【作者】 周丽明；

【导师】 李春美；

【作者基本信息】 华中农业大学 ， 食品科学， 2007， 硕士

【摘要】 为了充分利用芒果，开发芒果多酚，本实验主要以芒果核仁为材料，通过单因素和正交实验确立了芒果多酚的最佳提取条件。通过大孔树脂结合SephadexLH—20对芒果多酚粗提物进行分离纯化和分级制备，采用HPLC-ESI-MS对主要组分的结构做了初步分析。在此基础上对芒果多酚的粗提物和不同组分进行了抗氧化、抑菌作用的初步研究，主要研究结果如下：1．比较了乙醇回流法、微波提取法、超声波提取法从紫花芒核仁中提取多酚类物质的最佳提取工艺条件。乙醇回流法的最佳工艺为60％乙醇水溶液为提取溶剂，提取时间60min，料液比1∶10，水浴温度60℃；在此工艺条件下多酚得率为7.16％。微波提取法的最佳工艺为60％乙醇水溶液为提取溶剂，料液比1∶15，385W功率下微波2.5min；在此工艺条件下多酚得率为6.85％。超声波提取法的最佳工艺为60％乙醇水溶液为提取溶剂，料液比为1∶20，超声2次，每次60min；在此工艺条件下多酚得率为4.92％。相比乙醇回流法和超声波提取法，微波提取法具有耗时短、能耗低和提取效率高的优点。2．通过筛选采用2号树脂对芒果多酚粗提物进行初步分离纯化，其最佳吸附条件为4mg／ml料液浓度，上柱流速选择2BV／h；最佳洗脱条件为以3BV的60％乙醇水溶液在2BV／h的流速下对2号大孔树脂进行洗脱。通过2号大孔树脂初步纯化结合Sephadex LH20柱层析分离，可使芒果多酚各组分得到有效的分离，初步的HPLC-ESI-MS分析表明，芒果核多酚主要活性组分为三没食子酰基葡萄糖、四没食子酰基葡萄糖等化合物。3．芒果多酚的抗氧化、抑菌作用的研究结果表明，苹果芒多酚组分Ⅲ活性最高，对·OH以及O₂^-·有较好的清除效果，0.5mg／ml的该组分在水杨酸体系和2-脱氧-D-核糖体系对·OH的清除率分别为91.49％、88.79％，对O₂^-·的清除率为89.66％；1mg／ml的该组分对脂质过氧化的抑制率为61.50％。该组分对供试的大肠杆菌、枯草芽孢杆菌、苏云金芽孢杆菌和金黄葡萄球菌都有较强的抑菌活性，最低抑制浓度为2-3mg／ml；但是对供试的黑曲霉和啤酒酵母均无明显抑菌活性。更多还原

【Abstract】 In order to make full use of mango, polyphenols was extracted from mango kernel seeds and the optimum extracting method and conditions were comfirmed through single factor and orthogonal test. Macroporous adhesive resin column and Sephadex LH20 column were employed to separate and fractionate the crude extract and the structures of the main compounds were analyzed by HPLC-ESI-MS. The antioxidant and antimicrobial activity of the crude extract and its fracions were also inverstigated. The main results were shown as follows:1. Methods of ethanol refluxing extraction, microwave-assisted extraction and supersonic wave-assisted extraction method were used to extract polyphenols from mango kernel seeds and the optimum extraction conditions were shown as follows:①the optimum extracting condition for ethanol refluxing method was as follows: 60% ethanol as extracting solvent with a solid/solvent ratio of 1∶10 （w/v）, extracting for 60 min at 60℃. Under this condition, the extracting yield was 7.16%.②the optimum extracting condition for microwave-assisted extraction method was as follows: 60% ethanol as extracting solvent with a solid/solvent ratio of 1∶15 （w/v） and microwave power of 385W, extracting for 2.5 min. Under this condition, the extracting yield was 6.85%.③for ultrasonic-assisted extraction method, the optimum condition was as follows: 60% ethanol as extracting solvent with a solid/solvent ratio of 1∶20, extracting for two times with 60 min per time. Under this condition, the extracting yield was 4.92%.Compared with ethanol refluxing extraction and ultrasonic extraction methods, microwave-assisted extraction has the advantages of faster extraction, lower energy consumption and high extraction yield.2. It was showed that the crude extract could be separated and purified by number 2 macroporous adhesive resin column and Sephadex LH20 column. The optimum adsorption and separation conditions for the crude extract on number 2 macroporous adhesive resin column were confirmed as follows: the feed concentration of 4mg/ml with flow rate of 2BV/h; The desorption solvent was 3BV of 60% ethanol with flow velocity of 2BV/h. HPLC-ESI-MS analysis showed that the main active constituent of mango polyphenols were gallotannins compounds such as tri-O-galloyl-glucose and tetra-O-galloyl-glucose.3.The antioxidant and antimicrobial activity of mango polyphenols were studied. The results showed that the mango polyphenols of fractionⅢhad effective scavenging effect on the hydroxyl radical （·OH） and the superoxide anion radical （O₂·）. The scavenging ratio of·OH was 91.49% in salicylic acid system and 88.79% in DR system when the concentration of the fragment was 0.5mg/ml. The scavenging ratio of O₂·was 89.66%. The inhibition ratio of lipid peroxidation was 61.50% when the concentration of the fraction was 1mg/ml. The fraction had effective antimicrobial activity on four kinds of bacteria tested with MIC of 2-3mg/ml. But it had no remarkable effective antimicrobial activity on yeast and aspergillus niger.更多还原