Yeast: the soul of beer’s aroma—a review of flavour-active esters and higher alcohols produced by the brewing yeast

• Published in: Applied microbiology and biotechnology Vol. 98; no. 5; pp. 1937 - 1949
• Main Authors: Pires, Eduardo J, Teixeira, José A, Brányik, Tomás, Vicente, António A
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01-03-2014; Springer; Springer Berlin Heidelberg; Springer Nature B.V
• Subjects: Alcohol; alcohols; Alcohols - metabolism; Amino acids; Analysis; Beer; Beer - microbiology; Beer aroma; beers; biochemical pathways; Biomedical and Life Sciences; Biosynthesis; Biotechnology; brewing; Brewing yeast; Enzymes; Esters; Esters - metabolism; Fermentation; Flavoring Agents - metabolism; Fusel alcohols; Higher alcohols; Life Sciences; Metabolic Networks and Pathways; Metabolism; Microbial Genetics and Genomics; Microbiology; Mini-Review; odors; Organic acids; organic acids and salts; Physiological aspects; Production processes; Proteins; Saccharomyces; Saccharomyces spp; Saccharomycesspp; Science & Technology; Solvents; Studies; Yeast; Yeasts; Yeasts - growth & development; Yeasts - metabolism; Portugal; Beer aroma; Esters; Fusel alcohols; spp; Higher alcohols; Brewing yeast
• ISSN: 0175-7598; 1432-0614
• DOI: 10.1007/s00253-013-5470-0

Among the most important factors influencing beer quality is the presence of well-adjusted amounts of higher alcohols and esters. Thus, a heavy body of literature focuses on these substances and on the parameters influencing their production by the brewing yeast. Additionally, the complex metabolic pathways involved in their synthesis require special attention. More than a century of data, mainly in genetic and proteomic fields, has built up enough information to describe in detail each step in the pathway for the synthesis of higher alcohols and their esters, but there is still place for more. Higher alcohols are formed either by anabolism or catabolism (Ehrlich pathway) of amino acids. Esters are formed by enzymatic condensation of organic acids and alcohols. The current paper reviews the up-to-date knowledge in the pathways involving the synthesis of higher alcohols and esters by brewing yeasts. Fermentation parameters affecting yeast response during biosynthesis of these aromatic substances are also fully reviewed.