Formulation and characterization of calcium alginate capsules and different strains of the yeast Saccharomyces cerevisiae: impact on the sensory profile of fermented products obtained from a base malt wort

Abstract

This study looked at how the sensory profile of beer wort changed because of the action of encapsulated yeast fermentation. Initially, various concentrations of sodium alginate and calcium chloride were tested. Following that, several mechanical properties of the capsules were determined to establish the most convenient encapsulating formulation for performing the corresponding fermentations. The yeast was then encapsulated with the formulation based on 3% (w/v) alginate and 0.1M calcium chloride as reticulating agent. The fermentations were then carried out with this encapsulating formulation using a Pilsen malt-based wort and four S. cerevisiae strains, which were tested individually over 14 days. Following fermentation, the beer was aged for two weeks at 4°C in an amber glass container. Finally, color, turbidity, taste, and flavor profile were measured and compared with those of similar products in the marketplace. The cell growth was monitored in parallel to the fermentation, and the concentration of ethanol, sugars and organic acids in the samples were measured using high-performance liquid chromatography. It was found that encapsulation caused variations in the sensory profile that varied significantly between strains. A repeated batch experiment under the same conditions demonstrated that both cell viability and mechanical properties reduced significantly. Additionally, it was observed that the encapsulation improved the performance of the wild strain evaluated in terms of ethanol production and substrate consumption.