NON-SACCHAROMYCES YEASTS TO MODULATE THE SECONDARY AROMA OF THE WINES: INCREASE OF THE 2-PHENYLETHYL ACETATE THROUGH MIXED CULTURES


ABSTRACT
      
At present the winemakers confront to the need to improve the vinification process and the sensory qualities of the wine in an increasingly competitive sector and global. Between these challenges, stands out the need to produce wines more attractive and complexes from the aromatic point of view. In this context, the non-Saccharomyces wine yeasts could represent a suitable tool given his potential to form volatile compounds. In this work has evaluated the capacity of these yeasts to produce acetate esters, and his possible inclusion in mixed starters, capable not only to carry out the alcoholic fermentation but to enter differential aromatic characteristics in the like this obtained wines. Like result of the initial screening we selected the strain Hanseniaspora vineae 1471 by his stood out production of 2-phenylethyl acetate as well as by his good enological characteristics. Later we designed mixed starters with Saccharomyces cerevisiae, confirming the properties of H. vineae 1471, and the possibility to modulate the concentration of 2-phenylethyl acetate varying the initial proportions of these yeasts in the mixed culture. Likewise, employing non-sterile natural musts, we confirmed the growth of H. vineae 1471, inoculated of sequential form, in spite of the presence of an indigenous microflora high, and the obtaining of wines with concentrations increased of 2-phenylethyl acetate. Finally, the immobilization of H. vineae 1471 on calcium alginate beads resulted a suitable technician to control his permanence and production of 2-phenylethyl acetate during the fermentation.