Quantitative analysis and detection of chaptalization and watering down of wine using isotope ratio mass spectrometry

¹ SG Isotech DOO Pančevo, Maksima Gorkog 58/C, 26000 Pančevo, Republic of Serbia
² C.N.R.I.F.F.I. – China National Institute of Food and Fermentation Industries Limited, Building 6, No.24, Jiuxianqiao Middle Road, Chaoyang District, Beijing, Post 10015, People's Republic of China
³ IZOTOPTECH LTD. Bem ter 18/C., 4026 Debrecen, Hungary
⁴ COIL (Cornell University, Stable Isotope Laboratory), Corson Hall, E149, Ithaca, NY 14853, USA
⁵ Center for Viticulture and Oenology, Bul. Kralja Aleksandra 84, Office No. 15, 11111 Belgrade, Republic of Serbia
⁶ Faculty of Agriculture, Belgrade University, Nemanjina 6, 11080 Belgrade, Republic of Serbia

^a e-mail: ivan@sgisotech.com

Abstract

In early 1990's European Union has established new isotopic approach for detection of wine authenticity. In this article we setup the possibility of using new approach using new EIM – Module – IRMS (Ethanol Isotope Measurement – Module – Isotope Ratio Mass Spectrometry) instrumental technique and new analytical parameter δD_n(δ²H_n) wine ethanol value, which represents δ²H value of non-exchangeable hydrogen stable isotope ratio in ethanol, with other isotopic species (δ¹⁸O values in wine water) to improve detection of illegal wine production practices such as addition of sugar and/or dilution with water. Total of 42 wine samples were analyzed. 10 wine samples (out of 42) were prepared from grapes by alcoholic fermentation and analyzed for δD_n values of ethanol. 19 wine samples (out of 42) were collected from wine producers in Serbia plus 1 wine samples designated from United States was taken from Serbian market and analyzed for δD_n values of ethanol, δ¹⁸O values in wine water and also δ¹³C values in wine ethanol. Furthermore 9 wine samples (out of 42) were taken from Hungarian market and analyzed for δD_n values of ethanol, and also 3 wine samples (out of 42) were taken from Austrian market and analyzed for δD_n values of ethanol. All experiments were done in 4 isotope laboratories located in US, Austria, Hungary and People's Republic of China. δD_n values of ethanol were measured by using EIM Module connected to FlashHT 2000 pyrolizer (one laboratory – Imprint Analytics GmbH, Austria), while in other 3 laboratories (US – COIL – Cornell University, Stable Isotope Laboratory, Hungary – Isotoptech Ltd, Debrecen, Hungary and China – C.N.R.I.F.F.I. – China National Institute of Food and Fermentation Industries Limited) EIM Module was connected to TC/EA (High Temperature Conversion Elemental Analyzer). Peripherals in all laboratories were further interfaced with isotope ratio mass spectrometer. Furthermore δ¹⁸O values in wine water were measured by using Gas Bench II interfaced also with isotope ratio mass spectrometer (one laboratory – US). Obtained results from all 4 laboratories have shown that this new approach which uses δD_n in wine ethanol is more effective in improving detection of illegal wine production practices (sugar enrichment and water dilution) and origin of ethanol, and also detecting the addition of corn or beet sugar, sugar syrup to wine, or dilution of grape must with water prior to alcoholic fermentation.

Keywords: Wine authenticity; EIM – Module – IRMS; Stable Isotope; Isotope Ratio Mass Spectrometry; Wine; Watering; Chaptalization.