Exploring the influence of S. cerevisiae mannoproteins on wine astringency and color: Impact of their polysaccharide part.

The impact of the polysaccharide moiety of mannoproteins (MPs) on the color and astringency of red wines was studied respectively through spectrophotometry and their impact on tannin interactions with BSA. To this end, MPs with conserved native structures from four different Saccharomyces cerevisiae strains were used: a Wild-Type strain (BY4742, WT) taken as reference, mutants ΔMnn4 (with no mannosyl-phosphorylation) and ΔMnn2 (linear N-glycosylation backbone), and a commercial enological strain. MPs affected tannin-BSA interactions by delaying aggregation kinetics.