Hydrogen Sulfide Inhibits Enzymatic Browning of Fresh-Cut Chinese Water Chestnuts

This work investigates the role of hydrogen sulfide (H₂S) in the browning and regulating the antioxidant defensive system in fresh-cut Chinese water chestnuts. The samples were fumigated with 0, 10, and 15 μl L^-1 of H₂S and stored at 10°C for 8 days. The results indicated that the H₂S treatment significantly inhibited the browning of fresh-cut Chinese water chestnuts, reduced superoxide anion ( ${\text{O}}_2^{·-}$ ) production rate and H₂O₂ content accumulation, promoted the increase of total phenol content, and enhanced activities of catalase (CAT), superoxide dismutase (SOD), ascorbate peroxidase (APX), and glutathione reductase (GR) (P < 0.05). On the other hand, phenylalanine ammonia lyase (PAL), polyphenol oxidase (PPO), and peroxidase (POD) activities remained at a low level in the H₂S treatment (P < 0.05). This result suggested that H₂S treatment might be a promising approach to inhibit browning and prolong the shelf life by enhancing oxidation resistance and inhibiting browning enzyme activity of fresh-cut Chinese water chestnuts during storage. Among them, the 15 μl L^-1 H₂S treatment had the best effect on fresh-cut Chinese water chestnuts.