title: Determination of volatile monophenols in beer using acetylation and headspace solid-phase microextraction in combination with gas chromatography and mass spectrometry.
abstract: Monophenols are widely spread compounds contributing to the flavour of many foods and beverages. They are most likely present in beer, but so far, little is known about their influence on beer flavour. To quantify these monophenols in beer, we optimised a headspace solid-phase microextraction method coupled to gas chromatography-mass spectrometry. To improve their isolation from the beer matrix and their chromatographic properties, the monophenols were acetylated using acetic anhydride and KHCO(3) as derivatising agent and base catalyst, respectively. Derivatisation conditions were optimised with attention for the pH of the reaction medium. Additionally, different parameters affecting extraction efficiency were optimised, including fibre coating, extraction time and temperature and salt addition. Afterwards, we calibrated and validated the method successfully and applied it for the analysis of monophenols in beer samples.
authors.affiliation: Centre for Malting and Brewing Science, Faculty of Bioscience Engineering, K.U. Leuven, Kasteelpark Arenberg 22, Box 2463, 3001 Heverlee, Belgium. femke.sterckx@biw.kuleuven.be
authors.forename: Femke L
authors.initials: FL
authors.lastname: Sterckx
authors.forename: Daan
authors.initials: D
authors.lastname: Saison
authors.forename: Freddy R
authors.initials: FR
authors.lastname: Delvaux
mesh_terms: D000107:Acetylation; D001515:Beer / Q000032:analysis*; D005421:Flavoring Agents / Q000032:analysis* / Q000302:isolation & purification; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D010636:Phenols / Q000032:analysis* / Q000302:isolation & purification; D012492:Salts / Q000737:chemistry; D052617:Solid Phase Microextraction / Q000379:methods*; D013696:Temperature; D014835:Volatilization
chemical_list: D005421:Flavoring Agents; D010636:Phenols; D012492:Salts