THE CLASSIFICATION OF NATURAL GUMS .4. IDENTIFICATION AND DISCRIMINATION OF ACACIA, COMBRETUM AND PROPOSIS GUM EXUDATES

Principal component projection, discriminant component projection and, for classification, linear discriminant analysis (LDA) have been used to study the relationship between and distinguish closely related Aca cia, Combretum and Proposis gum exudates, all arabinogalactan proteins . A set of eight gums from the Acacia and seven from Combretum series, selected randomly, could be all correctly classified using LDA. Combr etum gums can readily be distinguished from Acacia gums (Vulgares and Gummiferae series) using either analytical parameters associated with either the carbohydrate or protein moieties. The Proposis gums form a closely identifiable grouping, apart from P.Juliflora, which is indist inguishable from Acacia senegal. Gums of the Phyllodinaea series can r eadily be discriminated from other Acacia species used in the food ind ustry. The method offers a basis for a quality control system to ensur e the compliance of commercial gum products with national and internat ional legislative requirements.