RT Journal Article SR Electronic T1 Comparison of Multivariate Regression Methods for the Analysis of Phenolics in Wine Made from Two Vitis vinifera Cultivars JF American Journal of Enology and Viticulture JO Am. J. Enol. Vitic. FD American Society for Enology and Viticulture SP ajev.2015.15063 DO 10.5344/ajev.2015.15063 A1 Christopher W. Beaver A1 James F. Harbertson YR 2015 UL http://www.ajevonline.org/content/early/2015/10/29/ajev.2015.15063.abstract AB The quantification of key phenolic classes during different stages of red wine production has important industrial applications. Decisions of this nature require greater speed and economy than current bench or instrumental methodologies offer. Efforts to create rapid analysis have utilized models created from multivariate regression of easily obtained spectra (UV/visible or near infrared) and reference phenolic measurements. For this experiment, reference measures of phenolics and UV/Visible spectra were gathered from 100 Cabernet Sauvignon and Syrah red wine samples each throughout fermentation in order to create a model that could rapidly predict several phenolic classes in red wine must. The reference method, UV/Visible spectra sample dilution, and multivariate regression method were all varied in order to determine which combination gave the greatest predictive power. Ridge regression unanimously outperformed the other regression methods tested when calibrated with the modified assay at pH 7 and UV-visible sample dilution at 10-fold for only the Cabernet Sauvignon samples. Correlation coefficients obtained for anthocyanins, small and large polymeric pigments, tannins and total iron reactive phenolics were 0.83, 0.78, 0.76, 0.92 and 0.90 respectively. When the same multivariate regression evaluation was performed for Syrah, none of the methods tested gave accurate predictions, suggesting some cultivar specificity.