Colour correction in white wines by use of immobilized yeasts on kappa-carragenate and alginate gels.

摘要

Pale white wines of the sherry type were subjected to different colour correction treatments based on the use of gel beads consisting of variable proportions of yeasts immobilized on 2 different polysaccharides ( kappa-carragenate and alginate). All treatments were found to reduce colour in the control wine, the reduction increasing in a non-proportional way with the increase in yeasts concn. and the decrease in polysaccharide/yeasts ratio. At the same polysaccharide/yeast ratio, kappa-carragenate gels proved more efficient than alginate gels. Except for some acids, concn. of phenolic compounds were reduced by all treatments (especially those involving kappa-carragenate). Based on their colour-correcting ability, moderate retention of human healthy phenolic compounds and similarity to activated C in sensory terms, kappa-carragenate gels containing a 2 g/l concn. of yeasts in a 2:2 polysaccharide/yeast ratio represent an effective alternative to the fining agents traditionally used in the production of white wines.