【作者】 秦早；

【导师】 屈凌波； 张勋；

【作者基本信息】 郑州大学 ， 分析化学， 2012， 硕士

【摘要】 芝麻油具有重要的食用和药用价值,深受各国人民喜爱。芝麻香油区别于其它调味油的主要特点就是其独特的香味。芝麻油香味是芝麻油质量标准的重要组成部分,是衡量芝麻香油质量好与次的重要指标。不同的生产工艺、不同的生产条件对芝麻油的风味具有重要影响。探讨芝麻油风味的物质基础,以及不同生产工艺条件对芝麻油风味的影响,对于揭示芝麻油风味的组成和来源,客观评价芝麻油的质量以及优化芝麻油生产工艺具有重要意义。然而,纵观文献报导,芝麻油风味成分研究主要局限于单一有效成分或指标成分的定性定量分析,缺乏对风味成分组成的有效群体分析,以及各种生产工艺条件对芝麻油风味的影响探讨。本研究通过实验条件的优化,确定了芝麻油中风味成分检测的固相萃取—气相色谱—质谱(SPME-GC-MS)分析方法体系；在建立的分析体系基础上,通过大量样本的检测,构建了芝麻油风味成分的指纹图谱体系,确定了芝麻油风味成分的主要特征性成分；以上述的特征性成分为指标,考察了制油工艺、炒制温度、香型和储存时间对芝麻油风味成分的影响,并结合化学计量学的方法,探讨芝麻油风味成分与生产工艺的相关性,建立了二者之间的相关性方程。本研究所获结果对于揭示芝麻油风味成分的组成、来源以及进一步优化芝麻油生产工艺具有重要意义。(一)芝麻油风味成分检测的SPME-GC-MS分析方法体系的建立通过固相微萃取、气相色谱、质谱试验参数的优化,确定了芝麻油风味成分的固相微萃取条件,气相色谱—质谱分析检测条件。SPME条件：选用DVB-CAR-PDMS(50/30μm)萃取头,将1mL的芝麻油放入4mL的萃取瓶中,在60℃下水浴中平衡20min后,插入萃取头,在60℃下吸附1h,然后插入250℃进样口,解吸6min。GC-MS条件：气相色谱柱为HP-5MS(30m×0.25mm,0.25μm),载气：氦气；流速：0.8mL/min;升温程序：起始温度为30℃,保持5min,再以10℃/min的速率升温到100℃,保持7min,最后以15℃/min的速率升温到180℃,保持7min。在建立的分析条件下,对实际的样品进行了分析,并考察了方法的精密度、重复性和稳定性。研究表明：在建立的色谱条件下,可以达到对芝麻油中风味物质近118个成分的分析能力,6次分析结果的相对保留时间和相对峰面积的精密度、重复性和稳定性在0.01%-0.17%和3.83%-11.70%范围内。(二)芝麻油风味成分的指纹图谱研究通过对57个芝麻油样品的SPME-GC-MS分析,根据指纹图谱的建立原则,建立了芝麻油风味成分的指纹图谱体系,确定了芝麻油风味成分的主要特征性成分：丙酮、2-丁酮、冰醋酸、戊醛、四氢呋喃、吡嗪、二甲基二硫、吡啶、己醛、4-甲基噻唑、甲基吡嗪、(2-丙烯基)-2-呋喃、2-糠醛、1,2-乙二醇二乙酸酯、2,4-二甲基噻唑、2,3-二甲基吡嗪、乙烯基吡嗪、2-庚烯醛、5-甲基-2呋喃甲醛、2-呋喃羧酸甲酯、2-戊基呋喃、3,5-二甲基异噻唑、3-乙基-2,5-二甲基吡嗪、2-甲氧基苯酚、5H-5-methyl-6,7-dihydrocyclopentapyrazine。(三)不同生产工艺条件对芝麻油风味物质的影响研究在建立的指纹图谱体系基础上,以确定的25个指纹峰为考察对象,以风味成分的含量及相对比例组成为指标,研究了不同工艺条件(制油工艺、炒制温度、香型和储存时间)对芝麻油主要风味物质的影响。结果表明：水代法生产的芝麻油的风味物质含量明显高于螺旋压榨法和液压压榨法芝麻油；温度的控制对于芝麻油的风味具有重要意义,过低的温度不利于芝麻油风味物质的生成,过高的温度也会破坏芝麻油风味成分；风味物质的含量高低与芝麻油风味的浓淡具有重要相关性；芝麻油中分子量小、极性低的物质随着储存时间的增加,其含量逐渐减少,而分子量大、极性高的物质比较稳定。(四)芝麻油风味成分与制油工艺之间的相关性研究应用主成分分析和聚类分析研究了制油工艺与芝麻油主要风味成分的内在联系,构建了二者之间的相关性方程,研究表明：不同制油工艺得到的芝麻油在挥发性成分上存在显著不同。其中：甲基吡嗪、己醛、3,5-二甲基异噻唑、2-庚烯醛5H-5-methyl-6,7-dihydrocyclopentapyrazine、2-甲氧基苯酚和戊醛这七种物质的含量差别,直接影响了芝麻油制油工艺的分类。57个芝麻油样品按不同工艺各自聚为一类,且不交叉。更多还原

【Abstract】 Edible and medicinal value of sesame oil is very high, and it is peoples’favorite. The main characteristic of sesame oil different from other seasoning oil is its unique flavor. Sesame oil flavor is an important part of sesame oil quality standard, is an important index of the sesame oil of good quality. The different production technology, different production conditions for sesame oil flavor has important implications.Discussing on sesame flavor material foundation, as well as the different process conditions on the sesame oil flavor impact, to reveal the sesame oil flavor composition and origin, objective evaluating of sesame oil quality and optimization of sesame oil production process have great significance.However, review the literatures, the researches of sesame oil flavor mainly confined to the single active ingredient or index constituents of qualitative and quantitative analysis, lacking of flavor components of effective group analysis, as well as various process conditions on the effect of sesame oil flavor.This research through the optimization of the experimental conditions, determine the sesame oil flavor components in detection of solid phase microextraction-gas chromatography-mass spectrometry(SPME-GC-MS)analysis method system; in the establishment of the analysis system on the basis of, through a large number of samples, constructed the sesame oil flavor components of fingerprint system, determine the main feature of composition in the flavor components of sesame oil; the characteristic constituents as index, inspected oil preparation technology, pressing temperature, flavor and storage time on sesame oil effect on the flavor components, and combined with chemometric method, explore the sesame oil flavor composition and production process correlation, established the correlation between the two equation. This study was to reveal the sesame oil flavor compositions, sources and further optimization of sesame oil production technology has important significance.(1)The SPME-GC-MS analysis system for sesame oil flavor components.By solid phase microextraction-gas chromatography-mass spectrometry, test, parameter optimization, determined the testing conditions of SPME-GC-MS in sesame oil flavor. The optimized experimental conditions are as follows:1m L of sesame oil was placed in a4mL vial. The vial was immersed in a wat er bath at60℃for20min. Then, the fiber needle penetrated the septa of the vial and the fiber was exposed in the sample headspace for1h at60℃.Aft er extraction, the fiber was removed and inserted into the injection port of the GC for thermal desorption of the volatile components (250℃for6min).Heli um was used as carried gas at a constant flow of0.8mL/min. The oven tempe rature was initially held at30℃for5min, and increased to100℃by10℃/m in,100℃for7min. Subsequently, the temperature was increased to180℃at15℃/min and180℃for7min.The method’s precision, repeatability and stability are verified,6consecuti ve measurements, the relative retention time and relative peak area of RSD bo th in0.01%-0.17%and3.83%-11.70%range, the method is stable, reliable, an d can be used in analysis of flavor components of sesame oil.(2) The research of the GC-MS fingerprint of the sesame oil flavor components.Through the57sesame oil samples for SPME-GC-MS analysis,we obtained25common fingerprint material, in which methyl-pyrazine is most stable,as the reference peak. The similarity of chromatographic fingerprints is greater than0.850, indicating the samples similarity with fingerprint technology requirements.Therefore, to establish the GC-MS fingerprint can be used as sesame oil flavor quality control reference standard.25common fingerprint material includes:acetone,2-butanone, acetic acid, pentanal, vinylfuran, pyrazine, dimethyl-disulfide, pyridine,hexanal,4-methylthia zole,methyl-pyrazine,2-(2-propenyl)-furan,2-furanmethanol,1,2-ethanediol,diace tate,2,4-dimethyl-thiazole,2,3-dimethyl-pyrazine, ethenyl-pyrazine,(E)-2-hepten al,5-methyl-2-furancarboxaldehyde, methyl-2-furoate,2-pentyl-furan,3,5-dimethy1-isoxazole,3-ethyl-2,5-dimethyl-pyrazine,2-methoxy-phenol,5H-5-methyl-6,7-dih ydrocyclopentapyrazine.(3)The effect of the different process conditions on sesame oil flavor.In the establishment of the fingerprint system, to determine the25fingerprint peaks as the study object, the flavor components of absolute content and the relative proportions of the constituent as an index, the effects of different processing conditions(oil producing technology, pressing temperature, flavor and storage time) for sesame oil flavor impact. The results show that:the change of oil producing technology of sesame oil flavor substances of the peak area and relative content have great impact. Method of water content in sesame oil in area and is superior to the other two kinds of technology. Different pressing temperature on sesame oil flavor substances of small effect. And high temperature press is easy to damage the sesame oil flavor. The differences of flavor have a large effect on the peak area of the sesame oil flavor substances, without affecting its relative content. Sesame oil flavor components, small molecular weight, low polarity material as the storage time increases,its contents decreased. While the molecular weight, highly polar material is relatively stable.(4) Study the correlation between sesame oil flavor components and oil processing technology.The results show that:different oil preparation technology of sesame oil in the volatile components in the different. Among them:methyl-pyrazine,hexanal,3,5-dimethyl isothiazolone,2-heptenal,5H-5-methyl-6,7-dihydrocyclopentapyrazine,2-methoxy phenol and aldehyde with these seven substances content difference, directly affect the sesame oil preparation technology classification.57sesame oil samples according to the different processes are clustered together, and do not cross.更多还原