Effect And Mechanism Of Ergothioneine On Enzymatic Browning Of Agaricus Bisporus

Browning will seriously affect the quality of postharvest Agaricus bisporus to loss its nutritional and commercial value. In this paper, a representative variety of Agaricus bisporus called AS2796 was carried out as test materials, then we used ergothioneine solution（0.12mmol/L） spraying on these Agaricus bisporus, studied some main changes in terms of quality and physiological and biochemical indices of Agaricus bisporus during storage at 4℃.We also researched the energy metabolism and gene expression level of polyphenol oxidase （PPO）, phenylalanine ammonia lyase （PAL） and other enzymes related to browning to explore the possible browning inhibition mechanism that ergothioneine treated on postharvest Agaricus bisporus.The main results were as follows:1. As compared to control, ergothioneine treatment can slow browning of harvest Agaricus bisporus and extend the storage time of its preservation. Treatment on the table has a good effect on reducing the bacteria browning and internal organization browning of Agaricus mushroom, and can effectively maintain a high level of vitamin C, soluble protein and total phenolic content so that improve the nutrition and quality of postharvest Agaricus bisporus during storage period. Ergothioneine treatment also reduced the membrane lipid peroxidation, maintained the structure and function of integral membrane systems, delayed the aging of fruiting bodies.2. As compared to control, ergothioneine treatment increased the content and utilization level of ATP in cells of Agaricus bisporus, it also enhanced the activity of H+-ATPase、Ca2+-ATPase and succinate dehydrogenase（SDH） which are important enzymes on mitochondrial membrane related to energy metabolism, thus, maintaining the level of energy charge in Agaricus bisporus during storage, then ensured the energy supply for physiological metabolism in Agaricus bisporus after harvest.3. As compared to control, ergothioneine treatment reduced the activity of PPO、PAL、catalase（CAT） and peroxidase（POD） in harvested Agaricus bisporus during storage, reduced the relative expression levels of PPO₁、PPO₃、PPO₅ associated withpolyphenol oxidase genes and the relative expression levels of PAL₁、PAL₂ associated with phenylalanine ammonia-lyase genes, while enhanced the relative expression level of PPO₂ and PPO 6 genes during storage.