叶绿素与膜分离乳蛋白相互作用及复合物性质研究  

Interaction between chlorophyll and milk protein from membrane separation and the properties of their complexes

作　　者：苏小红 刘成力 杨敏[2] 季伟[2] 魏玉梅 SU Xiaohong;LIU Chengli;YANG Min;JI Wei;WEI Yumei(Lanzhou Industry Research Institute,Lanzhou 730050,China;College of Science,Gansu Agricultural University,Lanzhou 730070,China;Experimental Education Department,Northwest Minzu University,Lanzhou 730000,China)

机构地区：[1]兰州工业研究院,甘肃兰州730050 [2]甘肃农业大学理学院,甘肃兰州730070 [3]西北民族大学实验教学部,甘肃兰州730000

出　　处：《食品与发酵工业》2023年第23期173-180,共8页Food and Fermentation Industries

基　　金：兰州市科技计划项目(2021-1-147);国家自然科学基金项目(32060549);甘肃省自然科学基金项目(21JR1RA207)。

摘　　要：叶绿素是一种广泛分布于高等植物中的天然色素,具有多种生物活性,但稳定性较差。该文采用荧光光谱法研究了酪蛋白胶束、乳清蛋白以及脱脂乳与叶绿素的结合常数;利用喷雾干燥技术制备了乳蛋白与叶绿素的复合物,采用傅里叶变换红外光谱、扫描电镜等手段表征了复合物结构;分析了复合物的溶解性、热稳定性和色度,并评价了复合物中叶绿素的胃肠模拟消化释放性。结果显示,不同类型乳蛋白与叶绿素的结合常数均高于10^(6)L/mol。结合叶绿素后,喷干乳清蛋白多数由葡萄干状转变为半球形中空结构,而酪蛋白胶束与脱脂乳形貌变化不大。叶绿素的结合改善了3种类型乳蛋白在pH 4.5~8的溶解性。乳蛋白负载改善了叶绿素在贮藏30 d内的颜色稳定性。模拟消化试验表明,消化24 h后,游离叶绿素累计释放率最低,酪蛋白胶束负载的叶绿素累计释放率最高,表明乳蛋白负载提高了叶绿素在胃肠道系统中的稳定性。该研究结果可为叶绿素以及乳蛋白在功能食品中的应用提供参考依据。Chlorophyll is a kind of natural pigment with multiple bioactivities but low stability,which is distributed in higher plants extensively.In this study,the binding constants between chlorophyll and micellar casein,whey protein,and skim milk protein were analyzed by using fluorescence spectroscopy,and the structures of their spray-dried complexes were characterized by Fourier transform infrared spectroscopy,and scanning electron microscope as well.The solubility,thermal stability,and chromaticity of the complexes were evaluated,as well as the release properties of chlorophyll from the complexes during simulated gastrointestinal digestion.Results showed that the binding constants between chlorophyll and milk proteins were all higher than 10^(6) L/mol.After combining with chlorophyll,the morphology of most spray-dried whey protein changed from a raisin-like shape to a hemispherical one with a hollow structure,but those of micellar casein and skim milk protein were not altered.The binding of chlorophyll improved the solubility of three kinds of milk proteins in the pH range of 4.5-8.In addition,loaded milk protein enhanced the color stability of chlorophyll during 30-day storage.After 24 h simulated digestion,the cumulative release rate of free chlorophyll was the lowest and the cumulative release rate of the micellar caseinchlorophyll complex was the highest.Thus,the complexation with milk proteins enhanced the stability of chlorophyll in simulated gastrointestinal digestion fluids.Results would provide the basic references for the application of chlorophyll in functional foods,as well as milk proteins.

关 键 词：叶绿素 酪蛋白胶束 乳清蛋白 脱脂乳 结合常数 溶解性 色度 

分 类 号：TS201.2[轻工技术与工程—食品科学]