Effects of UV-C irradiation on the physiological and antioxidant responses of button mushrooms (Agaricus bisporus) during storage

Novel postharvest technology not only preserves the freshness of fruits and vegetables, but also triggers the biosynthesis of antioxidant compounds as a secondary response. This study examined the browning and antioxidant properties of button mushrooms (Agaricus bisporus) treated with UV-C irradiation in combination with cold storage. Three sample preparation methods for antioxidant activity analysis, simulative gastrointestinal digestion (GAR), direct evaluation (QUENCHER) and traditional solvent extraction (TSE), were used to evaluate the samples, and followed analysing by both FRAP and ABTS assays. Broadly, the results indicated that, following an initial increase, UV-C irradiation suppressed browning during a cold storage period of 18 days. And the total phenolic content of the treated mushrooms were higher than that of the control, while the ascorbic acid content decreased sharply during storage, and UV-C treatment had negative effects on ascorbic acid content. Results from the QUENCHER and GAR methods showed that UV-C treatment significantly increases the total antioxidant capacity (TAC) of mushrooms throughout the entire storage period, and have a larger magnitude than that of TSE method. In conclusion, the combination of UV-C irradiation and cold storage showed great potential for improving mushroom quality as a new postharvest technology.