Effect of X-ray irradiation on quality, cell ultrastructure and electrical parameters of postharvest kiwifruit

In this research, kiwifruit was irradiated with different doses (0, 200, 400 Gy) of X-ray and stored in cold storage for 120 days (0– 1 °C, 90– 95% relative humidity) to investigate the postharvest preservation effect of X-ray. The results indicated that 400 Gy X-ray reduced the decay rate and respiration rate, delayed the rise in soluble solids content (SSC), and inhibited chlorophyll decomposition, maintained higher peroxidase and phenylalanine deaminase activities and lower polyphenol oxidase activity compared to the control group. Microscopically, the 400 Gy group displayed a clear and well-integrated cell structure at the end of storage. Based on the electrical parameters, Rs was screened as a characteristic electrical parameter common in all groups, and decay rate and SSC as characteristic qualities. The study proved that X-ray irradiation has a positive effect on kiwifruit preservation and the electrical parameter Rs can be used to predict the quality of kiwifruit after X-ray irradiation.