Conversion of spent brewer’s yeast biomass to produce dairy cattle supplements: process conditions and economic feasibility

Abstract

Given the volume of spent brewer’s yeast generated in the brewing process and the potential benefits of its composition as a supplement for dairy cattle, the present study processed this biomass to obtain cell walls as a biobased substance for animal nutrition supplementation. The assessed aspects include biomass autolysis conditions, spray drying parameters, the effects of daily supplementation on dairy cattle, and the economic feasibility of production on an industrial scale. Autolysis conditions included temperature at 50 °C, initial pH of 6.0, sodium chloride and ethanol concentrations of 15%, and an assessment period of 21 days. The dry cell wall processed in a spray dryer with an outlet temperature of 75 °C and a drying air flow rate of 1.95 m³/min showed the best conditions for storage. The beta-glucan content of the bioproduct was 45%, increasing dairy cattle milk productivity and quality with a daily supplementation of 12 g. The economic feasibility of processing brewer’s yeast biomass on an industrial scale to obtain the biobased substance was validated by the main economic indicators. The conversion of spent brewer’s yeast biomass has resulted in a powdered bioproduct that is suitable for supplementing dairy cattle. Furthermore, the developed bioprocess employs low-cost inputs and can be scaled up for industrial-scale production.