title: Yeast diversity of sourdoughs and associated metabolic properties and functionalities.
abstract: Together with acidifying lactic acid bacteria, yeasts play a key role in the production process of sourdough, where they are either naturally present or added as a starter culture. Worldwide, a diversity of yeast species is encountered, with Saccharomyces cerevisiae, Candida humilis, Kazachstania exigua, Pichia kudriavzevii, Wickerhamomyces anomalus, and Torulaspora delbrueckii among the most common ones. Sourdough-adapted yeasts are able to withstand the stress conditions encountered during their growth, including nutrient starvation as well as the effects of acidic, oxidative, thermal, and osmotic stresses. From a technological point of view, their metabolism primarily contributes to the leavening and flavour of sourdough products. Besides ethanol and carbon dioxide, yeasts can produce metabolites that specifically affect flavour, such as organic acids, diacetyl, higher alcohols from branched-chain amino acids, and esters derived thereof. Additionally, several yeast strains possess functional properties that can potentially lead to nutritional and safety advantages. These properties encompass the production of vitamins, an improvement of the bioavailability of phenolic compounds, the dephosphorylation of phytic acid, the presence of probiotic potential, and the inhibition of fungi and their mycotoxin production. Strains of diverse species are new candidate functional starter cultures, offering opportunities beyond the conventional use of baker's yeast.
authors.affiliation: Research Group of Industrial Microbiology and Food Biotechnology, Department of Bioengineering Sciences, Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium. Electronic address: ldvuyst@vub.ac.be.
authors.forename: Luc
authors.initials: L
authors.lastname: De Vuyst
authors.affiliation: Research Group of Industrial Microbiology and Food Biotechnology, Department of Bioengineering Sciences, Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium.
authors.forename: Henning
authors.initials: H
authors.lastname: Harth
authors.affiliation: Research Group of Industrial Microbiology and Food Biotechnology, Department of Bioengineering Sciences, Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium.
authors.forename: Simon
authors.initials: S
authors.lastname: Van Kerrebroeck
authors.affiliation: Research Group of Industrial Microbiology and Food Biotechnology, Department of Bioengineering Sciences, Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Leroy
mesh_terms: D000597:Amino Acids, Branched-Chain / Q000378:metabolism; D044822:Biodiversity; D001939:Bread / Q000382:microbiology*; D002175:Candida / Q000378:metabolism; D002245:Carbon Dioxide / Q000378:metabolism; D000431:Ethanol / Q000378:metabolism; D005285:Fermentation / Q000502:physiology*; D005516:Food Microbiology; D007777:Lactobacillaceae / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D015002:Yeast, Dried / Q000378:metabolism*
chemical_list: D000597:Amino Acids, Branched-Chain; D002245:Carbon Dioxide; D000431:Ethanol
keywords: Acetate; Bakery; Functional starter cultures; Metabolism; Sourdough; Yeast