Extraction of valuable compounds from brewing residues: Malt rootlets, spent hops, and spent yeast

Abstract

Brewing generates large amounts of residues including barley malt rootlets, spent hops, and spent yeast. These residues are sustainable and rich sources of compounds with valuable nutritional and functional properties such as proteins, polyphenols, and polysaccharides. The growing scarcity of natural resources and the increasing unsustainability of waste management, in the context of a rising global population, stress the need for reusing these wastes. This requires the development of suitable methodologies to recover interesting compounds. This work reviews the characteristics of brewery residues, the methodologies employed for the recovery of their valuable compounds, their functionalities, and their potential applications. A special consideration was focused to those methods employing i