Electron-beam irradiation delayed the postharvest senescence of kiwifruit during cold storage through regulating the reactive oxygen species metabolism

Abstract

The purpose of this study was to investigate the effects of electron-beam (e-beam) irradiation (0, 0.3, 0.4, and 0.5 kGy) on fruit firmness, total soluble solids (TSS), and active oxygen metabolism related indexes of kiwifruit during postharvest storage at 0–1 °C for up to 90 d. Results showed that e-beam irradiation retarded decrease in firmness as well as increase in TSS content in kiwifruit. The water-soluble pectin (WSP) content and ethylene production of the fruit decreased effectively after triggered by e-beam treatment. In addition, e-beam irradiation was able to improve the activities of peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX), thus reducing the superoxide anions (O2−·) production rate, hydrogen peroxide (H2O2) content, malondialdehyde (MDA) content, and Lipoxygenase (LOX) activity. In general, 0.5 kGy e-beam irradiation presented the optimal preservation effects as the active oxygen metabolism and membrane lipid oxidation were inhibited to the greatest extent. The results of this work suggested that the appropriate dose of e-beam irradiation is an effective method for slowing down the increase in reactive oxygen species, maintaining normal metabolic processes and reducing the loss of fruit quality in kiwifruit during cold storage.