The formation of methanol, ethanol, ethyl acetate, propanol-1, isobutyl alcohol, and amyl alcohols (mixture of 2-methylbutanol-l and 3-methylbutanol-1) in continuous wine making by kissiris-supported biocatalyst, in comparison with free cells, was studied. The effect of temperature was also examined. Methanol content was not affected by the process and temperature, but the concentrations of ethyl acetate, propanol-1, isobutyl alcohol, amyl alcohols (total content of 2-methylbutanol-l and 3-methylbutanol-1), and total volatiles determined plus methanol were reduced by the reduction of the temperature. Although the concentration of the main aromatic compound, ethyl acetate, was slightly reduced in the wine, its percentage content in the total volatiles determined plus methanol was increased. Continuous wine making by the aforementioned biocatalyst gave higher ethyl acetate concentrations compared to that with free cells.

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Two alcohol resistant strains of Saccharomyces cerevisiae species were isolated from a Greek vineyard plantation. The strain AXAZ-1 gave a concentration of 17.6% v/v alcohol and AXAZ-2 16.5%, when musts from raisin and sultana grapes, respectively, were employed in alcoholic fermentations. They were found to be more alcohol tolerant and fermentative in the fermentation of molasse than the traditional baker's yeast. Specifically, using an initial [symbol: see text] Be density of 16 [symbol: see text] Be at the repeated batch fermentation process, in the first as well as fourth batch, the better AXAZ-1 gave final [symbol: see text] Be densities of 6.0 and 10.5 respectively, and the baker's yeast 11.6 and 14.5.

Using gamma-alumina pellets, more than threefold increase of the ethanol productivity in the fermentation molasse has been obtained in the present work. Also, molasse fermentation in the presence of gamma-alumina gave 78.4 g/L ethanol, ethanol yield factor 0.44 g/g, and conversion 89.4% at initial sugar concentration (ISC) 179.5 g/L, compared to 53.9 g/L, 0.30 g/g and 62.7% in its absence, respectively. Furthermore, it was found that gamma-alumina reduces the activation energy Ea of fermentation. This inorganic material does not promote the fermentation of raisin extract.