Abstract: The volatiles in Lager beer were identified by headspace solid phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS) and the flavor differences among three brands of Lager beer were discriminated by principal component analysis (PCA), partial least squares-discriminant analysis (PLS-DA) and random forest classifier (RFC). Using divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) SPME fibers, we extracted the samples for 5 min at room temperature, then desorbed the analytes at the GC inlet and analyzed them. Among the identified flavor compounds, ethyl octanoate and ethyl decanoate were the key components to discriminate the brands. In the established PLS-DA and RFC models, both giving a prediction accuracy of 100%, the two components contributed the most to the difference in beer flavor. This strategy could play a positive role in the establishment of a flavor-based method for beer classification.

Key words: Lager beer; flavoromics; gas chromatography-mass spectrometry; flavor difference