Acids in chicory roots and malt

Abstract

A determination method for non-volatile acids in roasted chicory roots and roasted barley malt is described. The clean-up was accomplished using preparative gel electrophoresis followed by gas chromatography (GC)/mass spectrometry of the methoximes (ketonic acids) or trimethylsilyl derivatives (all acids). Using these methods, 64 non-volatile acids have been identified in chicory (among those 48 for the first time). In barley malt 60 acids could be detected (47 for the first time). Ten commercially unavailable substances have been synthesized. Most of the acids have been quantified using the same clean-up and GC/selected ion monitoring or GC/flame ionisation detection (FID). The recoveries range from 41 to 105% (average 79%), the detection limits from 1 to 72μg/kg being somewhat lower for the FID and considerably lower for malt, and the relative standard deviations from 1 to 10% for the main acids, from 2 to 89% for the minor acids and from 8 to 133% for the trace acids. In addition formic and acetic acids were determined by isotachophoresis.