Caracterización de Vinagres de Jerezmediante FT-IR en combinación conanálisis multivariante

Abstract

Sherry Vinegar is a high quality Spanish product with a Designationof Origin that comes exclusively from Sherry Wines. Thisvinegar is aged following the traditional system of criaderas andsoleras, which confers unique organoleptic characteristics. Theprice of Sherry Vinegar is higher than that of other vinegars, soit is frequently subject to adulteration. For this reason, effectiveanalytical tools are required to guarantee the quality and originof these vinegars. In this study, a set of 48 Sherry vinegar samplesfrom different raw material (Palomino Fino, Moscatel andPedro Ximenez wines) were analyzed by Fourier Transform infrared(FT-IR) spectroscopic technique. The spectroscopic datawere combined with supervised exploratory techniques such asRandom Forest (RF), as well as unsupervised, such as hierarchicalcluster analysis (HCA) and principal component analysis(PCA). The result of unsupervised techniques, shows a clearclustering trend of vinegars according to their raw material. TheRF model allowed to select the 6 most important wavelengthsand classify 100% of the samples according to the type of vinegarfor cross-validation leaving one out (LOOCV) and the Outof Bag (OOB) set. Finally, a spectralprint characteristic of eachtype of vinegar and a web application that allows sharing thealgorithms was developed. This facilitates the characterizationof vinegars for other users.