DEVELOPMENT OF ENZYME-LINKED IMMUNOSORBENT ASSAYS FOR SUDAN DYES IN CHILLI POWDER, KETCHUP AND EGG YOLK

Laura Anfossi (1) , Claudio Baggiani (2) , Cristina Giovannoli (2, 3) , Gianfranco Giraudi (2)

1 Anlytical Chemistry
2 Analytical Chemsitry
3 Analytical Chemistry

This study aimed at developing sensitive competitive enzyme-linked immunosorbent assays (ELISAs) for the banned Sudan dyes, using polyclonal antibodies. Three different formats were developed and characterized in terms of sensitivity, selectivity and rapidity. A competitive indirect ELISA was developed, which showed an IC50 of 3.8 µg L-1. Two competitive direct ELISAs, were also developed, which differ in the fact that the antibody is added before or simultaneously with the other reagents; the first showed an IC50 of 8.3 µg L-1 and the second one showed an IC50 of 4.9 µg L-1. Nevertheless, considering dilution of extracts which is needed to offset matrix interference, the limits of detection of the three formats were substantially the same (10 µg kg-1). The antibodies in all three test formats were able to recognize Sudan I and partially Sudan II, III, and IV; no cross-reactivity was observed with five edible dyes. Twenty food samples, including chilli powder, paprika, ketchup, and egg, were extracted by simple sample preparation and very limited dilution. Extracts were analyzed by the developed competitive direct ELISA with the simultaneous addition of reagents. A good correlation was observed (y=1.19x-10.0, r2 = 0.991, n=20) when the data was compared with that obtained through conventional HPLC method.

Mots clés: Life Sciences

Laura Anfossi, Claudio Baggiani, Cristina Giovannoli, Gianfranco Giraudi. DEVELOPMENT OF ENZYME-LINKED IMMUNOSORBENT ASSAYS FOR SUDAN DYES IN CHILLI POWDER, KETCHUP AND EGG YOLK. Food Additives and Contaminants, 2009, 26 (06), pp.800-807. ⟨10.1080/02652030902755283⟩. ⟨hal-00577355⟩