Protein stabilization of white wines by stabilizing filtration: pilot studies

Abstract

Protein stabilization is an important part of the winemaking process of white wines, and in this work we present the results of protein stabilization of different monovarietal wines (Xarel.lo, Chardonnay, and Muscat) by a continuous stabilizing filtration process using a column packed with zirconium oxide operating in a continuous regime in a closed loop at pilot scale. The treatments in these conditions allow stabilizing the wines and reducing their protein content. No relation was found between the time necessary to stabilize the wine and the total protein content. The protein profile of the wine along the treatment shows four different fractions of macromolecules, of 15 kDa, 25 kDa, around 67 kDa and >190 kDa, except the 67 kDa fraction not found in Chardonnay. A fraction of 25 kDa was found in all three wines and could be directly involved in protein stability because the stability point of wines matched the lowest value of this fraction.