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High-quality wine vinegars protected by the indication “Protected Designation of Origin” (PDO) need efficient tools to protect their brands and prevent adulteration and unfair competition. In this sense, Near-Infrared spectroscopy (NIRs) combined with chemometrics has demonstrated its usefulness in food authentication. This work assessed NIRs and Chemometrics as a rapid and non-destructive methodology for this purpose. In this study, 83 high-quality wine vinegars of the Spanish PDOs “ Vinagre de Jerez ”, “ Vinagre de Condado de Huelva ” and “ Vinagre de Montilla-Moriles ” of different categories, and 11 wine vinegars without PDO, were analyzed in the range 12000-4000 cm −1 . Principal component analysis (PCA) was performed to explore the spectra and Partial Least Squares-Discriminant Analysis (PLS-DA) was used to build classification models. The high ability of prediction obtained (>90% correct classification) demonstrated the usefulness of this methodology for authentication of PDO wine vinegars and their categories. [ABSTRACT FROM AUTHOR]

Wine vinegars from three Protected Designations of Origin (PDO), Vinagre de Jerez (J), Vinagre de Montilla-Moriles (MM) and Vinagre del Condado de Huelva (CH) from Andalusia, Southern Spain, were investigated for their mineral elements content. Al, As, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, S, Sr, V and Zn were determined by inductively coupled plasma optical-emission (ICP-OES). Jerez vinegars had a statistically significant higher Sr content than the others, while with respect to B the same was true for Montilla-Moriles vinegars. Moreover, the ageing time of the vinegars clearly played a role in vinegar mineral content, with higher mineral levels found in aged vinegars than in young ones, especially in samples from Condado de Huelva. Multivariate analysis was performed in order to assess if the vinegars' geographical classification was possible through their elemental profile. Classification models were obtained by LDA and SVM, achieving good prediction abilities, 73 and 80%, respectively. [ABSTRACT FROM AUTHOR]

Abstract: Production of wine vinegar by fermenting dried grapes and rehydrating with tap water is not allowed by European Regulations. In this study we proved experimentally that δ18O analysis of beverage water, officially used to detect the watering of wine and rehydration of concentrated fruit juice, can also be applied to vinegar to detect this kind of fraud. We considered fourteen production chains from wine to the corresponding raw vinegar and diluted vinegar (6% of acidity), and the official European wine databank established according to . δ18O limit values of −2‰ and −5‰ were defined for raw and diluted vinegars produced from fresh grapes. Values lower than these limits indicate a significant addition of water to a starting matrix with a sugar concentration much higher than fresh grapes. On this basis, more than 60% of 92 suspicious wine vinegars imported to the Italian market were shown not to be authentic, but rather obtained by diluting a concentrated source such as dried grapes with water. [Copyright &y& Elsevier]