Sodium nitroprusside (SNP) spray to maintain fruit quality and alleviate postharvest chilling injury of peach fruit

Abstract

Peaches, cultivar ‘G.H. Hill’, from trees that were sprayed with 0, 25, 50 and 100μmolL−1 sodium nitroprusside (SNP) 14days before harvest were stored at 4°C for 4 weeks. Chilling injury (CI), ethylene production, weight loss, firmness, malondialdehyde, hydrogen peroxide and vitamin C concentrations, antioxidant capacity (AC), and superoxide dismutase, peroxidase and polyphenol oxidase activities in the fruit were measured during storage. SNP treatments reduced ethylene production and maintained firmness, AC and vitamin C of the fruit. Treatment with 25 and 50μmolL−1 SNP reduced CI but 100μmolL−1 SNP increased it. SNP at 100μmolL−1 promoted the accumulation of reactive oxygen species, decreased the activity of antioxidant enzymes and accelerated peroxidation in fruit during storage. These results indicated that preharvest SNP (25 and 50μmolL−1) treatment increased chilling tolerance of peach fruit through suppressing ethylene production, maintaining firmness, AC and vitamin C and enhancing anti-oxidative enzyme activity.