Hydrogen sulfide extends the postharvest life and enhances antioxidant activity of kiwifruit during storage

BACKGROUND: Exogenous hydrogen sulfide (H₂S) treatment can prolong the postharvest life of cut flowers and strawberries. Little work has been done to explore the effects of H₂S on respiratory climacteric fruits such as kiwifruits during storage. Therefore the aim of the present study was to evaluate the effects of H₂S treatment at concentrations of 15–1000 µmol L⁻¹ on the postharvest life of kiwifruit during 25 °C storage and the role of H₂S in regulating the antioxidant defensive system of kiwifruit. RESULTS: Treatments with 45 and 90 µmol L⁻¹ H₂S significantly inhibited the increase in soluble sugar content and the decrease in vitamin C (Vit C), chlorophyll content and firmness, inhibited ethylene production and both superoxide production rate (O(·2)⁻) and hydrogen peroxide content. Kiwifruits with 45 and 90 µmol L⁻¹ H₂S exhibited significantly higher activities of superoxide dismutase, catalase and peroxidase. Treatment with 180 µmol L⁻¹ H₂S promoted the ripening of kiwifruits. CONCLUSION: Treatments with 45 and 90 µmol L⁻¹ H₂S could delay the maturation and senescence of kiwifruits and maintain higher titratable acid (TA) and Vit C during eating-ripe storage by inhibiting ethylene production, improving protective enzyme activities and decreasing the accumulation of reactive oxygen species to protect the cell membrane during storage.