Changes in free and glycosidically bound volatile compounds of nectarine fruit during low-temperature storage

Abstract

Free and glycosidically bound volatiles are two essential aroma compounds contributing to the flavour of nectarine fruits. To explore the relationship between free and bound volatiles in nectarine fruits during postharvest storage, they were first harvested and then subjected to the temperatures of 1, 5, and 8°C for 35 d, and the changes in volatile compounds, β-glucosidase (β-Glu) activity, and the expression of UGT (UDP-glucosyltransferase) involved in the accumulation of bound linalool were determined. Results showed that nectarine fruits stored at 5°C had the lowest contents of free volatile compounds due to damage from chilling injury, and the contents of esters and lactones decreased at 1 and 5°C. The contents of bound volatiles increased during the early storage period, and decreased afterwards due to an increase in β-Glu activity. Corresponding to the higher contents of bound volatiles at 1°C, the β-Glu activity in nectarine fruits stored at 1°C was significantly lower than that in nectarine fruits stored at the other two temperatures.