臭氧精准处理提高采后草莓抗氧化酶活性和酚类物质含量.

Ozone treatment is considered as an effective and non-polluting method of storage and preservation, and the strong oxidizing effect of ozone is also considered to have an effect on the active oxygen scavenging system of harvested fruits and vegetables. The inhibition of reactive oxygen species of non-enzymatic, enzymatic scavenging system of post-harvest ‘Jing Tao Xiang’ strawberry，which are wide-planted in Tianjin, treated with different ozone concentrations (0, 2.144, 6.432, 10.72 and 15.008 mg/m3) was investigated in this study. Post-harvest strawberries were treated for 5 h every 7 days in an ozone preservation device independently developed by the National Preservation Engineering Technology Research Center (Tianjin), and then quickly transferred to a 4 °C cold storage. Total phenols content (TPC), total flavonoids content (TFC), and ascorbic acid (ASA) were detected as key non-enzymatic antioxidants, while superoxidase (SOD), peroxidase (POD), and ascorbate peroxidase (APX) were detected as key enzymes in the enzymatic antioxidant system. Results showed that for non-enzymatic antioxidant system, the total phenolics of post-harvest strawberry in the ozone treatment group of 2.144, 6.432 and 15.008 mg/m3 had a certain accumulation during the whole storage period, but lower than the control group. The content of flavonoids in the 2.144 and 15.008 mg/m3 treatment groups decreased continuously throughout the storage period, while the content in the 6.432 mg/m3 treatment group decreased and then increased, but the contents in the three treatment groups were lower than the control group; the ASA content did not change much in the control group, but decreased continuously in the 2.144, 6.432 and 15.008 mg/m3 treatment groups, and the 15.008 mg/m3 ozone treatment group had the largest decline. Compared with the control group and other three different concentrations of ozone treatment group. However, 10.72 mg/m3 ozone treatment significantly promoted the formation of phenolic compounds and ascorbic acid, maintained the total flavonoid content at a higher level, and which was conducive to the formation and accumulation of non-enzymatic antioxidant nutrients. For the enzymatic antioxidant system, high concentrations of O3 treatment rapidly induced an increase in POD activity in strawberry fruit. However, as the storage time prolonged, the decreasing trend appeared rapidly in the 15.008 mg/m3 treatment group. Compared with the control group, the enzyme activity of the 2.14 mg/m3 concentration O3 treatment group did not change much, but the enzyme activity of the 6.432 mg/m3 treatment group was inhibited. However, the SOD activity of 10.72 mg/m3 ozone treatment group was significantly increased (P<0.05), and the maximum value was advanced, the activity of APX was also enhanced. The activity of POD enzyme activity of 10.72 mg/m3 O3 treatment group was stimulated, and the peak of POD activity was delayed. Overall, ozone treatment at a concentration of 10.72 mg/m3 could enhance the enzymatic reaction activity of the redox system of postharvest strawberry and increase the content of non-enzymatic reaction substances, which had a positive effect on the accumulation of antioxidants in postharvest strawberries and was conducive to improving the edible value and economic value of post-harvest strawberries. [ABSTRACT FROM AUTHOR]