芝麻油中芝麻素、芝麻林素的研究

本文利用高效液相色谱测定不同芝麻样本提取油以及市购芝麻油中芝麻素、芝麻林素的含量。色谱柱为HibarRT250-4(C18,250mm×4.6mm,填充粒度5μm);流动相:甲醇:水=75:25(V/V);流速:1ml/min;检测波长:280nm。测定结果表明:被测两峰完全分离,且峰形较好,线性范围10～100μg/ml,芝麻素、芝麻林素平均回收率分别为101.1%、100.2%重现性(n=5)分别为芝麻素RSD=2.31%、芝麻林素的RSD=3.05%,最低检出限:芝麻素为1.5μg/ml,芝麻林素为2.5μg/ml(以进量浓度计)。油样中芝麻素的含量范围为0.35%～0.72%、芝麻林素的含量范围为0.32%～0.48%,制油工艺中焙炒工序强度对芝麻林素含量变化具有一定影响。     

正相高效液相色谱法同时测定芝麻油中生育酚、芝麻素及芝麻林素含量

建立了正相高效液相色谱法同时测定芝麻油中生育酚(α-、β-、γ-、δ-生育酚)、芝麻素及芝麻林素含量的方法。样品经正庚烷溶解后,在二醇基硅胶色谱柱上以四氢呋喃-正庚烷溶液洗脱、荧光检测器分析。结果表明:芝麻素及芝麻林素荧光特性良好,样品分析在20 min内完成;方法学评价结果显示生育酚在1.0~5.0μg/m L、芝麻素及芝麻林素在0.1~5.0μg/m L范围内线性关系良好,相关系数R~2均大于0.99;生育酚、芝麻素以及芝麻林素的检出限为0.29~0.74 mg/kg,定量限为0.91~2.10 mg/kg;6种化合物加标回收率为83.47%~104.57%,相对标准偏差为0.38%~6.55%。采用该方法分析了12个芝麻香油、冷榨芝麻油、浸出成品芝麻油中生育酚、芝麻素以及芝麻林素含量,发现芝麻油中生育酚以γ型为主,芝麻素、芝麻林素含量较高。该方法简单、灵敏度高、重复性好,可用于芝麻油中生育酚、芝麻素及芝麻林素含量的同时检测。     

微波处理对芝麻中脂肪酶活性及木脂素的影响研究

对芝麻进行微波处理,选择初始水分、微波功率以及微波时间为影响因素,芝麻物料脂肪酶活性为考察指标,进行单因素试验,在单因素试验基础上,进行正交试验,确定最佳微波处理条件。同时研究了微波处理对芝麻原料和压榨芝麻油中芝麻素、芝麻林素等微量成分的影响。结果表明,微波处理抑制芝麻中脂肪酶活性的最佳条件:芝麻的初始水分5.35%、微波加热功率640 W、微波加热时间4 min。微波处理前后对芝麻原料中芝麻素和芝麻林素的含量无明显影响,但是有利于提高压榨芝麻油中芝麻素和芝麻林素的含量。     

高效液相色谱法测定芝麻油中芝麻素及芝麻林素

建立高效液相色谱(HPLC)法测定芝麻油中芝麻素和芝麻林素的方法。结果表明：方法以甲醇-水为流动相，梯度洗脱；提取溶剂为乙腈；净化剂为50 mg硅胶键合乙二胺-N-丙基(PSA)+50 mg C₁₈;芝麻素和芝麻林素在1～100μg/mL范围内呈线性关系，相关系数(r)均大于0.998;方法检出限(LOD)为0.03 mg/g、定量限(LOQ)为0.06 mg/g。加标回收率和相对标准偏差(RSD)均符合GB/T 27417—2017的要求。方法前处理操作简单、重复性好，适用于芝麻油中芝麻素和芝麻林素的测定。     

吸附脱色对芝麻油中木酚素及维生素E影响的研究

采用不同用量的活性白土、活性炭对芝麻油进行吸附脱色,通过对脱色芝麻油中芝麻酚、芝麻素、芝麻林素、细辛素、维生素E含量及脱色率的测定,分析研究不同吸附剂对芝麻油中木酚素、维生素E含量及脱色效果的影响,并优化芝麻油吸附脱色工艺条件。结果显示:活性白土脱色芝麻油中芝麻素和芝麻林素含量大幅度降低(平均降幅31.33%和44.70%),芝麻酚含量降低幅度较小(平均降幅25%),细辛素含量从无到有并随活性白土用量的加大持续增加,维生素E损失较大(平均损失率13%),脱色率较高(平均65.15%);活性炭脱色芝麻油中芝麻素和芝麻林素平均含量较脱色前基本没减少,芝麻酚含量明显降低(平均降幅41.2%),细辛素未检出,维生素E损失较少(平均损失率5.7%),脱色率较低(平均23.27%)。为提高脱色芝麻油中芝麻酚含量和脱色率,应选用活性白土脱色,且适宜的用量为3%;为提高脱色芝麻油中木酚素和维生素E含量,应选用活性炭脱色,且适宜的用量为2%;采用活性白土对芝麻油进行吸附脱色时,为减少脱色芝麻油中木酚素的损失,采用40 min、100℃的脱色条件为宜;为减少维生素E损失同时又能兼顾脱色效果,采用20~30 min、80℃脱色条件为宜。     

芝麻林素的酸催化反应与抗氧化性分析

采用石油醚、甲醇和乙醇溶解芝麻林素,研究不同溶剂体系芝麻林素酸催化反应的现象;以1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基清除能力评价芝麻林素及其分解产物的抗氧化能力;采用磷钨杂多酸（phosphotungstic heteropoly acid,HPW）催化芝麻油中芝麻林素的转化,研究芝麻林素酸催化对冷榨芝麻油氧化稳定性的影响。结果表明：芝麻林素在3 种溶剂体系中酸催化反应的产物不尽相同,芝麻酚是共同产物,石油醚体系产生Semin和芝麻素酚,甲醇和乙醇体系均出现不同未知物;芝麻林素和芝麻素的DPPH自由基清除能力远低于特丁基对苯二酚、丁基羟基茴香醚、丁基羟基甲苯和芝麻酚,但石油醚体系芝麻林素酸催化产物的DPPH自由基清除能力大幅提高,为HPW催化芝麻林素提高冷榨芝麻油氧化稳定性提供了理论依据;随着HPW催化剂添加量的增加,冷榨芝麻油中的芝麻林素含量逐渐减少,芝麻酚和芝麻素酚的含量逐渐升高,同时冷榨芝麻油的氧化诱导时间逐渐延长,氧化稳定性增强。     

HPLC测定芝麻油中木脂素类化合物含量研究

建立了HPLC同时测定芝麻油中芝麻素、芝麻林素、芝麻酚和芝麻素酚4种木脂素化合物含量的方法。首先确定了HPLC法分离和测定这4种物质的色谱条件,色谱柱为ODS-C18(250 mm×4.6 mm,5μm);检测波长:芝麻素和芝麻林素为287 nm,芝麻酚和芝麻素酚为293 nm;柱温30℃;流速0.8 mL/min,流动相为甲醇(A)和水(B)进行梯度洗脱,梯度为0 min(A,60%)→6 min(A,60%)→9 min(A,75%)→24min(A,70%)→27 min(A,60%)→32 min(A,60%)。同时比较筛选了皂化法、氧化铝柱层析法和薄层层析法3种去除脂肪类成分的前处理方法,确定薄层层析法为最有效的前处理方法。     

芝麻油中芝麻素、芝麻林素和细辛素检测方法优化

采用有机溶剂甲醇提取、HPLC同时分析芝麻油中芝麻素、芝麻林素和细辛素含量。为提高分析质量与准确性,优化甲醇提取溶剂用量和超声辅助提取的时间,并对检测方法进行方法学考察。结果表明：最佳提取条件为甲醇用量10 mL（芝麻油0.1 g）,超声时间2 min;芝麻素、芝麻林素和细辛素线性范围分别为4～100 mg/L、4～100 mg/L和1～40 mg/L,线性关系良好,相关系数分别为0999 5、0.999 6和0.999 2;芝麻素、芝麻林素和细辛素的检出限分别为0.03、0.02 mg/g和0.02 mg/g,定量限分别为0.06、0.06 mg/g和0.04 mg/g,加标回收率分别为87.17%～92.59%、9271%～102.24%和95.66%～108.93%,加标回收率的相对标准偏差均小于5%,方法的稳定性、准确性和精密度均符合检测要求。该方法操作简单、耗时短(完成一次分析只需30 min)、成本低、稳定性高,能有效应用于芝麻油中3种木脂素组分的分析检测。     

不同产地和品种芝麻营养成分差异分析

为分析不同产地和品种芝麻之间营养品质差异，以及营养品质之间的相关性，选取了山东省、河北省和湖南省200份芝麻样品，测定芝麻中脂肪、蛋白质、芝麻素和芝麻林素含量，并进行差异性和相关性分析。结果表明，不同芝麻品种之间蛋白质、脂肪、芝麻素和芝麻林素的平均含量分别为27.07%、52.27%、3.34 g/kg和1.48 g/kg。不同种皮颜色的芝麻营养品质略有差异，但差异不显著。山东省和河北省芝麻的蛋白质、脂肪含量显著高于湖南省芝麻(P<0.05)。河北省芝麻的芝麻素含量显著高于湖南省(P<0.05)，但山东省、湖南省之间差异不显著。3个省份之间的芝麻林素含量差异不显著。蛋白质与脂肪含量间呈极显著负相关(P<0.01)，芝麻素与脂肪含量间呈显著正相关，相关系数为0.145(P<0.05)，这与之前的研究结果一致。芝麻素与芝麻林素含量间呈极显著正相关(P<0.01)。蛋白质、脂肪与芝麻林素之间相关性不显著。     

微波处理对芝麻出油率及油脂品质的影响

对芝麻油料进行微波处理,选择微波功率、微波时间、增湿比例、缓苏时间为影响因素,饼残油率为考察指标,进行单因素实验,再在单因素实验结果基础上,进行正交实验,确定最佳微波条件,最后对比未经微波处理和最佳条件微波处理后所得油脂的品质。结果表明,微波处理能够提高芝麻出油率,且微波处理能够提高油中芝麻素和芝麻林素的含量,但对芝麻油的色泽、碘值、酸值、主要脂肪酸含量影响不大。微波处理后芝麻油的过氧化值会提高,但其含有的芝麻素、芝麻林素等抗氧化物质会使其氧化稳定性提高。微波处理油料可用作油料的预处理。     

Variation of sesamin,sesamolin and tocopherols in sesame (Sesamum indicum L.) seeds and oil products in Thailand

Sesame (Sesamum indicum L.) seed and oil contain abundant lignans, including sesamin, sesamolin and lignan glycosides. The aim of the present study was to determine sesamin, sesamolin and tocopherol contents in sesame seed and oil available in Thailand. The results showed that there was a large variation of sesamin and sesamolin contents in products. The distribution plot of sesamin and sesamolin contents in seeds showed that the mean values of sesamin and sesamolin were 1.55 mg/g (SD = 1.63; range n.d.–7.23 mg/g) and 0.62 mg/g (SD = 0.48; range n.d.–2.25 mg/g), respectively. The range of total tocopherols of these sesame lines was 50.9–211 μg/g seed. In commercial sesame oils, the ranges of sesamin and sesamolin were 0.93–2.89 mg/g oil and 0.30–0.74 mg/g oil, respectively, and tocopherol contents were 304–647 μg/g oil. The study reveals the extensive variability in sesamin, sesamolin and tocopherol contents among sesame products.     

APPLICATION OF SEMIPREPARATIVE RP-18 HPLC FOR THE PURIFICATION OF SESAMIN AND SESAMOLIN

A relatively simple chromatographic protocol was established to provide good separation of the unsaponifiable constituents from the seed oil of Sesamum indicum Linn. The protocol employs classical column chromatography using alumina and petroleum ether to collect furofuran lignans from sesame oil. Semipreparative RP-18 HPLC was used to separate the sesamin and sesamolin constituents in high purity (> 99%). The purity and identity of the separated compounds was confirmed by rechromatography using an analytical HPLC set up and GC-MS, respectively. The method described offers a means to isolate and collect sesamin and sesamolin in high purity for use as standards in furofuran lignan studies of sesame seed oil.     

芝麻核心种质芝麻素和芝麻酚林的关联分析

选用来源我国黄河流域至长江流域8省215份芝麻核心种质材料,对其种子中芝麻素（sesamin）和芝麻酚林（sesamolin）含量进行测定,芝麻素平均值5．24mg／g,变异范围为0．88～11．05mg／g,变异系数38．56％,芝麻酚林平均值3．30mg／g,变异范围为0．93—6．96mg／g,变异系数22．68％,二者均符合正态分布,且相关分析表明两者间呈极显著正相关;采用标记一性状关联分析法,进行芝麻素和芝麻酚林与SSR、SRAP、AFLP标记的关联分析。利用GLM模型共检测到33个标记与芝麻素和芝麻酚林极显著（P〈0．01）关联,同时与两种成分显著关联的有4个;利用MLM模型共检测到8个显著关联的标记,与两种成分显著关联的分别有4个;其中SSR标记SSll82-3在两种模型中同时极显著关联到芝麻素和芝麻酚林,且解释率较高。该研究将为芝麻功能性成分遗传改良和分子标记研究奠定重要基础。     

Extraction,separation and characterisation of sesame oil lignan for nutraceutical applications

Nutraceutical aspects of sesame oil (SO) are well reported. However, an efficient process for commercial production has not yet been reported. In this study we have aimed at separating lignans from SO aiming at use as nutraceuticals. SO was subjected to sequential extraction with methanol under selected conditions of temperature (70 °C), time (100 min) and solvent:oil ratio (1:1). Under the optimised conditions, the yields of pooled methanolic extract concentrate and residual oil were 10.09 ± 1.0 g and 89.2 ± 1.0 g, respectively. On HPLC analysis, the methanol concentrate showed a total lignan content of 9.32 ± 0.19% (6.54 ± 0.12% sesamin and 2.78 ± 0.31% sesamolin). The concentrate was subjected to low temperature crystallization (4 °C) for the separation of lignan crystals and 51% of the lignans in the oil with 94.4% purity. The crystal-removed methanolic concentrate was saponified and purified; the total lignan content (sesamin and sesamolin) in the unsaponifiable matter (USM) was 64%.The distribution of sesamin and sesamolin in the purified USM was in the proportion 46:54, unlike that in the pure crystals (84:16). Lipid classes (triglycerides, TG; free fatty acids, FFA; diglycerides, DG; monoglycerides, MG; polar lipid, PL) in SO, methanolic extract concentrate and residual oil were separated using thin-layer chromatography (TLC). The amounts of lipid classes were determined by relating the total area of the fatty acid peaks to the area of the peak for internal standard (methyl heptadecanoate), using gas chromatography (GC). The process reported here describes a simple and less cumbersome procedure to produce lignans with high yield and purity for nutraceutical applications.     

Microwave Heating Affects Composition and Oxidative Stability of Sesame (Sesamum indicum) Oil

The effects of microwave heating on antioxidative components and lipid quality of sesame seeds were studied. Amounts of antioxidative components were 576, 18, and 8 mg/kg oil for γ-, δ-, and α-tocopherols; 6,824, 5,642, and 54 mg/kg oil for sesamin, sesamolin, and sesamol, respectively. During microwave treatments, concentrations of tocopherols, sesamin and sesamolin gradually decreased, and ca. 20% of these dominant components was lost after 30 min heating. However, microwave treatments for 16 to 20 min, which would be optimal to prepare sesame oil with better quality, still retained over 85% of the antioxidative components (with few exceptions) and caused no significant chemical changes in lipids.     

不同品种类型芝麻品质性状的比较分析

为全面分析不同品种类型芝麻的品质性状及其与重要农艺性状间的关系,筛选294个代表性芝麻品种资源,通过多点种植和测定籽粒脂肪、蛋白质、芝麻素和芝麻林素含量,对不同品种类型芝麻的品质性状进行了差异比较,并对品质性状之间和品质性状与农艺性状的相关性进行了分析。结果表明,294个芝麻品种脂肪、蛋白质、芝麻素和芝麻林素平均含量分别为52.77%、20.41%、310 mg/g和1.92 mg/g。不同株型芝麻,单秆型品种脂肪、芝麻素含量极显著高于分枝型品种,蛋白质含量显著低于分枝型品种,芝麻林素含量差异不显著;不同叶腋花数芝麻,单花型品种脂肪、芝麻素含量极显著低于三花型品种,蛋白质含量极显著高于三花型品种,芝麻林素含量显著低于三花型品种。不同品种芝麻脂肪含量与蛋白质含量呈极显著负相关,与芝麻素、芝麻林素含量呈极显著正相关;蛋白质含量与芝麻素、芝麻林素含量呈极显著负相关;芝麻素与芝麻林素含量呈极显著正相关;脂肪含量与生育期、籽粒颜色L*值、b*值呈极显著正相关,与千粒重、籽粒长度、宽度、长宽比和籽粒颜色a*值呈极显著负相关;蛋白质含量与千粒重、籽粒长度、籽粒宽度、籽粒长宽比呈极显著正相关,与生育期、籽粒颜色L*值及b*值呈极显著负相关,与籽粒颜色a*值相关性不显著;芝麻素含量与生育期呈显著正相关,与籽粒长宽比、籽粒颜色L*值及b*值呈极显著正相关,与千粒重、籽粒长度呈极显著负相关,与籽粒宽度、颜色a*值相关性不显著;芝麻林素含量与生育期、籽粒颜色a*值及b*值呈极显著正相关,与千粒重、籽粒长度、籽粒宽度呈极显著负相关,与籽粒长宽比、籽粒颜色L*值相关性不显著。     

Effect of refining on the lignan content and oxidative stability of oil pressed from roasted sesame seed

Oxidative stability of pressed and refined sesame oils during seven consecutive months of storage at room temperature was studied comparatively. Lignans, peroxide value (PV), p‐anisidine value (AV) and total oxidation value (TOTOX) were determined as evaluation indices. PV, AV and TOTOX of sunflower, corn and peanut oils were simultaneously monitored to compare their oxidative storage stabilities with the sesame oils. The total amount of lignans in the pressed and refined sesame oils were 1103 and 790 mg per 100 g respectively. The contents of sesamin and sesemolin in the pressed sesame oil were 734 and 369 mg per 100 g respectively. Sesamin and sesamolin content were reduced by 256 and 159 mg per 100 g, respectively, after refining. Nearly 40% of the sesamin epimerised to asarinin after oil refining. The results indicate that sesame oils pressed from roasted seed have far superior storage stability to oxidation than the other vegetable oils. This difference may be due to much higher sesamin and sesamolin contents in the pressed sesame oils. The results suggest lignan compositions and levels could be used as key indicators for evaluating the oxidative storage stability of sesame oil products as well as to differentiate between pressed and refined sesame oils.     

不同工艺芝麻油的品质研究

分析了热榨芝麻油、冷榨芝麻油、水代法芝麻油及精炼芝麻油的酸值、过氧化值、脂肪酸组成,以及VE、芝麻素、芝麻林素、苯并(a)芘含量。结果表明:热榨芝麻油的酸值最高,冷榨芝麻油的酸值最低,精炼芝麻油的过氧化值最高,冷榨芝麻油的过氧化值最低;热榨芝麻油的反式脂肪酸含量高,冷榨芝麻油中未检出反式脂肪酸;冷榨芝麻油的V_E含量是热榨芝麻油的1.12倍,是水代法芝麻油的1.17倍;热榨芝麻油与精炼芝麻油的苯并(a)芘含量均为冷榨芝麻油的2.9倍。冷榨芝麻油品质较好。