Scientific journal

51 2012

Journal of Food and Nutrition Research
Summary No. 3 / 2012

Grégrová, A. – Čížková, H. – Mazáč, J. – Voldřich, M.
Authenticity and quality of spirit vinegar: Methods for detection of synthetic acetic acid addition
Journal of Food and Nutrition Research, 51, 2012, No. 3, s. 123-131

Helena Čížková, Department of Food Preservation, Institute of Chemical Technology Prague, Technická 5, 166 28 Prague 6, Czech Republic. E-mail: Helena.Cizkova@vscht.cz, tel.: +420 220443014, fax: +420 220444455

Summary: A set of authentic spirit vinegars and mixtures of vinegars with synthetic acetic acid was analysed. Isotopic ratios, 2H/1H (SNIF-NMR; site-specific natural isotopic fractionation-nuclear magnetic resonance) and 13C/12C (IRMS; isotope ratio mass spectrometry), were determined and compared with the already published data. Gas chromatography analyses of volatiles and sensory analyses were applied to distinguish spirit vinegars, synthetic acetic acids and their mixtures. Concentrations of minor volatiles such as acetaldehyde and acetone were very low and too variable to be used as authenticity markers. The samples of authentic spirit vinegars contained ethanol and ethyl acetate, the indicators of the fermentation process, in concentrations ranging from 0.50 g?l-1 to 3.40 g·l-1 and from 0.10 g?l-1 to 0.50 g·l-1, respectively. Both the sensory assessment and the chromatographic method were found to be useful for fast screening of suspicious samples or for the detection of highly adulterated samples. However, these methods do not allow quantification of added synthetic acetic acid or confirmation of mixtures. In such cases, only the coupled SNIF-NMR and IRMS methods are able to authenticate the contents of the samples credibly with the estimated detection limit of 15% of synthetic acid addition.

Keywords: spirit vinegar; synthetic acetic acid; authenticity; SNIF-NMR; IRMS; GC-FID

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