不同挥发性物质对桃果实品质及抗氧化活性影响的多变量分析

采用单因素方差分析、主成分分析、相关性分析、偏最小二乘回归分析、通径分析5种数据分析方法考察1-甲基环丙烯(1-MCP)、二氧化氯、百里酚和乙醇处理对桃果实品质及抗氧化活性的作用效果。结果表明：乙醇处理可显著抑制常温贮藏4d后桃果实侵染性病害的发生，其他处理与空白对照无显著性差异；1- MCP 处理延缓了桃果皮b*值的升高，乙醇处理提高果皮L*值的同时降低了果皮a*值；与空白对照相比，乙醇、1-MCP及二氧化氯处理对总黄酮含量、总抗氧化能力、清除DPPH自由基能力、清除·OH能力4个指标的影响较为显著。结合相关性分析与回归分析可知，腐烂率仅与可溶性固形物含量(SSC)呈显著负相关；对果皮L*值、果皮a*值、果皮b*值的直接效应最为强烈的参数分别是总黄酮含量、清除DPPH自由基能力、SSC；总酚含量与清除DPPH自由基能力具有显著正相关性；总黄酮含量与总抗氧化能力、清除DPPH自由基及·OH能力也存在显著或极显著相关性效应。

Multivariate Analysis of Fruit Quality and Antioxidant Properties of Peach Treated with Different Volatile Compounds

The effects of individual treatments with different volatile compounds(1-MCP,chlorine dioxide,thymol and ethanol) on fruit quality and antioxidant properties of peach were analyzed by one-way analysis of variance,principal component analysis(PCA),correlation analysis,partial least squares regression(PLSR),and path analysis(PA).The results indicated that ethanol treatment could alleviate peach decay rate after 4 days of storage at 20 ℃.In addition,an increase trend of b* value in fruit skin was observed in peach treated with 1-methylcyclopropene(1-MCP),whereas ethanol treatment resulted in increased L* value and decreased a* value in peach fruit skin.In comparison with control fruits,1-MCP,ethanol and chlorine dioxide treatments had significant effects on total flavonoid content,total antioxidant capacity,and DPPH and hydroxyl free radical scavenging capacities.Collectively,the PLSR and PA results demonstrated that the decay rate of peach fruits was negatively correlated with soluble solid content(SSC).In addition,total flavonoid content,DPPH radical scavenging capacity and SSC revealed the strongest direct impact on fruit skin L*,a* and b* values,respectively.Moreover,the correlation analysis indicated that total phenol content was positively correlated with DPPH radical scavenging capacity.Furthermore,total flavonoid content revealed a significant or highly significant correlation with total antioxidant capacity or scavenging capacity against DPPH and hydroxyl free radicals.