骆驼乳、牛乳、山羊乳中蛋白质和脂肪酸成分的比较

Comparison of Protein and Fatty Acid Composition among Camel,Cow and Goat Milks

采用凝胶电泳法和气相色谱法比较骆驼乳、牛乳和山羊乳在蛋白质和脂肪酸两方面的差异。电泳结果显示:不同产地骆驼乳粉乳蛋白成分比例存在差异,生产工艺对其乳蛋白和乳脂球膜蛋白的组成比例均有显著影响;骆驼乳、牛乳和山羊乳蛋白成分存在显著差异,其中骆驼乳不含β-乳球蛋白和αs1-酪蛋白,而牛乳和山羊乳中不含免疫球蛋白G2(immunoglobulin G2,IgG2)和IgG3,因此凝胶电泳法可用于骆驼乳中掺牛乳、山羊乳的鉴别分析。气相色谱检测结果显示:骆驼乳和羊乳中均检出31种脂肪酸,牛乳检出29种脂肪酸;骆驼乳中短链脂肪酸较牛乳和山羊乳少,而大部分长链脂肪酸含量显著高于牛乳和山羊乳。脂肪酸主成分分析结果显示,不同物种乳类脂肪酸差异明显,并且掺假骆驼乳与骆驼乳可明显区分,可用于掺加牛乳、山羊乳的骆驼乳中脂肪酸的鉴别分析。

In this research,the differences in protein and fatty acid composition among camel,cow and goat milks were analyzed by gel electrophoresis(GE)and gas chromatography(GC).The GE results showed that there were differences in the proportion of proteins in camel milk from different regions,and the production process had a significant effect on both camel milk protein and milk fat globule membrane protein composition.There were significant differences in protein composition among camel,cow and goat milks,and camel milk did not containβ-lacglobulin orαs1-casein,while cow and goat milks did not contain immunoglobulin G2(IgG2)or IgG3.Therefore,GE could be used for the identification of camel milk mixed with cow or goat milk.The GC results showed that 31 fatty acids were detected in both camel and goat milks,and 29 fatty acids in cow milk.Camel milk contained fewer short-chain fatty acids than cow and goat milks,while the contents of most long-chain fatty acids were significantly higher than those in cow and goat milks.Principal component analysis(PCA)of the fatty acid composition data showed a clear separation of milks from different species and a clear discrimination between pure and adulterated camel milk.PCA can be used for the identification and analysis of fatty acids in camel milk mixed with cow milk and goat milk.