Effects of Storage Temperature on Efficacy of Postharvest Ethanol Vapor Treatment to Suppress Broccoli Senescence

Abstract

　Broccoli (Brassica oleracea L. Italica Group) senesces rapidly after harvest at room temperature. Ethanol vapor treatment with ethanol pads effectively delays senescence at 20℃. We investigated the effects of storage temperature on the efficacy of vapor treatment with ethanol pads to suppress senescence. Broccoli branchlets were placed in a perforated polyethylene bag with or without (control) a 3-g ethanol pad and stored at 25, 20, 15, 10, and 5℃ in the dark. Ethanol treatment delayed yellowing of the broccoli at all temperatures tested except for 5℃. Shelf life of broccoli stored at 15 to 25℃ and at 10℃ was significantly prolonged by ethanol treatment (～1.8- and 1.3-fold, respectively), and there was no effect of ethanol treatment at 5℃. Furthermore, ethanol treatment was effective for maintaining broccoli composition without negative impact, although the effectiveness varied depending on the temperature and composition. Ethanol treatment reduced weight loss and suppressed the decrease in total ascorbic acid, protein, and total sugar content after harvest under storage temperatures of 15 to 25℃, 10 to 25℃, 10 to 25℃, and 20 to 25℃, respectively. These findings indicate the potential applicability of ethanol vapor treatment with ethanol pads to effectively prolong the shelf life of broccoli at a wide range of ambient temperatures.