Abstract

Tests of fermentability of yeast were carried out with two species of malt; Sympa malt and Nymphea malt, and with their EP (Ethanol Precipitate). Flocculation ofSaccharomyces uvarum was not observed with any of them. However, Flocculation can be induced by the EP from the bark of another specie of malt Trumpf malt. Analysis of the Trumpf malt EP was carried out using paper chromatography, fractionation on de Cellulose 23, IR (infrared) and UV (ultraviolet) Spectroscopy. Analysis of the effective (F1) fraction revealed the presence of ferrulic acid, arabinose and xylose. Effectiveness of the F1 osidic fraction and the results of IR spectra, which showed the presence of glucosidics bonds, plead for an active role of ferrulic acid and hemi-cellulose ester functions in yeast flocculation process.

Key words: Flocculation, Saccharomyces uvarum, malt, EP, osidic fraction, spectrographic analysis.