Authenticity assessment of 2- and 3-methylbutanol using enantioselective and/or 13C/12C isotope ratio analysis

Enantioselective gas chromatography and/or ¹³C/¹²C isotope ratio analysis are suitable tools for the authenticity assessment of the fusel alcohols, 2- and 3-methylbutanol (1 and 2, respectively). The chiral compound, 1 is biosynthesised almost completely as the (S)-enantiomer, regardless of which carbohydrate source is used for fermentation. The type of CO₂ fixation and some plant-specific influences were of prime importance to the ¹³C/¹²C isotope ratios of the starting materials in alcoholic fermentation, and the δ¹³C values of 1 and 2 differed significantly. In general, the δ¹³C values of 2 were about 4–5ö lower than those of 1 produced via the same fermentation process. ¹³C/¹²C isotope ratio analysis results can be used to determine between fusel alcohols produced from different sources, and provides a new and valuable method of authenticity assessment.