Consideration of fluorescence properties for the direct determination of erythrosine in saffron in the presence of other synthetic dyes

Stella A Ordoudi (1) , Maria Z Tsimidou (2)

1 Laboratory of Food Chemistry and Technology
2 Department of Chemistry, Laboratory of Food Chemistry and Technology

Direct selective detection of erythrosine in saffron in the presence of other synthetic dyes considers its fluorescence at 532 nm excitation / 548 nm emission. Saffron pretreatment was according to the ISO 3632-2 trade standard test methods. On account of calculated quantum yield values none of the yellow dyes is expected to interfere. Among red ones, reservations about allura red AC, azorubine and red 2G were not verified by experimentation signifying excellent method specificity. Detection and quantification limits (0.56 and 1.70 nM) were of the same magnitude to those reported in literature after chromatographic separation of erythrosine. Percent recovery from spiked saffron samples ranging from 63 - 141 was acceptable for residue levels in foods. Matrix effect from crocins (saffron pigments) was evidenced only at a lower spiking level (0.02 mg kg-1). The minimum required performance limit (MRPL) value was 0.04 mg kg-1 indicating that the method is appropriate for traces of erythrosine in saffron. Our approach offers improved sensitivity (by three orders of magnitude) and specificity than the direct spectrophotometric detection of certain synthetic dyes in saffron and deserves attention by the ISO Technical Committee for "Herbs, culinary spices and condiments"

Mots clés: Life Sciences

Stella A Ordoudi, Maria Z Tsimidou. Consideration of fluorescence properties for the direct determination of erythrosine in saffron in the presence of other synthetic dyes. Food Additives and Contaminants, 2011, pp.1. ⟨10.1080/19440049.2010.551423⟩. ⟨hal-00671651⟩