Development of an HPLC-DAD Method Combined with Chemometrics for Differentiating Geographical Origins of Chinese Red Wines on the Basis of Phenolic Compounds

In this work, a high-performance liquid chromatography-diode array detection (HPLC-DAD) method combined with chemometrics was developed for differentiating geographical origins of Chinese red wines. Phenolic compounds were firstly detected and quantified by direct injection HPLC-DAD method in thirty red wines originated from two famous wine-growing regions in China. Given the high complexity of the wine samples and the co-elution problems during chromatographic separation, multivariate curve resolution-alternating least squares (MCR-ALS) was utilized to extract pure chromatographic and spectral profiles of each co-eluted compound. Quantification of phenolic compounds was thus achieved even in the presence of overlapping peaks and uncalibrated interferents. The quantitative data of the phenolic compounds in wines provided by the MCR-ALS algorithm were afterwards analyzed by unsupervised principal component analysis (PCA) and hierarchical cluster analysis (HCA) methods and supervised orthogonal partial least squares-discrimination analysis (OPLS-DA) method. Both PCA and HCA results showed that the thirty red wines from different geographical origins could be obviously distinguished, and the OPLS-DA could successfully predict the geographical origins of red wines. This study demonstrated that the HPLC-DAD method combined with chemometrics can be used as an effective tool for differentiating geographical origins of Chinese red wines on the basis of phenolic compounds.