25 Years authentication of wine with stable isotope analysis in the European Union – Review and outlook

Abstract

Abstract. The implementation of stable isotope applications in official food analyses began in 1990. At that time the first method to detect sucrose from sugar beet or sugar cane in wine by Deuterium-Nuclear Magnetic Resonance ( 2 H-NMR) of ethanol, also known as SNIF-NMR ® -Method became adopted officially by the European Commission. This was a milestone for an improved authentication of wines and other food stuffs. In connection with methods using Isotope Ratio Mass Spectrometry (IRMS), stable isotope ratio analysis is one of the most powerful analytical tools for authentication of wine. The fundamentals of biotic and abiotic stable isotope fractionation and the analytical methods which are used in authentication of wine are summarized. Principles of authentication of some wine constituents like sugar, ethanol, organic acids, glycerol, and carbon dioxide as well as proof of geographic origin are reviewed. By selected example of anonymized cases, proof of adulterations (e.g. chaptalization, addition of water or mislabeling) using monovariate, bivariate, and multivariate data evaluations are discussed. It is shown that for this purpose databanks are generally indispensable. In their absence cut-off values, derived from long-term observations help to detect clear adulterations.

Grapes from the geographical areas of the Black Sea: Agroclimatic growing conditions and evaluation of stable isotopes compositions in scientific study

“…For example, it was shown that the carbohydrates (sugars) of grapes which are grown up in the conditions of water deficiency and high level of active temperatures are enriched by "heavy" 13 C carbon isotopes. In this case the δ 13 C VPDB reaches maximum values from −21, 0 to −20, 0 [11][12][13]. In our study the width of the range of values for natural carbohydrates (sugars) in 8 grape varieties amounts to 4 .…”

“…The carbon isotopes 13 C & 12 C which are a part of the organic matter will form the structure of the isotopomers of CO 2 which are generated during the combustion. Thus, the measurement of carbon dioxide molecules with masses of 44 and 46 allows the quantification of the carbon isotopes and calculation the δ 13 C VPDB value, which characterize the ratio of carbon isotopes 13 C and 12 C in test sample material relative to the selected reference substance (e.g.…”

“…Thus, the measurement of carbon dioxide molecules with masses of 44 and 46 allows the quantification of the carbon isotopes and calculation the δ 13 C VPDB value, which characterize the ratio of carbon isotopes 13 C and 12 C in test sample material relative to the selected reference substance (e.g. IAEA-CH-6 Sucrose).…”

“…The fresh musts were obtained under the laboratory conditions by mechanical grape crusher after stemming. The musts were used for later measurements of the composition of the carbon isotopes 13 C/ 12 C in carbohydrates (sugars) and organic acids by the FC-IRMS/SIRA method (see 2.1.3). The composition of oxygen isotopes 18 O/ 16 O was studied by the EQ-IRMS/ SIRA method directly in the musts without prior isolation of intracellular water from the samples (see 2.1.4).…”

“…The results of measurements of isotope compositions of stable carbon & oxygen isotopes presented as δ 13 C VPDB and δ 18 O VSMOW values, are shown below in Tables 1-4. The tables contain the average values obtained in a batch of five parallel determinations of carbon isotopes measurements for carbohydrates (sugars) and organic acids of each studied grape variety, as well as in a batch of three parallel determinations of oxygen isotopes measurements in the intracellular water of each grape variety and water samples from surface, atmospheric and underground sources.…”