Differentiation of certified brands of origins of Spanish white wines by HS-SPME-GC and chemometrics

A headspace solid-phase microextraction gas-chromatographic (HS-SPME-GC) procedure was used to determine the composition of the volatile fraction of white wine samples from several Spanish certified brands of origin (CBO). The compounds present were previously identified by gas chromatography-mass spectrometry (GC-MS) and quantitative determinations were carried out by GC-FID. Four CBO, Rueda, Ribeiro, Penedes, and Condado de Huelva, were studied. Rueda wines present the highest concentrations of ethyl acetate (55.86-125.27 mu g mL(-1)), isoamyl acetate (0.91-6.72 mu g mL(-1)), hexyl acetate (0.09-0.81 mu g g mL(-1)), and 2-phenethyl acetate (0.14-0.66 mu g mL(-1)). Compounds such as ethyl hexanoate (0.88-2.15 mu g mL(-1)) and ethyl decanoate (0.29-0.96 mu g mL(-1)) appeared in higher concentration in Ribeiro, Rueda, and Penedes samples. According to the results obtained and by applying pattern-recognition procedures differentiation of the considered CBO was attained. Principal-component analysis (PCA), linear discriminant analysis (LDA), and multilayer perceptrons neural networks (MLP-NN) were used as chemometric tools for pattern-recognition studies.