Ultraviolet/visible/near-infrared spectral analysis and chemometric tools for the discrimination of wines between subzones inside a controlled designation of origin: a case study of Rías Baixas

Abstract

Background and Aims Chemometrics combined with ultraviolet (UV), visible (VIS) and near-infrared (NIR) spectral analysis were evaluated to classify wines belonging to the controlled designation of origin (DO) Rias Baixas (Spain). Methods and Results Samples of wines made solely from the Albarino cultivar from subzones Condado, Salnes, Rosal and Ribeira do Ulla were analysed in transmittance mode using UV, VIS and NIR ranges alone or in combination. Principal component analysis was used to explore and determine data patterns. Soft independent modelling of class analogy (SIMCA), linear discriminant analysis and support vector machine classification were used to classify the samples. Condado wines were completely classified by applying SIMCA to the UV/VIS/NIR, NIR or VIS/NIR spectral ranges. Salnes and Ribeira do Ulla wines were completely classified by applying SIMCA to the UV/VIS spectral range. Finally, Rosal wines were completely classified by applying linear discriminant analysis to the VIS/NIR spectral range. Conclusions These results show that combinations of UV/VIS/NIR spectra and chemometric methods can be used as a rapid technique to classify subzones into a DO such as Rias Baixas. This technique may also assist authentication because the models also discriminated wines from outside Rias Baixas. Significance of the Study The importance of spectral range selection and chemometric tools for the classification of wines inside a DO was demonstrated.