Spent brewer’s yeast as a source of high added value molecules: a systematic review on its characteristics, processing and potential applications

• Published in: World journal of microbiology & biotechnology 2020-07, Vol.36 (7), p.95-95, Article 95
• Main Authors: Marson, Gabriela Vollet, de Castro, Ruann Janser Soares, Belleville, Marie-Pierre, Hubinger, Miriam Dupas
• Format: Article
• Language: English
• Subjects: Animal Feed - analysis; Animal protein; Applied Microbiology; Autolysis; Beer - microbiology; Biochemistry; Biological activity; Biomass; Biomedical and Life Sciences; Biotechnology; Brewing; By products; Byproducts; Cell disruption; Cell Wall - metabolism; Cell walls; Chemical and Process Engineering; Databases, Factual; Engineering Sciences; Environmental Engineering/Biotechnology; Fermentation; Food Handling; Food industry; Food sources; Fungal Proteins - metabolism; gamma-Aminobutyric Acid - metabolism; Glass beads; Hydrolysis; Kynurenic Acid - metabolism; Life Sciences; Microbiology; Nutritive Value; Peptides; Pharmaceutical industry; Polyphenols - metabolism; Proteins; Review; Saccharomyces cerevisiae - metabolism; Ultrasonic processing; Ultrasound; Yeast; Yeasts
• ISSN: 0959-3993; 1573-0972
• DOI: 10.1007/s11274-020-02866-7

Development of new strategies to add-value to agro-industrial by-products are of environmental and economical importance. Innovative and low-cost sources of protein and bioactive peptides have been explored worldwide. Spent brewer’s yeast (SBY) is the second most relevant by-product from the brewing industry, and despite its nutritional (about 50% protein, dry weight) and technological potential, it is still underused or needs to be disposed of. SBY cells need to be disrupted to release intracellular and cell wall proteins. This procedure has been performed using autolysis, glass bead milling, enzymatic hydrolysis and ultrasound processing. Enzymatic treatment is usually performed without prior purification and is a challenging process, which involves multiple factors, but has been successfully used as a strategy to add value to agro-industrial by-products. Scope and approach: in this review, we particularly focused on enzymatic hydrolysis as a strategy to promote SBY valorisation, illustrating the state-of-the-art processes used to produce protein extracts from this material as well as exploring fundamental concepts related to the particularities of yeast cell disruption and protein hydrolysis. Furthermore, innovative applications of value-added yeast by-products in food, biotechnological and pharmaceutical industries are presented and discussed. Key findings and conclusions: the discovery of valuable compounds found in spent yeasts as well as the development of new processing methodologies have been widening the possibilities of reuse and transformation of SBY as an ingredient and innovative matrix. Once released, yeast proteins and peptides may be applied as an innovative non-animal protein source or a functional and bioactive ingredient.