Department of Soft Matter Science and Dairy Technology, University of Hohenheim, Garbenstraße 21, 70599, Stuttgart, Germany.
Department of Flavor Chemistry, University of Hohenheim, Fruwirthstraße 12, 70599, Stuttgart, Germany.
Anal Bioanal Chem. 2021 Apr;413(9):2577-2586. doi: 10.1007/s00216-021-03222-w. Epub 2021 Mar 2.
To understand aroma perception from complex food matrices' determination of dynamic aroma release during simulated oral processing is necessary. In this study optimization, validation and application of a novel method coupling headspace-solid phase microextraction (HS-SPME) with gas chromatography-ion mobility spectrometry (GC-IMS) is presented. Thirteen character impact compounds imparting different chemical properties are studied to understand capabilities and limitations of the method. It was shown for the first time that the temperature of the IMS sample inlet can be increased up to 200 °C without instrumental constraints. Linear calibration was possible for eleven of the thirteen compounds with one decade dynamic range. The limit of detection and quantitation were 2.1-63.0 ppb and 7.2-210.1 ppb, respectively. Diacetyl could be detected in negative polarity mode of IMS, however with lower precision compared to the compounds detected in positive mode. Limitations of the method were short HS-SPME extraction time, which in the case of caproic acid was not sufficient for reliable quantification. Additionally, δ-decalactone could not be detected due to maximum GC temperature of 200 °C. Application of the method to determine dynamic aroma release from a dairy matrix was successfully shown for nine compounds. Analysis of complex food matrix was performed with similar precision compared to analysis in aqueous solution, thus proving high robustness of the method towards matrix effects.
为了理解从复杂食物基质中感知香气,有必要确定在模拟口腔加工过程中动态释放的香气。本研究优化、验证并应用了一种新的方法,将顶空固相微萃取(HS-SPME)与气相色谱-离子迁移谱(GC-IMS)相结合。研究了 13 种具有不同化学性质的特征影响化合物,以了解该方法的能力和局限性。首次表明,在没有仪器限制的情况下,IMS 样品入口的温度可以升高到 200°C。对于 13 种化合物中的 11 种,可以进行线性校准,动态范围为 1 个数量级。检测限和定量限分别为 2.1-63.0 ppb 和 7.2-210.1 ppb。在 IMS 的负极性模式下可以检测到二乙酰,但与正模式下检测到的化合物相比,其精密度较低。该方法的局限性在于 HS-SPME 萃取时间短,对于己酸而言,萃取时间不足以进行可靠的定量。此外,由于 GC 的最高温度为 200°C,因此无法检测 δ-癸内酯。该方法成功应用于从乳制品基质中测定动态香气释放,共检测到 9 种化合物。与在水溶液中分析相比,对复杂食物基质的分析具有相似的精度,从而证明该方法对基质效应具有很高的稳健性。