Protein recovery from brewery solid wastes

Brewing produces significant amounts of solid waste during the process: spent cereals (BSG), hops and spent yeast (BSY). These residues are sustainable sources of valuable nutrients and functional compounds like proteins, polyphenols, and polysaccharides. This review describes the three solid wastes and the different extraction techniques for protein recovery. The protein obtained can be used as a new source of non-animal protein or as a functional and bioactive ingredient. Particular attention was given to methods using conventional technologies (alkaline and ethanolic extraction) and more innovative approaches (enzymes, microwaves, ultrasound, pres-surized liquids and sub-critical water extraction). Although the BSG is used in some industrial applications, studies in operating conditions, cost, energy efficiency, and product performance are still required to consolidate these solid wastes as a source of non-animal protein. The application of proteins is also an important question when choosing the extraction method.

Automated summary

Brewing produces significant amounts of solid waste, including spent cereals, hops, and spent yeast. These wastes contain valuable nutrients and functional compounds such as proteins, polyphenols, and polysaccharides. This review discusses different extraction techniques for protein recovery, including conventional methods and more innovative approaches. The application of proteins and further studies on operating conditions, cost, energy efficiency, and product performance are important considerations in utilizing these solid wastes as a source of non-animal protein.