Determination of simple carbohydrates in beer using SPME, on fiber derivatization and gas chromatography mass spectrometry

Fermentable sugars directly contribute to the sweetness of beer, whereas carbohydrates with more than four glycosyl units can be beneficial to the perception of beer in that they contribute to body or mouthfeel. GC/MS has not been widely used for the analysis of carbohydrate contents in beer. The analysis of beer by using L-SPME, on fiber derivatization with bis(trimethylsilyl) trifluoroacetamide (BSTFA) and GC-MS showed the presence of some carbohydrates (D-arabinose, -D-arabinopyranose, D-galactose, Dxylose, and D-mannose) never detected in beer. The analysis of three different types of beer showed that the presence of these carbohydrates can represent a significant part of the total amount of carbohydrates present in the beer.