Abstract: In order to explore the effect of ozone micro-nano-bubbles (MNBs) on the postharvest quality of fruits and vegetables, spinach was treated with 4 mg/L ozone MNBs for 5 min and stored at (20 ± 1) ℃ for 8 d. By measuring and analyzing the changes of physiological indexes during storage, the effect of this treatment on the quality of spinach was studied. The results showed that ozone MNB treatment could effectively alleviate cell membrane damage, reduce the accumulation of malondialdehyde (MDA) and maintain the integrity of cell structure. This treatment could inhibit respiration and ethylene release and slow down the consumption of nutrients and the senescence process, thereby improving the storability of spinach. It also could delay the loss of chlorophyll and vitamin C, reduce the deterioration of sensory quality and nutrient quality of spinach, and alleviate oxidative damage by reducing the accumulation of hydrogen peroxide and enhancing peroxidase, catalase and ascorbic acid peroxidase activity. To sum up, ozone MNBs can preserve the quality of spinach with a low mechanical damage, and the experimental results from this study provide a theoretical basis for the application of ozone micro-nano-bubbles in the preservation of postharvest fruits and vegetables.

Key words: ozone micro-nano-bubbles; spinach; postharvest preservation