MeJA处理对枇杷果实采后抗氧化活性的影响

为了探讨MeJA处理对枇杷果实抗氧化能力的影响,研究了10μmol/L MeJA处理的"大红袍"枇杷果实在1℃贮藏过程中维生素C、总酚、总黄酮、总类胡萝卜素含量及抗氧化活性的变化。结果表明,枇杷果实在贮藏过程中维生素C和总黄酮含量下降,而总酚和总类胡萝卜素含量呈先上升后下降的趋势。10μmol/L MeJA处理可显著抑制果实中维生素C和总黄酮含量的下降,促进贮藏前期总酚和总类胡萝卜素含量的上升。在1℃贮藏过程中,枇杷果实DPPH和超氧阴离子自由基清除能力随着贮藏时间的延长呈先上升后下降趋势,并且抗氧化活性的变化与总酚和总类胡萝卜素含量的变化呈显著正相关,而与维生素C和总黄酮含量的变化相关性较低。这表明MeJA是通过影响枇杷果实中酚类和类胡萝卜素物质的代谢来维持枇杷果实采后较高的抗氧化能力和营养价值。

Effect of MeJA Treatment on Antioxidant Activity of Postharvest Loquat Fruit

The change of vitamin C,total phenolics,flavonoids,caroteinoids contents and antioxidant activity in Dahongpao loquat treated with 10 μmol/L MeJA and stored at 1 ℃ was investigated.Results showed that,there was a decline of vitamin C and total flavonoid content and an increase of total phenolic and carotenoids content during the initial storage period but declined during later period.10 μmol/L MeJA inhibited the decline of vitamin C and total flavonoid content and promoted the increase of total carotenoids and phenolic contents during the first 15 days.Both of the DPPH and superoxide anion radical scavenging activities increased in the earlier period and then decreased after 15 days during storage at 1℃.Statistical analysis showed a significant positive relationship between total phenolic and carotenoids content with DPPH and superoxide anion radical scavenging activities.However,no significant correlation among the contents of vitamin C and total flavonoids with radical scavenging activity was observed.These results suggest that 10 μmol/L MeJA treatment maintained higher antioxidant activity and nutrient value in loquat fruit stored at 1 ℃ may be attributed to the effect of MeJA on the metabolism of phenol and carotenoids in loquat fruit.