Comparative study of sodium bentonite and sodium-activated bentonite fining during white wine fermentation: its effect on protein content, protein stability, lees volume, and volatile compounds

Abstract

In this work, we compare the effect of the addition during fermentation of both sodium bentonite and sodium-activated bentonite on the protein content, protein stability, lees volume, and aroma compounds of a Sauvignon blanc wine. Protein unstable Sauvignon blanc juices were vinified with or without bentonite added at three different stages: before fermentation, early during fermentation, and towards the end of fermentation. Different addition doses of bentonite were used (X, X − 0.1, X − 0.2 g/L) according to protein instability of the grape juice (X = 1.7 and 2.7 g/L to sodium bentonite and sodium-activated bentonite, respectively). The wines stabilized with sodium-activated bentonite presented a higher content of volatile compounds and a lower volume of lees were produced than those treated with sodium bentonite, an effect that was greater when the fining treatment was done before the start of the fermentation.