Membrane lipid metabolism changes and aroma ester loss in low-temperature stored Nanguo pears

Cold storage is an effective method used to retard the senescence of Nanguo pears after harvest. However, this causes aroma loss in the fruit. To elucidate the role of membrane lipid metabolism in aroma reduction, we investigated the contents of total aroma eaters and major fatty acid components, the membrane permeability, and the activity and gene expression of key enzymes in membrane lipid metabolism and aroma formation. The results showed that the contents of total aroma esters, oleic acid and linoleic acid, and alcohol dehydrogenase activity were at a lower level in cold stored fruit than that in control fruit. However, the palmitic acid content, membrane permeability, and the activities and gene expression of alcohol acyltransferase, lipoxygenase, phospholipase D, and lipase were higher. In conclusion, the loss of aroma esters may be caused by membrane lipid metabolism disruption during cold storage.