title: Occurrence of (Z)-3,4-Dideoxyglucoson-3-ene in Different Types of Beer and Malt Beer as a Result of 3-Deoxyhexosone Interconversion.
abstract: In beer, 3-deoxyglucosone (3-DG) and 3-deoxygalactosone (3-DGal) are important sugar degradation products, but little is known about the relevance of the interconversion reaction between these compounds in different types of beer. In the present study, 3-DG was quantitated at concentrations of 12.9-52.7 mg/L and 3-DGal at concentrations of 6.0-26.4 mg/L in different types of beer (pilsner, wheat, bock, dark, and alcohol-free beers). The concentrations in malt beer tended to be higher. Largely overlapping concentration ranges precluded a classification of beers by their 3-deoxyglycosone contents. 3,4-Dideoxyglucoson-3-ene (3,4-DGE) was identified as an important intermediate and quantitated in beer and malt beer for the first time. The E and Z isomers of the corresponding quinoxaline were synthesized by a new synthetic approach and isolated by semipreparative HPLC. An assay was developed for quantitation of (E)- and (Z)-3,4-DGE by HPLC-MS/MS, and the Z isomer was determined at concentrations of 0.3-1.7 mg/L in beer and 0.5-4.8 mg/L in malt beer samples. The E isomer was shown to be of little importance. Concentrations of 5-hydroxymethylfurfural (HMF) were twice as high as those of (Z)-3,4-DGE in beer samples (0.4-3.7 mg/L) but much higher in malt beer samples (1.6-336 mg/L).
authors.affiliation: Institute of Food Chemistry, Technische Universität Dresden , D-01062 Dresden, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Hellwig
authors.affiliation: Institute of Food Chemistry, Technische Universität Dresden , D-01062 Dresden, Germany.
authors.forename: Arndt
authors.initials: A
authors.lastname: Nobis
authors.affiliation: Institute of Food Chemistry, Technische Universität Dresden , D-01062 Dresden, Germany.
authors.forename: Sophia
authors.initials: S
authors.lastname: Witte
authors.affiliation: Institute of Food Chemistry, Technische Universität Dresden , D-01062 Dresden, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Henle
mesh_terms: D001515:Beer / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D003847:Deoxyglucose / Q000031:analogs & derivatives* / Q000378:metabolism; D005662:Furaldehyde / Q000031:analogs & derivatives / Q000032:analysis; D005690:Galactose / Q000031:analogs & derivatives* / Q000378:metabolism; D013237:Stereoisomerism; D053719:Tandem Mass Spectrometry; D014908:Triticum / Q000378:metabolism
chemical_list: C555526:3-deoxygalactosone; C008046:5-hydroxymethylfurfural; D003847:Deoxyglucose; D005662:Furaldehyde; C016350:3-deoxyglucosone; D005690:Galactose
keywords: 3,4-DGE; 3,4-dideoxyglucoson-3-ene; 3-deoxygalactosone; 3-deoxyglucosone; Maillard reaction; beer; glycation; malt beer