Stable Isotope Ratio Analysis for Verifying the Authenticity of Balsamic and Wine Vinegar

Abstract

In this paper, we investigate whether the analysis of stable isotope ratios D/H and ¹³C/¹²C in ethanol and acetic acid and of ¹⁸O/¹⁶O in water can be applied to the ingredients of "aceto balsamico di Modena IGP" (ABM) to evaluate their authenticity. We found that impurities in the extraction solution do not affect the ¹³C/¹²C of acetic acid and the D/H values of acetic acid are not affected under a composite NMR experiment. The standard deviation of repeatability and standard deviation of reproducibility are comparable in wine vinegar and ABM and generally lower than those quoted in the official methods. This means that the validation parameters quoted in the official methods can also be applied to the ingredients of ABM. In addition, we found no changes in the isotopic values from wine to vinegar and to ABM, and from the original must to the ABM must, providing experimental evidence that reference data from wine databanks can also be used to evaluate the authenticity of vinegar and ABM.

Combination of sugar and stable isotopes analyses to detect the use of nongrape sugars in balsamic vinegar must

“…For an ABM residue after acetic acid extraction, which can be assimilated to a must, this general reference can be adopted . The ABM product specifications allow the addition of up to 2% caramel for colour stability.…”

“…International Organization of Vine and Wine (OIV) methods are currently adopted: OIV‐MA‐AS311‐05 for site‐specific analysis of the D/H ratio using 2 H‐SNIF‐NMR ( 2 H‐site‐specific natural isotope fractionation–nuclear magnetic resonance [NMR]) and OIV‐MA‐AS312‐07 for analysis of the 13 C/ 12 C ratio (expressed as δ 13 C ‰) using isotope ratio mass spectrometry (IRMS). As demonstrated by Perini et al, these methods can also be effectively applied to ABM ingredients, including must . The limits for D/H and δ 13 C isotopic ratios are those in the official wine databank, when the origin and year of production are declared, or the more general limits reported in Dordevic et al…”

Internal Referencing for 13C Position-Specific Isotope Analysis Measured by NMR Spectrometry

“…Previous studies performed in relation to irm-2 H NMR demonstrated the feasibility of such an in situ method, 28 and it is used for current analyses of vinegars. 29 Thus, it has been demonstrated that the mass/purity ratio K′ of both standard and compound (eq 2) is equal to ratio K (eq 3), corresponding to the concentration ratio obtained by 1 H NMR,…”

Quantitative NMR Studies of Multiple Compound Mixtures

“…Pages et al [238] identified and quantified adulterants in sexual enhancement and weight loss dietary supplements (DS) with a benchtop cryogen-free low-field 1 H NMR spectrometer. To control the authenticity of vinegar [206][207][208] and rice spirits [203], a method named SNIF (sitespecific natural isotope fractionation)-NMR has been proposed to monitor adulteration. SNIF-NMR can distinguish acetic acid or ethyl alcohol from different raw materials on the basis of significant differences in the sitespecific ratio of deuterium to hydrogen.…”