title: Generation of thiols by biotransformation of cysteine-aldehyde conjugates with baker's yeast.
abstract: Baker's yeast was shown to catalyze the transformation of cysteine-furfural conjugate into 2-furfurylthiol. The biotransformation's yield and kinetics were influenced by the reaction parameters such as pH, incubation mode (aerobic and anaerobic), and substrate concentration. 2-Furfurylthiol was obtained in an optimal 37% yield when cysteine-furfural conjugate at a 20 mM concentration was anaerobically incubated with whole cell baker's yeast at pH 8.0 and 30 degrees C. Similarly to 2-furfurylthiol, 5-methyl-2-furfurylthiol (11%), benzylthiol (8%), 2-thiophenemethanethiol (22%), 3-methyl-2-thiophenemethanethiol (3%), and 2-pyrrolemethanethiol (6%) were obtained from the corresponding cysteine-aldehyde conjugates by incubation with baker's yeast. This work indicates the versatile bioconversion capacity of baker's yeast for the generation of thiols from cysteine-aldehyde conjugates. Thanks to its food-grade character, baker's yeast provides a biochemical tool to produce thiols, which can be used as flavorings in foods and beverages.
authors.affiliation: Nestec Ltd., Nestlé Research Center, Vers-chez-les-Blanc, P.O. Box 44, 1000 Lausanne 26, Switzerland.
authors.forename: Tuong
authors.initials: T
authors.lastname: Huynh-Ba
authors.forename: Walter
authors.initials: W
authors.lastname: Matthey-Doret
authors.forename: Laurent B
authors.initials: LB
authors.lastname: Fay
authors.forename: Rachid
authors.initials: R
authors.lastname: Bel Rhlid
mesh_terms: D001711:Biotransformation; D003545:Cysteine / Q000378:metabolism*; D005524:Food Technology; D005662:Furaldehyde / Q000378:metabolism*; D005663:Furans / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010100:Oxygen / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D013438:Sulfhydryl Compounds / Q000378:metabolism*; D013649:Taste
chemical_list: D005663:Furans; D013438:Sulfhydryl Compounds; C455106:furfuryl mercaptan; D005662:Furaldehyde; D003545:Cysteine; D010100:Oxygen