Comparison of the yeast Saccharomyces cerevisiae var. boulardii and top-fermenting brewing yeast strains during the fermentation of model nutrient media and beer wort
¹ITMO University, Faculty of Biotechnologies (BioTech), Lomonosov street 9, RU191002 Saint-Petersburg, Russia
²Innovation & Research Department, Baltika Breweries, 6-th Verkhnij ln. 3, RU194292 St. Petersburg, Russia
³Russian Research Institute of Food Biotechnology, Department of Biotechnology and Food Safety, Samokatnaya street 4b, RU111033 Moscow, Russia
Recently, the yeast Saccharomyces cerevisiae var. boulardii have attracted the attention of Food Science researchers due to their unique properties, the main among which are probiotics. Thus, research is conducted on the use of this yeast as a starter culture in the technology of yogurt, fermented vegetables, fruit, vegetable juices, as well as beer. This paper is aimed at studying Saccharomyces cerevisiae var. boulardii ‘s fermentation performance compared to top-fermenting brewing yeast strains during fermentation of model nutrient media and beer wort. Fermentation activity of the studied strains was assessed based on the character of fermentation curves, as well as the values of the maximum substrate assimilation rate and apparent degree of fermentation. Moreover, during the study, beer was produced using the yeast Saccharomyces cerevisiae var. boulardii as a starter culture. According to the obtained results, it can be concluded that Saccharomyces cerevisiae var. boulardii have less fermentation activity compared to brewing strains. In turn, beer produced with Saccharomyces cerevisiae var. boulardii significantly differed in physicochemical, microbiological, and organoleptic parameters from the control sample obtained using the 047A brewing strain. Thus, it contained less ethanol and secondary metabolites; however, the concentration of living cells was significantly higher, which indicates a relatively high viability of the yeast Saccharomyces cerevisiae var. boulardii. From an organoleptic point of view, final beer has a positive sensory profile. The aroma of the product had a complex character: it included caramel, spicy, fruity and phenolic notes, as well as smoked and wine elements; while honey was the dominant note of the taste.