Impact of commercial scale ultrafiltration on the composition of white and rose wine

Ultrafiltration (UF) was performed on six white and rose & PRIME; wines, at commercial scale (5400-71,000 L), to remove phenolic compounds associated with astringency. Dynamic UF parameters (permeate flux, transmembrane pressure, temperature) were monitored during filtration, and wine composition compared before and after treatment. Over 90% wine permeation was achieved although flux declined progressively throughout UF and dropped significantly after 80% fractionation. Wine macromolecules, especially phenolics and proteins, were substantially concentrated in retentate, such that the resulting permeate achieved clarification and heat stabilization specifications eliminating the need for fining. Other wine compositional properties (pH, free and total SO2, volatile acidity, and viscosity) were not significantly affected. Membrane fouling resulted in the rejection of small wine constituents (sugars, acids, and low molecular weight phenolics) suggesting complex membrane/solute interactions. To our knowledge, this is the first study to demonstrate the efficacy of UF in producing clarified and stabilized permeate, which reduced the negative effects of excess phenolics and proteins in wine.