Discrimination of whisky brands and counterfeit identification by UV–Vis spectroscopy and multivariate data analysis

Influence of the Scanning Temperature on the Classification of Whisky Samples Analysed by UV-VIS Spectroscopy

“…Changes in the UV-VIS spectra of the whisky samples at specific wavelengths were observed in either the raw (Figure 1) or the second derivative ( Figure 2) spectra as a function of the increase in the temperate during scanning. The observed changes in the values of absorbance in the UV region can be associated with the presence of chromophores originated from compounds present during the maturation process in oak barrels, the presence of volatile phenolic compounds from peat burning during drying, as well as the presence of caramel added to adjust the colour of the whisky during the process, as reported by other authors [2,27]. Absorption bands in the UV-VIS region between 210 nm and 282 nm ( Figure 1, raw spectra) were reported to be associated with the presence of furfural and hydroxymethylfurfural (HMF) in aged alcoholic beverages stored in oak barrels [27,28].…”

“…The observed changes in the values of absorbance in the UV region can be associated with the presence of chromophores originated from compounds present during the maturation process in oak barrels, the presence of volatile phenolic compounds from peat burning during drying, as well as the presence of caramel added to adjust the colour of the whisky during the process, as reported by other authors [2,27]. Absorption bands in the UV-VIS region between 210 nm and 282 nm ( Figure 1, raw spectra) were reported to be associated with the presence of furfural and hydroxymethylfurfural (HMF) in aged alcoholic beverages stored in oak barrels [27,28]. These authors also reported that, when furfural is extracted from the oak barrels, HMF might be the main component of caramel present in whisky [27,28].…”

“…Although few reports have been published on the use of spectroscopy combined with chemometric methods to classify and authenticate alcoholic beverages such as whisky [2,3,7,27], no reports were found in relation to the effect of temperature during spectra collection and its consequences on the classification performance. The objective of this study was to evaluate the effect of increasing temperature on both the UV-VIS spectra of whisky and on the classification results of the samples according to country of origin.…”

Chemometrics in analytical chemistry – an overview of applications from 2014 to 2018

“…Oliveira et al 65 discriminated banknotes authenticity of Brazilian Real (R$ 20, R$ 50 and R$ 100) using a portable NIR spectrometer combined with SIMCA and successive projections algorithm-LDA (SPA-LDA) models. Martins et al 66 proposed a method for direct analysis of seven whisky brands. The authors used UV-Vis spectroscopy combined with PLS-DA to classify 164 genuine and 73 false samples.…”

The application of FT-IR spectroscopy in discrimination of differently originated and aged whisky

“…It is hard to unambiguously state which one is better or worse as scientific publications inform about use of all of them in different cases presenting 1 3 advantages and disadvantages of each one. However, the number of scientific publications presenting the application of optical spectroscopy in whisky [15][16][17] and other spirit beverages' [14] authenticity control and monitoring has increased recently. These techniques successfully compete with conventional analytical techniques.…”