DETERMINATION OF FREE FATTY-ACIDS AND THEIR ETHYL-ESTERS IN MUSTS ANDWINES

White must and wine fatty acids are present mainly in the free form, o r esterified as ethyl esters, and both contribute to flavor and foam p roperties of wine. A reliable and sensitive analytical procedure for a nalyzing the free fatty acids (C6-C18) and their ethyl eaters has been developed. Sulfuric acid (3%) in methanol was selected as a derivativ e reagent, and optimal derivatization conditions were established (3 h at room temperature). This reagent gives total methylation of fatty a cids and partial transesterification of ethyl eaters to methyl esters and, through the study of this transesterification, free and bound fra ctions were determined satisfactory. (C) 1997 Elsevier Science B.V.