Estudo do potencial fermentativo de Saccharomyces cerevisiae isolada de polpa de fruta para produção de cerveja Lager

Abstract

In the brewing of beer, the fermentation time is an important factor for the producer, involved principally with the production volume capacity and the costs. During the production of lager fermentation beer, the fermentation is 10 days long, resulting in a bottleneck on the produced volume, as well as limiting the capacity of available fermenters. Aiming at optimizing the production time of such type of beer and reducing the production costs, the behavior of the Saccharomyces cerevisiae PF23 yeast isolated from guava pulp subjected to fermentation was studied. The studied culture was standardized (6.0 x 109 cells/mL) following the recommendations for a commercial culture (S. cerevisiae US-05), which was used as the control. The wort, prepared with water, pilsen malt and hop, was splitted into four fermenters, being two of them inoculated with S. cerevisiae PF23, and the remaining ones with the commercial culture. The fermenters were subjected to the temperature of 12ºC in static conditions during 10 days. The alcohol by volume, total sugars, pH and titratable acidity were measured at the initial time and after 2, 4, 6, 8 and 10 days. At the end of the fermetation, the sugar consumption by the S. cerevisiae PF23 and the commercial culture were equal to 15.41 mg/mL and 17.67 mg/mL, respectively, while the alcohol by volume produced by both the cultures was equal to 3.6%. Despite that, the alcohol by volume produced by the S. cerevisiae PF23 at the day 8 (3.4%) was higher than the one for the commercial culture (2.9%) (p < 0.05), being more advantageous for commercial beer brewing in terms of savings on the production time. The pH and titratable acidity do not present statistical differences between the beverages fermented with both the cultures. The S. cerevisiae PF23 has potential of technological application on the wort fermentation for beer brewing.