Capillary gas chromatographic determination of free amino acids in honey as a means of discrimination between different botanical sources
Pirini, A.; Conte, L.S.; Francioso, O.; Lercker, G.
HRC Journal of High Resolution Chromatography 15(3): 165-170
The chemical analysis of honey tends to concentrate on factors related to its state of preservation, e.g. HMF, diastase activity, and water content. Although there is no characteristic of honey officially regarded as suitable for certification of its botanical origin, literature is available in which several of the "minor" components of honey, such as flavors, di- and trisaccharides, and free amino acids, have been used to certify the botanical origin of the product. In this paper, six kinds of honey from different botanical sources (acacia, citrus fruit, chestnut-tree, rhododendron, rosemary, and lime-tree) were analyzed by capillary gas chromatography, and the data obtained evaluated statistically to determine whether the amino acid profile could be used to verify the botanical source of the material. The results have shown that the presence of amino acids such as arginine, tryptophan, and cystine is characteristic of a particular kind of honey, and that others, such as proline, asparagine, lysine, and methionine, can be used for discrimination if quantitative data is available about the levels of the compounds present. Evaluation of optimum split ratio for amino acid determination, and problems concerning the derivatization process, are also discussed.