Nowadays commercial preparations of yeast polysaccharides (in particular mannoproteins) are widely used for wine colloidal and tartrate salt stabilization. In this context, the industry has developed different processes for the isolation and purification of polysaccharides from the cell wall of S. cerevisiae.
Indeed, S. cerevisiae releases low amounts of mannoproteins in the growth medium thus rendering economically disadvantageous their isolation directly from the culture broth.
In contrast, Schizosaccharomyces japonicus, a non-Saccharomyces yeast isolated from wine, releases a high quantity of polysaccharides (in particular galactomannoproteins) during the alcoholic fermentation. Therefore, this yeast could be useful for the industrial production of exogenous polysaccharide preparations that could be easily purified and subsequently used as additives in winemaking.
In the present work, the polysaccharides (PSs) released from Sch. japonicus, recovered directly from the growth medium by ultrafiltration, have been chemically characterized and their impact on the wine colloidal stability evaluated. Interestingly, these PSs contribute positively to the wine protein stability.
Report presented at the Enoforum Awards 2020. The paper reproduced in this video-seminar was presented at the 1st Spanish edition of Enforum Web (5-7 May 2020)