Potential Role of Clarifying Agents in the Removal of Pesticide Residues During Wine Production and Their Effects upon Wine Quality

Fermentation studies were carried out during the production of white and red wines to determine whether the addition of bentonite or kieselsol to the must, or to the finished wine, would reduce the final content of 15 pesticides added prior to fermentation. Eleven of the 15 pesticides were present in more than 40% of initial concentration in the finished wines not treated with clarifying agents. Post-fermentation treatment was usually more effective than pre-fermentation treatment, and kieselsol was generally superior to bentonite. There was no difference between the two concentrations (0.25 g l - 1 and 0.5g l - 1) of clarifying agents employed. For most pesticides in both white and red wines, post-fermentation treatment with 0.25 g l - 1 kieselsol can be recommended as the best procedure or as good as any other.