The effect of pre-fermentation enzyme maceration on extraction and colour stability in Pinot noir wine

Abstract

The effect of pre-fermentation enzyme maceration on anthocyanins, phenolics, colour and colour parameters was investigated in Pinot noir (Vitis vinifera L.) wines. Wines were made from Pinot noir musts that were macerated for 12 hours at 20°C with a commercial enzyme preparation, Rohapect VR-C (Rohm, Darmstadt, Germany), with and without additions of SO₂. Anthocyanins and phenolics were determined by spectrophotomeric and HPLC methods. Extraction of anthocyanins was not increased by enzyme treatment. However, wines produced by enzyme maceration had increased visible colour intensity which corresponded with increased colour density and polymeric pigment formation. By the end of fermentation, enzyme treated wines had more polymeric pigment and less monomeric anthocyanins than non-enzyme treated wines. The promotion of the formation of polymeric pigments in enzyme treated wines continued after the wines were bottled, and the greater content of polymeric pigment led to greater colour density in the enzyme treated wines. The promotion of polymeric pigment formation in wines by macerating enzyme treatment of the must may be due to the breakdown of protective polysaccharides-protein colloids by hemicellulase and protease activities in the enzyme preparation.