Organic and Phenolic Acids in Beer

In a previous study we evaluated the effects of brewing on compounds potentially involved in the antioxidant defence system. The objectives of this paper were to determine organic acids and to characterize the quantity and quality of phenolic acids in four Italian lager beers. The data obtained on organic acids are in line with the values reported in the literature for malic, pyruvic, lactic, acetic, ketoglutaric, citric, succinic, citramalic and fumaric acid. Phenolic acid composition was determined using two different high-performance liquid chromatography (HPLC) methodologies: HPLC-ECD (amperometric electrochemical detection) and HPLC-DAD (photodiode array detection). The most common phenolic acid was found to be m-coumaric followed by ferulic, o-coumaric, p-coumaric and 3-OH-benzoic. Vanillic, chlorogenic, homovanillic, p-OHbenzoic, 2,6-dihydroxybenzoic, syringic, gallic, protocatechuic, caffeic and finally, 3,5-dihydroxybenzoic acids were present in small quantities. The amount of phenolic acids is quite low in absolute terms and in relationship to data available in the literature. Statistically significant differences were not found between the two different analytical methods utilized.