Effect of hydrogen sulfide on surface pitting and related with cell wall metabolism in sweet cherry during cold storage

This study was to determine whether postharvest H2S fumigation effects surface pitting development of ‘Lapins’ and ‘Regina’ cherries after cold storage, and if so, how H2S takes participate in minimizing pitting injury and its relation to cell wall metabolism. Fruit were exposed to hydrogen sulfide (H2S) gas released from sodium hydrosulfide (NaHS at rates of 0.5, 1, 2, or 3 mM), then stored at 0 °C for 4 weeks. Fruit treated with 1 and 2 mM NaHS in both cultivars had the significantly higher firmness and lower respiration rate than the control fruit. However, no treatment retarded the losses in soluble solids content (SSC) and titratable acidity (TA). After 4 weeks of storage, H2S suppressed stem browning, decay, and surface pitting, but it did not affect the weight loss. The greater positive effect of H2S for reducing surface pitting development was due to the lower yields of water-soluble polysaccharides (WSP) and CDTA-soluble polysaccharides (CSP) and the inhibited activities of polygalacturonase (PG), pectate lyase (PL), and β-D-galactosidase (β-GAL). Overall, results demonstrated that H2S applied as postharvest vapor is an effective tool to control surface pitting development in sweet cherry with protected cell wall structure and reduction of cell wall metabolism.