牛乳及其主要成分相的介电谱及解析  

Dielectric Spectral Analysis of Milk and Its Primary Constituents

作　　者：何克娟[1,2] 运凤侠[1] 赵孔双[1] 

机构地区：[1]北京师范大学化学学院,北京100875 [2]北京理工大学理学院化学物理研究所,北京100081

出　　处：《食品科学》2009年第19期147-152,共6页Food Science

基　　金：国家自然科学基金项目(20673014);中国博士后科学基金项目(20070410467)

摘　　要：测量市售牛乳及其主要成分相蛋白质(胶体溶液)和脂肪(有机溶液和水分散系)的介电弛豫谱,并分别进行介电模型化解析,得到介电参数和相参数,从中获取牛乳,脂肪粒子分散系和蛋白质水溶液的介电和表面性质的信息。研究表明:蛋白质分子被一层结合水包围,使其较高的介电常数降低到水的程度;牛乳中的脂肪颗粒不是实心球体,水分子渗透进入脂肪颗粒内部,这也反映其介电常数与水相差不多。The dielectric relaxation spectra of milk and its primary components like fat particles and protein micell measured and analyzed to obtain dielectric parameters and phase parameters reflecting the dielectric properties and interface characteristics. It was concluded that protein molecules in milk are surrounded by a thin layer of bound water, and thus the permittivity of protein is decreased to the magnitude of pure water （79.02 at 25 ℃）; fat particles in milk can not be considered as solid-core spheres because of the penetration of water, which can be accounted for by the fact that the permittinty of fact is similar to that of water.

关 键 词：介电弛豫谱 介电解析 牛乳 脂肪 蛋白质溶液 

分 类 号：O648.2[理学—物理化学]