Abstract: To provide a theoretical basis for developing an electron beam irradiation technique for the preservation of kiwifruit, this study investigated the effect of electron beam irradiation on the storage quality and gray mold of kiwifruit. Freshly harvested ‘Hayward’ kiwifruit were artificially infected with Botrytis cinerea, treated with high-energy electron beam irradiation, and then stored at 0–1 ℃ and relative humidity of 90%–95%. Samples were taken every 15 days to determine fruit physicochemical index and resistance-related enzyme activities. The results showed that compared with the untreated control, electron beam irradiation treatment effectively reduced the fruit mass loss, maintained the soluble solid content, and inhibited the decrease in titratable acid content. The peak value of flavonoids in the 0.4 kGy irradiation group increased by 25.52% in comparison with the control group. Electron beam irradiation increased the peak values of peroxidase (POD), phenylalanine ammonia-lyase (PAL) and β-1,3 glucanase (GLU) activity as compared with the control group, at 0.8 and 1.2 kGy doses advancing the first appearance of peak of β-1,3 glucanase activity by 30 days and elevating the content of malondialdehyde (MDA). This indicates that electron beam irradiation triggers slight lipid peroxidation in the cell membrane. Electron beam irradiation at 0.4 kGy dose caused only marginal changes in the fruit quality but induced strong fruit resistance. Accordingly, an appropriate dose of electron beam irradiation can be used as an effective means to improve the preservation of kiwifruit and inhibit the decay loss.

Key words: electron beam irradiation; ‘Hayward’ kiwifruit; storage quality; gray mold; disease resistance