Impact du Colorant E1 29 (Rouge Allura AC) sur la Microflore intestinale humaine.

Abstract

This work is situated within the context of studying the interactions between diet and the intestinal microbiota, which is considered a key actor in human metabolism and health. Scientific interest has focused on food additives, particularly azo synthetic dyes, including Allura Red AC (E129), which is widely used in the food industry. Despite their regulated use, these compounds raise concerns due to their potential metabolism by the intestinal microbiota and the formation of byproducts that may influence microbial balance and certain physiological functions. The aim of this study was to evaluate the presence of E129 in different food products, to investigate its degradation through chemical (Fenton) and biological processes, and to analyze the properties and impact of the resulting by-products on representative intestinal microbiota microorganisms. The dye quantification was performed using UV-Visible spectrophotometry, while its antioxidant activity (DPPH assay) was found to be very weak. The pure dye showed no antimicrobial activity against the tested strains. The results showed concentrations ranging from 8.45 to 65.92 mg/L in the analyzed food products, remaining compliant with the acceptable daily intake (ADI). The degradation of the dye reached a maximum rate of 80.86%, and chromatographic analyses (TLC, HPLC) confirmed the formation of degradation by-products. These by-products exhibited moderate antimicrobial activity, with inhibition zones ranging from 7.4 to 10.7 mm. Overall, although the pure dye is biologically inactive and the measured concentrations comply with safety standards, its transformation may generate metabolites capable of affecting the intestinal microbiota and being involved in digestive, metabolic, and behavioral disorders.