摘要采用乙醇浸提法提取桑叶多酚，单因素试验考查影响桑叶多酚提取的因素，在此基础上采用正交试验确定桑叶多酚的最佳提取条件：乙醇浓度55%，提取时间0。5 h，料液比1:50，提取含量为27。128 mg/g。80806

采用薄膜水化法制备桑叶多酚脂质体，单因素试验考察影响包封率的因素，在此基础上采用响应曲面优化法确定桑叶多酚脂质体制备工艺，以包封率为响应值，结果显示：当大豆卵磷脂﹕胆固醇值为5，有机相﹕水相值为5，药脂比为55﹕100，预测值为42。97%，验证实验包封率为41。28%。采用光学显微镜观察桑叶多酚脂质体形态，脂质体多呈圆形或椭圆形球体，其粒径约为4 μm。

测定了游离桑叶多酚和桑叶多酚脂质体的体外抗氧化活性。结果表明，脂质体的DPPH自由基清除能力低于游离桑叶多酚，其IC50值分别为：19。41 mg/mL、3。02 mg/mL；脂质体对羟基自由基清除能力高于桑叶多酚，其IC50值分别为8。77 mg/mL、61。14 mg/mL。进一步采用碘量比色法测定桑叶多酚对油脂抗氧化值（POV）的影响，结果显示：反应经过120 h，桑叶多酚脂质体（0。02%）的POV值比空白对照大豆油脂POV值降低了21。01%，BHT降低了27。53%，桑叶多酚（0。02%）升高了5。81%。

毕业论文关键词：桑叶多酚；脂质体；抗氧化

Abstract Mulberry polyphenols were extracted with ethanol。 The optimum condition determined by one-factor tests and orthogonal test were as follow: ethanol concentration 55%, extraction time 0。5 h, the ratio of solid and liquid was 1:50,extract content was 27。128 mg/g。

Mulberry polyphenols liposomes was prepared by the film dispersion-ultrasonic emulsify method。The optimum conditions determined by one-factor tests and response surface analysis were as follow: the ratio of Soy lecithin and cholesterol was 5, the ratio of organic phase and aqueous phase was 5 and the ratio of drug and lecithin was 55: 100。The encapsulatin of Mulberry polyphenols liposome prepared under this condition was 41。28% averagely,close to 42。97% resulted from response surface analysis。 Mulberry polyphenols liposomes were observed with an optical microscope, liposomes were round or oval sphere having a particle size of about 4 μm。

The antioxidant activities of free mulberry polyphenols and mulberry polyphenols liposomes were tested。 The results showed that the IC50 value of liposomes’ DPPH free radical scavenging capacity was 19。41 mg/mL,while the free mulberry polyphenols was 3。02 mg/mL; the IC50 value of liposomes’ hydroxyl free radical scavenging capacity was 8。77 mg/mL,while the free mulberry polyphenols was 61。14 mg/mL。When the soybean oil was tested after 120h,POV value of mulberry polyphenol liposomes(0。02%) decreased 21。01% ,while BHT decreased 27。53% and Mulberry polyphenols increased 5。81%。

Keywords: mulberry polyphenols; liposome; Antioxidant

目  录

第一章 绪论 1

1。1 引言 1

1。2 桑叶多酚 2

1。2。1桑叶多酚概述 2

1。2。2 桑叶多酚的提取方法 2

1。2。3 桑叶多酚的生理活性研究应用 3

1。3 脂质体 3

1。3。1 脂质体概述 3

1。3。2 脂质体的制备方法 4

1。3。3 多酚脂质体的应用 4

1。4立题依据及内容 5

1。4。1 立题依据及意义 5