l -Cysteine Treatment Delayed the Quality Deterioration of Fresh-Cut Button Mushrooms by Regulating Oxygen Metabolism, Inhibiting Water Loss, and Stimulating Endogenous H2S Production

Although fresh-cut button mushrooms are popular with consumers, quality deterioration presents a significant shelf-life challenge. In this study, fresh-cut button mushrooms were treated with 0.25 g/L l - cysteine ( l - Cys) and evaluated in terms of quality, physiology, and transcriptome sequencing. The results indicated that l -Cys application significantly delayed the browning degree of fresh-cut button mushrooms and reduced weight loss. l -Cys treatment reduced the malondialdehyde content, lipoxygenase activity, and reducing sugar levels while enhancing the soluble protein and total phenolic content. Furthermore, l - Cys treatment reduced the O 2 – generation rate and H 2 O 2 accumulation while enhancing the catalase activity. Moreover, l - Cys improved the superoxide dismutase, glutathione reductase, and phenylalanine ammonia-lyase activities while reducing those of polyphenol oxidase and peroxidase. Additionally, l -Cys treatment increased endogenous H 2 S production and AbCBS enzyme activity while decreasing AbCSE enzyme activity. Notably, additional treatment with 1 mM propargylglycine significantly reduced the effect of l -Cys. Moreover, transcriptome sequencing analysis indicated that the differentially expressed genes in the l -Cys group were primarily related to the reactive oxygen species metabolism, oxidoreductase process, membrane integrality, and sulfur metabolism. These findings suggested that l -Cys treatment delayed the aging and extended the shelf life of fresh-cut button mushrooms by regulating the active oxygen species metabolism and water loss and stimulating endogenous H 2 S production.