减压处理对草莓贮藏效果及活性氧代谢影响的多变量解析

Multivariate Analysis of Hypobaric Treatment on Fruit Quality and Active Oxygen Metabolism of Strawberry during Postharvest Ripening

综合主成分分析、偏最小二乘回归分析、通径分析以及相关性分析探讨减压处理对草莓果实氧化及抗氧化活性的影响。结果表明,两种减压处理均抑制了贮藏前期草莓腐烂指数的增加,相对而言76.3 k Pa的作用效果更为显著。此外,减压处理还提高了贮藏2 d时果实中GSH含量,延缓了羟自由基、超氧阴离子、ABTS自由基清除能力及PPO活性的下降。主成分分析结果显示,76.3 k Pa压力对草莓贮藏前期总抗氧化能力、总酚含量以及后期腐烂指数、超氧阴离子清除能力、DPPH自由基清除能力、过氧化氢和MDA含量均有显著的影响;51.3k Pa压力对贮藏后期花青素含量、CAT活性及总还原能力作用效果更为显著。由偏最小二乘分析可知草莓果实腐烂指数与LOX活性、MDA含量呈正相关,与过氧化氢含量、GSH含量、超氧阴离子清除能力、DPPH自由基清除能力、羟自由基清除能力呈负相关。由通径分析可知,过氧化氢含量与CAT活性对草莓的腐烂指数起决定作用。

The effects of hypobaric treatments on fruit quality and active oxygen metabolism of strawberries 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 of one-way analysis of variance indicated 51.3 kPa treatment significantly inhibit the increase of the fruit decay rate and the decrease of total polyphenols and flavonoids content, as well as elevated the DPPH radical scavenging capacity, total reducing power and the CAT activity at the end of the storage. 76.3 kPa showed an efficient elevation of PPO and POD activity, in addition, a remarkable increase of total antioxidant capacity （FRAP） and TEAC （ABTS scavenging capacity） were observed in the fruit after 2 days of storage. In addition, fruit of 76.3 kPa exhibited a obvious impact on total antioxidant capacity （FRAP） and total reducing power at the storage of 2 days, as well as the fruit decay index, NBT, DPPH radical scavenging capacity and H202 content, MDA content after 4 days from the result of the principal component analysis（PCA）. In contrast, 51.3 kPa showed a greater impact on anthocyanins, CAT activity and total reducing power. While partial least squares regression （PLSR） showed that fruit decay rate was positively correlated with .LOX activity and MDA content but showed an negative correlation with H202 con- tent, NBT, GSH content, DPPI-I radical scavenging capacity and hydroxyl radical-scavenging capacity. Result from the path coefficient analysis indicated that H202 content and the CAT activity had the most prominent impact on the fruit decay rate, whereas the decay rate and the CAT activity seemed to be the key factor of the H202 content.