Ethanol vapor ameliorates chilling injury and maintains postharvest quality by increasing antioxidant capacity of hardy kiwifruit (Actinidia arguta)

Hardy kiwifruit (Actinidia arguta) stored at room temperature has a limited shelf life, and improper low-temperature storage can cause chilling injury. To address this issue, we applied ethanol vapor pre-treatment at concentrations of 250, 500, and 1000 μL L−1 and evaluated postharvest quality under low-temperature conditions (1 ± 1 °C). Our research revealed that lower concentrations of ethanol vapor (250–500 μL L−1) effectively mitigated chilling injury, delayed adverse physiological changes, such as superficial scald, softening, and rot, and enhanced the antioxidant system of A. arguta fruit. Ethanol treatment increased the activity of antioxidant enzymes like peroxidase, superoxide dismutase, and glutathione reductase while maintaining higher levels of non-enzymatic antioxidants like total phenolics, total flavonoids, ascorbic acid, and glutathione. It also improved the antioxidant capacity as assessed by various methods. Principal component analysis and overall scores demonstrated that ethanol vapor treatment significantly improved A. arguta fruit's antioxidant capacity and postharvest quality, extending the optimal consumption period by 14 d. This highlights ethanol's potential application in preserving A. arguta fruit's postharvest quality and enhancing its antioxidant capacity.