基于HS-SPME-GC-MS技术结合化学计量法对菜籽油中特征风味物质的差异化分析和定量检测

Differential Analysis and Quantitative Detection of Characteristic Flavor Substances in Rapeseed Oil Based on HS⁃SPME⁃GC⁃MS Technology Combined with Stoichiometry

采用顶空-固相微萃取-气相色谱-质谱(headspace-solid-phase microextraction-gas chromatography-mass spectrometry,HS-SPME-GC-MS)联用仪技术对菜籽油的风味物质进行分析,分别对最佳固相微萃取的萃取头类型、萃取温度和萃取时间等进行了研究,实验结果显示:采用HS-SPME-GC-MS技术共定性测出118种挥发性化合物,利用正交偏最小二乘判别进行差异化分析,其中62个挥发性物质可用于浓香菜籽油和普通菜籽油的区分。结合相对气味活度值对浓香菜籽油特征风味物质进行筛查,确定了8种贡献较大特征风味物质:2,5-二甲基吡嗪、2-乙基吡嗪、糠醛、3-丁烯基异硫氰酸酯、苯乙腈、5-甲基-2-糠醛、3,5-二乙基-2-甲基吡嗪、菜籽多酚,采用内标法对8种风味物质含量进行定量,线性方程的相关性大于99.5%,方法的精密度优于10%,检出限在:0.025μg/kg~3.4μg/kg,回收率在79.2%~109.8%,较好地解决了浓香菜籽油中特征风味物质准确定量的难题,克服了风味感官评价的主观性和差异较大的缺点。

By using combined instrument of head space⁃solid⁃phase,micro extraction⁃gas chromatography and mass spectrometry(HS⁃SPME⁃GC⁃MS),this article researched the characteristic flavor compounds in strong fra⁃grant rapeseed oil.The types of extraction heads,extraction temperatures,and extraction times are studied.By u⁃sing HS⁃SPME⁃GC⁃MS method,totally 118 kinds of volatile compounds are detected.62 volatile substances could be used to distinguish from strong fragrant rapeseed oil and ordinary rapeseed oil by using orthogonal partial least squares discriminant analysis.Eight characteristic flavor compounds(2,5⁃dimethylpyrazine,2⁃ethylpyrazine,fur⁃fural,3⁃butenyl isothiocyanate,phenyl acetonitrile,5⁃methyl⁃2⁃furfural,3,5⁃diethyl⁃2⁃methylpyrazine and rape⁃seed polyphenol)with significant contribution were identified by relative odor activity values in characteristic flavor compounds in strong flavored rapeseed oil.The internal standard method was used to quantify the content of eight flavor substances,and the correlation of linear equation was greater than 99.5%,the precision of the method is better than 10%,The detection limit is between 0.025μg/kg and 3.4μg/kg,and the recovery rate is between 79.2%and 109.8%.Effectively solved the problem of accurate quantification of characteristic flavor substances in strong fragrant rapeseed oil and and overcome the shortcomings of subjectivity and large difference in sensory evalu⁃ation of flavor.