X-ray irradiation-nonthermal processing and preservation of fresh winter jujube (Zizyphus jujuba mill. cv. Dalidongzao)

In this research, winter jujubes were treated with X-ray doses of 0, 0.3, 0.5 kGy and stored at 0 degrees C. Then jujubes from early (day 0) and late (day 60) storage were transferred to 20 +/- 1 degrees C and qualities were evaluated every 3 days to explore the preservation effect of X-ray. Results indicated that 0.3 kGy X-ray inhibited the jujube decay by preventing 8.20% of fungal and 29.12% of aerobic bacterial growth. The pectin decomposition was prevented (0.21% on day 60), softening was alleviated, and reddening was delayed for 5 days correspondingly. Microscopic observation validated the integrity of the treated jujube tissue. Furthermore, the highest inhibition rates of 0.3 kGy X-ray on the activities of polygalacturonase (PG), cellulase and 8-glucosidase (8-Glu) were 47.32%, 74.71% and 68.00%, respectively. Research demonstrated X-ray's potential in winter jujube preservation, which can provide a solid theoretical reference for the development and industrial application.