Fermentation of barley wort with Saccharomyces boulardii to generate a beverage with probiotic potential.

Developing non-dairy functional beverages based on probiotics is a potential alternative for vegan consumers. It also becomes a big challenge since microorganisms can easily change chemical composition, acidity, color, and consumers' acceptability. In this work, the probiotic yeast Saccharomyces boulardii was used to elaborate a fermented barley wort beverage. For the beverage formulations, the use of two flavors strawberry (SPB) and nutty (NPB) and two different inoculum concentrations (1 × 103 (SPB or NPB103) and 1 × 104 CFU/mL (SPB or NPB 104)) were considered. The fermentation was carried out at 37°C under anaerobic conditions. The effect of the inoculum concentration was evaluated over reducing sugar consumption, the concentration of soluble solids, and pH. The best formulation was selected through a sensory evaluation. The profile of oligosaccharides and the resistance of the yeast to gastrointestinal conditions were determined only in the nutty flavor formulation (NPB 104). During the fermentation process, the content of oligosaccharides was increased compared to the unfermented wort, which improved the nutritional value. The analysis of resistance to simulated gastrointestinal conditions showed a decrease from 8.0 × 107 to 1.5 × 107 CFU/mL in the NPB 104 beverage. Barley wort is a potential medium to produce probiotic beverages with the yeast S. boulardii.