Gas Chromatography with Time-of=Flight Mass Spectrometry for Aroma Profiling
Characterization of aroma compounds provides useful information in the food and beverage industry that can provide insight to quality control, process optimization, and brand awareness. Non-targeted methods that isolate and identify individual analyte components within the complex food matrix can provide a great deal of information. Here, methods were developed that utilize gas chromatography (GC) to separate individual analyte components from each other and time-of-flight mass spectrometry (TOFMS) for identification of the individual analytes. Aroma profile samples were prepared for analysis with headspace solid phase micro-extraction (HS-SPME) to collect and concentrate the volatile and semi-volatile compounds associated with a sample. These techniques were utilized to investigate both processing of raw materials and characterization of finished products. Changes in the aroma profile associated with the duration of boil time of hops were determined. The differences were readily apparent in the overall sample complexity and also clearly noted by changes to individual analyte concentrations. Characterization and comparison of final products was also accomplished with these analytical techniques. Principal component analysis (PCA) was used to investigate the similarities and differences of the sample groups with clear differences determined. These methods allowed for comparing sample types by their overall chromatographic features and by individual analyte differences in order to differentiate changes to a production process and to characterize beer samples.