Harnessing yeast metabolism of aromatic amino acids for fermented beverage bioflavouring and bioproduction

Aromatic amino acid metabolism in yeast is an important source of secondary compounds that influence the aroma and flavour of alcoholic beverages and foods. Examples are the higher alcohol 2-phenylethanol, and its acetate ester, 2-phenylethyl acetate, which impart desirable floral aromas in wine, beer and baker's products. Beyond this well-known influence on the organoleptic properties of alcoholic beverages and foods, there is a growing interest in understanding and modulating yeast aromatic amino acid metabolism. The tryptophan derivatives melatonin and serotonin have bioactive properties and exert positive effects on human health, and aromatic amino acids are also the precursors of products of industrial interest, such as nutraceuticals, fragrances, and opium-derived drugs. This mini-review presents current knowledge on the formation of compounds from aromatic amino acids by Saccharomyces cerevisiae, from genetic and environmental influences on their flavour impacts in alcoholic beverages to their potential as bioactive compounds, and the use of yeast as microbial factories for the production of commercially relevant aromatic compounds.