Allergie aux colorants alimentaires : une pathologie à évoquer avec parcimonie

Effect of the synthesis pH, the nature of the divalent cations and the metal salt concentration on the formation of layered double hydroxides for removal of Cochineal Red A dye from aqueous solutions

In this research work, removal of Cochineal Red A dye from aqueous solution was studied using layered double hydroxide materials prepared by a coprecipitation method at variable pH. The effects of the synthesis pH, the nature of the divalent cations and the total metal salt concentration on the formation of layered double hydroxides and their application to the removal of Cochineal Red A dye from aqueous solution were investigated. The structure of the materials prepared was characterized by X-ray diffraction and Fourier transform infrared. It was found that the nature and content of the bi- and trivalent metal ions in the layered double hydroxide influenced the adsorption. Ni–Fe had 0.96 to 1.70 times more adsorption capacity before reaching its equilibrium adsorption than Zn–Fe prepared at pH 7–9 with 2.2 M of total metal salt concentration. No difference was observed in the amount of Cochineal Red A dye adsorbed onto Zn–Fe prepared at both pH 7–9 and pH 10–11 in the range 1.1–3.3 M of total metal salt concentration. The results show that the increase in the precipitation pH leads to decreasing adsorption capacity. The Cochineal Red A dye adsorption follows the Temkin model for the Ni–Fe and Zn–Fe prepared at pH 7–9 and follows the Langmuir model for the Zn–Fe synthesized at pH 10–11 with high coefficient correlation. The adsorption kinetics data fitted the pseudo-second-order model. A thermodynamic study indicates that the adsorption process is both spontaneous and endothermic in nature.

Adverse reactions to food additives in children: A retrospective study and a prospective survey

BACKGROUND

Allergic reactions to food additives are often suspected by families. The aim of this study was to describe oral food challenge (OFC) outcomes in a pediatric cohort with a suspected diagnosis of allergy to food additives (food dyes or sodium benzoate).

METHODS

All patients who underwent an open OFC to carmine red, cochineal red, erythrosine, patent blue V, tartrazine, yellow sunset S, and/or sodium benzoate were included. A survey was sent to families after testing to evaluate whether the OFC results had altered feeding behaviors with food additives.

RESULTS

Twenty-three patients were included. The main suspected food was candy (n=11/23; 48%). Only one OFC out of 45 was formally positive for the carmine and cochineal red. Subsequently, most OFCs were negative (44/45; 97.8%). Despite the negativity of the challenge, four families out of 14 reported occurrences of supposed allergic reactions to food additives and six out of 15 continued to completely avoid the additive of concern in their children's diet.

CONCLUSIONS

Allergies to food additives remain rare. Even if an IgE-mediated allergy was excluded with a negative OFC, families remained suspicious about ready-made products. Health professionals and parents should be reassured about the low risk of food dye intolerance or allergies.

Electron beam irradiation treatment of Ag/Bi2WO6/CdWO4 heterogeneous material with enhanced photocatalytic activity

Ag/Bi₂WO₆/CdWO₄ ternary heterostructure materials treated by electron beam irradiation are used for the highly efficient degradation of inorganic and organic pollutants.