【作者】 戴洪平；

【导师】 王兴国；

【作者基本信息】 江南大学 ， 粮食、油脂及植物蛋白工程， 2004， 硕士

【摘要】 芝麻素是一种脂溶性的木脂素类化合物,具有多种生理活性功能。本课题以芝麻油厂的废弃物—芝麻油脚为原料,从中提取芝麻素,进行结晶纯化;并对芝麻素的抗氧化性能进行初步研究。首先,对芝麻油中芝麻素含量的测定方法进行了研究。采用氧化铝层析柱对芝麻油进行预处理,再用高效液相色谱(HPLC)对芝麻素定性、定量;经过检验,加样回收率为95.6%,变异系数CV为1.19%。然后,对国内芝麻代表性产区的十五种芝麻进行芝麻素含量的测定,并分析芝麻素含量与芝麻品质之间的关系;研究结果表明:芝麻含油率为46.48%-58.28%,油中芝麻素的含量为0.1152%-0.7773%,芝麻素含量与芝麻含油率呈正的显著相关,相关系数为0.556((=0.05)。白芝麻油的芝麻素平均含量比黑芝麻油的芝麻素平均含量高,从棕黄色芝麻中提取的油中芝麻素平均含量与白芝麻油的芝麻素平均含量接近。对芝麻油脚进行分析,结果显示芝麻油的含量68.9%,固形物含量31.0%,芝麻素含量0.251%。用正己烷从芝麻油脚中提取出芝麻油;以此芝麻油为原料,采用甲醇提取芝麻素。对芝麻素的提取工艺进行研究,确定最佳提取工艺条件为:提取温度60℃、萃取时间2.5h、料液比1:3;提取率83.7%,产品纯度为67.5%。采用乙醇对芝麻素粗提产品进行结晶纯化,确定最佳结晶纯化条件为:料液比(g/mL)1:40、养晶温度25℃、养晶时间2h。在上述结晶条件下,经过四次结晶,最终产品的纯度为91.2%;通过GC-MS分析,发现产品中还含有芝麻酚林、甾醇。最后对芝麻素的抗氧化性做了初步研究。烘箱法、Rancimat仪法的测定表明:芝麻素具有一定的抗氧化性,但是抗氧化性能没有BHA、BHT、TBHQ、VE好;对芝麻素消除体外自由基的能力作了初步研究,结果表明:芝麻素对DPPH·、·0H、O2-·有一定的消除作用。从分子结构的角度,对芝麻素的抗氧化机理进行了探讨。更多还原

【Abstract】 Sesamin,a lipid-soluble lignan, has many biological activities. The objective of this research was to extract and purify sesamin by crystallization from sesame oil residue which is the by-products of sesame oil plants.The antioxidant activity of sesamin was also studied here.Firstly, determination method of sesamin in sesame oil was studied.Based on it, sesame oil was pretreated with chromatographic column packed with alumina and then HPLC was applied to qualitatively and quantitatively analyze sesamin.The average recoveries and coefficient variation were 95.6% and 1.19% for sesamin respectively. The method was simple and accurate in sesamin determination.Oil and minor components of sesamin were studied in 15 strains of Sesamum indicum L from different regions in China where sesame is abundant.The percentage of sesamin in the oil ranged from 0.1152% to 0.7773%.The oil contents of the seed ranged from 46.48% to 58.28%.There was a significant positive correlation between the oil content of seed and the sesamin content of the oil( r=0.556,significant at the 5% level).No significant difference in sesamin content was found between the means of white and brown seed strains.The average sesamin content of the white seed strains is higher than that of the black seed strains.Secondly,compositions of sesame oil residue were analyzed .The results showed the content of sesamin, total solid and sesame oil in sesame oil residue were 0.251%, 31.0% and 68.9% respectively. Methanol was used to extract sesamin from the sesame oil after sesame oil was extracted from the sesame oil residue by hexane.The influences of several factors for extration were studied. The extraction temperature of 60℃, extraction time of 2.5 h , methanol with the ratio of 3:1 to sesame oil were selected as the optimum parameters .Under these conditions,the extraction rate of the sesamin was 83.7% and the purity of this product was 67.5%. This product was purified by the ethanol solvent with the following conditions: the ratio of sesmin to the ethanol solvent 1:40(w/m), crystallization temperature 25℃, time 2 hours. The purity of the product increased from 67.5% to91.2% by crystallization for four times. Sesamolin and sterol were determined in the product by GC-MS analysis. It was showed from Schaal oven test and Rancimat experiments that sesamin in oil has lower antioxidant activity than that of BHA,BHT,TBHQ and VE.. The free radical scavenging capacity of sesamin was investigated. The results showed sesmin could scavenge the free radical (DPPH·、·0H、O2-·). The mechanism of antioxidative activity of sesamin was discussed on the basis of sesamin molecule structure.更多还原