Gas Chromatographic and Mass-Spectrometric Study of Fermentation Products from Varietal Grape Must (Red Bobal), With and Without Selected Killer Yeast

¹ Dept. of Chemistry, Polytechnic University of Valencia, Camino de Vera s/n. 46022 Valencia. Spain.

Selection of a particular yeast strain can provide better control over the fermentation process; the use of a select yeast strain can improve resulting wine quality. For these reasons, yeast selection is a routine practice in winemaking. The active dry yeast L-2226 was employed as the starter culture in this investigation; it was chosen for its special fermentation characteristics and suitability to the winemaking practices of the region (wines with high concentrations of sugars). The role of L-2226 cultures in aroma production was studied over Bobal variety must, using capillary columns and gas chromatography-mass spectrometry (GC/MS). For comparison purposes, two classes of fermentation were carried out: on a single grape must of Red Bobal: (a) indigenous yeast and (b)a selection of Killer yeast L-2226. The differences in the aroma components for both treatments are discussed.

Key words: killer yeast, fermentation

Submitted on October 17, 1996