title: Occurrence of Theaspirane and its Odorant Degradation Products in Hop and Beer.
abstract: In model oxidized media, six theaspirane-derived compounds were identified by gas chromatography-high resolution mass spectrometry: 4-hydroxy-7,8-dihydro-β-ionone, 6-hydroxy-7,8-dihydro-α-ionone, dihydrodehydro-β-ionone, two monoepoxides, and a derived alcohol. Only 4-hydroxy-7,8-dihydro-β-ionone and dihydrodehydro-β-ionone have been described previously in the literature. Investigation of hop revealed five of these compounds in free form together with theaspirane (especially in the Mosaic variety), while the Citra and Amarillo hop varieties emerged as very interesting for the release of theaspirane, 4-hydroxy-7,8-dihydro-β-ionone, and dihydrodehydro-β-ionone from glucoside precursors. For the first time, theaspirane, 4-hydroxy-7,8-dihydro-β-ionone, 6-hydroxy-7,8-dihydro-α-ionone, and both monoepoxides were found in a fresh commercial top fermentation beer (only theaspirane, 4-hydroxy-7,8-dihydro-β-ionone, and dihydrodehydro-β-ionone have recently been mentioned as Gueuze constituents).
authors: Unité de Brasserie et des Industries Alimentaires, Earth and Life Institute ELIM, Faculté d'Ingénierie biologique, agronomique et environnementale, Université catholique de Louvain , Croix du Sud, 2 box L7.05.07, B-1348 Louvain-la-Neuve, Belgium.
authors: Caroline
authors: C
authors: Scholtes
authors: Unité de Brasserie et des Industries Alimentaires, Earth and Life Institute ELIM, Faculté d'Ingénierie biologique, agronomique et environnementale, Université catholique de Louvain , Croix du Sud, 2 box L7.05.07, B-1348 Louvain-la-Neuve, Belgium.
authors: Sabrina
authors: S
authors: Nizet
authors: Unité de Brasserie et des Industries Alimentaires, Earth and Life Institute ELIM, Faculté d'Ingénierie biologique, agronomique et environnementale, Université catholique de Louvain , Croix du Sud, 2 box L7.05.07, B-1348 Louvain-la-Neuve, Belgium.
authors: Hadrien
authors: H
authors: Massart
authors: Organic Chemistry Laboratory, Mass Spectrometry Center, University of Mons , U-MONS, Place du Parc, 23, B-7000 Mons, Belgium.
authors: Pascal
authors: P
authors: Gerbaux
authors: Unité de Brasserie et des Industries Alimentaires, Earth and Life Institute ELIM, Faculté d'Ingénierie biologique, agronomique et environnementale, Université catholique de Louvain , Croix du Sud, 2 box L7.05.07, B-1348 Louvain-la-Neuve, Belgium.
authors: Sonia
authors: S
authors: Collin
mesh_terms: D001515:Beer / Q000032:analysis*; D002849:Chromatography, Gas / Q000379:methods; D004852:Epoxy Compounds / Q000032:analysis; D005285:Fermentation; D008401:Gas Chromatography-Mass Spectrometry; D005960:Glucosides / Q000378:metabolism; D027582:Humulus / Q000737:chemistry*; D006868:Hydrolysis; D045792:Norisoprenoids / Q000032:analysis*; D009812:Odorants / Q000032:analysis*; D064367:Olfactometry; D010084:Oxidation-Reduction
chemical_list: D004852:Epoxy Compounds; D005960:Glucosides; D045792:Norisoprenoids
keywords: beer aging; hop aroma; theaspirane degradation