Application of Saccharomyces rouxii for the Production of Non-alcoholic Beer

Successive application of Saccharomyces cerevisiae DSM 70424 and Saccharomyces rouxii DSM 2535 or DSM 2531 in the production of non-alcoholic beer was investigated. The aim of the study was to consider the impact of the 2 mentioned strains of S. rouxii on the reduction of alcohol content in wort fermented at 12 or 24 degrees C for 96 hr, applying periodic aeration. The 2 S. rouxii strains were added at the 48(th) hr of fermentation after thermal inactivation of S. cerevisiae cells. The greatest alcohol decrease rate was observed for the treatment containing S. rouxii DSM 2535-fermented at 24 degrees C (from 1.56 to 0.36%). The concentration of acetaldehyde, diacetyl, and 2,3-pentandione, that have a key role in appearance of 'wort' and 'buttery' off flavors, were significantly lower in S. rouxii-containing treatments fermented at 24 degrees C. S. rouxii-containing treatment fermented at 24 degrees C showed slightly lower overall flavor acceptability compared to S. cerevisiae-containing treatment fermented at the same temperature. Such score was improved for the products obtained at 12 degrees C.