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

Abstract

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 ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup><mml:mrow><mml:mtext>O</mml:mtext></mml:mrow> <mml:mrow><mml:mn>2</mml:mn></mml:mrow> <mml:mrow><mml:mo>·</mml:mo> <mml:mo>-</mml:mo></mml:mrow> </mml:msubsup> </mml:math> ) 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) (<i>P</i> < 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 (<i>P</i> < 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.