Effect on the autolysis process and the colouring matter of several commercial preparations with β-glucanase action in red winemaking

The present work studies the action of three commercial preparations with β-glucanase activity in the autolytic release of polymeric materials from the cell walls of a selected yeast strain of Saccharomyces cerevisiae and a commercial yeast species Saccharomyces uvarum, in a model medium over a 10 week period of simulated ageing over lees. HPLC with refractive index detection was used to monitor the enrichment of the medium in polymeric materials derived from cell wall fragments. In this work, modified cell wall fragment profiles are obtained when autolysis is enzyme-induced through β-glucanase addition, more fragments of smaller molecular weight and greater grouping among them. Moreover, significant differences have also been found from the very first measurements in the hydrolytic action between commercial β-glucanase preparations. The incidence on the anthocyanin evolution during the first stages of autolysis after enzyme addition was examined by HPLC with photodiode array detection. Colour parameters were also assessed by UV–VIS spectrophotometry at the end of the experimental stage. No improvements have been arisen in relation to anthocyanin stability and chromatic features of wines when rapid and important cell wall fragments degradations are promoted through enzyme addition.