Multiplexed colorimetry collaborated with smartphone-based image analysis for simultaneous and fast visualization of dyes in both environmental and food samples.

In this work, a multiplexed colorimetric strategy was initiated for simultaneous and fast visualization of dyes using low-cost and easy-to-prepare indicator papers as sorbents. Response surface methodology (RSM) was employed to model statistically and optimize the process variables for dyes extraction and colorimetric assays. Multiplexed colorimetry was realized by virtue of synchronous color alignments from different dimensions of multiple dyes co-stained colorimetric cards under RSM-optimized conditions, and smartphone-based image analysis was subsequently performed from different modes to double-check the credibility of colorimetric assays. As concept-to-proof trials, simultaneous visualization of dyes in both beverages and simulated dye effluents was experimentally proved with results highly matched to HPLC or spiked amounts at RSM-predicted staining time as short as 50 s ∼3 min, giving LODs as low as 0.97 ± 0.22/0.18 ± 0.08 µg/mL (tartrazine/brilliant blue) for multiplexed colorimetry, which much lower than those obtained by single colorimetry. Since this is the first case to propose such a RSM-guided multiplexed colorimetric concept, it will provide a reference for engineering of other all-in-one devices which can realize synchronous visualization applications within limited experimental steps.

Comparison of in vitro Toxicities of 8-Prenylnaringenin, Tartrazine and 17ß-Estradiol, Representatives of Natural and Synthetic Estrogens, in Rat and Human Hepatoma Cell Lines.

BACKGROUND: Phytoestrogens have been praised for their beneficial health effects, whereas synthetic xenoestrogens have been connected to ailments. AIMS: To ascertain whether the toxicities of natural and synthetic estrogens differ, we examined the potent phytoestrogen 8-prenylnaringenin (8-PN), the common synthetic xenoestrogen tartrazine, and the physiological estrogen 17ß-estradiol (E2). METHODS: These three compounds were tested for cytotoxicity, cell proliferation and genotoxicity in human HepG2 and rat H4IIE hepatoma cells. RESULTS: All three estrogens elicited cytotoxicity at high concentrations in both cell lines. They also inhibited cell proliferation, with E2 being the most effective. They all tended to increase micronuclei formation. CONCLUSION: Natural estrogens were no less toxic than a synthetic one.

A novel and efficient voltammetric sensor for the simultaneous determination of alizarin red S and tartrazine by using poly(leucine) functionalized carbon paste electrode.

In the current work, a rapid, selective, and sensitive technique was developed for the detection of Alizarin Red S (ARS) by applying poly leucine modified carbon paste electrode (PLMCPE). Electrochemical impedance spectroscopy (EIS) and Scanning electron microscopy (SEM) were utilized to study the surface morphology of unmodified carbon paste electrode (UMCPE) and PLMCPE. The active surface area for UMCPE and PLMCPE was found to be 0.0012 cm2 and 0.0026 cm2 respectively. The electrochemical response of ARS at UMCPE and PLMCPE was analyzed using cyclic voltammetry (CV) in the potential window of 0.4 to 1.0 V. The cyclic voltammogram obtained for varying the pH of 0.2 M phosphate buffer (PB) solution showed maximum current for the oxidation of ARS at pH 6.5. The electrochemical reaction of ARS was found to be irreversible and adsorption controlled. The effect of variation of concentration of ARS on the oxidation peak current was evaluated using CV and linear scan voltammetry (LSV). A linear relationship between the concentration variation and current was obtained in the linear range of 1.5 µM-3.5 µM and 0.2 µM-5.0 µM for CV and LSV respectively. The limit of detection (LOD) of 0.68 µM for the CV method and 0.29 µM for the LSV method was exhibited by the developed sensor. The simultaneous study of ARS along with tartrazine (TZ) showed good selectivity for ARS. The interferents of foreign molecules showed no effect on the selectivity of the electrode. The applicability of PLMCPE on real samples gave good recovery ranging from 97.46-101.2%; hence, the sensor can be utilized on real samples. The developed sensor has good stability and sensitivity.

Simple and rapid determination of tartrazine in fake saffron using the metal organic framework (Fe SA MOF@CNF) by HPLC/PDA.

The present study of a novel metal-organic framework containing Fe single atoms doped on electrospun carbon nanofibers (Fe SA-MOF@CNF) based on dispersive micro solid phase extraction (D-µ-SPE) using HPLC-PDA for detection tartrazine in fake saffron samples was designed. The Fe SA-MOF@CNF sorbent was extensively characterized through various techniques including N2 adsorption-desorption isotherms, X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. The specific area of surface of the sorbent was 577.384 m2/g. The study variables were optimized via the central composite design (CCD), which included a sorbent mass of 15 mg, a contact time of 6 min, a pH of 7.56, and a tartrazine concentration of 300 ng/ml. Under the optimum condition, the calibration curve of this method was linear in the range of 5-1000 ng/mL, with a correlation coefficient of 0.992. The LOD and LOQ values were ranged 0.38-0.74 and 1.34-2.42 ng/ml, respectively. This approach revealed significant improvements, including high extraction recovery (98.64), recovery rates (98.43-102.72%), and accuracy (RSDs < 0.75 to 3.6%). the enrichment factors were obtained in the range of 80.6-86.4 with preconcentration factor of 22.3. Consequently, the D-µ-SPE method based on synthesized Fe SA-MOF@CNF could be recommended as a sustainable sorbent for detecting tartrazine in saffron samples.

Intensified degradation of tartrazine dye present in effluent using ultrasound combined with ultraviolet irradiation and oxidants.

Effluent containing tartrazine can affect the environment and human health significantly prompting the current study into degradation using a sonochemical reactor operated individually and combined with advanced oxidation processes. The optimum conditions for ultrasound treatment were established as dye concentration of 10 ppm, pH of 3, temperature as 35 °C, and power as 90 W. The combination approach of H2O2/UV, H2O2/US, and H2O2/UV/US resulted in higher degradation of 25.44%, 57.4%, and 74.36% respectively. Use of ZnO/UV/US approach increased the degradation significantly to 85.31% whereas maximum degradation as 93.11% was obtained for the US/UV/Fenton combination. COD reduction was found maximum as 83.78% for the US/UV/Fenton combination. The kinetic analysis showed that tartrazine dye degradation follows pseudo first-order kinetics for all the studied processes. Combination of Fenton with UV and US was elucidated as the best approach for degradation of tartrazine.

Ameliorative effects of thymoquinone on the caspase 3, kidney function and oxidative stress tartrazine-induced nephrotoxicity.

First in the literature this study aimed to investigate the effects of Tartrazine, a common industrial food dye, on kidney and whether Thymoquinone has a protective effect in tartrazine-induced nephrotoxicity. The study conducted on the rats bred at Inönü University Experimental Animals Production and Research Center. Wistar albino rats were randomly divided into 4 groups, where each group included 8 rats: control, Tartrazine, Thymoquinone, and Tartrazine + Thymoquinone groups. The experiments continued for 3 weeks and then, kidney tissues and blood samples were collected from the rats under anesthesia. Malondialdehyde (MDA), super oxidized dismutase (SOD), total oxidant status (TOS), increase in Oxidative stress index (OSI), glutathione (GSH), Glutathione peroxidase (GSH-Px), catalase (CAT), Total antioxidant status (TAS) levels decreased in the kidney tissues collected from the tartrazine group. Serum Bun and Creatinine levels increased in the tartrazine group. Tartrazine administration damaged and degenerated the glomeruli and cortical distal tubes in the histopathology of kidney tissues, also different degrees of inflammatory cell infiltration were observed in the renal cortex and medulla. Thymoquinone and tartrazine administration improved both biochemical and histopathological parameters. Tartrazine administration induced nephrotoxicity. This could be observed with the increase in oxidant capacity and the deterioration of kidney functions. Thymoquinone was observed to demonstrate strong antioxidant properties. Thymoquinone could be used primarily as a protective agent against Tartrazine-induced toxicity.

Ginkgo biloba extract protects against tartrazine-induced testicular toxicity in rats: involvement of antioxidant, anti-inflammatory, and anti-apoptotic mechanisms.

The use of additives, especially colorants, in food and pharmaceutical industry is increasing dramatically. Currently, additives are classified as contaminants of emerging concern (CECs). Concerns have been raised about the potential hazards of food additives to reproductive organs and fertility. The present study investigates the reproductive toxicity of tartrazine (TRZ), a synthetic colorant, in male rats and aims to explore the curative effect of Ginkgo biloba extract (EGb) against TRZ-induced testicular toxicity. Twenty-four rats were divided into four groups: the control (0.5 ml distilled water), the EGb group (100 mg/kg EGb alone), the TRZ group (7.5 mg/kg TRZ alone), and the TRZ-EGb group (7.5 mg/kg TRZ plus 100 mg/kg EGb). The doses were administered orally in distilled water once daily for 28 days. Toxicity studies of TRZ investigated testicular redox state, serum gonadotropins, and testosterone levels, testicular 17 ß-hydroxysteroid dehydrogenase activity, sperm count and quality, levels of inflammatory cytokines, and caspase-3 expression as an apoptotic marker. Also, histopathological alterations of the testes were examined. TRZ significantly affected the testicular redox status as indicated by the increase in malondialdehyde and the decrease in reduced glutathione, superoxide dismutase, and catalase. It also disrupted serum gonadotropins (follicle stimulating hormone and luteinizing hormone) and testosterone levels and the activity of testicular 17ß-hydroxysteroid dehydrogenase. Additionally, TRZ adversely affected sperm count, motility, viability, and abnormality. Levels of tumor necrosis factor-α, interleukin-1ß, interleukin-6, and expression of caspase-3 were increased in the testes. Histopathological examination of the testes supported the alterations mentioned above. Administration of EGb significantly ameliorated TRZ-induced testicular toxicity in rats. In conclusion, EGb protected against TRZ-induced testicular toxicity through antioxidant, anti-inflammatory, and anti-apoptotic mechanisms.

Harnessing the power of polyethyleneimine in modifying chitosan surfaces for efficient anion dyes and hexavalent chromium removal.

In this investigation, synthesis of a surface-functionalized chitosan known as amino-rich chitosan (ARCH) was achieved by successful modification of chitosan by polyethyleneimine (PEI). The synthesized ARCH was characterized by a specific surface area of 8.35 m2 g-1 and a microporous structure, with pore sizes predominantly under 25 nm. The Zeta potential of ARCH maintained a strong positive charge across a wide pH range of 3-11. These characteristics contribute to its high adsorption efficiency in aqueous solutions, demonstrated by its application in removing various anionic dyes, including erioglaucine disodium salt (EDS), methyl orange (MO), amaranth (ART), tartrazine (TTZ), and hexavalent chromium ions (Cr(VI)). The adsorption capacities (Qe) for these contaminants were measured at 1301.15 mg g-1 for EDS, 1025.45 mg g-1 for MO, 940.72 mg g-1 for ART, 732.96 mg g-1 for TTZ, and 350.15 mg g-1 for Cr(VI). A significant observation was the rapid attainment of adsorption equilibrium, occurring within 10 min for ARCH. The adsorption behavior was well-described by the Pseudo-second-order and Langmuir models. Thermodynamic studies indicated that the adsorption process is spontaneous and endothermic in nature. Additionally, an increase in temperature was found to enhance the adsorption capacity of ARCH. The material demonstrated robust stability and selective adsorption capabilities in varied conditions, including different organic compounds, pH environments, sodium salt presence, and in the face of interfering ions. After five cycles of adsorption, ARCH maintained about 60% of its initial adsorption capacity. Due to its efficient adsorption performance, simple synthesis process, low biological toxicity, and cost-effectiveness, ARCH is a promising candidate for future water treatment technologies.

Potential of Capparis decidua plant and eggshell composite adsorbent for effective removal of anionic dyes from aqueous medium.

The presence of hazardous dyes in wastewater poses significant threats to both ecosystems and the natural environment. Conventional methods for treating dye-contaminated water have several limitations, including high costs and complex operational processes. This study investigated a sustainable bio-sorbent composite derived from the Capparis decidua plant and eggshells, and evaluated its effectiveness in removing anionic dyes namely tartrazine (E-102), methyl orange (MO), and their mixed system. The research examines the influence of initial concentration, contact time, pH, adsorbent dosage, and temperature on the adsorption properties of anionic dyes. Optimal removal of tartrazine (E-102), methyl orange (MO), and their mixed system was achieved at a pH of 3. The equilibrium was achieved at 80 min for MO and mixed systems, and 100 min for E-102. The adsorption process showed an exothermic nature, indicating reduced capacity with increasing temperature, consistent with heat release during adsorption. Positive entropy values indicated increased disorder at the solid-liquid interface, attributed to molecular rearrangements and interactions between dye molecules and the adsorbent. Isotherm analysis using Langmuir, Freundlich, Temkin, and Redlich-Peterson models revealed that the Langmuir model best fit the experimental data. The maximum adsorption capacities of 50.97 mg/g, 52.24 mg/g, and 56.23 mg/g were achieved for E-102, MO, and the mixed system under optimized conditions, respectively. The pseudo-second-order kinetic model demonstrated the best fit, indicating that adsorption occurs through physical and chemical interactions such as electrostatic attraction, pore filling, and hydrogen bonding. Hence, the developed bio-sorbent could be a sustainable and cost-effective solution for the treatment of anionic dyes from industrial effluents.

The protective effect of aqueous extract of Stevia rebaudiana against tartrazine toxicity in male Wistar rat.

Tartrazine is a yellow colouring agent that is commonly used in foods; however, high dosages of Tartrazine affect fertility and create oxidative stress by generating free radicals. A plant species known as Stevia rebaudiana has natural antioxidants that show promise for protecting testicular tissue. Consequently, this study was intended to examine the ameliorative effect of the aqueous extract of S. rebaudiana (Stevia) on the fertility of male Wistar rats induced by the daily oral intake of Tartrazine. Utilizing gas chromatography-mass spectrometry, phytochemical identification was accomplished for Stevia extract. Study groups were separated into several groups: the first group (the control) got distilled water for up to 56 days; the Stevia group (1000 mg/kg), the Tartrazine group (300 mg/kg) and the Stevia and Tartrazine group (the group was given Tartrazine after 1 h of Stevia extract intake). Also, the oxidative damage in testicular tissues was assessed by measuring the levels of malondialdehyde (MDA) and antioxidants (catalase [CAT], superoxide dismutase [SOD] and glutathione reductase [GSH]). Further, histological alterations were examined. In addition, cyclic AMP-responsive element modulator (Crem) gene expression levels and their relative proteins were measured in the testicular tissues using quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assays, respectively. Sperm analysis and testosterone concentration were also performed. SPSS version 25 was used for the analysis of results while (p < .05) was regarded as significant. Compared with the control group, the results demonstrated that Tartrazine caused a significant reduction (p < .05) in the testosterone hormone level (0.70 ± 0.21) and the Crem protein quantity (1.21 ± 0.23) in the treated Tartrazine group. Also, it had a significant decrease (p < .05) in sperm motility, viability, count and antioxidant levels. Moreover, there was a significant increase (p < .05) in sperm abnormalities, MDA level (7.40 ± 1.10), kidney and liver function parameters, and DNA degradation in the treated Tartrazine group compared with the control group. On the contrary, the Stevia extract intake enhanced the testosterone (2.50 ± 0.60), antioxidants and Crem protein levels (2.33 ± 0.10) with an improvement in sperm quality in the Stevia and Tartrazine-treated group compared with the Tartrazine group. Stevia also caused a significant decrease (p < .05) in the MDA level (3.20 ± 0.20), and sperm abnormalities with an enhancement of the liver and kidney function parameters in the Stevia and Tartrazine-treated group compared to the Tartrazine group. Stevia administration has a protective effect on the testicular tissues and sperm quality against toxicity induced by Tartrazine exposure, so it will be a good antioxidant drug to be administered daily before daily administration of Tartrazine.

Changing Despicable Me: Potential replacement of azo dye yellow tartrazine for pequi carotenoids employing ionic liquids as high-performance extractors.

Color is a crucial sensory attribute that guides consumer expectations. A high-performance pequi carotenoid extraction process was developed using ionic liquid-based ethanolic solutions and a factorial design strategy to search for a potential substitute for the artificial azo dye yellow tartrazine. All-trans-antheraxanthin was identified with HPLC-PAD-MSn for the first time in pequi samples. [BMIM][BF4] was the most efficient ionic liquid, and the maximization process condition was the solid-liquid ratio R(S/L) of 1:3, the co-solvent ratio R(IL/E) of 1:1 ([BMIM][BF4]: ethanol), and three cycles of extraction with 300 s each and yielded 107.90 µg carotenoids/g of dry matter. The ionic liquid-ethanolic solution recyclability was accomplished by freezing and precipitating with an average recovery of 79 %. In CIELAB parameters, pequi carotenoid extracted with [BMIM][BF4] was brighter and yellower than the artificial azo dye yellow tartrazine. A color change of 11.08 and a hue* difference of 1.26° were obtained. Furthermore, carotenoids extracted with [BMIM][BF4] showed antioxidant activity of 35.84 µmol of α-tocopherol. These findings suggest the potential of employing the pequi carotenoids to replace the artificial azo dye yellow tartrazine in foods for improved functional properties.

Preparation, analysis and toxicity characterisation of the redox metabolites of the azo food dye tartrazine.

Tartrazine (E102, FD&C Yellow 5) is a vibrant yellow azo dye added to many processed foods. The safety of this ubiquitous chemical has not been fully elucidated, and it has been linked to allergic reactions and ADHD in some individuals. In our study, bacterial species isolated from human stool decolourised tartrazine and, upon exposure to air, a purple compound formed. Tartrazine is known to undergo reduction in the gut to sulfanilic acid and 4-amino-3-carboxy-5-hydroxy-1-(4-sulfophenyl)pyrazole (SCAP). These metabolites and their derivatives are relevant to the toxicology of tartrazine. The toxicity of sulfanilic acid has been studied before, but the oxidative instability of SCAP has previously prevented full characterisation. We have verified the chemical identity of SCAP and confirmed that the purple-coloured oxidation derivative is 4-(3-carboxy-5-hydroxy-1-(4-sulfophenyl)-1H-pyrazol-4-yl)imino-5-oxo-1-(4-sulfophenyl)-4,5-dihydro-1H-pyrazole-3-carboxylic acid (purpurazoic acid, PPA), as proposed by Westöö in 1965. A yellow derivative of SCAP is proposed to be the hydrolysed oxidation product, 4,5-dioxo-1-(4-sulfophenyl)-4,5-dihydro-1H-pyrazole-3-carboxylic acid. SCAP and PPA are moderately toxic to human cells (IC50 89 and 78 µM against HEK-293, respectively), but had no apparent effect on Escherichia coli and Bacillus subtilis bacteria. These results prompt further analyses of the toxicology of tartrazine and its derivatives.

Green synthesis of N,S-doped carbon dots for tartrazine detection and their antibacterial activities.

A simple, green and low-cost method was developed for the synthesis of highly fluorescent N,S-doped carbon dots (N,S-CDs) via the hydrothermal treatment of Gandha Prasarini (GP) leaves as a natural source of carbon, nitrogen and sulfur. The as-prepared N,S-CDs exhibited excitation-dependent green fluorescence emission (λex = 450 nm, λem = 525 nm) with excellent stability, and were used as a fluorescent probe for the selective detection of tartrazine with a limit of detection of 0.18 µM. The fluorescence quenching of N,S-CDs was due to the inner filter effect. The developed method has been employed for the determination of tartrazine in honey and soft drinks with satisfactory recovery ranging from 92 to 110.2%. In addition, the antibacterial activity of the N,S-CDs was explored against both Gram-negative bacteria, Escherichia coli (E. coli) and Pseudomonas aeruginosa (P. aeruginosa), and Gram-positive bacteria, Staphylococcus aureus (S. aureus). The antibacterial mechanism of the N,S-CDs was investigated. The results indicated that the antibacterial activity was due to the membrane damage of the bacteria by the N,S-CDs. Besides, the N,S-CDs showed negligible lytic effects on human erythrocytes. These findings will inspire further exploitation of CD-based nano-bactericides in biomedical applications.

Separation and quantification of Tartrazine (E102) and Brilliant Blue FCF (E133) in green colored foods and beverages.

In the present study we investigated the capacities of a panel of 25 solid sorbents represented by layered structures, inorganic oxides and hydroxides, and phyllosilicates, to effectively remove in high yield Tartrazine (E102) and Brilliant Blue FCF (E133) from aqueous solutions, and more notable, green colored food matrices. Quantification of the title compounds have been achieved by HPLC-DAD analyses. Contents of E102 and E133 in real samples were in the range 1.3-36.5 µg/mL and 1.0-20.1 µg/mL, respectively. After a treatment of 1 min., in most cases a complete bleaching of solutions and deep coloring of the solid phase was recorded. The most effective solids to this aim were seen to be aluminium based ayered double hydroxides. In the case of magnesium oxide for E102, and magnesium aluminium D. benzensulfonate SDS 01 H8L and Florisil for E133, a selective adsorption (>99.9 %) of only one dye was observed. The adsorption recorded was strictly dependent on the loading of the sorbent. Related values were 300 mg for the separation of E102 by magnesium oxide from all the five food matrices under investigation, and in the range 200 mg-300 mg for magnesium aluminium D. benzensulfonate SDS 01 H8L and Florisil in the case of E133. The application of Langmuir and Freundlich models suggested that the adsorption may take place in the inner layers of the solids with a favourable thermodynamique outcome. Findings described herein offer the concrete possibility of quantifications of individual dyes in matrices containing more than one food colorant.

Efficient adsorption of tartrazine from an aqueous solution using a low-cost orange peel powder.

Orange peel powder was activated using different methods and was used to remove tartrazine (E102) from an aqueous solution. The following three adsorbents were synthethized: orange peel powder activated thermally (POAT), orange peel powder activated with sulfuric acid (POAA), orange peel powder activated with soda (POAS). These adsorbents were then characterized by Fourier Transform Infra-Red Spectrometry (FTIR), Raman spectroscopy, powder X-Ray Diffraction (XRD), and point-of-zero charge. The experimental parameters such as contact time, dose of adsorbent, initial concentration of tartrazine, pH, and temperature were studied. The adsorption capacities of tartrazine for the optimal POAT, POAA, and POAS were found to be 121.74, 122.25, and 116.35 mg/g, respectively. The experimental data were analyzed by Freundlich and Temkin isotherm models, as well as the pseudo-second-order kinetic model.

Electrochemical detection of carmoisine in the presence of tartrazine on the surface of screen printed graphite electrode modified with nickel-cobalt layered double hydroxide ultrathin nanosheets.

Toxic effluents containing azo dyes are discharged from various industries and they adversely affect water resoures, soil and aquatic ecosystems. Also, excessive use of food azo dyes can be carcinogenic, toxic, and adversely affect human health. Therefore, the determination of food azo dyes is significant from the perspective of human health and aquatic organisms. In the present work, nickel-cobalt layered double hydroxide nanosheets were prepared and analyzed by various techniques (field emission-scanning electron microscopy, X-ray diffraction, and Fourier Transform-Infrared spectroscopy). Then, the screen printed graphite electrode modified with nickel-cobalt layered double hydroxide nanosheets was used for the detection of carmoisine. The nickel-cobalt layered double hydroxide nanosheets/screen printed graphite electrode significantly improved the oxidation of carmoisine by increasing the response current and lowering potentials compared to unmodified screen printed graphite electrode. Based on the findings from differential pulse voltammetry, the nickel-cobalt layered double hydroxide nanosheets/screen printed graphite electrode sensor response towards carmoisine was linear (0.3-125.0 µM) with a detection limit of 0.09 µM. A sensitivity of 0.3088 µA µM-1 was achieved. Also, the nickel-cobalt layered double hydroxide nanosheets/screen printed graphite electrode was used for voltammetric detection of carmoisine in the presence of tartrazine. Due to the catalytic activity of prepared layered double hydroxide, the prepared sensor exhibited remarkable separation of the peaks when carmoisine and tartrazine coexist. In addition, the prepared sensor showed good stability. Finally, the proposed sensor had promising applicability for analysis of study analytes in powdered juice and lemon juice, with commendable recoveries between 96.9%-104.8%.

Azo dyes in the food industry: Features, classification, toxicity, alternatives, and regulation.

Azo dyes, including Tartrazine, Sunset Yellow, and Carmoisine, are added to foods to provide color, but they have no value with regard to nutrition, food preservation, or health benefits. Because of their availability, affordability, stability, and low cost, and because they provide intense coloration to the product without contributing unwanted flavors, the food industry often prefers to use synthetic azo dyes rather than natural colorants. Food dyes have been tested by regulatory agencies responsible for guaranteeing consumer safety. Nevertheless, the safety of these colorants remains controversial; they have been associated with adverse effects, particularly due to the reduction and cleavage of the azo bond. Here, we review the features, classification, regulation, toxicity, and alternatives to the use of azo dyes in food.

Optimization of iron-ZIF-8 catalysts for degradation of tartrazine in water by Fenton-like reaction.

Optimization of iron zeolitic imidazole framework-8 (FeZIF-8) nanoparticles, as heterogeneous catalysts, were synthesized and evaluated by the Fenton-like reaction for to degrade tartrazine (Tar) in aqueous environment. To achieve this, ZIF-8 nanoparticles were modified with different iron species (Fe2+ or Fe3O4), and subsequently assessed through the Fenton-like oxidation. The effect of different parameters such as the concentration of hydrogen peroxide, the mass of catalyst and the contact time of reaction on the degradation of Tar by Fenton-like oxidation was studied by using the Box-Behnken design (BBD). The BBD model indicated that the optimum catalytic conditions for Fenton-like reaction with an initial pollutant concentration of 30 ppm at pH 3.0 were T = 40 °C and 12 mM of H2O2, 2 g/L of catalyst and 4 h of reaction. The maximum Tar conversion value achieved with the best catalyst, Fe1ZIF-8, was 66.5% with high mineralization (in terms of decrease of total organic carbon - TOC), 44.2%. To assess phytotoxicity, the germination success of corn kernels was used as an indicator in the laboratory. The results show that the catalytic oxidation by Fenton-like reaction using heterogeneous iron ZIF-8 catalysts is a viable alternative for treating contaminated effluents with organic pollutants and highlighted the importance of the validation of the optimized experimental conditions by mathematical models.

Tartrazine Modifies the Activity of DNMT and HDAC Genes-Is This a Link between Cancer and Neurological Disorders?

In recent years, artificial additives, especially synthetic food colorants, were found to demonstrate wider properties compared to their natural equivalents; however, their health impact is still not totally mapped. Our study aimed to determine the long-term (30 and 90 days) exposure effect of one of the commonly used artificial food colorants, tartrazine, on NMRI mice. The applied dose of tartrazine referred to the human equivalent dose for acceptable daily intake (ADI). Further, we evaluated its impact on the transcription of a range of epigenetic effectors, members of the DNA methyltransferase (DNMT) as well as histone deacetylase (HDAC) families. Following the exposure, organ biopsies were collected from the lungs, kidneys, liver, and spleen, and the gene expression levels were determined by real-time quantitative reverse transcription PCR (RT-qPCR). Our results demonstrated significant upregulation of genes in the tested organs in various patterns followed by the intake of tartrazine on ADI. Since DNMT and HDAC genes are involved in different steps of carcinogenesis, have roles in the development of neurological disorders and the effect of dose of everyday exposure is rarely studied, further investigation is warranted to study these possible associations.

Fluorescent detection of tartrazine based on the supramolecular self-assembly of cationic perylene diimide.

A cationic perylene probe was designed and synthesized for sensitive determination of tartrazine. In the presence of tartrazine, the fluorescence of the perylene probe was quenched by efficient supramolecular self-assembly of the perylene derivate. The quenching is caused by the synergistic effect of noncovalent interactions including static electricity, π-π stacking, and hydrophobic interaction. Benefiting from these advantages, the probe exhibited excellent sensing performance to tartrazine within 2 min. The detection and quantification limit of tartrazine are as low as 2.42 and 8.07 nmol L-1, respectively, with a wide linear operation range from 15 to 500 nmol L-1. Most importantly, due to the high binding affinity (3.22 × 107 mol L-1) between the perylene probe and tartrazine, the sensing system shows great anti-interference capacity. Subsequently, the visualization application of the approach was evaluated by portable device, and the limits of detection for visual detection for test strip, membrane, and hydrogel were 0.5, 0.5, and 5 µmol L-1, respectively. The approach has been applied to monitor tartrazine in various food condiments with recoveries in the range 91.29-108.83%. As far as we know, this is the first report of using perylene-based probe for tartrazine determination, offering a promising strategy for the construction of perylene-based detection system in the field of food safety.