Abstract: To evaluate the effect of ozone treatment on maintaining the postharvest storage quality of fresh sweet-waxy corn, fumigation treatment with 90 mg/m3 ozone for 20 minutes was applied, followed by storage at 20 ℃. Compared with the control group, ozone treatment significantly inhibited the growth of the spoilage microorganism Pseudomonas and starch accumulation on day 8 of storage. Additionally, the treatment maintained higher levels of soluble sugars and α-amylase activity, significantly suppressed lipoxygenase (LOX) activity while preserving alcohol dehydrogenase (ADH) activity, thereby helping to maintain corn sweetness and flavor. Regarding stress resistance, ozone treatment markedly increased the activity of phenylalanine ammonia-lyase (PAL) and elevated the contents of total phenols, flavonoids, and reduced glutathione (GSH), while decreasing malondialdehyde (MDA) accumulation. Furthermore, it enhanced the activities of key antioxidant enzymes, including catalase (CAT), superoxide dismutase (SOD), ascorbate peroxidase (APX), and peroxidase (POD), while inhibiting polyphenol oxidase (PPO) activity, collectively strengthening the antioxidant defense system of corn. In conclusion, ozone treatment effectively delays the senescence of fresh sweet-waxy corn during storage and extends its shelf-life by inhibiting microbial growth and activating the antioxidant defense system.

Key words: fresh sweet-waxy corn; ozone; microbial diversity; ripening and senescence; quality