Enhanced H 2 S biogenesis followed by its postharvest application retarded senescence development by promoting multiple antioxidant protection systems in button mushroom during cold storage.

Rapid postharvest quality deterioration of button mushroom as fruit body surface browning brings about senescence development and limits its distribution potential and postharvest storage. In this investigation, 0.5 mM of NaHS as the optimum concentration for H 2 S fumigation was applied to retain the quality of Agaricus bisporus mushrooms concerning some qualitative and biochemical attributes evaluation throughout 15 storage-day at 4°C and 80-90% relative humidity. In H 2 S fumigated mushrooms, pileus browning index, weight loss and softening decreased, concomitant with higher cell membrane stability as revealed by subsidiary electrolyte leakage, malondialdehyde (MDA) and H 2 O 2 contents compared to the control during the cold storage period. H 2 S fumigation boosted total phenolics, as presented by the enhanced phenylalanine ammonia-lyase (PAL) activity and total antioxidant scavenging activity, while polyphenol oxidase (PPO) activity diminished. Moreover, in H 2 S fumigated mushrooms not only peroxidase (POD), catalase (CAT), superoxide dismutase (SOD), glutathione reductase (GR) and glutathione peroxidase (GPx) activities but also ascorbic acid and glutathione (GSH) contents increased, even though glutathione (GSSG) content declined. The raised endogenous H 2 S level prompted by greater cystathionine ß-synthase (CBS), cystathionine ?-lyase (CSE), cysteine synthase (CS), L-cysteine desulfhydrases (LCD) and D-cysteine desulfhydrases (DCD) enzymes activities until 10d in fumigated mushrooms. In general, the increase in endogenous H 2 S biogenesis promoted by H 2 S fumigation in button mushrooms resulted in retarding senescence development, maintaining redox balance by boosting multiple enzymatic and non-enzymatic antioxidants defense parameters.