1-MCP和ClO_2对蓝莓果实抗氧化活性影响的多变量分析

Multivariate Analysis of Effect of 1-Methylcylclopropene and Chlorine Dioxide on Antioxidant Activity of Blueberry

利用多变量分析方法探讨1-甲基环丙烯(1-MCP)和二氧化氯(ClO_2)单独及其复配处理对蓝莓果实的贮藏效果及抗氧化活性的影响。单因素方差分析表明,在1℃贮藏及货架期内,5μL/L 1-MCP+25μg/L ClO_2处理可有效促进果实总黄酮含量、还原力和DPPH清除能力的提高;75μg/L ClO_2处理可显著抑制蓝莓果实总酚下降,提高果实羟离子清除能力;5μL/L 1-MCP在货架期期间能明显提高蓝莓果实FRAP、还原力、超氧阴离子和DPPH清除能力,延缓果实总黄酮含量降低。主成分分析表明,15μL/L 1-MCP对蓝莓果实在低温贮藏22 d时的总酚、FRAP、超氧阴离子和DPPH清除能力的影响较显著,而15μL/L 1-MCP处理和75μg/LClO_2处理在贮藏后期对果实还原力、TEAC和羟自由基清除能力的影响有明显差异。由通径分析结果可知,DPPH清除能力和超氧阴离子清除能力与FRAP呈极显著正相关性,超氧阴离子清除能力是影响FRAP、还原力变化的决定因素。

The influence of five postharvest fumigation treatments on storage effect and antioxidant properties of blueberry were analyzed using multivariate analysis. The results of one-way analysis of variance showed that the treatment of 1-MCP＋ClO2 significantly promoted total flavonoids, reducing power and DPPH radical scavenging ability tff blueberry fruit during storage at 1 ℃ and subsequent shelf life. In similar, the decline of total phenol was restrained and the hydroxyl radical scavenging capacity was improved in fruit treated by 75 ~g/L ClO2. In contrast, the treatment of 5 μL/L 1- MCPenhanced FRAP, reducing power and the scavenging activity of superoxide and DPPH radical, whereas delayed the content of total flavonoids during the shelf life. Principal component analysis （PCA） showed that total phenol, superoxide and DPPH radical scavenging activity, and FRAP were influenced by 15 μL/L 1-MCP at the early stage of storage. 15 μL/L 1-MCP and 75 μg/L ClO2 had a significant difference in reducing power, TEAC and hydroxyl radical scavenging capacity. Path analysis showed that FRAP was correlated strongly in a positive manner with DPPH radical and superoxide scavenging activity, while superoxide scavenging activity were the key factors which affected FRAP and reducing power of the blueberry fruit.