Determination of free phenolic acids in wort and beer by coulometric array detection.
The simultaneous determination of 19 phenolic compounds was performed directly in wort and beer by a combination of reverse-phase high-performance liquid chromatography coupled with coulometric array detection. Chromatographic separation was achieved with an appropriate gradient of flow and a binary solvent based on phosphate buffer, methanol, and acetonitrile in a 45-min run. Eight serial coulometric detectors were used for on-line generation of voltammetric data to resolve coeluting compounds. The method was reliable and sensitive, the regression coefficient of standard calibration curves is 0.972 < or = r < or = 1.000, and the standard deviation value ranges from 0.010 to 0.129 mg/L for wort and from 0.002 to 0.332 mg/L for beer. The mean concentrations of phenolic acids were 22.1 and 33.8 mg/L, respectively, in worts and beers produced in Italy. These amounts represent 5 and 10% of the non-tannic, non-flavonoid phenols in wort and beer, respectively.
Floridi
Simona
S
Department of Food Science, Division of Food Technology and Biotechnology, University of Perugia, via S. Costanzo, Italy.
Montanari
Luigi
L
Marconi
Ombretta
O
Fantozzi
Paolo
P
D001515:Beer / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D062385:Hydroxybenzoates / Q000032:analysis*; D007558:Italy; D010636:Phenols / Q000032:analysis; D012680:Sensitivity and Specificity
D062385:Hydroxybenzoates; D010636:Phenols; C017616:phenolic acid