Multivariate analysis of commercial and laboratory produced Sherry wine vinegars: influence of acetification and aging

One of the problems in the characterization of vinegars is the wide range of values obtained for the main physicochemical and sensorial parameters. The production method, raw material, and wood aging are factors of variation among wine vinegars. Twenty-seven vinegar samples corresponding to different wine substrates (Sherry wine, white wine) and different acetification methods (traditional method, acetification by submerged culture in acetators) were used to perform this study. Selected variables include those that play a major role in the final quality: aroma compounds and organic acids. Principal component analysis (PCA), cluster analysis (CA), linear discriminant analysis (LDA), and classification by artificial neural networks training by back-propagation (BPNN) were used to carry out the characterization. Sherry vinegars made by traditional methods and obtained either in the market or in the wineries were differentiated from Sherry vinegars obtained in the laboratory fermentor (aged or not in wood). Thus, the acetification method plays a major role in the characterization when these variables are considered.