Authentication of Transylvanian Spirits Based on Isotope and Elemental Signatures in Conjunction with Statistical Methods

Abstract

The potential association between stable isotope ratios of light elements and mineral content, in conjunction with unsupervised and supervised statistical methods, for differentiation of spirits, with respect to some previously defined criteria, is reviewed in this work. Thus, based on linear discriminant analysis (LDA), it was possible to differentiate the geographical origin of distillates in a percentage of 96.2% for the initial validation, and the cross-validation step of the method returned 84.6% of correctly classified samples. An excellent separation was also obtained for the differentiation of spirits producers, 100% in initial classification, and 95.7% in cross-validation, respectively. For the varietal recognition, the best differentiation was achieved for apricot and pear distillates, a 100% discrimination being obtained in both classifications (initial and cross-validation). Good classification percentages were also obtained for plum and apple distillates, where models with 88.2% and 82.4% in initial and cross-validation, respectively, were achieved for plum differentiation. A similar value in the cross-validation procedure was reached for the apple spirits. The lowest classification percent was obtained for quince distillates (76.5% in initial classification followed by 70.4% in cross-validation). Our results have high practical importance, especially for trademark recognition, taking into account that fruit distillates are high-value commodities; therefore, the temptation of “fraud”, i.e., by passing regular distillates as branded ones, could occur.

Shedding Light on Metals Release from Chestnut Wood to Wine Spirit Using ICP-MS

“…After a first stage of depletion, very slight enrichment, compatible with Smailagić et al [ 4 ] observations for some botanical species, occurred between 60 and 270 days, with WS from CO15 showing the highest level (253 ng/L). Our results are of the same order of magnitude or lower than the reported levels for different spirits [ 22 ], including tequila [ 60 ], whisk(e)y [ 12 ], Transylvanian spirits [ 14 ], and cachaça [ 56 ]. Concerning the ageing technology, the distinct behaviour of CB and MOX modalities from 180 to 365 days was interesting: the former showed almost steady concentration, and the latter presented significant increases (180–270 days) followed by a decrease (270–365 days).…”

“…As aforementioned, it is thought that Mn 2+ activates molecular oxygen by forming reactive oxygen species (e.g., hydroxyl radicals), similarly to Fe 3+ , probably catalysing oxidation reactions in WS. The contents of Mn in the studied WSs are comparable or lower than those reported for other spirits, namely, Serbian plum brandies [ 4 ], tequila and mezcal [ 11 , 60 ], whisk(e)y [ 12 ], grape spirits [ 21 ], several Transylvanian spirits [ 14 ], Brazilian sugarcane spirit [ 56 ], and Cognac WS [ 43 ].…”

“…However, as the transference of mineral elements from wine to WS during distillation is unlikely, geographical fingerprinting techniques based on multi-element composition of WS will reflect mainly anthropogenic factors [ 54 ]. In spite of that, some studies on authentication of spirits based on this approach have been published [ 14 ].…”

“…These observations contradict the results of Smailagić et al [ 40 ] study that revealed no evidence of As extraction from different kinds of wood to spirit model solution. It should be emphasized that, excluding the WSs from CO30, CO60, and CN (365 days), the concentrations were always extremely low (<0.4 µg/L), compared with tequila and mezcal [ 60 ], and especially with Transylvanian spirits (from several fruits’ distillates) in which levels from 4 to 50 µg/L were found [ 14 ]. It is noteworthy that OIV establishes the maximum acceptable limit of 0.200 mg/L for wines [ 62 , 65 ], very far (500-fold) from the levels found in the WSs of this study, especially keeping in mind that the daily intake of WS is much lower than that of wine.…”

“…In distillates characterized by increased Cu content and some sulphurous acid content, a reddish deposit of copper-sulphide is formed under the action of light [ 4 ]. Some elements can remove unwanted odours—Cu stands out for its role in the treatment of sulphidic off-odours [ 6 , 7 ]—while others can be used as authentication markers [ 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ]. As trace elements, some metals, such as manganese (Mn), Fe, cobalt (Co), nickel (Ni), Cu, zinc (Zn), and molybdenum (Mo), are essential for human health, but their accumulation can be adverse [ 16 ].…”