草鱼肌原纤维蛋白加热过程中理化特性的变化  

Changes in physiochemical properties of grass carp(Ctenopharyngodon Idellus) myofibrillar protein during heat-treatment

作　　者：潘锦锋[1] 沈慧星[2] 尤娟[1] 宋永令[1] 罗永康[1] 

机构地区：[1]中国农业大学食品科学与营养工程学院,北京100083 [2]中国农业大学理学院,北京100083

出　　处：《中国农业大学学报》2009年第6期17-22,共6页Journal of China Agricultural University

基　　金：现代农业产业技术体系建设专项资金资助(NYCYTX-49);国家自然科学基金(30871946);国家科技支撑计划(2008BAD94B06)

摘　　要：考察草鱼肌原纤维蛋白在加热过程中各理化特性的变化规律和机理。结果表明:随着温度的上升,浊度呈S型曲线增加,48℃时上升迅速;黏度呈反S型曲线下降,46℃时下降剧烈;Ca2+-ATPase活性下降,在36～42℃略有上升,46℃时完全失活;总巯基含量从40℃开始显著下降,60～70℃时下降显著。分别于45、55和65℃恒温加热,Ca2+-ATPase活性和黏度随时间延长而下降,浊度上升,温度越高变化越显著;大于50℃恒温加热,总巯基随时间延长而显著下降。草鱼肌原纤维蛋白的DSC扫描图谱在46.37℃和62.59℃出现2个焓变点。SDS-PAGE电泳表明草鱼肌原纤维蛋白在加热过程中(大于45℃)产生了二硫键,说明草鱼肌球蛋白在加热过程中发生了构象变化和分子聚集从而导致了肌原纤维蛋白的热变性。This experiment investigated the changes in physiochemical properties of myofibrillar protein from grass carp during heat-treatment so as to expose the law and mechanism of its thermal denaturation. As temperature rose, turbidity of protein solution increased by s-shape curve and climbed quickly at 48 ℃ Viscosity decreased by inverse sshape curve and greatly declined at 46 13 ℃; Ca^2＋ -ATPase activity decreased gradually with a slight increase from 36 to 42 ℃ and reduced to blank at 46 ℃ ; Total sulfhydryl group began to decrease at 40 13 and distinctively dropped between range of 60 - 70 ~C. As heated under stable temperatures （45, 55, 65 ℃ ）, Ca^2＋-ATPase activity and viscosity declined while turbidity increased as time prolonged, and the higher temperature is, the changes is more obvious; Total sulfhydryl group decreased distinctively as time prolonged under temperatures higher than 50 ℃. Two enthalpy transitions were found at 46.37 ℃and 62.59 ℃ in DSC graph of myofibrillar protein. SDS-PAGE electrophoresis showed the formation of disulfide group at temperature higher than 45 ℃. Results suggested that myosin suffered conformation changes and aggregation during heating period, leading to the great denaturation of myofibrillar protein.

关 键 词：草鱼 肌原纤维蛋白 热变性 理化特性 

分 类 号：TS252.7[轻工技术与工程—农产品加工及贮藏工程]