Studies Of The Preservative Effects And Mechanism Of Clove Oil On Postharvest Dong Jujube

The inhibitory efficacy of fungi and Physiological effect of Clove oil on postharvest Dong jujube was studied in this paper. The results were summarized as follows:Inhibitory efficacy of Clove oil and Clove oil in combination with Chitosan on pathogens of postharvest Dong jujube was tested in vitro. The Minimal Inhibitory Concentration(MIC),Minimal Lethal Concentration(MLC) have been testified, the MIC and MLC of Penicillium citrinum were 2.5μL/mL ,MIC of Botrytis cinerea, Alternarea alternat, Emericella nidulans was 2.5μL/mL,MLC was 5.0μL/mL. The spore germination and hypae growth of poatharvest fungi were tested by sunk slide and growth rate testing method. The results showed that Clove oil had strong inhibitory effects on tested pathogens. When its concentration was 10μL/mL, the inhibition rate of Clove oil on spore germination and hyphal growth of four pathogens were 85%. The efficacy on Clove oil in combination with chitosan was 80% (including effective ingredient of Clove oil 5μL/mL) and when its concentration was 5μL/mL, the inhibition rate of Clove oil on spore germination and hyphal growth for those four pathogens were lower than 80%. Therefore, the inhibitory efficacy on Clove oil with combination of chitosan had higher MIC than that of Clove oil.Dipping(concentration: 0.1%,0.3%,0.5%) and fumigating treatments (concentration:0.5 mL,1 mL,2mL)have been applied to study its physiological effects of Clove oil on Dong jujube. It was showed that two treatments improved the activities of POD,PPO,PAL on Dong jujube; stimulated the synthetizing the production of enzymes and induced the increasing the contents of phenols; inhibited Dong jujube's contents of hardness,titratable acids,reducing saccharide,TSS and Vc which reached its peak content 15 days later than contract; decreased the production of ethanol and releasing the ethene effectively. But as for inhibiting effect of respiratory intensity was not obvious and there was no respiratory peak. It indicated that Dong jujube belonged to the characteristic of non-respiratory peak pattern. The inhibiting effect of fumigating treatment on reducing saccharide and respiratory intensity was more significant than dipping treatment and other physiological effects of Dong jujube on two treatments were in reverse.