible mushrooms disturbed in the city of Sari (north of Iran). Material and methods: This study was done in laboratory on 108 samples of commercial mushrooms widely found in supermarkets in Sari. They were coded 1 to 6 and their stem and cap were studied. Finally, the amount of lead, cadmium, and chromium were determined using atomic absorption spectrometer (AAS). Results: The concentrations of lead and cadmium were found to be less than standard levels recommended by Codex guidelines. But the amount of chromium in all samples was observed to be more than Codex standards (20 mg/kg). The Provisional Tolerable Weekly Intake (PTWI) for chromium in cap was similar to standard levels while this was lower in stem. Conclusion: High concentrations of chromium could be due to high levels of that found in composts used for growing mushrooms or contaminated water. [ABSTRACT FROM AUTHOR]