title: Formation of alpha-dicarbonyl compounds in beer during storage of Pilsner.
abstract: With the aim of determining the formation of alpha-dicarbonyl intermediates during beer aging on the shelf, alpha-dicarbonyls were identified and quantified after derivatization with 1,2-diaminobenze to generate quinoxalines. The sensory effects of alpha-dicarbonyls were evaluated by the quantification of key Strecker aldehydes and by GC-olfactometry (GCO)analysis of beer headspace using solid phase microextraction. Four alpha-dicarbonyls, reported here for the first time, were detected in fresh and aged beers, three were derived from the 2,3-enolization pathway of mono- and disaccharides, and the fourth was derived from the epimerization of 3-deoxy-2-hexosulose. Ten alpha-dicarbonyls were quantified during beer processing and during different periods of beer aging at 28 degrees C. The aging periods were from 15 to 105 days. During beer aging, 1-deoxydiuloses were produced and degraded, while 1,4-dideoxydiuloses were produced at the highest rates. The GCO analysis indicated that forced beer aging increased the amounts of furaneol, trans-2-nonenal, and phenylacetaldehyde. The blockage of alpha-dicarbonyls inhibited the accumulation of sensory-active aldehydes in the beer headspace.
authors.affiliation: Unidad de Investigacion e Innovacion, Empresas Polar, Caracas, Venzuela. adriana.bravo@empresas-polar.com
authors.forename: Adriana
authors.initials: A
authors.lastname: Bravo
authors.forename: Julio C
authors.initials: JC
authors.lastname: Herrera
authors.forename: Erika
authors.initials: E
authors.lastname: Scherer
authors.forename: Yon
authors.initials: Y
authors.lastname: Ju-Nam
authors.forename: Heinrich
authors.initials: H
authors.lastname: Rübsam
authors.forename: Jorge
authors.initials: J
authors.lastname: Madrid
authors.forename: Carsten
authors.initials: C
authors.lastname: Zufall
authors.forename: Rafael
authors.initials: R
authors.lastname: Rangel-Aldao
mesh_terms: D000079:Acetaldehyde / Q000031:analogs & derivatives / Q000032:analysis; D000447:Aldehydes / Q000032:analysis; D001515:Beer / Q000032:analysis*; D002849:Chromatography, Gas; D003847:Deoxyglucose / Q000031:analogs & derivatives / Q000032:analysis; D005511:Food Handling; D005519:Food Preservation; D005663:Furans / Q000032:analysis; D006801:Humans; D012903:Smell; D013997:Time Factors
chemical_list: D000447:Aldehydes; D005663:Furans; C013166:2-nonenal; C058427:furaneol; D003847:Deoxyglucose; C016350:3-deoxyglucosone; D000079:Acetaldehyde; C013192:phenylacetaldehyde