Abstract: 【Objective】This research was conducted to study the effect of postharvest treatment on the storage quality and antioxidant enzyme system of Pleurotus eryngii and to provide a theoretical guide for the application and development of postharvest preservation of Pleurotus eryngii. 【Method】Fresh mushrooms, treated by 1.5% chitosan coating, 0.03 mm and 0.05 mm PE film packaging, respectively, were stored at 4℃ and RH 85%-95%. Mushrooms packed with 0.05 mm PE without sealing were used as the control. Based on analysis of main quality indexes, including weight loss rate, color, firmness, total soluble solids (TSS) content, reducing sugar content and total soluble protein content, antioxidant enzyme activities of peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT), conductivity, malondialdehyde content, superoxide anion and H₂O₂ content, effects of different postharvest treatment methods on the storage quality and antioxidant enzyme system were studied in stored P. eryngii.【Result】The results showed that compared with the control, 0.05 mm and 0.03 mm PE film packaging could significantly reduce the weight loss rate (P＜0.01). On the 18 d of storage, the weight loss rates of 0.05 mm and 0.03 mm PE treatments were 0.20% and 0.35%, respectively. The firmness of mushrooms in two PE treatments were significantly higher than those in the control (P＜0.05). Moreover, there were two peak values in the firmness curves of 0.05 mm and 0.03 mm PE treatments, appearing on 3rd day and 12th day, respectively. Browning in two PE treatments was not obvious. However, browning degree of 0.03 mm PE treatment significantly increased during the final storage (P＜0.05). Two PE treatments could significantly inhibit the increase of total soluble solids (TSS) and soluble proteins and slow down the decrease of reducing sugar content (P＜0.05). The 1.5% chitosan coating treatment could significantly increase the firmness during 0-9 d storage (P＜0.05), then the firmness decreased rapidly. But mushrooms in 1.5% chitosan coating treatment exhibited higher weight loss rate, which had no significance compared with the control (P＞0.05). Chitosan coating mushrooms showed low browning index, but at the end of storage, browning in chitosan coating treatment was significantly higher (P＜0.05). The changes of total soluble solids (TSS), reducing sugar and total soluble protein of chitosan coated mushrooms were significantly lower than those of the control in the mid and late storage. To a certain extent, the three treatments enhanced the antioxidant ability of stored P. eryngii compared with control. Three treatments could significantly decrease the cell membrane permeability and the content of membrane lipid peroxidation products MDA (P＜0.05). The conductivity and malondialdehyde content of chitosan coated mushrooms were significantly higher than those of two PE treatments in the mid and late storage. The 0.03 mm PE packaging and chitosan coating treatment could effectively reduce superoxide anion (O₂^-.) generation rate and inhibit hydrogen peroxide (H₂O₂) generation rate (P＜0.05). Meanwhile, 0.05 mm PE packaging treatment could significantly reduce hydrogen peroxide (H₂O₂) generation rate (P＜0.05). However, the superoxide anion (O₂^-.) generation rate of 0.05 mm PE treatment was significantly higher than the control during 3-12 d storage. And the higher peroxidase (POD) and catalase (CAT) activities were observed in these treatments in the early and late storage (P＜0.05). However, no significant difference in superoxide dismutase (SOD) activity was observed in these treatments throughout storage.【Conclusion】From the above mentioned, better storage qualities and higher antioxidant ability were observed in two PE packaging treatments during the whole storage, of which, 0.05 mm PE packaging was clearly superior in terms of maintaining overall quality of stored P. eryngii.

Key words: Pleurotus eryngii, postharvest treatment, storage quality, antioxidant enzyme system