title: Qualitative study of ethanol content in tequilas by Raman spectroscopy and principal component analysis.
abstract: Using Raman spectroscopy, with an excitation radiation source of 514.5 nm, and principal component analysis (PCA) was elaborated a method to study qualitatively the ethanol content in tequila samples. This method is based in the OH region profile (water) of the Raman spectra. Also, this method, using the fluorescence background of the Raman spectra, can be used to distinguish silver tequila from aged tequilas. The first three PCs of the Raman spectra, that provide the 99% of the total variance of the data set, were used for the samples classification. The PCA1 and PCA2 are related with the water (or ethanol) content of the sample, whereas the PCA3 is related with the fluorescence background of the Raman spectra.
authors.affiliation: Centro de Investigaciones en Optica A.C., Unidad Aguascalientes, Prolong., Constitución 607, Apartado Postal 507, Fracc. Reserva Loma Bonita, C.P. 20200 Aguascalientes, México. cfraus@cio.mx
authors.forename: C
authors.initials: C
authors.lastname: Frausto-Reyes
authors.forename: C
authors.initials: C
authors.lastname: Medina-Gutiérrez
authors.forename: R
authors.initials: R
authors.lastname: Sato-Berrú
authors.forename: L R
authors.initials: LR
authors.lastname: Sahagún
mesh_terms: D000434:Alcoholic Beverages / Q000032:analysis*; D000431:Ethanol / Q000032:analysis*; D025341:Principal Component Analysis; D013059:Spectrum Analysis, Raman; D014867:Water / Q000032:analysis
chemical_list: D014867:Water; D000431:Ethanol