Effects Of 1-MCP Treatment On Storage Quality And Ethanol Metabolism During Postharvest Ripening Of Nanguo Pear Fruit

Nanguo pear(Pyrus ussriensis Maxim)is a common climacteric fruit,and the alcohol flavor produced during its ripening is caused by ethanol metabolism.Ethylene is an important endogenous hormone in the regulation of ripening and senescence of the climacteric fruit.1-methylcyclopropene(1-MCP)is an ethylene action inhibitor which is often used to study the physiological effects of ethylene.Until now,the effects of 1-MCP treatment on ethanol metabolism during postharvest ripening of Nanguo pear fruit are still unclear.In this paper,the commercially mature Nanguo pear fruit were used as material,and the effects of 1-MCP treatment on storage quality and ethanol-metabolism related physiology of Nanguo pear fruit during storage at room temperature(20±2?,RT 45?50%)were studied.The main results were as follows:(1)The Nanguo pears were fumigated with 1.0?L L^-11-MCP at room temperature for 24 h,and then stored in carton boxes at room temperature.The results showed that,compared with the control group,1-MCP treatment could significantly delay the decrease of fruit firmness,reduce the malondialdehyde(MDA)content,reduce the respiratory intensity and ethylene release,and delay the their climacteric peak simultaneously.1-MCP treatment also delayed the decrease of vitamin C(V_C)and titratable acid(TA)contents,and make the total soluble solids(TSS)content at a higher level.These above results indicated that 1-MCP treatment maintained the storage quality of Nanguo pear fruit and delayed its senescence.(2)The effects of 1.0?L L^-11-MCP treatment on the ethanol metabolism during ripening and senescence of postharvest Nanguo pear fruit were studied.The results showed that,compared with the control group,1-MCP treatment reduced the pyruvate content and delayed its peak,and also delayed the secondary peak of glucose content and reduced its peak value during storage.1-MCP treatment also reduced the acetyl-Co A content,increased the contents of oxaloacetic acid and citric acid(CA),and at the same time it also reduced the activities of pyruvate decarboxylase(PDC)and alcohol dehydrogenase(ADH),and delayed the their peaks.Meanwhile,1-MCP treatment inhibited the accumulation of acetaldehyde and ethanol.These results showed that ethylene regulated the ethanol metabolism of Nanguo pear fruit during storage at room temperature.In summary,1-MCP treatment could maintain the storage quality and delay the ripening and senescence of postharvest Nanguo pear fruit.The 1-MCP treatment effectively delayed the accumulation of ethanol and the production of“wine taste”in postharvest Nanguo pear fruit during storage at room temperature.Therefore,ethylene can regulate the ethanol metabolism during ripening and senescence of postharvest Nanguo pear fruit.