Innovative regenerable polyamide particles as new filter aids for wine lees filtration

In oenology, the conventional dead-end filtration with filter aids, used for the processing of wine lees, consumes a high quantity of diatomaceous earth and brings serious environmental, sanitary and economic implications. In a real concern to improve wine quality and to decrease pollution, the "ecological filtration" concept based on the utilisation of a regenerative filter aid is proposed in this study. Polyamide particles were investigated as innovative filter aids for wine lees filtration. Trials were performed with two grades of polyamide particles D80 (D-50 = 91.8 mu m) and D100 (D-5(0) = 111 mu m). Filtration was carried out with wine added with two concentrations of lees (10.8 % and 20.2 %). The impact on wine quality was determined with oenological analyses, showing that the filtration made with polyamide particles did not modify wine organoleptic characteristics, improved turbidity and the filtrate fluxes arc higher in comparison to the usual precoat filtration. Then, polyamide particle regeneration experiments proved that these particles could be reused as filter aids several times after cleaning.