Effects of postharvest application of methyl jasmonate on physicochemical characteristics and antioxidant system of the blueberry fruit

The effects of postharvest methyl jasmonate (MeJA) treatment on quality, antioxidant system, and H2O2 content in blueberry fruit were investigated. Results indicated that 50 and 100 mu mol/L MeJA treatment could reduce the increase in weight loss, maintain sensory and nutritional qualities, and prolong the shelf-life of blueberry. Meanwhile, MeJA significantly increased the antioxidant capacity by increasing the content of non-enzymatic antioxidants, namely, phenolics, flavonoids, anthocyanin, ascorbic acid, reduced glutathione, and the activity of enzymatic antioxidants, namely, superoxide dismutase, catalase and ascorbate peroxidase. However, increased H2O2 generation was detected in MeJA-treated fruits during the initial period, which occurred before peaks in antioxidant levels. This result suggests that H2O2 was induced by MeJA, which may act as a signaling molecule involved in the regulation of antioxidant system of blueberry during storage. In summary, MeJA treatment could increase the antioxidant capacity of postharvest blueberry by activating the generation of H2O2.