基于电子鼻与气相色谱-质谱法探究小麦与碎麦挥发性香气成分差异

Study on the difference of aroma components between wheat and crushed wheat based on electronic nose and gas chromatography-mass spectrometry

中文关键词:  小麦  碎麦  电子鼻  气相色谱-质谱法  挥发物  正交偏最小二乘法

英文关键词:wheat  crushed wheat  electronic nose  gas chromatography-mass spectrometry  volatiles  orthogonal partial least squares-discriminate analysis

中文摘要:

      目的 解析小麦与碎麦挥发性香气成分差异。方法 采用顶空固相微萃取(headspace solid-phase microextraction, HS-SPME)技术联用电子鼻(electronic nose, E-nose)与气相色谱-质谱法(gas chromatography-mass spectrometry, GC-MS)分析小麦与碎麦香气成分, 通过多元统计分析正交偏最小二乘法(orthogonal partial least squares-discriminant analysis, OPLS-DA)挖掘小麦与碎麦差异挥发物。结果 小麦与碎麦的香气成分存在显著差异, 整体上小麦挥发物响应强度高于碎麦, 小麦变成碎麦后部分香气值损失, 氧化分子和芳香化合物显著降低, 脂肪酸类化合物变化不明显, 酮类和胺类化合响应值较为接近。通过GC-MS共鉴定出42种化合物, 10种挥发物组分在小麦和碎麦共同检出, 小麦和碎麦中烷烃类化合物较多, 小麦主要挥发物为柠檬烯、十五烯和壬醛; 碎麦的主要挥发物是苯乙烯、柠檬烯和间乙基甲苯。基于小麦和碎麦挥发组分建立了OPLS-DA评估模型, 共筛选出7种差异挥发物判别小麦品质。结论 本研究成功建立了区别小麦和碎麦的方法, 分析了小麦与碎麦香气成分差异, 为小麦品质判别提供了科学依据。

英文摘要:

      Objective To analyze the differences in aroma components between wheat and crushed wheat. Methods Headspace solid-phase microextraction (HS-SPME) combined with electronic nose (E-nose) and gas chromatography-mass spectrometry (GC-MS) was used to analyze the aroma components of wheat and crushed wheat. Differential volatiles between wheat and crushed wheat was digged through multivariate statistical analysis by orthogonal partial least squares-discriminate analysis (OPLS-DA). Results There was significant difference in the aroma components between wheat and crushed wheat. Overall, the response intensity of wheat volatiles was higher than that of crushed wheat, and some aroma values were lost after wheat became crushed wheat, oxidative molecules and aromatic compounds significantly decreased, fatty acid compounds showed no significant changes, and the response values of ketone and amine compounds were relatively close. A total of 42 compounds were identified through GC-MS, and 10 kinds of volatile components were detected in both wheat and crushed wheat. There were more alkane compounds in wheat and crushed wheat, and the main volatiles in wheat were limonene, pentadecene, and nonanal; styrene, limonene, and m-ethyltoluene were the main volatiles of crushed wheat. Based on the volatile components of wheat and crushed wheat, the OPLS-DA evaluation model was established, and a total of 7 differential volatiles were screened to distinguish wheat quality. Conclusion The method is successfully established to distinguish between wheat and crushed wheat, and analyzed the differences in aroma components between wheat and crushed wheat, provides a scientific basis for wheat quality discrimination.