本科毕业论文大蒜总黄酮的提取及纯化.doc

摘 要 大蒜在我国资源丰富，是我们常见的一种食物，也是重要的药用植物，其中含黄酮类化合物、大蒜素等多种活性成分。 本实验以乙醇作为溶剂提取大蒜中的总黄酮，对其提取工艺条件进行研究。首先对水提取法、乙醇回流提取法以及超声波辅助乙醇提取法进行对比，确定了超声波辅助乙醇提取法为最佳提取方法；并通过单因素试验探讨提取次数、料液比、提取温度、乙醇浓度及提取时间对总黄酮得率的影响，然后又通过响应面分析确定了超声波辅助乙醇回流提取法的最佳工艺条件：料液比1:19，提取温度67℃，乙醇浓度为8%，总黄酮得率达到1.32%。然后采用AB-8大孔吸附树脂进行纯化，同时进行紫外光谱和红外光谱实验分析，初步确定了大蒜黄酮主要为橙酮类。最后进行抗氧化试验和抑菌试验，证明大蒜总黄酮有比较强的抗氧化性和较好的抑菌效果。与研究比较多的大蒜素相比，大蒜黄酮没有刺激性气味，将来可以作为功能性食品的基础原料。 关键词: 大蒜总黄酮；响应面；纯化；抗氧化；抑菌 Extraction and urification of the Total Flavones in Garlic Abstract Garlic Allium is a rich resource in China. It is not only a kind of most common foods but also important medicinal plants. It contains flavonoids, allicin and other active ingredients. This experiment use ethanol as extractive solvent to extract the total flavonoids, and study the optimal extraction conditions. At first, compared water extraction, ethanol extraction and ultrasonic assisted ethanol extraction were to determine the optimum extraction method was ethanol extraction. Then the effection of extraction temperature, solid to liquid ratio, extraction times, and ethanol concentration on the yield of total flavonoids was investigated by single factor test and the optimum extraction conditions with ethanol as solvent was determined by a response surface analysis. The result was liquid ratio 1:19, extraction temperature 67℃, 82% ethanol, lavones extraction rate reached 1.32%. The AB-8 macro-porous resin was used to purify, UV and IR spectra analysis initially identified garlic flavonoids which was orange ketones. Finally, inhibitory effect of the total flavonoids in garlic was determined by the antibacterial test. The result proved that garlic had strong oxidation resistance and better antibacterial effects. Garlic flavonoids had no irritating odor compared with the allicin studied more and they could be used as the basic raw material in functional foods. Keywords: Garlic flavonoids; Response surface; Purification; Antioxidant activity; Antibacterial activity 目 录 摘 要 I Abstract II