H2O2促进采后龙眼果实果皮褐变及其对活性氧代谢的影响

H2O2促进采后龙眼果实果皮褐变及其对活性氧代谢的影响张珅1, 2，林艺芬1, 2，林河通1, 2 基金项目：教育部高等学校博士学科点专项科研基金项目（20093515110011）、国家自然科学基金项目（30671464、30972070、31171776）、福建省自然科学基金项目（2008J0044、2011J01079）、福建省高等学校新世纪优秀人才支持计划资助（闽教科〔2007〕20号）作者简介：张珅，博士生。主要从事农产品加工及贮藏工程研究。Email：23dfyf6@163.com 通讯作者：林河通，教授，博士，博士生导师。主要从事农产品加工及贮藏工程研究。Email：hetonglin@163.com ，陈艺晖1, 2，陈梦茵1, 2，林钟铨1, 2 （1.福建农林大学食品科学学院, 福州 350002；2.福建农林大学农产品产后技术研究所, 福州 350002）摘要：研究了外源活性氧过氧化氢（H2O2）对采后龙眼果皮褐变和活性氧代谢的影响。采后龙眼果实用6% H2O2浸泡20 min,以蒸馏水处理的果实为对照，果实晾干后用0.015mm厚的聚乙烯薄膜袋包装，在（15±1)℃下贮藏。结果表明，与对照果实相比，H2O2提高了龙眼果皮褐变指数。同时，H2O2促进了产生速率增加，且在整个贮藏过程维持较高水平。H2O2促进果皮活性氧清除酶SOD和APX活性和内源抗氧化物质GSH、AsA、类胡萝卜素含量下降，MDA含量增加。据此认为，H2O2促进龙眼果皮褐变可能是因为H2O2促进活性氧的产生，降低活性氧清除能力，导致活性氧积累和膜脂过氧化作用增强而破坏细胞膜系统的区室化功能，最终使酚酶和酚类物质接触，酚类物质被氧化而形成黑褐色高聚物的结果。关键词：龙眼；果实；果皮；褐变；活性氧；过氧化氢（H2O2）；活性氧代谢 The Relationship between the Hydrogen Peroxide-induced Browning and the Metabolism of Active Oxygen in Pericarp of Harvested Longan Fruits Zhang Shen1, 2, Lin Yifen1, 2，Lin Hetong1, 2∗, Chen Yihui1, 2, Chen Mengyin1, 2, Lin Zhongquan1, 2 (1.College of Food Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China; 2.Institute of Postharvest Technology of Agricultural Products, Fujian Agriculture and Forestry University, Fuzhou 350002, China) Abstract: Effects of H2O2 (hydrogen peroxide), an exogenous reactive oxygen, on browning and active oxygen metabolism in pericarp of harvested longan fruits were investigated in this paper. The harvested longan fruits were dipped in 6% H2O2 for 20 min, while the control fruits were dipped in distilled water. The fruits were dried prior to packaging and stored at (15±1) ℃. The results showed that，compared with the control fruits, there was a higher browning index in pericarp of H2O2-treated longan fruits. The longan fruits treated with H2O2 resulted in increased rate of production and kept higher rate of production during the whole storage, reduced the activities of SOD, and APX, decreased amounts of AsA, GSH and carotenoid, and increased MDA content. From the results it can be concluded that H2O2-induced browning of longan pericarp may be due to the increased production of active oxygen, the decreased capacity of scavenging active oxygen and the accumulation of active oxygen caused by H2O2 treatment, which may destroy cell membrane system, allowing phenolase to react with phenolic substrates and oxidation phenolics to form brown polymers. Key words: longan (Dimocarpus longan Lour.); fruit; pericarp; browning; active oxygen; hydrogen peroxide (H2O2); active oxygen metabolism 2