| Popis: |
Commercial samples of gum arabic from Ethiopia, Senegal, Nigeria, Chad and Sudan have been compared with authenticated A.Senegal (L.) Willd. specimens from Mauritania, Mali, Senegal, Ethiopia and Oman using a chemometric analysis based on their amino acid compositions. The majority of these form a cluster which encompassed both normal geographic and commercial variability. The three samples outside the cluster possess chemical or taxonomic features which account for their exceptional behaviour. For comparison, Acacia gums from non-African sources (Phyllodineae Benth.) and the Leucaena gums from Hawaii and Mexico, which are closely related chemically and physically to gum arabic were analysed also by principal component analysis. These gums can be identified individually and distinguished from commercial gum arabic. It is proposed that chemometric methods could provide a basis for setting commercial specifications for gum arabic, which would take account of the anticipated variability of this complex natural product and eliminate the possibility of serious adulteration by unacceptable related gums of arabinogalactan protein origin. |
