Effects of Short-Wave Ultraviolet (UV-C) Light and 60Co-γ Irradiation on the Storage Quality of Cherry Fruits

In order to investigate the efficacy of different radiation treatments in preserving the quality of ‘Agate Red'cherries, cherry fruit were treated with different doses of short-wave ultraviolet light (UV-C) irradiation (1.37, 2.05 and 2.74 kJ/m2) or 60Co-γ irradiation (0.75, 1.5 and 2.25 kGy) and then stored under cold conditions. Physiological quality attributes and pericarp ultrastructure were regularly assayed during storage. The results showed that compared to the control group, 1.37 kJ/m2 UV-C irradiation and 0.75 kGy 60Co-γ irradiation significantly delayed the decline of marketable fruit percentage, inhibited the loss of fruit mass, maintained better textural characteristics, promoted anthocyanin synthesis, effectively inhibited the decline of peroxidase (POD) and superoxide dismutase (SOD) activities, but they had little effect on soluble solids content, and even increased malondialdehyde (MDA) content. Due to the positive effects of both irradiation treatments on the core sensory quality indicators such as marketable fruit percentage, hardness, mass loss percentage and anthocyanin content, the adverse changes in MDA content was not enough to affect the commodity quality evaluation of cherry fruit. The results of electron microscopy showed that compared to the control group, the damage of cell membrane, mitochondria, chloroplast and other cell structures could be reduced to a certain extent after the irradiation treatments, thereby significantly delaying senescence in pericarp cells. In addition, each treatment exerted different effects at the early and late stages of storage. For short-term storage for up to 5 days, 1.37 kJ/m2 UV-C irradiation is appropriate, while 0.75 kGy 60Co-γ irradiation is appropriate for long-term storage. © 2019, China Food Publishing Company. All right reserved.