Bioprospecção e caracterização de leveduras on flavor

Abstract

Recently, there has been an expansion of the beer market, resulting in the concomitant growth of new technologies for the development of quality products. Given the importance of yeasts in production and their role in forming the aromas and flavors of beer, several studies have stood out in investigating the ability of yeasts to produce natural aromas and provide aromatic sensations in compliance with the German law of purity of beer production, which defines that the drink should be produced only with barley, hops, water and yeast. Due to the potential of yeasts and the natural ways of obtaining aromas through secondary metabolites, companies have endeavored to isolate potential flavor-producing microorganisms that are effective in beer fermentation, based on the biodiversity of the environments. The present work aimed to bioprospect yeast on flavor for the preparation of a beer with aromatic identity. In order to identify microorganisms capable of producing aromatic compounds of interest, yeast strains were isolated from four fruits collected in the city of Dois Vizinhos, Parand. Subsequently, the isolated and purified strains were cryopreserved by testing three distinct cryoprotectants (skim milk, glycerol and dimethyl sulfoxide) for maintenance and preservation of the strains. The strains were screened using methodologies to determine: the fermentation potential of different carbon sources, morphological characteristics, response to physical-chemical stress and the production of hydrogen sulfide. In this work, the isolation methods used provided the isolation of 19 strains after the exclusion tests, in which we searched for relevant characteristics in the beer fermentation, thus meeting the process requirements.