Effect of the production site on stable isotopes of ethanol in fruit spirits

Abstract

Stable isotope ratio analyzes are powerful analytical methods that can be used to check the authenticity of alcoholic beverages and to detect any adulteration. The Forensic Institute of National Tax and Customs Administration applies stable isotope techniques - SNIF-NMR (Site specific Natural Isotope Fractionation), IRMS (Isotope Ratio Mass Spectrometry) to determine the botanical origin of the alcoholic beverages. The process starting from fruit until the Hungarian ‘pálinka’ has several steps, most of them well studied: fermentation from fruit sugar to ethanol, sample preparation (Cadiot distillation) and isotopic measurements (SNIF-NMR, IRMS). To keep the complete process under control only the study of the isotope fractionation effect of distillation step during the production procedure is missing. In this study the control of the different scale fermentation and distillation step was investigated by comparing isotope ratios: (D/H), δ13C of ethanol distilled from spirits produced in laboratory and in a commercial/Hungarian distillery. The experimental results of multivariable F-test (MANOVA) show that the scale of the fermentation and distillation – laboratory or commercial - has no impact on measured stable isotope ratios. This is a practical proof that the stable isotope database of the Forensic Institute can be used for the evaluation of the authenticity of spirits produced in any distillery.