气相色谱-质谱法分析啤酒中酒花香气成分

利用顶空固相微萃取-气相色谱质谱技术(HS-SPME/GC-MS)建立了定量分析啤酒中19种源自酒花的微量香气成分的方法。研究了不同萃取头、萃取时间、萃取温度对萃取效果的影响,最终确定HS-SPME最佳萃取条件为采用PDMS萃取头对啤酒样品在50℃下萃取60 min。在最佳萃取条件下,采用啤酒为基体以减少基体干扰,建立标准曲线,随后在SIM模式下以萜品烯-4-醇为内标定量测定了啤酒中酒花香气物质的含量。19种物质的回收率在81.2%～116.8%之间,相对标准偏差(RSD)低于9.8%,在5个加标浓度下,R2大于0.99。相比于传统方法,本方法所需样品量少、灵敏度高、操作过程简便,能准确的检测出啤酒中酒花香气物质的含量。

Determination of hop aroma compounds in beer by gas chromatography-mass spectrometry couple with headspace solid-phase micro-extraction

A gas chromatography–mass spectrometrics(GC/MS) method coupled with headspace solid-phase micro-extraction was used for the determination of 19 hop aroma compounds in beer.The major factors including type of the fiber,extraction time and temperature were studied.The results showed that a PDMS-coated SPME fiber extracting the beer sample for 60 min at 50 ℃ was the optimal SPME extraction condition.After compared with ethanol/water matrix,beer matrix was finally adopted as it reduced matrix discrimination and gave a better recovery of spiked standards.The recoveries of the 19 compounds were found to be in the range of 81.2%~116.8% while the RSD of the method was less than 9.8%,the responses of the 19 compounds were found to be linear in the validated range,with correction coefficients(R2) better than 0.99,which make it possible for us to use this method to detect the hop aroma compounds in the commercial beer.What’s more,it also provides the basis for brewing hop aroma beer.