青花椒干燥过程叶绿素光降解原因初探

Studies on the Photodegradation Mechanism of Chlorophyll from Green Prickleyash during Drying Process

为了探究青花椒干燥过程中变色的机理,以鲜青花椒为研究对象,采用黄、蓝、紫外光3种单色光及日光(复合光)照射鲜青花椒至干燥。以遮光干燥为对照,研究干燥过程中青花椒中还原型谷胱甘肽(GSH)、抗坏血酸(ASA)、超氧化物歧化酶(SOD)、过氧化物酶(POD)、超氧自由基(O2-)、过氧化氢(H2O2)、丙二醛(MDA)等与活性氧有关的指标的变化以及叶绿体膜脂肪酸组成和含量的变化。结果表明:紫外光是造成青花椒干燥过程中叶绿素降解的主要单色光。在光照射下,青花椒体内活性氧的产生,活性氧清除系统能力的降低及叶绿体膜脂的脂肪酸比例改变,使活性氧中的小分子更容易进入叶绿体中,从而加速叶绿素的降解。

In order to explore the green pepper discoloration during drying mechanism, the paper use fresh green pepper as the research object, using yellow, blue, ultraviolet three kinds of monochromatic light and sun（composite light） irradiation of fresh green pepper until dry, shading to dry for comparison. To study the green pepper glutathione（GSH）, ascorbic acid（ASA）, superoxide dismutase（SOD）, peroxidase（POD）, superoxide radical（O2-）, peroxide（H2O2）,malondialdehyde（MDA） etc. which is related reactive oxygen species changes and chloroplast membrane fatty acid composition and content changes in the drying process. The results showed that UV light is green pepper drying process caused the degradation of chlorophyll a major monochromatic light. Green pepper chlorophyll photodegradation mechanism ： In the light irradiation, green pepper in vivo generation of reactive oxygen species, reactive oxygen scavenging system and the ability to reduce the proportion of chloroplast membrane lipid fatty acids alter the activity of small molecules of oxygen easier access to the chloroplast, which accelerate the degradation of chlorophyll.