Determination of free amino acids in beers: A comparison of Czech and foreign brands

The content of 16 free amino acids in 35 beers commercially available in Czech Republic was measured using high-performance liquid chromatography method with pre-column derivatization by AccQ·Tag agent and separation in reverse phase column followed by fluorescent detection. Content of proline, which was the amino acid most commonly found, varied in range from 40 to 250 mg/L. Czech beers were characterized by a significantly higher amino acid content in comparison to imported global brands (450.41±27.66 vs. 257.53±46.46 mg/L). Among individual amino acids, nine amino acids were significantly (p<0.01) more concentrated in the Czech beer brands than in the studied foreign brands, and those amino acids were from three distinctive taste groups: bitter tasting amino acid (isoleucine, leucine, lysine, phenylalanine and histidine), bitter sweet amino acids (valine and proline) and salty-umami amino acids (glutamic acid and aspartic acid).