Effects Of 1-MCP Treatment On Fruit Quality Associated With Ethanol Metabolism And GABA-shunt In Kiwifruit During Storage At Room Temperature

The effects of 1-MCP(1-methylcyclorpropene)treatment on fruit quality associated with ethanol metabolism and GABA-shunt in kiwifruit(Actinidia deliciosa.cv.Bruno and Actinidia deliciosa.cv.Xuxiang)during storage at room temperature were investigated in this paper,after the harvested kiwifruits were treated with 1.0 ?L/L 1-MCP or water(as control),and then stored at 23?.The main results were as follows:1.1-MCP treatment reduced the decay rate and showed a significant effect on maintaining the quality of the fruit during storage,as 1-MCP effectively delayed the decrease of the firmness,inhibited the increase of soluble solid content(SSC),and decreased the titratable acid(TA)and sugar/acid ratio.The treatment could decrease the ascorbic acid content,and inhibit the content of tartaric acid,malic acid and citric acid content in 'Bruno',while the treatment could increase the content of tartaric acid and malic acid in 'Xuxiang' fruit in the later storage.It was indicated that 1-MCP treatment could delay the ripening process and maintain the quality in kiwifruit during storage.2.1.0 ?L/L 1-MCP treatment reduced the respiration rate of 'Bruno'and 'Xuxiang' during storage,delayed the peaks of respiration rate,and inhibited the pyruvate acid content of 'Bruno'and 'Xuxiang'during climacteric.Moreover,the treatment effectively inhibited the accumulation of acetaldehyde and ethanol content in 'Bruno' and'Xuxiang' by decreased by 91.4%and 99.3%respectively,as well as reduced the activities of the pyruvate decarboxylase(PDC)and alcohol dehydrogenase(ADH).It was indicated that 1.0 ?L/L 1-MCP treatment could significantly reduce the accumulation of ethanol and acetaldehyde in kiwifruit of the two cultivars,and in turn alleviated the occurrence of alcohol odor during storage.3.1.0 ?L/L 1-MCP treatment could maintain the activity of pyruvate dehydrogenase(PDH)of the 'Bruno' fruit during storage,but inhibited the PDH activity of the 'Xuxiang' fruit at the later period of storage.The treatment improved the glutamic acid content of the 'Bruno' in the middle and later stages,but inhibited the glutamic acid content of 'Xuxiang'.Also,to some extent,the treatment inhibited the ?-aminobutyric acid(GABA)content as well as the glutamate decarboxylase(GAD)activity in these two cultivars during storage,and decreased the activity of GABA-transaminase(GABA-T)in the middle storage period of 'Bruno'and the late storage of 'Xuxiang,and significantly inhibited the accumulation of succinic acid during storage.