INFLUENCE OF PREFERMENTATION CLARIFICATION ON NITROGENOUS CONTENTS OFMUSTS AND WINES

A correct must clarification process improves fermentation and the qua lity of the wine obtained; however, if clarification is extensive, the wines obtained are of lower quality. The aim of this study was to det ermine the influence of two prefermentation clarification treatments ( static sedimentation and vacuum filtration) on nitrogenous contents of musts (Vitis var. garnacha and viura), fermentation kinetics, and the resultant composition of the wines. The results show that neither sta tic sedimentation nor filtration can alter the concentration of ammoni um nitrogen, although both treatments increase amino nitrogen, and fil tration decreases protein nitrogen remarkably. Consumption of amino ni trogen is not dependant on the degree of clarification, although in a more clarified must direct assimilation of amino acids (Thorne's mecha nism) and other assimilation processes (Ehrlich's and Stickland's mech anisms) are possible.