The use of glucose oxidase and catalase for the enzymatic reduction of the potential ethanol content in wine. (1st November 2016) - Röcker, Jessica
Highlights: The glucose oxidase method was improved by adding appropriate amounts of catalase. Industrial scale experiments were conducted. The sensory impact of the treatment included higher acidity and less fruitiness. The two deacidification methods used still need further improvement. Abstract: Due to the increase of sugar levels in wine grapes as one of the impacts of climate change, alcohol reduction in wines becomes a major focus of interest. This study combines the use of glucose oxidase and catalase activities with the aim of rapid conversion of glucose into non-fermentable gluconic acid. The H2 O2 hydrolysing activity of purified catalase is necessary in order to stabilize glucose oxidase activity. After establishing the adequate enzyme ratio, the procedure was applied in large-scale trials (16 L- and 220 L-scale) of which one was conducted in a winery under industrial wine making conditions. Both enzyme activity and wine flavour were clearly influenced by the obligatory aeration in the different trials. With the enzyme treatment an alcohol reduction of 2 % vol. was achieved after 30 h of aeration. However the enzyme treated wines were significantly more acidic and less typical.