Studies On The Control Of Aging Process Of Postharvest Sweet Cherry Fruit

The cultivar of sweet cherry,"Summit"’, was used as the raw material, and studied their postharvest physiological properties, quality and storability treated by different concentrations of CaCl2, chlorine dioxide and methyl jasmonate(MeJA) during storage periods. In the experiment, the color, firmness, soluble solids content, titritable acid, vitamin C and respiration rate of the sweet cherry by different treatment were measured; peroxidase(POD). polyphenoloxidase(PPO), superoxide dismutase(SOD), lipoxygenase(LOX), catalase(CAT), reduced glutathione(GSH), malondialdehyde(MDA) content and the generation superoxide anion radical of sweet cherry by different treatment were analyzed.This experiments included following contents:effect of different concentrations of CaCl2(0,10g/L,20g/L) treatment on postharvest fruit browning, physiological properties and storability of sweet cherry; effect of different concentrations of chlorine dioxide (0,0.15mmol/L,0.3mmol/L) treatment on the senescence process of sweet cherry; effect of different concentrations of methy jamonate (0,0.25mmol/L,0.5mmol/L) treatment on the senescence process of sweet cherry. The results showed as following:1. Different concentrations of CaCl2treatment could maintain the color of fruit surface, firmness, soluble solid content, titritable acid and vitamin C content, inhibited the activities of PPO, POD and LOX, and reduced the generation of MDA. CaCl2could reduce the cell oxidation and membrane lipid peroxidation, make membrane structure more firm, in order to maintain the integrity of the cell wall and membrane, slow membrane structure oxidation, maintain the cell wall and cell membrane structure and function. The appropriate concentration of CaCl2treatment can effectively extend the shelf life of the sweet cherry, maintain good sense of the quality and the flavor, prevent the happening of the decay and browning.2. The treatment of chlorine dioxide could make sweet cherry fruit maintain the original color, delay the fruit firmness and the soluble solids content down and the losses, and reduce the fruit of respiration intensity. The treatment of chlorine dioxide reduced fruit the O2- generation rate, delayed the Vc content down, maintain GSH at high content, improved the activity of SOD and CAT, and to reduce the POD activity of postharvest sweet cherry, which slowed the process of mature and senescence of the sweet cherry. The treatment of chlorine dioxide have certain stimulative effect to postharvest sweet cherry fruit fresh-keeping.3. The treatment of methy jamonate could improve the surface color, reduce the change rate of the fruit quality during the storage. The treatment of methy jamonate could improve the activities of antioxidant enzymes such as SOD, CAT and the content of antioxidant such as GSH, Vc of postharvest sweet cherry, clear the fruit of excessive active oxygen free radicals, and slow down the mature and senescence of the sweet cherry. MeJA was beneficial to keep postharvest sweet cherry the original flavor and quality, and prolong storage life and shelf life.