Chemical profiling and probiotic viability assessment in Gueuze-style beer: Fermentation dynamics, metabolite and sensory characterization, and in vitro digestion resistance.

Probiotic viability, metabolite concentrations, physicochemical parameters, and volatile compounds were characterized in Gueuze beers formulated with probiotic lactic acid bacteria (LAB) and yeast. Additionally, the sensory profile of the beers and the resistance of the probiotics to digestion were determined. The use of 2 International Bitterness Units resulted in high concentrations of probiotic LAB but a decline in probiotic yeast as pH decreased. Secondary fermentation led to the consumption of maltose, citric acid, and malic acid, and the production of lactic and propionic acids. Carbonation and storage at 4 °C had minimal impact on probiotic viability. The addition of probiotic LAB resulted in a distinct aroma profile with improved sensory characteristics. Our results demonstrate that sour beers produced with probiotic LAB and a probiotic yeast, and fermented using a two-step fermentation process, exhibited optimal physicochemical parameters, discriminant volatile compound profiles, promising sensory characteristics, and high probiotic concentrations after digestion. [Display omitted] • Lactic acid bacteria (LAB) reduced S. boulardii concentrations by lowering pH. • LAB used maltose, citric and malic acids, and produced lactic and propionic acids. • Carbonations and cold storage maintained probiotic viability after 10 days. • Probiotic LAB generated a distinct aroma profile with better sensory characteristics. • Most probiotic-enriched sour beers provided high LAB levels post-digestion. [ABSTRACT FROM AUTHOR]