Sauce-flavor baijiu is a popular Chinese baijiu. To avoid adulteration and market cheating, this study aims to develop a new, reliable, and accurate traceability system for characterization of the geographical origins. Totally, 100 samples collected from seven regions in Guizhou Province of China are analyzed, involving 13 trace elements, 5 organic acids, and stable carbon isotope composition of acetic acid. Based on these data, a geographical classification model is established. The origin accuracy is found to reach as high as 83%, thus providing a useful technique for authentication of the sauce-flavor baijiu and contributing to the healthy development of the baijiu industry in China.

To explore the regional characteristics of multielement and stable isotopes in tequila and the viability of tracing the geographical origin, both inductively coupled plasma mass spectrometry (ICP-MS) and stable isotope ratio mass spectrometry (IRMS) were applied in this study to determine the multielement content and stable isotope ratios of tequila. Then, principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) as chemometrics were conducted in combination to establish a model for determining the geographical origin of Mexican tequila. According to the analytical results, the content of 22 elements varied, as did the ranges of stable isotope δ13C and δ18O values for the tequila obtained from the 4 producing areas. Besides, there were regional characteristics shown to some extent. PCA and PLS-DA methods can be adopted to identify the geographical origin of tequila in Mexico. According to the discriminant verification of 16 samples, the accuracy of prediction reached 93.75%. It has been demonstrated that it is possible to distinguish tequila of different geographical origins in Mexico by combining the determination of the multielement content and stable isotope ratios with chemometric analysis, which lays a foundation for tracing the geographical origin of tequila.