Effects on Disease Resistance and Quality in Harvested Grape by UV-C Treatment

[Objectives] Influences of low energy short wave ultraviolet(UV-C) to decay of grape and action mechanism were studied for providing scientific basis of UV-C application in fresh-keeping.[Method] Grape fruits were exposed to UV-C irradiation energy levels of 0、0.5、1.0、1.5、2.0 kJ/m2 and then stored for 12 weeks at 0±1 ℃,90% RH.Decay index,total phenols(TP),total flavonoids(TF),enzymatic activity of phenylalanine ammonia-lyase(PAL),polyphenoloxidase(PPO),chitinase and β-1,3-Glucanase were measured thereafter every 2 days.[Result] UV-C treatment maintained lower decay percentage and increased shelf life of fruit.These benefits correlated positively with higher levels of TP,TF,PAL,PPO,chitinase and β-1,3-Glucanase.[Conclusion] These results suggested that the inhibition of postharvest grape fruit decay by UV-C was related to the induction of defensive enzyme activities and accumulation of phenolic and flavonoids compounds