Ca 1-mcp On The Pink Lady Apples During Storage Aroma And Its Related Enzyme Activity In The Study

The change of aroma components and relatively contents of 'pink lady' apples which were treated by 1-MCP at harvest during cold storage and controlled atmosphere(CA)storage,and tested the change of fruit firmness,total soluble solids,respiration rates,ethylene production rates.In addition the activities of lipoxygenase(LOX),alcohol dehydrogenase(ADH),alcohol acetyltransferase(AAT) and pyruvate decarboxylase(PDC) were investigated in the volatile formation during the storage.The apples treated by 1-MCP after 120 days cold storage were used test material,and studied the effects of recover esters volatile with salicylic acid or ethephon.The aroma components of apple were measured by HS-SPME and GC-MS.The main results were as follows:1.The process of apples ripening was delayed and the quality of apples were maintained during storage.Apples treated by 1-MCP could keep fresh better than the CA storage.This implied that 1-MCP could reduce the dependence of fruits for the long-term srorage on the CA condition.2.Aroma formation were suppressored by CA and 1-MCP treatment in 'pink lady' apple during storage,the effect of 1-MCP on the fruit aroma formation reached the maximum in the 90 days,the effect of CA on the fruits aroma formation mainly manifested in the late storage.3.The formation of the esters,alcohols and alkanes were inhibited significantly in 'pink lady' apples by 1-MCP treatment during storage,decreased 23.73%,33.33%and 66.67%respectively compared with the cold control fruits.The formation of aroma of alcohols and alkane were inhibited by CA storage,reduced 33.33%and 38.4%compared with the cold control fruits respectively.4.The activity of LOX were inhibited by1-MCP in the 'pink lady' apples during storage,CA had no effect on LOX activity during storage;The activity of AAT were suppressed by 1-MCP and CA after 90 days in storage,and the butyl and hexyl esters aroma had a large number of synthetic at that time,which showed AAT was not the rate-limiting enzyme of butyl and hexyl ester aroma biosynthesis.The activity of PDC were suppressed by 1-MCP and CA after 60 days in storage,the activity of PDC reached the maximum in 90 days storage,and the esters aroma were the peak of the release at that time,which showed PDC might be the crucial enzyme of ester aroma biosynthesis of 'pink lady' apples in post-storage.5.The esters aroma biosynthesis of apples treated by 1-MCP was induced by SA and ETH in different levels.The release of the fruit aroma esters was promoted SA of 0.5 mmol / L;SA of 1.0 mmol / L was the best solution on the recovery of the types of aroma esters.The effects of different concentrations ETH were different on the release of aroma esters of fruits,and the ETH of 50mg/kg was the best solution.