Prolonged use of the food dye tartrazine (FD&C yellow no 5) and its effects on the gastric mucosa of Wistar rats.
ABSTRACT Tartrazine is one of the most widely used artificial foods, drugs and cosmetic dyes. It is a nitrous derivative and is known to cause allergic reactions such as asthma and urticaria, as well as having been the focus of studies on mutagenesis and carcinogenesis due to its transformation into aromatic amine sulfanilic acid after being metabolized by the gastrointestinal microflora. 45 male Wistar rats were assigned to a control group (A) or a treatment one (B). The treatment group received 7.5 mg x kg(-1) x day(-1) of tartrazine daily in drinking water offered ad libitum for ten months from weaning to the age of twelve months. There was a significant increase in the number of lymphocytes and eosinophils of the gastric antrum mucosa. No carcinogenetic changes in any gastric area were observed during the study. As tartrazine belongs to the azo class, it is still a possible food carcinogen. Other studies with different doses and schedules, observing their effects associated to other carcinogens should be carried out if their safe use is to be recommended.
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ABSTRACT: The removal of the dye—tartrazine by photodegradation has been investigated using titanium dioxide surface as photocatalyst under UV light. The process was carried out at different pH, catalyst dose, dye concentration and effects of the electron acceptor H2O2. It was found that under the influence of TiO2 as catalyst, the colored solution of the dye became colorless and the process followed a pseudo first order kinetics. The optimum conditions for the degradation of dye were 6 × 10− 5 M dye concentration, pH of 11, and 0.18 mg/L of catalyst dose. In order to evaluate the effect of electron acceptor, the effect of H2O2 on the degradation process was also monitored and it was found that the hydroxyl radical formation and retardation of electron–hole recombination took place simultaneously. The adsorption studies of tartrazine at various dose of TiO2 followed the Langmuir isotherm trend. In order to determine the quality of waste water, Chemical Oxygen Demand (COD) measurements were carried out both before and after the treatment and a significant decrease in the values was observed, implying good potential of this technique to remove tartrazine dye from aqueous solutions.Graphical abstractResearch highlights►Degradation efficiency increases with increase in catalyst concentration. ►Adsorption of tartrazine on TiO2 followed the Langmuir isotherm. ►The photocatalytic kinetics follows first order.Materials Science and Engineering C 07/2011; 31(5):1062-1067. DOI:10.1016/j.msec.2011.03.006 · 2.74 Impact Factor
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ABSTRACT: The adsorption of azobenzene FD&C Red No. 40 (C.I. 16035) from aqueous solutions by chitosan was studied through adsorption isotherms. The effects of pH (5.7, 6.6 and 7.5), particle size ranges (0.10 ± 0.02, 0.18 ± 0.02 and 0.26 ± 0.02 mm), deacetylation degree (42 ± 5%, 64 ± 3% and 84 ± 3%) and temperature (25, 35 and 45 °C) were investigated. Langmuir, Freundlich and Redlich–Peterson (R–P) adsorption models were applied in order to describe the experimental isotherms and isotherm constants. Coefficients of determination (R2 > 0.95) and mean relative error (MRE < 0.10) values showed that Langmuir and R–P models presented better fit with the experimental data. The maximum monolayer adsorption value has been found to be 529 mg g−1, at pH 6.6, temperature 35 °C, particle size range 0.10 ± 0.02 mm, and deacetylation degree 84 ± 3%.Journal of Food Engineering 11/2009; 95:16-20. DOI:10.1016/j.jfoodeng.2009.03.017 · 2.58 Impact Factor