El potencial de levaduras no convencionales para la producción de cervezas con bajo contenido de alcohol

SOFIA SAMPAOLESI; LAURA PÉREZ TRAVES; ROBERTO PÉREZ TORRADO; AMPARO QUEROL

San Carlos de Bariloche

Workshop; International Workshop on Brewing Yeasts; 2021

IPATEC COMAHUE

In recent years, beer consumption worldwide slightly diminished although, at the same time, an increase of 2.8% and 8.8% in low ethanol and alcohol-free beer consumption, respectively, was observed. These changes in consumers' habits are related to the general public concern for adopting a healthier lifestyle. In this context, the increase of the consumers ́ demand for low alcohol beers and more variety of styles stimulated the interest for applying novelty yeast strains in brewing. In this sense, Saccharomyces non-cerevisiae and non-Saccharomyces yeasts offer certain advantages, such as new aroma and flavor profiles, reduced ethanol levels and organic acids production, with the potential for improvement of existing beer styles and providing the emergence of new ones. The present investigation provides insights into the potential of non-conventional yeasts isolated from yeast sludge wastes of craft breweries from La Plata, Argentina, in the production of low-ethanol content beers. Pichia kudriavzevii MBELGA61, isolated from a Belgian style wheat beer sludge, demonstrated full attenuation of brewing wort, with minimum ethanol and CO2 yields and the capability of producing glycerol. Meyerozyma guilliermondii MUS122, isolated from a golden ale sludge, partially attenuated the brewing wort, with a minimum ethanol and CO2 output, and probed to assimilate maltotriose during growth kinetics studies, carried out in a microplate reader (incubation at 20° C with stirring). Apparently, these yeasts favor respiratory over fermentative pathway and P. kudriavzevii MBELGA61 leads a major carbon flux to biomass generation. Both non-conventional yeasts produce 1.19% V/V of ethanol, a significantly lower value than those yielded by S. cerevisiae brewing strains, ranging from 6.16 to 8.03% V/V, in microfermentations carried out under the same conditions. These results reinforce the approach of using non-conventional strains as candidates for production of fully attenuated and very low ethanolic beers, in co-cultures with Saccharomyces strains