小麦粉多酚氧化酶活性测定方法的改进  

Improvement in methods for activity measurement of polyphenol oxidase in wheat

作　　者：周小玲 杨代明 李娜 

机构地区：[1]湖南省振华食品检测研究院,湖南长沙410000

出　　处：《食品与机械》2015年第6期84-87,共4页Food and Machinery

摘　　要：选取3个小麦粉作为试验材料,对国家标准征求意见稿《粮油检验小麦粉多酚氧化酶测定》的方法进行检验,发现该法因缺少PPO粗酶提取过程,参加反应的酶量较少,不能反映小麦粉真实的PPO活性;其次PPO与底物的反应温度不是最适宜的,导致酶反应不充分;第三酶反应后再离心,使得一部分酶反应产物被沉淀截留,导致检测数据小且不准确。文章在该基础上对其进行改进,考察浸提时间、最适反应温度、底物邻苯二酚添加时间对PPO活性检测的影响,优化该检验方法。结果表明:优化后的检验方法测得的结果较为理想,采用浸提4h、离心后添加邻苯二酚、反应温度70℃,测得的PPO活性数值大大提高,重复性好,稳定可靠。并采用改进后的方法检测了50种小麦粉,得出不同等级的小麦粉PPO的范围。Three wheat varieties were selected as experimental materials to measure the activity of polyphenol oxidase According to the method from Measurement of Polyohenol Oxidase Activity in Wheat Flourin national standard draft.And found it has three deficiencies：first,because of the lack of crude extcation of polyphenol oxidase,it led to the less quantity of polyohenol oxidase,and couldn＇t reflect the real state of the activity of polyphenol oxidase;second,because of the unsuitable reaction temperature,it couldn＇t help the enzyme reaction completely;third,adding catechol before centrifuge made a part of product intercepted by precipitation,thus it has poor stability and exhibited small activity of polyphenol oxidase.Based on this method,explored the influences of different factors on the determination of activity of the polyphenol oxidase to optimize the method,including the extraction time,the heat temperature,and the time for adding substrate.The results revealed of the optimum method seems to be better than before,the optimum process were：extraction 4h,add catechol after centrifuge,heat at 70 ℃in 15 min,and could get higher activity of polyphenol oxidase and had better repeatability,it was more reliable and stable.Also detected 50 wheat varieties by these two methods,and divided special noodles flour into different level by the activity of polyphenol oxidase.

关 键 词：多酚氧化酶 最佳条件 小麦粉等级与PPO范围 

分 类 号：TS211.7[轻工技术与工程—粮食、油脂及植物蛋白工程]