茶叶中脂肪含量检测方法比较及脂肪酸含量分析  

Comparison of fat determination methods and analysis of fatty acids in tea

作　　者：韦莹[1] 王秀莉[1] 庄美慧 胡越 刘柏林[1] 谢继安[1] 丁刚[1] Wei Ying;Wang Xiuli;Zhuang Meihui;Hu Yue;Liu Bolin;Xie Ji′an;Ding Gang(Center for Disease Control and Prevention of Anhui Province,Hefei 230601,China)

机构地区：[1]安徽省疾病预防控制中心,合肥230601

出　　处：《卫生研究》2023年第6期907-911,共5页Journal of Hygiene Research

基　　金：中国食物成分监测项目。

摘　　要：目的对比茶叶样品中两种脂肪的测定方法,分析脂肪酸含量。方法分别采用索氏抽提法和酸水解法测定了茶叶中游离态脂肪含量、总脂肪含量,同时用气相色谱法测定脂肪酸含量,并对5个地区21份茶叶中的脂肪酸组成及含量进行了分析。结果索氏抽提法测定的茶叶中游离态脂肪含量明显低于酸水解法测定的总脂肪含量。酸水解法测定的茶叶中总脂肪含量与气相色谱法测定的总脂肪酸含量相符,且含量符合逻辑关系。茶叶中总脂肪的含量范围为0.6~4.1 g/100 g,绿茶、白茶、黄茶、红茶中总脂肪含量分别为2.2、1.8、1.6和0.6 g/100 g。茶叶中游离态脂肪的含量低于58%,42%~80%的脂肪以结合态形态存在。茶叶中脂肪酸以不饱和脂肪酸为主,占总脂肪酸的67.52%~99.03%。不同种类茶叶中的脂肪酸组成存在差异,其中黄茶中不饱和脂肪酸占总脂肪酸的比例为98.84%,明显高于绿茶、白茶和红茶。绿茶中(汤池小兰花、霸王剑绿茶和柳溪玉叶除外)含量较高的脂肪酸为α-亚麻酸、亚油酸和棕榈酸。结论酸水解法较索氏抽提法更适用于茶叶样品总脂肪的测定。茶叶中的脂肪组成及含量、脂肪酸组成及含量因茶叶种类、发酵程度等因素存在差异。OBJECTIVE Comparative analysis of two method for determining fat and analysis of fatty acid content in tea samples.METHODS The content of freefatand total fat in tea was determined by Soxhlet extraction method and acid hydrolysis method,and the content of fatty acids were determined by gas chromatography.The composition and content of fatty acids in 21 tea samples from 5 regions were analyzed.RESULTS The freefat content of tea determined by Soxhlet extraction method was significantly lower than that determined by acid hydrolysis method.The totalfat content in tea determined by acid hydrolysis method was consistent with the total amount of fatty acids determined by gas chromatography,and their content conformed to the logical relationshipsimultaneously.The totalfat content in tea ranged from 0.6 to 4.1 g/100 g,which in green tea,white tea,yellow tea,and black tea were 2.2,1.8,1.6 and 0.6 g/100 g,respectively.The content of free fat in tea was less than 58%,with 42%-80%of the fat existing in a bound form.The fatty acids in tea were mainly unsaturated fatty acids,accounting for 67.52%-99.03%of the total fatty acids.There were differences in the composition of fatty acids in different types of tea,with the proportion of unsaturated fatty acids in yellow tea accounting for 98.84%of the total fatty acids,which was significantly higher than that of green tea,white tea,and black tea.The fatty acids with high content in green tea(except Tang chi xiaolan tea,Bawangjian green tea and Liuxi yuye tea)wereα-linoleic acid,linoleic acid,and palmitic acid.CONCLUSION Theacid hydrolysis method is more suitable for the determination of fat in tea samples.The composition and content of fat and fatty acids in tea vary depending onfactors such as the type of tea and the degree of fermentation.

关 键 词：茶叶 脂肪 脂肪酸 酸水解 索氏抽提法 气相色谱 

分 类 号：R151.3[医药卫生—营养与食品卫生学]