INFLUENCE OF FATTY-ACIDS ON THE GROWTH OF WINE MICROORGANISMS SACCHAROMYCES-CEREVISIAE AND OENOCOCCUS-OENI

The effects of fatty acids, extracted during prefermentation grape ski n-contact on Saccharomyces cerevisiae and Oenococcus oeni, were studie d, The influence of skin-contact on total fatty acid content was evalu ated both in Chardonnay must and in synthetic medium. Prior to alcohol ic fermentation, the skin-contact contributes to a large enrichment of long-chain fatty acids (C-16 to C-18:3). These results induced a posi tive effect on yeast growth and particularly on cell viability. In the skin-contact fermented media, levels of C-12 and especially C-10 are lower and macromolecules content higher than in controls. This product ion of extracellular mannoproteins and the reduction of medium-chain f atty acids in media by S. cerevisiae increased growth of O. oeni, The influence of fatty acids (C-10 to C-18:3), in their free and esterifie d forms, on bacterial growth and on malolactic activity was also exami ned. Only C-10 and C-12, especially in their esterified forms, always appeared to be toxic to O, oeni.