基于固相微萃取-气相色谱-质谱法结合相对气味活度值分析影响牦牛肉风味的关键化合物

Analysis the key compounds affecting the flavor of yak meat based on solid-phase microextraction-gas chromatography-mass spectrometry combined with relative odor activity value

目的辨别影响不同部位牦牛肉风味特征及关键化合物。方法采用固相微萃取气相色谱-质谱法(solid phase microextraction-gas chromatography-mass spectrometry,SPME-GC-MS)和电子鼻检测技术,运用相对气味活度值(relative odor activity value,ROAV)、偏最小二乘法(partial least squares discriminant analysis,PLS-DA)分析影响牦牛肉风味的关键化合物。结果牦牛肉共检测出60种化合物,醛类是牦牛肉含量最高化合物类别。ROAV最终确定影响牦牛肉风味关键化合物是:2-乙基-1-己醇、2-乙酰吡咯、壬醛、烯丙基甲基硫醚、辛醛、苯乙醛、丁酸、己醛、己酸、苯甲醛、1-辛醇、2-戊基-呋喃、间二甲苯13种共有化合物。其中,2-乙基-1-己醇使牦牛肉呈现芳香味,壬醛、辛醛带来清涩香味,烯丙基甲基硫醚、2-乙酰吡咯、2-戊基-呋喃使牦牛肉呈现烤肉、烤面包的香气,苯乙醛使牦牛肉具有花香气。影响牦牛肉风味的变量投影重要度值大于1的关键化合物:2-乙基-1-己醇、苯甲醛、1-辛醇、间二甲苯、己酸。电子鼻感应器数据与牦牛肉关键化合物存在相关性。结论PLS-DA证明腰大肌、胸横肌、肋间肌、臂肌风味相似,半膜肌独立区别于其他样品。电子鼻能够区分不同部位牦牛肉气味特征,且与PLS结果一致;本研究结果为玉树牦牛肉特征及风味研究提供理论参考依据。

Objective To identify the flavor characteristics and key compounds affecting different parts of yak meat.Methods Using solid phase microextraction-gas chromatography-mass spectrometry(SPME-GC-MS)and electronic nose detection technology,relative odor activity value(ROAV)and partial least squares discriminant analysis(PLS-DA)were used to analyze the key compounds affecting the flavor of yak meat.Results A total of 60 compounds were detected in yak meat,and aldehydes were the highest compounds in yak meat.ROAV value results showed that the key compounds that ultimately affect the flavor of yak meat were:2-ethyl-1-hexanol,2-acetylpyrrole,nonanal,allyl methyl sulfide,octanal,phenylacetaldehyde,butyric acid,hexanal,caproic acid,benzaldehyde,1-octanol,2-pentylfuran,m-xylene,and 13 kinds of common compounds.Among them,2-ethyl-1-hexanol gave yak meat an aromatic aroma,nonaldehyde octanal gave it a clear and astringent aroma,allyl methyl sulfide,2-acetylpyrrole,and 2-pentylfuran gave yak meat a roasted meat and toast aroma,and phenylacetaldehyde gave yak meat a floral aroma.The key compounds with variable projection importance value greater than 1 affecting yak flavor were 2-ethyl-1-hexanol,benzaldehyde,1-octanol,m-xylene and caproic acid.The data of electronic nose sensor were correlated with key compounds of yak meat.Conclusion PLS-DA proves that the flavors of yak tenderloin,brisket,sirloin,round are similar,and bottom round are independently different from other samples.The electronic nose can distinguish the odor characteristics of different parts of yak meat,and was consistent with the PLS results.The research results provide theoretical references for the flavor characteristics of Yushu yak meat in the future.