Effect of ozone treatment on the quality and enzyme activity of Lentinus edodes during cold storage

The purpose of this research was to optimize ozone treatment concentration and investigate the one-time ozone treatment (OOT) and intermittent ozone treatment (IOT) on the physicochemical characteristics and enzyme activity of Shiitake mushroom (Lentinus edodes). The results indicated that the optimal ozone-treated concentration was 3.21 mg/m(3). IOT effectively delayed mushroom browning through the inhibition of polyphenol oxidase (PPO) activity, and promotion of phenylalanine ammonia-lyase (PAL), peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) activities. It also maintained high levels of total phenolic and soluble protein content, and reduced the accumulation of free amino acids in mushrooms. The treatment reduced the total number of colonies, molds, and yeasts. Statistical analysis indicated that L* was remarkably positively correlated with POD, CAT, PAL, SOD activity, total phenolic content, and was negatively correlated with the total number of colonies, yeast, and mold. It was concluded that IOT was effective in maintaining mushroom quality and prolong storage life. Practical applications Lentinus edodes are one of the most popular edible fungi due to its high nutrition value; however, they are prone to quality deterioration during storage. This study presents the application of one-time ozone treatment (OOT) and intermittent ozone treatment (IOT) to improve the physicochemical characteristics and antioxidant enzyme activities of mushrooms. The finding revealed that IOT could effectively improve the quality of mushrooms by maintaining high level of nutrients, improving the antioxidant enzyme activities, and inhibiting the growth of the microorganisms. This work may provide a potential preservative for maintaining quality and extending the shelf-life in the processing and preservation of shiitake mushrooms.