Short hot water as safe treatment induces chilling tolerance and antioxidant enzymes, prevents decay and maintains quality of cold-stored cucumbers

This study investigated the effects of treating cucumbers with short hot water dipping at 45 (SHW45) and 55 °C (SHW55) for 5 min compared to fruit dipped in 25 °C water (C). The purpose was to alleviate chilling injury, prevent decay, maintain sensory quality and induce antioxidant enzymes during storage. The cucumbers were held at 4 °C for 7, 14 and 21 d and shelf life at 20 °C for 2 and 4 d. Weight loss, appearance, decay, color, firmness, taste, soluble solids content (SSC), chilling injury (CI), total, reducing and non-reducing sugars, phenolics, electrolyte leakage (EL), peroxidase (POD) and catalase (CAT) activity were measured. The results revealed that SHW55 treatment had the lowest weight loss, CI, EL and POD activity, and had the best appearance, color, taste, and the highest CAT activity during cold storage and shelf life compared with C and SHW45. However, no significant effects were found between C, SHW45 and SHW55 on total, reducing sugars and SSC. No decay appeared on cucumber fruit with SHW55 treatment during the storage period. It may be possible to use SHW55 in a packinghouse as a safe commercial treatment to maintain quality, prevent decay and mitigate chilling injury, prolong storage period and possibility to store cucumber fruit at a non-optimal low temperature.