Research on the reduction of SO2 doses in winemaking using lysozyme and oenological tannin

Abstract

The effect of reducing the dose of sulfur dioxide on the physico-chemical and organoleptic properties of wines with Murfatlar controlled designation of origin was studied in this paper, experimenting with different prefermentative oenological treatments. For this purpose, a series of experimental variants was carried out on two Romanian grape cultivars for white wines ('Fetească regală') and red wines ('Fetească neagră'), using two yeast strains that produce low amounts of SO2 (Saccharomyces cerevisiae var. bayanus and Metschnikowia pulcherrima, a Non-Saccharomyces strain) and four prefermentative treatments with different doses of sulfur dioxide, lysozyme and oenological tannin. The obtained results highlighted the fact that reducing the dose of sulfur dioxide using lysozyme and oenological tannin can provide oxidative protection during the alcoholic fermentation stage, improving the organoleptic characteristics of white and red wines. From the physico-chemical point of view, the wines did not show statistically significant differences, except for the color intensity, which was higher in the case of the variants supplemented with 500 mg/L lysozymes, for both of the yeast strains used for fermentation. This study encourages the continuation of research regarding the experimentation of alternative products, to reduce the sulfur dioxide normally used in the winemaking process, in order to obtain healthy products, in accordance with current consumer requirements.

Keywords

• oenology
• prefermentative treatments
• yeast strains
• low sulphites
• oxidative protection