Synergistic regulation of Chitosan and NaHS on energy metabolism and endogenous H2S metabolism of postharvest nectarines

•CS-NaHS treatment promotes the production of endogenous H2S.•CS-NaHS treatment maintains the structure and function of mitochondria.•CS-NaHS treatment ensures the energy supply for various metabolic activities. Chitosan (CS) and sodium sulphate (NaHS), as common chemical preservatives, are widely used in postharvest storage of fruit, but the synergistic effect of the combination of the two for fruit preservation remains unclear. The study aimed to investigate the synergistic regulation of CS and NaHS on energy metabolism and endogenous H2S metabolism of postharvest fruit. “Linqu” nectarine was used as experimental material, and treated with 5 g·L−1 chitosan and different concentrations of NaHS (0, 0.3, 0.4, 0.5 mmol·L−1). The endogenous H2S content and related enzyme activities of nectarine fruits during storage, as well as the activities of energy metabolism related enzymes were measured. The results showed that the synergistic treatment of chitosan and NaHS increased the activities of L-cysteine desulfhydrase, O-acetylserine sulfur lyase and serine acetyltransferase, and promoted the production of endogenous H2S in nectarine fruit. At the same time, the activities of succinate dehydrogenase, cytochrome oxidase, H+-ATPase and Ca2+-ATPase were increased by the synergistic treatment of chitosan and NaHS, so that the nectarine fruit maintained a higher ATP and ADP content and energy level. By comparison, it was found that the synergistic treatment of chitosan and 0.4 mmol·L−1 had the best preservation effect on nectarine fruit.