Changes in Anthocyanins and Color Characteristics of Pinot Noir Wines during Different Vinification Processes

TLDR

The study monitored simple and polymeric anthocyanins in Pinot Noir wines from fermentation onset to bottling using HPLC, and assessed color characteristics with tristimulus spectrophotometry. The analysis revealed 12 polymeric anthocyanins, with malvidin 3‑glucoside as the dominant monomer; higher fermentation temperatures boosted monomer extraction but overall anthocyanin levels fell, while polymeric anthocyanins rose during fermentation, peaked at bottling, and were strongly linked to color intensity. Keywords: wine color, polymeric anthocyanins, monomeric anthocyanins, flavonoids, fermentation temperature, HPLC analysis, tristimulus analysis.

Abstract

Simple and polymeric anthocyanins of Pinot noir wines produced by different vinification processes were monitored by high-performance liquid chromatography (HPLC) from the onset of fermentation to bottling. Color characteristics were determined by tristimulus measurement using a spectrophotometer with a color determination and match program. Up to 12 individual polymeric anthocyanins were found. Extraction of monomeric anthocyanins was increased with higher fermentation temperature, but anthocyanin concentration declined gradually after fermentation. In all wines, the dominant type of anthocyanin was malvidin 3-glucoside. In contrast, the content of polymeric anthocyanins increased during fermentation and thereafter, and reached the highest concentrations at bottling. Fermentation temperature was a critical factor for formation of polymeric anthocyanins. The presence of total or individual polymeric anthocyanins was directly related to wine color intensity, and all the polymeric anthocyanins were important to wine color. Keywords: Wine color; polymeric anthocyanins; monomeric anthocyanins; flavonoids; fermentation temperature; HPLC analysis; tristimulus analysis