Effects of chitosan‑calcium coating on the physiological characteristics and browning of Stropharia rugosoannulata during postharvest storage

The effects of chitosan‑calcium (CTSCa) coating on the physiological characteristics and browning of fresh Stropharia rugosoannulata were investigated. The 0.5 % CTS-Ca coating reduced the weight loss rate, opening rate, and browning of mushrooms. CTS-Ca could decrease the contents of total phenols and the activities of enzymes associated with enzymatic browning, increase the activities of antioxidant enzymes, and reduce the production of malondialdehyde, a product of membrane lipid metabolism. Based on transcriptomic analysis, CTS-Ca treatment down-regulated the expression of genes on the chorismate/tyrosine pathway to inhibit the synthesis of phenolic substrates and tyrosinase activity, up-regulated the three energy metabolism pathways of glycolysis, TCA cycle, and oxidative phosphorylation to maintain the integrity of the cell membrane, increased the expression of catalase and superoxide dismutase genes to scavenge ROS. Our results would provide a simple and practical preservation solution for S. rugosoannulata during the postharvest storage.