Characterization of antioxidant compounds in aqueous coriander extract (Coriandrum sativum L.)

An aqueous coriander extract obtained through a sequential extraction process, was analysed using chromatography and mass spectrometry in order to identify the phenolic compounds responsible for its antioxidant activity. Four fractions were identified from the crude extract using chromatography in a silica gel column. Their antioxidant activity, according to the β-carotene/linoleic acid model, was similar to one another but inferior to that of the crude extract and of butylated hydroxytoluene. Of the phenols identified through gas chromatography and mass spectrometry, it was noted that caffeic acid was present in high concentration (4.34 μg/ml in fraction I and 2.64 μg/ml in fraction III), whereas protocatechinic acid and glycitin were present in high concentration in fraction II (6.43 μg/ml) and fraction IV (3.27 μg/ml), respectively. These results, when considered with the recognized antioxidant ability of phenolic acids, suggest that they are principal components responsible for the antioxidant activity of the aqueous coriander extract.