桑叶有效成分提取与分析

【作者】 张军；

【导师】 穆莉；

【作者基本信息】 安徽农业大学 ， 特种经济动物饲养， 2004， 硕士

【摘要】 桑叶为桑属植物桑树(Morus alba L.)的叶子，我国大部分等地均有栽培，其味苦、甘、性寒、归肺、肝经，历代中医文献对其功能多有记载，认为其具有疏散风热、清肺润燥、平肝明目、凉血的功能。近年来，人们对桑叶的化学组成成分生理功能进行了研究，发现桑叶中营养丰富，含有人体必需的氨基酸、维生素、无机盐、黄酮、生物碱等多种成分，具有降血压、降血脂、降血糖、抗炎、抗衰老、抗肿瘤等功效。本文表明：桑叶中含有多种氨基酸，检验出氨基酸15种，组成桑叶蛋白质的氨基酸总含量平均为10％左右，其中人体必需的氨基酸含量平均为4.1％左右，占氨基酸总量的40％左右，其中人体必需的氨基酸7种。不同品种桑叶中氨基酸差异很大。鸡桑与白桑的天冬氨酸（ASP）的含量要高于湖桑32、 湖桑9001和广东桑。苏氨酸（THR）为湖桑9001和鸡桑含量最高。而湖桑32和广东桑最低。丝氨酸（SER）的含量，湖桑32，广东桑明显低于其他品种；脯氨酸（PRO）的 含量湖桑9001为最低，而鸡桑最高。几个品种中甲硫氨酸（MET）的含量都较低，属微量。植物蛋白第一限制氨基酸—赖氨酸的含量为0.82％左右，占氨基酸总量的8％左右。谷氨酸是一种在脑组织中起维持功能的作用的氨基酸，在糖代谢及蛋白质代谢过程中占有重要地位，桑叶中谷氨酸含量较高，平均为1％左右。由此可见，桑叶中氨基酸种类齐全，且人体必需氨基酸含量较高，因此，桑叶中所含的蛋白质是品质优良的蛋白质资源。 r-氨基丁酸，它是一种非蛋白质氨基酸，分布范围广泛，在植物体内含量较低，故作为食品功能因子可行性不大，但桑叶中含量比较高，例如，湖桑32的r-氨基丁酸为142mg/100g,广东桑为227 mg/100g。而豆类仅为0.04ug/g,因此，食用含有桑叶的食品或饮料，可以补充GABA。在桑叶黄酮提取过程中，PH值、温度、溶剂浓度等对桑叶黄酮浸出率都有影响。用醇提黄酮要好于用水提黄酮。随着温度的升高，黄酮浸出率也提高，但温度过高反而下降。乙醇的浓度对浸提效果影响较大，在70%、80%的乙醇有利于黄酮得率，超过90%反而下降。实验.表明： 溶剂为乙醇时，浸提的优化工艺条件为80%的乙醇溶液，80℃，固液比 1：30，浸提3个小时。溶剂为甲醇时，浸提的优化工艺条件为80%的甲醇溶液在固液比为1：20，60℃浸提2个小时，黄酮得率最高。 用毛细管电泳测定桑叶中黄酮含量表明：在合肥地区，6月份的桑叶中芦丁、槲皮素的含量较低，7月、8月、9月份的逐渐升高，10月份的桑叶中芦丁、槲皮素的含量最高，而11月份的芦丁、槲皮素的的含量迅速下降。另外，不同品<WP=6>种的桑叶中含量也不同，湖桑9001的芦丁的含量是湖桑32的2倍，白桑、鸡桑、广东桑的4倍。而槲皮素的含量，湖桑32最高，鸡桑最低。更多还原

【Abstract】 This paper indicates: mulberry leaves contains many kinds of amino acid, examines out 15 kinds of amino acid, total content of amino acid which makes up the leaf protein of the mulberry is about 10% on average , among them the human body’s essential content of amino acid is about 4.1% on average , accounts for about 40% of the total amount of amino acid, essential amino acid of the human body among them 7 kinds. The amino acid is widely different in different variety mulberry leaves.Content of ASP in Morus.albaL.and Morus.australis is higher than husang 32 mulberry, husang mulberry 9001 and M.atropurpurea. THR: Mulberry 9001 of lake and Morus.australis poir have the highest content. M.atropurpurea. and lake 32 mulberry and lowest. SER, mulberry 32 of lake, M.atropurpurea.are obviously lower than other varieties; The content of Pro in lake 9001 mulberry is most low, and Morus.australis poir most high. The content of MET is relatively low in several varieties, belonging to the trace.Plant albumen one restriction amino acid—content of lysine(LYS)， there is about in 0.82%,it account for the total amounts the 8% about for amino acid. The glutaminic acid(GLU) is a kind of amino acid playing a role in maintaining the function while organizing in the brain, occupying the important position in the course of candy supersession and protein supersession, the content of glutaminic acid(GLU) is relatively high in the leaf of the mulberry, it is about 1% on average . Therefore, the amino acid kind is complete in the leaf of the mulberry, and the content of human essential amino-acid is relatively high, so, the protein of mulberry leave is proteins resource best in quality.The extraction technology for flavones in mulberry leaves with orthogonal test using alcohol and methanol.The result showed that as alcohol was concerned, the optimun extracting conditions were: ratio of solid to liquid as1:30, alcohol volume80%, temperture80℃ and as methanol was concerned, the optimum extracting conditions were : ratio of liquid as 1:20,methanol volume 80％,temperature 60℃Determination of flavones in mulberry leaves by capillary electrophoresis indicate that in the same producing area being different to gather issue,content of rutin and quercetin in the leaves of June are relatively low, gradual rising of July, August, September, while rutin and quercetin in the leaves of October are the highest, the <WP=8>content of the rutin and quercetin of November drops rapidly. In addition,different mulberry leaves of variety have too different content. For example, lake mulberry 9001 content of rutin is 2 times lake mulberry 32,and is 4 times of Morus.albaL. Morus.australis poir . and M.atropurpurea. The content of quercetin , lake mulberry 32 is the highest, the Morus.australis poir is the lowest.GABA,it is that one kind is not protein amino acid, the distribution is in extensive range, the content is relatively low in the plant body, so regard as the function factor feasibility of food not big, but it is the getting higher to be in leaf content in mulberry. For example, lake mulberry 32 is for 142 mg/100g, G M.atropurpurea .is 227 mg/100g. And the beans are only 0.04ug/g, so, eating the food or beverage with mulberry can supplement GABA . While the flavones of the mulberry is drawn, pH-value, temperature, solvent, etc. has influence to soak the appearing rate on the flavones of the mulberry. By compare it showed that extracting with alcohol is better than and with water. With the rising of temperature, the flavones macerating efficiency is improved too, but temperature drops too high instead. Density of alcohol mentioned influence relatively heavy, in 70%, 80% alcohol help the flavones get macerating efficiency , over 90% drops instead.更多还原