活性氧在鲜切果蔬酚类物质合成积累中的信号作用研究

The consumption of fresh-cut fruits and vegetables has been increasing with the improvement of living condition and change of living style. How to increase phenolic antioxidants and thus improving the health benefits of these fresh-cut produce has become future research direction in fresh-cuts industry. In this project, the effects of different wounding intensity on quality parameters, main individual phenolic compounds as well as total phenolics content, activities and gene expression of major phenolic biosynthesis-related enzymes, reactive oxygen species (ROS) production and antioxidant enzymes activities in fresh-cut pineapple, Hami melon, carrot and purple radish will be investigated. Meanwhile, the effect of ROS production inhibitor or inducer treatment on biosynthesis of phenolic compounds will also be evaluated to explore the possible signaling role of ROS on the accumulation of phenolic antioxidants in these fresh-cut produce. In addition, the effects of UV-C or methyl jasmonate (MeJA) treatment on enhanced phenolics biosynthesis and its relation to ROS production will be investigated to further determine the signaling role of ROS. The study will not only facilitate to elucidate the regulation mechanisms of wounding -induced phenolics biosynthesis, but lay the foundation for increasing phenolic antioxidants and thus improving the health benefits of fresh-cut produce by postharvest treatments.

随着人们生活水平的提高和生活节奏的加快，鲜切果蔬已逐渐成为果蔬消费的主流。如何提高鲜切果蔬产品中多酚类物质等活性成分的含量和抗氧化活性，从而提高产品的营养保健功效，也已成为鲜切果蔬加工和保鲜技术研究的发展方向。本项目以菠萝、哈密瓜、胡萝卜和紫心萝卜等果蔬为试材，研究不同切割方式对鲜切产品主要品质指标、总酚和主要酚类物质单体含量、酚类物质合成关键酶活性和基因表达、活性氧（ROS）产生和清除酶活性变化的影响，同时研究ROS产生诱导剂和抑制剂处理对AOS产生和酚类物质合成的影响，以探索ROS在鲜切果蔬酚类物质合成积累中的信号作用；在此基础上，研究UV-C和MeJA处理对鲜切果蔬酚类物质合成和ROS产生的影响，进一步明确ROS在鲜切果蔬酚类物质合成中的信号作用。本研究不仅可以深入揭示鲜切果蔬中酚类物质合成的调控机理，同时也为通过采后处理提高鲜切果蔬中的酚类物质含量，从而提高产品的营养品质提供依据。

随着人们生活水平的提高和生活节奏的加快，鲜切果蔬已逐渐成为果蔬消费的主流。如何提高鲜切果蔬产品中多酚类物质等活性成分的含量和抗氧化活性，从而提高产品的营养保健功效，也已成为鲜切果蔬加工和保鲜技术研究的发展方向。本项目以火龙果和胡萝卜等8种果蔬为试材，研究了不同切割方式对鲜切产品主要品质指标、总酚和主要酚类物质单体含量、酚类物质合成关键酶活性和基因表达、活性氧（ROS）产生和清除酶活性变化的影响，同时研究ROS产生诱导剂和抑制剂处理及UV-C和MeJA处理对鲜切果蔬酚类物质合成和ROS产生的影响，以探索ROS在鲜切果蔬酚类物质合成积累中的信号作用。结果表明，鲜切果蔬贮藏期间酚类物质的合成积累与果蔬种类、切割方式和贮藏温度有关，鲜切火龙果、胡萝卜和红心萝卜酚类物质增加显著，且切割损伤强度越大和贮藏温度越高，ROS产生越多，酚类物质合成关键酶活性和基因表达越高，酚类物质的合成积累越多，抗氧化活性越高。采用ROS产生抑制剂碘化二苯基碘（DPI）处理可抑制鲜切胡萝卜和火龙果贮藏期间ROS产生和酚类物质的合成积累；而采用ROS产生促进剂葡萄糖/葡萄糖氧化酶（G/GO）处理则促进ROS产生和酚类物质的合成积累。UV-C和MeJA处理可延缓鲜切胡萝卜和火龙果贮藏期间品质的下降，同时促进ROS的产生，提高酚类物质合成关键酶活性和基因表达，进一步提高酚类物质的合成积累和抗氧化活性。这些结果证实了ROS在鲜切果蔬酚类物质合成积累中发挥着重要的信号作用。本研究不仅深入揭示了鲜切果蔬中酚类物质合成的调控机理，同时也为通过采后处理调控ROS产生进而提高鲜切果蔬中的酚类物质含量，从而提高产品的营养品质提供依据。