Fouling Colloids During Microporous Alumina Membrane Filtration of Wine

Abstract

ABSTRACT Three different wines, from the same cultivar, were microfiltered using a device operating under static conditions and equipped with a section of monochanelled tubular alumina membrane, pore size 0.2 μm. Filtration flux curves resembled permeation profiles observed in dynamic cross‐flow conditions using a similar membrane. Minute amounts of colloidal material deposited on the surface and inside the membrane were isolated for the first time and characterized as mixtures of high molecular weight moderately acidic grape proteoglycans (surface deposit) and low molecular weight acidic moieties (inner deposit). These fouling colloids were likely deposited by trace amounts not detectable in crude starting wines.