顶空固相微萃取-气相色谱-静电场轨道阱质谱法结合化学计量学比较分析酱油挥发性风味成分

Comparative analysis of volatile flavor compounds in soy sauce by headspace solid-phase microextraction-gas chromatography-orbitrap-mass spectrometry combined with chemometrics

中文关键词:  气相色谱-静电场轨道阱质谱  酱油  多元统计分析  挥发性香气

英文关键词:gas chromatography-orbitrap-mass spectrometry  soy sauce  multivariate statistical analysis  volatile aroma

中文摘要:

      目的 利用顶空固相微萃取-气相色谱-静电场轨道阱质谱法(headspace solid-phase microextraction-gas chromatography-orbitrap-mass spectrometry, HS-SPME-GC-Orbitrap-MS), 对生抽酱油和老抽酱油中挥发性风味成分进行比较分析。方法 以酱油为研究对象, 优化顶空固相微萃取的温度、平衡时间、萃取时间、盐浓度、样品量, 建立HS-SPME-GC-Orbitrap-MS测定酱油中挥发性化合物的方法, 实现生抽酱油和老抽酱油中挥发性香气化合物的定性和半定量, 通过主成分分析、正交偏最小二乘判别分析模型等对生抽酱油和老抽酱油进行差异分析。结果 HS-SPME-GC-Orbitrap-MS鉴定出生抽酱油中124种, 老抽酱油中88种特征挥发性香气化合物。通过正交偏最小二乘判别分析(变量重要性投影值≥1)以及Kruskal-Wallis H检验(P<0.05)进一步筛选出5种香气物质, 分别为苯乙醇、乙酸乙酯、2-甲基-1-丁醇、戊醛和4-乙基愈创木酚。结论 本研究建立了HS-SPME-GC-Orbitrap-MS, 能够高效鉴定酱油中的挥发性成分, 应用该方法结合化学计量学筛选出了生抽酱油与老抽酱油的5个差异化合物, 其中苯乙醇、乙酸乙酯和2-甲基-1-丁醇在生抽酱油中相对含量更高, 赋予了生抽酱油果香、醇香的特征。而戊醛和4-乙基愈创木酚在老抽酱油中的相对含量更高, 贡献了老抽酱油浓郁的脂香和酱香。研究结果为酱油行业质量评价提供了参考数据, 为进一步研究不同发酵工艺、用途的酱油风味特色提供新理论依据。

英文摘要:

      Objective To compare the volatile flavor compounds in light and dark soy sauce by headspace solid-phase microextraction-gas chromatography-orbitrap-mass spectrometry (HS-SPME-GC-Orbitrap-MS). Methods The study used soy sauce as the research object. Parameters such as extraction temperature, equilibration time, extraction time, salt concentration and sample volume were optimized to establish a method for determining volatile compounds in soy sauce by HS-SPME-GC-Orbitrap-MS. Based on this method, volatile aroma compounds in light and dark soy sauce were identified and semi-quantified. Principal component analysis and orthogonal partial least squares discriminant analysis were used to analyze the differences between the light and dark soy sauce. Results A total of 124 volatile aroma compounds were identified in light soy sauce, and 88 in dark soy sauce using HS-SPME-GC-Orbitrap-MS. Through orthogonal partial least squares discriminant analysis (variable importance for the projection≥1) and the Kruskal-Wallis H test (P<0.05), 5 kinds of key aroma compounds were further screened: Phenethyl alcohol, ethyl acetate, 2-methyl-1-butanol, pentanal and 4-ethyl guaiacol. Conclusion This study establishes a HS-SPME-GC-Orbitrap-MS method that can efficiently identify volatile components in soy sauce. By applying this method combined with chemometrics, 5 differential compounds between light soy sauce and dark soy sauce are screened out. Among them, the relative content of phenyleth anol, ethyl acetate and 2-methyl-1-butanol is higher in light soy sauce, endowing it with fruity and alcoholic characteristics. Meanwhile, the relative content of pentanal and 4-ethyl guaiacol is higher in dark soy sauce, contributing to its rich fatty and soy sauce-like aroma. The findings provide reference data for quality evaluation in the soy sauce industry and offer a new theoretical basis for further research on the flavor characteristics of soy sauces produced by different fermentation processes or for different uses.