Effects of 24-epibrassinolide on the postharvest quality and antioxidant activities of blueberry fruits

In this study, blueberry fruits (Vaccinium corymbosum cv. ‘Bluerain’) were sprayed with different concentrations (0.25, 0.5, 0.75, and 1 mg/L) of exogenous 24-epibrassionolide (EBR) after harvest and kept at 18°C and relative humidity of 90∼95% for 8 d. By observing the decay incidence and firmness changes, the optimal treatment concentration (0.75 mg/L) was screened, and then the effects of 0.75 mg/L EBR treatment on fruit quality and antioxidant activities were further explored. The results showed that EBR treatment could delay the decrease in firmness, total soluble solids, and acidity; maintain the contents of nutritional components, such as ascorbic acid, total phenol, and the total anthocyanin; and promote the activities of antioxidant enzymes, especially SOD and PAL, thereby helping to maintain the balance of reactive oxygen species and reduce the degree of membrane lipid peroxidation, as reflected by the content of MDA, and delaying the senescence process of blueberry fruit. Taken together, EBR treatment could help maintain the nutritional components of blueberry fruit and could be used as a new alternative reagent for blueberry preservation.