Cascade Recovery of Bioactive Compounds from Spent Brewer’s Yeast Using Pulsed Electric Field Treatment and Subsequent Enzymatic Hydrolysis

Spent brewer’s yeast (SBY) is a protein-rich by-product of the brewing industry and a valuable source of intracellular nutrients and bioactive compounds. In the present study, a cascade extraction process was developed to obtain bioactive compounds from this biomass. Pulsed electric field (PEF) treatment in continuous-flow mode was applied to achieve irreversible plasma membrane permeabilization of the cells. Following PEF treatment, the primary water fraction containing released intracellular compounds was recovered, and the residual biomass was incubated with 0.2% (v/v) Alcalase for 6 h at 40 °C. The enzymatic treatment generated hydrolysates characterized by high levels of protein and free amino nitrogen and strong antioxidant activity. Ultrafiltration analysis revealed that the <3 kDa fraction retained approximately 78% of the recovered protein and 90% of the overall antioxidant capacity. The biocompatibility of the water extracts was evaluated using HepG2, HaCaT, and A375 cell lines. They were well tolerated and enhanced cell viability in HaCaT and A375 cells after 48 h exposure. These findings demonstrate the potential of the proposed cascade extraction process for more efficient utilization of SBY biomass through the generation of value-added products for nutraceutical, cosmeceutical, and pharmaceutical applications.