Identification and quantitation of benzoxazinoids in wheat malt beer by qNMR and GC–MS

Abstract

Based on a previous identification of benzoxazinoids in wheat malt beer we performed a more in depth screening of beers that led to the identification and isolation of 6-methoxy-2-(3H)-benzoxazolone (6MBOA) as a new beer ingredient. In addition, a new methodology for the quantitative measurement of this compound in beer extracts was developed using quantitative Nuclear Magnetic Resonance (qNMR). Ten commercial samples of wheat beers were studied and 6MBOA was found in concentrations ranging from 0.4 to 3.6 mg/L. The same compound was not detected in seventeen samples of commercial beers (lager, ale) that were produced using barley malt. Similar concentrations (1.6–7.3 mg/L) of a relative compound, 2-(3H)-benzoxazolone, was found only in beers made with wheat malt. This is the first report of 6MBOA in beer and the first quantitation of benzoxazinoids in beer.