Integrated analysis of aromas and metabolites in beers with Smart Databases for GC-MS

Description:
Flavor evaluation of food is essential for quality control and product development. There are a variety of factors to make differences of flavor, so its analysis requires a great deal of time and labor. In this study, authors focused on aromas and metabolites in beers and tried to define the relation of the two factors. Smart Databases for GC-MS were utilized for the comprehensive analysis of those compounds. In these databases, GC-MS conditions for a wide-scope target analysis are pre-registered, and the information such as retention index, target ion, and mass spectrum is included, which achieve both efficiency and accuracy. Especially in aroma database, odor characteristics and semi-quantitative values are presented, so the contributions of each compounds for flavor can be easily identified. Acquired data were processed to visualize the characteristics of each sample and to investigate the interactions between aromas and metabolites. In this study, 9 different commercially available beers were analyzed by GC-MS. For the aroma analysis, a headspace sampler was used to collect only the headspace gas generated from the beers. On the other hand, the analysis of hydrophilic metabolites was performed using the samples which were methoximated and trimethylsilylated. Each comprehensive analysis was executed with Smart Database. The data obtained were processed by Principal Component Analysis (PCA) and Multiblock Orthogonal Component Analysis (MOCA). The score plots of PCA clarified the differences among the 9 beer samples. For example, it was confirmed that India Pale Ale (IPA) beer was relatively rich in monoterpen alcohols such as Linalool, Geraniol, and Nerol, one of the aroma groups. Furthermore, the score plot of MOCA showed a certain level of correlation between aroma and metabolites. It was indicated that both Linalool and a metabolite Inositol were abundant in IPA, which made a clear difference from other samples.