Effect of Preharvest Spraying of Diethyl Aminoethyl Hexanoate on Membrane Lipid Metabolism of Grapes during Storage

In order to investigate the effect of preharvest spraying of diethyl aminoethyl hexanoate (DA-6) on membrane lipid metabolism in ‘Kyoho’ grapes during postharvest storage, distilled water (control) and 50 mg/L DA-6 were used to spray grapes at the veraison stage. The grapes were harvested when they were ripe, stored at (0 ± 1) ℃ and relative humidity of 65%-70%, and evaluated for cell membrane related indicators of grape skin after 0, 20, 30, 40, 50, and 60 days. The results showed that compared with the control group, DA-6 treatment effectively inhibited the increase in the relative permeability of cell membrane during postharvest storage, maintained the activities of lipoxygense (LOX), lipase and phospolipase D (PLD), inhibited the decrease of phosphatidylcholine and phosphatidylinositol content and the increase of phosphatidyl acid content, and maintained a high relative content of unsaturated acids such as linoleic acid and linolenic acid as well as saturated fatty acids such as stearic acid, behenic acid, arachidic acid and palmitoleic acid, consequently maintaining the degree of unsaturation of fatty acids at a high level. Additionally, DA-6 treatment suppressed the expression of the LOX, Lipase, and PLD genes. In summary, preharvest spraying of 50 mg/L DA-6 can delay the senescence and prolong the storage period of ‘Kyoho’ grapes by effectively relieving the membrane lipid metabolism during storage.