Membrane comparison for wine clarification by microfiltration

In this work ten different polymeric microfiltration membranes of different materials polyethersulfone (PES), cellulose mixed esters (CE), cellulose acetate (CA), polypropylene (PP) and nylon (NY) with different pore diameters and of different commercial companies have been tested for wine clarification. A stirred cell has been used in all the membrane experiments. The objective has been to find the most suitable pore diameter, material and supplier that guarantees a suitable hygienisation and clearness without altering the organoleptic properties for the assayed red 12º ordinary wine.

As general conclusion and taking into account all the obtained results under the same operational conditions for red wine clarification the best membrane material seems to be cellulose acetate and both size pores, 0.2 and 0.45 (S&S) µm, are suitable for the physico-chemical and flux reduction point of view. If only the physicochemical characteristics are taken into account the best membrane of the tested ones would be the 0.8 CA (S&S) one. In any case in this work experiments have been carried out at a small scale and using a stirred cell and not a real crossflow filtration. For this reason the obtained polysaccharides retention for example is higher than the nowadays obtained one by crossflow microfiltration (retention under the 20%) [13–15]. This high retention can be the responsable of the observed accused flux reduction along the filtration essays. In order to prevent and reduce this fouling different methods could be applied as backflushing, backshocking or infrasonic pulsing [16]. Anyway, in order to check the obtained results, organoleptic test all together with more pilot scale study would be needed.