Cross Talk between Synthetic Food Colors (Azo Dyes), Oral Flora, and Cardiovascular Disorders

Exploring acylated anthocyanin-based extracts as a natural alternative to synthetic food dyes: Stability and application insights

This work explores the potential of anthocyanin-based extracts (hibiscus calyxes - HC, red cabbage - RC, and butterfly pea flower - BPF) as natural alternatives to synthetic dyes in the food industry. Analyses in a pH range for food applications revealed higher color stability for the BPF extract, keeping vibrant colors over the 7 days at room temperature. At pH 3 and 100 °C, the BPF was more stable, losing half of its anthocyanin concentration after 14 h, while RC and HC lost half of their color after 7 and 2 h, respectively. The bisulfite bleaching followed a second-order reaction for HC and RC, and a first-order reaction for BPF, suggesting a minor effect of the bisulfite on this extract. Incorporating these extracts into porcine protein and agar-agar gelatin formulations produced consistent products with appealing hues, particularly the blue and purple colors for BPF and RC, dependent on the pH.

Recent advances in electrochemical detection of common azo dyes

PURPOSE

Food forensics is an emerging field and the initial part of this review showcases the toxic effects and the instrumental methods applied for the detection of the most commonly used azo dyes. Electrochemical detection has a lot of advantages and hence the significance of the most important techniques used in the electrochemical detection is discussed. The major part of this review highlights the surface modified electrodes, utilized for the detection of the most important azo dyes to achieve low detection limit (LOD).

METHODS

A thorough literature study was conducted using scopus, science direct and other scientific databases using specific keywords such as toxic azo dyes, electrochemical detection, modified electrodes, LOD etc. The recent references in this field have been included.

RESULTS

From the published literature, it is observed that with the growing interests in the field of electrochemical techniques, a lot of importance have been given in the area of modifying the working electrodes. The results unambiguously show that the modified electrodes outperform bare electrodes and offer a lower LOD value.

CONCLUSION

According to the literature reports it can be concluded that, compared to other detection methods, electrochemical techniques are much dependable and reproducible. The fabrication of the electrode material with the appropriate modifications is the main factor that influences the sensitivity. Electrochemical sensors can be designed to be more sensitive, more reliable, and less expensive. These sensors can be effectively used by toxicologists to detect trace amounts of harmful dyes in food samples.

Photocatalytic Degradation of Organic Dyes by Magnetite Nanoparticles Prepared by Co-Precipitation

Iron oxide nanoparticles were synthesized by co-precipitation using three different iron salt stoichiometric mole ratios. Powder X-ray diffraction patterns revealed the inverse cubic spinel structure of magnetite iron oxide. Transmission electron microscopic images showed Fe3O4 nanoparticles with different shapes and average particle sizes of 5.48 nm for Fe3O4-1:2, 6.02 nm for Fe3O4-1.5:2, and 6.98 nm for Fe3O4-2:3 with an energy bandgap of 3.27 to 3.53 eV. The as-prepared Fe3O4 nanoparticles were used as photocatalysts to degrade brilliant green (BG), rhodamine B (RhB), indigo carmine (IC), and methyl red (MR) under visible light irradiation. The photocatalytic degradation efficiency of 80.4% was obtained from Fe3O4-1:2 for brilliant green, 61.5% from Fe3O4-1.5:2 for rhodamine B, and 77.9% and 73.9% from Fe3O4-2:3 for both indigo carmine and methyl red. This indicates that Fe3O4-2:3 is more efficient in the degradation of more than one dye. This study shows that brilliant green degrades most effectively at pH 9, rhodamine B degrades best at pH 6.5, and indigo carmine and methyl red degrade most efficiently at pH 3. Recyclability experiments showed that the Fe3O4 photocatalysts can be recycled four times and are photostable.

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.

Dietary exposure to food azo-colours in a sample of pre-school children from Southern Brazil

The dietary exposure of six food azo-colours was assessed in a sample of pre-schoolers from Guaratuba-Paraná, Brazil. Consumption data of 323 children aged 2 to 5 years was collected through 3-day food records. Dietary exposure, is expressed by milligrams of food colour by kilogram of body weight per day, as compared to the Acceptable Daily Intake (ADI). Three exposure scenarios were developed to account for uncertainties around consumption estimates. Intakes of Amaranth (INS 123) described in means, 50th and 95th percentiles exceeded ADI levels in the two most conservative scenarios, with the highest percentiles exceeding about four times the ADI. High intakes of Sunset Yellow FCF (INS 110) were also observed, of up to 85% of the ADI in the worst-case scenario. Findings suggest high exposure levels to azo-dyes in the survey population, with children likely exceeding the ADI for Amaranth (INS 123) and concerns for Sunset Yellow FCF (INS 110). Major food contributors were beverages (juice powders and soft drinks), dairy and sweets. Further studies on dietary exposure assessment are needed at the national level. The authors highlight the need of controlling the use of such additives through national policies that are aligned with the consumption patterns observed in the country.

Carbon Paper Modified with Functionalized Poly(diallyldimethylammonium chloride) Graphene and Gold Phytonanoparticles as a Promising Sensing Material: Characterization and Electroanalysis of Ponceau 4R in Food Samples

This paper presents a novel eco-friendly sensing material based on carbon paper (CP) volumetrically modified with a composite nanomodifier that includes functionalized poly(diallyldimethylammonium chloride) graphene (PDDA-G) and phytosynthesized gold nanoparticles (phyto-AuNPs). The functionalization of graphene was justified by Fourier-transform infrared spectroscopy. The phyto-AuNPs (d = 6 nm) were prepared by "green" synthesis with the use of strawberry leaf extract. The sensing material was characterized using scanning electron microscopy, electrochemical impedance spectroscopy, and voltammetry. The research results indicated a more than double increase in the electroactive surface area; a decrease in the resistance of electron transfer on nanocomposite-modified CP, compared to bare CP. The phyto-AuNPs/PDDA-G/CP was used for the electrosensing of the synthetic dye Ponceau 4R. The oxidation signal of colorant enhanced 4-fold on phyto-AuNPs/PDDA-G/CP in comparison to CP. The effect of the quantity of nanomodifier, solution pH, potential scan rate, accumulation parameters, and differential pulse parameters on the peak current of Ponceau 4R was studied. Under optimal conditions, excellent sensory characteristics were established: LOD 0.6 nM and LR 0.001-2 μM for Ponceau 4R. High selectivity and sensitivity enable the use of the sensor for analyzing the content of Ponceau 4R in food products (soft drinks, candies, and popsicles) without additional sample preparation.