Effects Of Hypobaric Treatment On Ethanol And Energy Metabolism In Actinidia Delicacies Kiwifruit Cv.bruno During Storage At Room Temperature

The delicious kiwifruit 'Bruno' are prone to occuring alcohol during postharvest storage,which affects the quality and commodity value of the fruit.In this paper,the kiwifruit 'Bruno'(Actinidia deliciosa.cv.Bruno)were used as the experimental material to study the high O2 modified atmosphere packaging(80%O2+20%N2,60%O2+40%N2)on kiwifruit at room temperature(25?).The effects of high O2 modified atmosphere packaging on quality,ethanol metabolism,energy metabolism,ascorbic acid metabolism and physiological mechanism in kiwifruit were studied,which provide theoretical basis on inhibiting the alcoholic odor in kiwifruit during postharvest storage.The main findings are as follows:1.High O2 modified atmosphere packaging(80%O2+20%N2,60%?2+40%N2)effectively delayed the decline of hardness and citric acid content in kiwifruit during postharvest storage,inhibited the increase of soluble solid content,and enhanced the sensory flavor of the fruit.It shows that the high ?2 modified atmosphere packaging delays the ripening of the fruit,maintain the taste of the fruit.2.80%?2+20%N2 high ?2 modified atmosphere packaging effectively inhibited the accumulation of acetaldehyde and lactic acid in kiwifruit during postharvest storage,and inhibited the enzymes related to ethanol metabolism,pyruvate decarboxylase(PDC),ethanol hydrogenase(ADH)and lactate dehydrogenase(LDH)activities,and the inhibition effection is obvious.It is indicated that high ?2 modified atmosphere packaging can reduce the production of ethanol in fruit ripening process by inhibiting the activity of enzymes related to ethanol metabolism,thus exerting a good regulation effect on the alcohol odor of fruits.3.In the later stage of storage,high O2 modified atmosphere packaging gradually increased the fruit energy load level,and increased the activity of respiratory metabolism enzymes in mitochondrial,including succinate dehydrogenase(SDH),cytochrome c oxidase(CCO)and Ca2+-ATPase activity.By promoting aerobic respiration on the fruit,the energy level of the fruit is maintained during storage.4.High O2 modified atmosphere packaging reduced the ascorbic acid content,enhanced the ascorbate oxidase(AAO)activity,promoted oxidation of ascorbic acid in kiwifruit 'Bruno'.Also the regeneration of ascorbic acid was inhibited by inhibiting glutathione reductase(GR)activity.It indicated that the high ?2 modified atmosphere packaging promotes the oxidation of ascorbic acid in the fruit and also inhibits the regeneration of ascorbic acid,resulting in a decrease in the ascorbic acid content during the post-ripening stage in the fruit.