Study On The Antioxidant Activity Of Agaricus Bisporus And Quality Control

Agaricus bisporus, a kind of edible fungus which is widely cultivated and consumed all over the world, has a strong antioxidant capacity to improve body’s immunity aganist various diseases. However, browning is a major phenomenon which can cause serious quality deterioration during storage. So the effects of storage temperature on activities of antioxidant enzymes and antioxidant capacity of Agaricus bisporus were studied in this work. The relationship among color, total phenolics, ascorbic acid and antioxidant capacity, the changes of antioxidant activities and quality index under different low temperatue combined preservative were also discussed, which can provide theoretical and technical support for the postharvest quality improvement of Agaricus bisporus.(1) Total phenolics, ascorbic acid, the activity of SOD, the antioxidant capacity decreased gradually, the activity of CAT increased firstly and then decreased during storage at 1℃,4℃,7℃, and the optimum storage time was obtained at 1℃. Correlation analysis results showed that phenols and ascorbic acid played an important role in antioxidant system. Bacteria context browning degree was closely related with the antioxidant ability, and L* value changes were mainly affected by the content of ascorbic acid, the activity of SOD, TEAC and FRAP during storage.(2) Based on the analysis of total phenols, AsA content, antioxidant enzymes and the total antioxidant activity, the dynamics models of each index which changed with storage time and temperature were created. The results showed that the first-order kinetic models were fitted well with the L* value, the content of ascorbic acid, TEAC and FRAP at different storage temperatures. Each index rate constant increased with the rise of storage temperature on the basis of Arrhennius dynamic equation. The final prediction model fitting equation could be fast and reliable prediction the changes of Agaricus bisporus browning and antioxidant capacity at 274.15 ~ 280.15 K.(3) Effect of 1-MCP, sodium nitroprusside(SNP), clove bud essential oil, tea tree oil and citrus essential oil on Agaricus bisporus was studied with the sensory evaluation for comprehensive index, in order to select the best treatment. The results showed that 1-MCP and plant oil treatment didn’t have obvious effect on preservation of Agaricus bisporus. Compared with the reference group, 0.5 mmol/L and 1 mmol/L SNP treatment on Agaricus bisporus achieved better refreshing effect. And 1 mmol/L SNP treatment still has edible value until the eighth day.(4) Effect of low temperature and sodium nitroprusside on the antioxidant enzymes, antioxidant activity and antioxidant capacity of Agaricus bisporus during storage were studied. The results showed that 0.5 mmol/L and 1 mmol/L SNP treatment on Agaricus bisporus could effecively control the degree of browning, the increase of weight loss rate and the decrease of hardness during storage. And it could also significantly inhibit the total phenolics, ascorbic acid, and the decrease on activity of SOD, increase the activity of CAT and delay the coming of the peak of CAT activity effectively, which is good to maintain the total antioxidant capacity.