Composite coating of guar gum with salicylic acid alleviates the quality deterioration of vibration damage in ‘Huangguan’ pear fruit through the regulation of antioxidant metabolism

Abstract

Vibration damage is commonly existed in the pear fruit postharvest logistics process, which can lead to serious fruit quality deterioration. In this study, we evaluated the effectiveness of composite coating of guar gum (GG) with salicylic acid (SA) on mitigating the quality deterioration of vibration damaged ‘Huangguan’ pear fruit stored at 22 ± 2 ℃ for up to 25 d. The GG-SA coating treatment could reduce weight loss, alleviate the decrease of firmness, SSC and TA, inhibit respiration, maintain a high cell membrane integrity and alleviate excessive oxidative damage of vibration damaged fruit. The combined GG-SA treatment was more effective in regulating antioxidant metabolism in vibration damaged fruit compared to GG or SA treatment alone. Superoxide dismutase, ascorbate peroxidase, catalase, peroxidase and glutathione reductase activity were improved in vibration damaged fruit coated with GG-SA, while polyphenol oxidase activity was inhibited in vibration damaged fruit coated with GG-SA. In addition, GG-SA coating treatment also increased the content of antioxidant substances and antioxidant capacity of vibration damaged fruit. GG-SA coating treatment can provide a practical solution to the vibration-induced postharvest losses of ‘Huangguan’ pear fruit.