基于顶空气相色谱-离子迁移质谱法结合化学计量对新疆黑小麦挥发性物质鉴定分析

Identification and analysis of volatile substances in black wheat in Xinjiang based on headspace gas chromatography-ion mobility mass spectrometry combined with stoichiometry

中文关键词:  黑小麦  顶空气相色谱-离子迁移质谱法  挥发性有机物  相对气味活性值

英文关键词:black wheat  headspace gas chromatography-ion mobility mass spectrometry  volatile organic compounds  relative odor activity value

中文摘要:

      目的 分析新疆不同地区黑小麦面粉、全麦粉及籽粒中挥发性有机物的差异。方法 采用顶空气相色谱-离子迁移质谱法对新疆4个不同地区6种黑小麦的面粉、全麦粉及籽粒挥发性成分进行检测, 并结合正交偏最小二乘判别分析(orthogonal partial least squares discriminant analysis, OPLS-DA)方法对挥发性成分进行分类与特征选择。结果 共检测到黑小麦中134种挥发性物质, 定性出97种挥发性有机物, 主要包括醛类23种、酯类21种、醇类19种、酮类12种和酸类6种。相对气味活性值(relative odor activity value, ROAV)表明, 1-辛烯-3-酮、(E)-2-辛烯醛、1-丙硫醇、2-甲酰基-5-甲基噻吩、2-甲基丁醛、4-甲基苯甲醛、异戊酸、辛-1-烯-3-醇、原愈创木醇是黑小麦中关键挥发性风味物质, 发挥主导作用。OPLS-DA分析显示, 黑小麦面粉、全麦粉与籽粒的挥发物之间存在差异, 其中(E)-2-辛烯醛主要存在于籽粒中, 2-甲基丁醛在面粉中含量较高, 4-甲基苯甲醛在全麦粉中含量较高。结论 气相色谱-离子迁移质谱法可作为区分不同处理黑小麦挥发性化合物差异的技术手段, 研究结果为黑小麦优化制粉工艺提供了数据支撑, 同时也为黑小麦全麦粉掺假辨别提供了新方向。

英文摘要:

      Objective To analyze the differences in volatile organic compounds in black wheat flour, whole wheat flour and seeds in different regions of Xinjiang. Methods The volatile components of flour, whole wheat flour and seeds of 6 kinds of black wheats from 4 different regions in Xinjiang were detected using headspace gas chromatography-ion mobility spectrometry, and the volatile components were classified and feature selected using orthogonal partial least squares discriminant analysis (OPLS-DA) method. Results A total of 134 kinds of volatiles were detected in black wheat, and 97 kinds of volatile organic compounds were characterized, mainly including 23 kinds of aldehydes, 21 kinds of esters, 19 kinds of alcohols, 12 kinds of ketones and 6 kinds of acids. Relative odor activity value (ROAV) showed that 1-octen-3-one, (E)-2-octenal, 1-propanethiol, 2-formyl-5-methylthiophene, 2-methylbutyraldehyde, 4-methylbenzaldehyde, isovaleric acid, 1-oct-1-ene-3-ol and proto-guaiacol were the major volatile odorants and played a dominant role in black wheat. OPLS-DA analysis showed that there were differences between the volatiles of black wheat flour, whole wheat flour and seeds, with (E)-2-octenal mainly present in seeds, 2-methylbutyraldehyde higher in flour and 4-methylbenzaldehyde higher in whole wheat flour. Conclusion Gas chromatography-ion mobility spectrometry can be used as a technical tool to distinguish the differences in volatile compounds between different treatments of black wheat, and the results of this study provide data support for optimizing the milling process of black wheat, as well as a new direction for the identification of adulteration of black wheat whole wheat flour.