Postharvest hot air and UV-C treatments enhance aroma-related volatiles by simulating the lipoxygenase pathway in peaches during cold storage

Hot air (HA) treatment and ultraviolet C (UV-C) irradiation have been demonstrated to control chilling injury in peaches. However, little is known about the effects of HA and UV-C treatments on volatiles changes in peach fruit during cold storage. In this study, peaches were treated with HA at 40 degrees C for 4 h or irradiated with UV-C lamp (1.5 kJ/m(2)), and then stored at 1 degrees C for 35 days plus 3 days of shelf life at 20 degrees C. Results showed that HA and UV-C suppressed chilling injury significantly, exhibiting lower internal browning index. Also, the two treatments enhanced emissions of esters and lactones in peaches by increasing enzymes of alcohol acyltransferase (AAT), fatty acid desaturase (FAD) acetyl coenzyme A transferase (ACX). These suggested that the increase of fruity note aromas in peaches by the two treatments is closely associated with aroma-related metabolism (LOX pathway and lactone pathway).