On sample preparation methods for fermentative beverage VOCs profiling by GCxGC-TOFMS

Abstract

AIM: Study the influence of sample preparation methods on the volatile organic compounds (VOCs) profiling for fermentative beverages by GCxGC-TOFMS analysis.

METHODS: Five common sample preparation methods were tested on pooled red wine, white wine, cider, and beer. Studied methods were DHS, Liquid-liquid extraction, mSBSE, SPE and SPME. VOCs were analyzed by GCxGC-TOFMS followed by data analysis with ChromaTOF. RESULTS: The volatile organic compounds (VOCs) profiling results were very dependent on the sample preparation methods. Consider the number of annotated VOCs: SPE sample preparation is most suitable for beer and red wine; 166 and 433 peaks were annotated respectively. For cider and white wine, most peaks were found by DHS (330) and L-L extraction (256). However, there is only a small fraction of VOCs can be found with all the sample preparation techniques. For known fermentative aromas, most of them can be found easily by all the sample preparation methods. SPME, compare to L-L extraction, mSBSE, and SPE, have a shortage of collection and concentration on lactone compounds and vinyl compounds.

CONCLUSIONS:

VOCs profiling results for the fermentative beverages vary based on the used sample preparation method. There isn’t one ideal method to collect and concentrate all the compounds. A good global coverage can be reached by combining the results from different sample preparation techniques.