红外辐照下马铃薯多酚氧化酶失活机理的研究

项目名称： 红外辐照下马铃薯多酚氧化酶失活机理的研究

项目编号： No.31071622

项目类型： 面上项目

立项/批准年度： 2011

项目学科： 金属学与金属工艺

项目作者： 李树君

作者单位： 中国农业机械化科学研究院

项目金额： 8万元

中文摘要： 马铃薯种植广、营养丰富、加工量越来越大，在很多地区已成为农民收入的重要支柱产业。加工过程常使用漂烫和脱水两个过程来延长货架期，使酶失去活性和降低水分活度。项目提出的红外能灭酶较漂烫灭酶具有处理时间短，能耗小，无污染水排放的优势。通过比较马铃薯片经红外和漂烫两种灭酶处理后，多酚氧化酶相对活性，亮度，色度及Vc含量的变化，采用多元非线性拟合方法优化得到两种方法的最佳工艺参数。利用圆二色谱分析处理后多酚氧化酶结构变化，结合酶活性的变化进行二者的比较，进而从蛋白质分子二级结构的角度探究红外灭酶下热和非热效应与多酚氧化酶失活关系。本项目的研究将水果蔬菜加工中能源的节约和减少环境污染，同时有助于理解红外能下微观结构上酶的失活机理。

中文关键词： 马铃薯;红外灭酶;漂烫灭酶;最佳工艺参数;蛋白质二级结构

英文摘要： Potato becomes an important pillar industry of many farmers’revenue, for its being widely planted, rich in nutrition and more and more production. Blanching and evaporation are two mainly used processing method to extend potato’ shelf life, which inactivate enzyme and decrease water activity. The method of using infrared to inactive enzyme proposed by the project has the advantages of processing time，energy consumption decreasing and clean water discharge. The changes of potato polyphenol oxidase relative activity, brightness, chromaticity and Vc content were inspected by comparing potato slice processed with infrared and hot water blanching inactivation process respectively. The optimum technology parameters were obtained by using multivariate nonlinear fitting method. Using circular dichroism(CD) application to analyse structure changes of PPO after processing. Comparing the activity of PPO under the two processing，explore the thermal and the non thermal mechanism of inactivation of PPO under the infrared processing from the secondary structure of protein. The research on this project will help to save the energy during the fruits and vegetables processing and to decrease environmental pollution understand the infrared diabatic process, the enzyme inactivating process, and help people to understand the mechanism of the enzyme inactivation of micro structure.

英文关键词： Potato;Infrared inactivation;Blanching inactivation;Optimum technology parameters;Secondary structure of protein