The Development of Immunoassays to Identify and Quantify Species Source of Gum Arabic

• Published in: Journal of agricultural and food chemistry 2004-12, Vol.52 (26), p.7804-7808
• Main Authors: Ireland, H. Elyse, Clutterbuck, Andy, Cloquet, Jean-Phillipe, Thurston, Milo I, Williams, Peter A, Cronk, Quentin C, Dewey, F. Molly, Williams, John H. H
• Format: Article
• Language: English
• Subjects: Acacia; Acacia - chemistry; Acacia mellifera; Acacia senegal; Acacia seyal; adulterated products; Antibodies, Monoclonal; Biological and medical sciences; Combretum; Combretum erythrophyllum; Combretum erythrophyllus; cross reaction; emulsifiers; enzyme-linked immunosorbent assay; Enzyme-Linked Immunosorbent Assay - methods; Food additives; Food industries; Fundamental and applied biological sciences. Psychology; General aspects; gum arabic; Gum Arabic - analysis; Gum Arabic - classification; monoclonal antibodies; Sensitivity and Specificity; Species Specificity; stabilizers; thickeners
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf048864h

Gum arabic from Acacia senegal is commonly used as an additive in foodstuffs. Adulteration of gum arabic by other gums is a potential problem for reasons of safety and quality. This study aimed to develop and evaluate the use of enzyme-linked immunosorbent assays (ELISAs) for the detection of potential adulterants of gum arabic. Indirect competitive ELISAs (IC-ELISAs) were developed using the monoclonal antibodies SY CC7 (A. senegal), SY HH3 (Acacia seyal), and SY J1A1 (Combretum erythrophyllum). All IC-ELISAs had a working range of 0.005−10 mg/mL. The antibodies used were tested using the IC-ELISAs for cross-reactivity with other Acacia species and other gums. The antibodies were very specific for their respective antigens. Significant cross-reactivity was found for SY CC7 (between A. senegal and A. melliferae) and SY J1A1 (between C. erythrophyllum and A. seyal). The IC-ELISA was adapted further to test confectionery samples for the presence of gum arabic, which was successful, although recovery rates were reduced. Both IC- and plate trapped antigen ELISA (PTA-ELISA) formats were able to distinguish an adulterated sample of gum arabic when blended with either A. seyal or C. erythrophyllum. The PTA-ELISA was more sensitive for A. seyal than the IC-ELISA, but both were equally sensitive for C. erythrophyllum. The results suggest that the antibodies SY CC7, SY HH3, and SY J1A1 could be used in combination with each other for the detection of potential adulterants of A. senegal and the detection of gum arabic in foodstuffs. Keywords: Gum arabic; Acacia; Combretum; ELISA