Novel Assessment Method of the Critical Parameters for Brewing Yeast Formulation as a Nutraceutical in Animal Diets

Brewing yeast biomasses may be converted into valuable products, including supplements for ruminant diets. This paper presents experimental data on a nutraceutical suspension formulation containing post-fermentation brewing yeasts and the brewing yeast strain, Saccharomyces pastorianus ssp. carlsbergensis W34/70, which was intended to be administered to ruminants. The brewing yeast biomass is a component of oral suspensions designed as dietary supplements that prevent digestive acidosis in ruminants. The brewing yeast strain W34/70 was cultivated using molasses (M) and glucose (G) as carbon sources and was lyophilized at different freezing temperatures (0 C, 10 C, 20 C, 30 C, and 40 C). The post-fermentation brewing yeast biomass was spray dried (AAY) and lyophilized (ALY). Both dried yeast biomasses were analyzed in terms of wettability using a contact angle (CA ) evaluation at the solid/liquid interface. Suspensions were subsequently formulated and tested. Their physical and aggregative stability was established in connection with controlled sedimentation and flocculation. The assays were performed following quality by design (QbD) principles. The critical process parameters (CPPs) corresponding to the technological process of yeast production, as well as the critical quality attributes (CQAs) for suspension formulations, were pointed out as preamble determinants when designing oral nutraceuticals destined to be included in ruminant diets.