Search Results (87)

Nuclear Magnetic Resonance (NMR) and Magnetic Resonance Imaging (MRI) are powerful techniques that have been employed to analyze foodstuffs comprehensively. These techniques offer in-depth information about the chemical composition, structure, and spatial distribution of components in a variety of food products. Quantitative NMR is widely applied for precise quantification of metabolites, authentication of food products, and monitoring of food quality. Low-field ¹H-NMR relaxometry is an important technique for investigating the most abundant components of intact foodstuffs based on relaxation times and amplitude of the NMR signals. In particular, information on water compartments, diffusion, and movement can be obtained by detecting proton signals because of H₂O in foodstuffs. Saffron adulterations with calendula, safflower, turmeric, sandalwood, and tartrazine have been analyzed using benchtop NMR, an alternative to the high-field NMR approach. The fraudulent addition of Robusta to Arabica coffee was investigated by ¹H-NMR Spectroscopy and the marker of Robusta coffee can be detected in the ¹H-NMR spectrum. MRI images can be a reliable tool for appreciating morphological differences in vegetables and fruits. In kiwifruit, the effects of water loss and the states of water were investigated using MRI. It provides informative images regarding the spin density distribution of water molecules and the relationship between water and cellular tissues. ¹H-NMR spectra of aqueous extract of kiwifruits affected by elephantiasis show a higher number of small oligosaccharides than healthy fruits do. One of the frauds that has been detected in the olive oil sector reflects the addition of hazelnut oils to olive oils. However, using the NMR methodology, it is possible to distinguish the two types of oils, since, in hazelnut oils, linolenic fatty chains and squalene are absent, which is also indicated by the ¹H-NMR spectrum. NMR has been applied to detect milk adulterations, such as bovine milk being spiked with known levels of whey, urea, synthetic urine, and synthetic milk. In particular, T2 relaxation time has been found to be significantly affected by adulteration as it increases with adulterant percentage. The ¹H spectrum of honey samples from two botanical species shows the presence of signals due to the specific markers of two botanical species. NMR generates large datasets due to the complexity of food matrices and, to deal with this, chemometrics (multivariate analysis) can be applied to monitor the changes in the constituents of foodstuffs, assess the self-life, and determine the effects of storage conditions. Multivariate analysis could help in managing and interpreting complex NMR data by reducing dimensionality and identifying patterns. NMR spectroscopy followed by multivariate analysis can be channelized for evaluating the nutritional profile of food products by quantifying vitamins, sugars, fatty acids, amino acids, and other nutrients. In this review, we summarize the importance of NMR spectroscopy in chemical profiling and quality assessment of food products employing magnetic resonance technologies and multivariate statistical analysis. Full article

Wastewater contains dyes originating from textile industries, and above a certain concentration, they can become dangerous due to their high toxicity. Divalent and trivalent metal coagulants, usually aluminum- or iron-based, have been studied worldwide. However, tetravalent coagulants, such as tin chloride, have not yet been extensively studied for application in wastewater treatment. Therefore, in this study, three types of coagulants were examined: SnCl₄, Cs, and a hybrid composite (CS@Sn) in two different mass ratios, abbreviated hereafter as CS@Sn_5% and CS@Sn_50%. The formation of the suggested CS@Sn hybrid coagulants was confirmed by applying SEM, XRD, and FTIR techniques. The results showed that the optimum conditions for RB5 removal was the addition of 20 mg Sn/L SnCl₄ (97.8%) and 50 mg Sn/L of CS@Sn_50% (64.8%) at pH 3.0. In addition, SnCl₄ was found to be an effective coagulant for all the examined anionic dyes, but it was not as effective for cationic dyes. Moreover, the coagulants were then tested in two mixed-dye solutions, both anionic dyes (RB5/RR120) and anionic/cationic (RB5/MV), resulting in a synergistic effect in the first one and a competitive effect in the secon. Finally, the proposed coagulants were successfully tested on real wastewater samples from an untreated textile dyeing industry. Therefore, the coagulants presented in this work for the removal of several dyes are also capable of being used for wastewater treatment. Full article

Synthetic dyes are commonly present in industrial wastewater and when discharged in water bodies without receiving a treatment capable of removing or destroying them, they turn into concerning water pollutants. These organic contaminants threaten living beings due to their toxicity, and some of them can even damage DNA. Consequently, in order to achieve sustainable development, it is necessary to develop eco-friendly tools that can efficiently manage this kind of pollution. In the present study the aqueous extract from the leaves of Leucaena leucocephala (an invasive plant species native to Mexico) was used to produce green nano zero-valent iron (nZVI). The nanomaterial was characterized (TEM, UV–vis, FTIR, SEM, EDS, XRD) and assayed regarding its antioxidant potential (DPPH test) and capacity to remediate the pollution caused by two dyes. It proved to be able to adsorb nigrosine (288.30 mg/g of nanomaterial) and tartrazine (342.50 mg/g of nanomaterial), and also displayed antioxidant activity (effective concentration to discolor 50% of the DPPH solution = 286.02 μg/mL). Therefore, the biogenic antioxidant nanoparticle proved also to be a possible nanotool to be applied to remediate water contamination caused by these synthetic dyes. Full article

This study investigates the efficiency of electrocoagulation (EC) in removing Tartrazine Yellow (TY) azo dye from synthetic wastewater using aluminium electrodes. The effects of current density, i (0.008–0.024 A cm⁻²), initial solution pH (3.0–7.0), and treatment time, t (10–50 min) on key process parameters, including pH, temperature (T), TY dye concentration (c) and removal efficiency (R), anode consumption, and sludge characterisation were studied. The experiments were conducted in a batch reactor according to the experimental plan developed in Design-Expert software, which was also used for the evaluation of the obtained results. As the EC process progresses, the removal efficiency of the TY dye increases, while the removal dynamics and the final value of R (ranging from about 28% to 99%) depend on the experimental conditions (i, initial pH, and t). A high R-value is reached faster with the application of higher current densities and lower initial pH. This is associated with a higher proportion of carbon and sulphur in the sludge (from the TY dye) after the EC process. Additionally, a mathematical model was developed to predict the experimental data. A numerical optimisation method using response surface methodology (RSM) was applied to determine the optimal operating conditions for TY dye removal. This resulted in the following conditions: pH = 3.37, t = 18.74 min, and i = 0.016 A cm⁻², achieving a removal efficiency of ≈70%. Full article

The present work examines pure and palladium photofixed TiO₂ and binary (TiO₂/ZnO) photocatalysts for breaking down tartrazine, a food coloring agent, in distilled water. Powders with the following compositions are obtained using the sol-gel process: 100TiO₂, 10TiO₂/90ZnO, 50TiO₂/50ZnO, and 90TiO₂/10ZnO. The composite materials are analyzed using SEM-EDS, UV-Vis, DTA-TG, and X-ray diffraction. The synthesized gels are then photo-fixed with UV light to incorporate palladium ions and are also examined for tartrazine (E102) degradation. The photocatalytic tests were carried out in a cylindrical glass reactor illuminated by ultraviolet light. Compared to mixed binary catalysts, the prepared pure TiO₂ catalyst demonstrated greater activity in the photodegradation of tartrazine (E102). The further of a specific quantity of zinc oxide reduced the catalytic properties of TiO₂. The recombination of photoinduced electron-hole pairs in ZnO may account for this. In comparison to the pure samples, the co-catalytic palladium-modified gels exhibited higher photocatalytic efficiency. Heterojunction and palladium modification of the composites partially captured and transferred the electrons. Consequently, the longer lifetime of the photogenerated charges improved the catalytic activity of the palladium titanium dioxide and binary gels. Additionally, under UV light, pure and palladium photofixed TiO₂ and binary sol-gel samples displayed excellent stability for tartrazine photodegradation. Full article

This study explores the photocatalytic efficiency of Zn/Fe/TiO₂ catalysts, synthesized via the wet impregnation method, for degrading the food colorings Allura Red and Tartrazine Yellow. A 2² factorial design with a central point replication guided the catalyst synthesis. Characterization involved BET surface area analysis, SEM-EDX, XRD, and PZC determination. Photocatalytic tests were conducted in batch mode under natural sunlight with 10 mg L⁻¹ food coloring solutions. Kinetic modeling and statistical analysis were performed, and catalyst reuse was evaluated under artificial light. Results showed that low calcination temperatures (200–273 °C) and Zn loadings of 2–10% led to nearly 99% discoloration and degradation efficiency. The Behnajady–Modirshahla–Ghanbery kinetic model best described the discoloration data, confirming the significant impact of both variables. The optimal catalyst for Allura Red degradation was 2%Zn/2%Fe/TiO₂ calcined at 200 °C, while for Tartrazine Yellow, 6%Zn/2%Fe/TiO₂ calcined at 300 °C was most effective. Both catalysts exhibited excellent stability, maintaining efficiency over four reuse cycles. These findings demonstrate the potential of Zn/Fe/TiO₂ catalysts for sustainable wastewater treatment. Full article

Background/Objectives: Tartrazine (TRZ), a synthetic red azo dye derived from coal tar, is widely used as a food colorant in various food products, pharmaceuticals, and cosmetics. This study aims to investigate the impact of TRZ on the expression levels of DNA methyltransferases (DNMT1, DNMT3a, and DNMT3b) and histone deacetylases (HDAC5 and HDAC6). Additionally, we evaluate genomic DNA stability using the alkaline comet assay in three human cell lines: immortalized human keratinocyte (HaCaT), human hepatocellular carcinoma (HepG2), and human lung adenocarcinoma (A549). The research question focuses on whether TRZ exposure alters epigenetic regulation and DNA integrity, potentially implicating its role in carcinogenesis. Methods: The selected human cell lines were exposed to different concentrations of TRZ (20 µM, 40 µM, and 80 µM), with DMBA serving as a positive control. After treatment, we quantified the expression levels of DNMT1, DNMT3a, DNMT3b, HDAC5, and HDAC6 using quantitative real-time PCR. Additionally, we assessed DNA fragmentation via the alkaline comet assay to determine the extent of DNA damage resulting from TRZ exposure. Results: Our findings indicate that TRZ significantly upregulates the expression of HDAC5, HDAC6, DNMT1, DNMT3a, and DNMT3b in comparison to the control group. Furthermore, TRZ exposure leads to a notable increase in DNA damage, as evidenced by elevated tail moments across all examined human cell lines. Conclusions: These results suggest that TRZ may play a role in carcinogenesis and epigenetic modifications. The observed upregulation of DNMTs and HDACs, coupled with increased DNA damage, highlights the potential risks associated with TRZ exposure. Further research is necessary to explore these mechanisms and assess their implications for human health. Full article

The suitability of advanced oxidation processes to industrial pollutants was evaluated. Three dyes were selected for research: Indigo carmine, Tartrazine, and Allura red AC. Single processes (oxidation by H₂O₂, Fenton process, ozonation), and hybrid processes (O₃ + H₂O₂, O₃ + Fenton) were applied. The results of the research obtained indicated that the use of hydrogen peroxide alone is not effective in the degradation of the analyzed dyes (max. efficiency was 9.38%). The use of the Fenton process (1 mg of Fe²⁺, 15 µL of H₂O₂, pH = 3) allows for the complete decolorization of all dyes tested, while the time for each dye is different (2 min for Indigo carmine, 15 min for Tartrazine, and 30 min for Allura red AC). Ozonation is effective in removing only Indigo carmine. Thirty minutes of ozonation (pH = 5.5) results in a 97% elimination of this dye, while for Tartrazine and Allura red AC, the results were 8.46% and 4.32%, respectively. The addition of H₂O₂ and Fe(II) ions during ozonation accelerates the degradation of Indigo carmine (from 30 min to 1 min) and increases the elimination degree to approx. 80% of Tartrazine and Allura red AC. It has been proven that AOPs, for example, the Fenton process and ozonation, are sustainable in removing industrial pollutants, e.g., dyes. Full article

This study presents an analysis of the effectiveness of the removal of three dyes, Indigo Carmine, Tartrazine, and Allura Red AC, using advanced oxidation methods. The research showed low efficiency in removing these dyes using acoustic waves. Neither the addition of hydrogen peroxide to assist the process nor increasing the intensity of the acoustic waves improved the degradation of the analyzed dyes. However, when ozone was applied, a 91% removal efficiency of Indigo Carmine was achieved after 30 min, while the other two dyes were resistant to degradation by ozone. The introduction of an additional amount of oxidant in the form of hydrogen peroxide and waste catalyst (steel shavings) resulted in an increased efficiency of removing all dyes and a shortening of the degradation process time. Ultraviolet radiation in the presence of a TiO₂ catalyst was also effective only for Indigo Carmine. After 30 min, the removal efficiency of this dye reached 95%. It was also demonstrated that the catalyst dose affected the rate constant of the reaction. Kinetic studies revealed that the degradation of Indigo Carmine in an aqueous solution through advanced oxidation processes followed the first-order reaction kinetics. Energy demand calculations confirmed that the most effective Indigo Carmine removal process is the one using ozone with the addition of a catalyst and an oxidizer at pH = 3. Full article

This study investigated the effects of combining sodium alginate (ALG) with various natural hydrocolloids on the microstructure and release behaviors of microbeads. The encapsulation solutions were prepared at a 1:1 (w/w) ratio with ALG as the control and carrageenan (CAR), locust bean gum (LBG), acacia gum (ACA), pectin (PEC), and carboxymethyl cellulose (CMC) as experimental groups. Each formulation contained 0.2% (w/v) tartrazine and was extruded into a CaCl₂ solution for bead production. Encapsulation efficiency varied across formulations, with the lowest in the control (ALG-ALG) and highest in ALG-CAR and ALG-CMC, reaching 74% and 78%, respectively. The microbead sizes ranged from 2.07 to 3.48 mm, with the lowest particle diameter observed in ALG-ACA composites. Surface analysis showed smooth and uniform microbeads in the control (ALG-ALG), while ALG-LBG microbeads were rougher. Release kinetics were assessed using various models, with the Higuchi model best describing the release for most formulations (highest R² values). Tartrazine release followed pseudo-Fickian behavior in all formulations, with slower release in ALG-ACA and faster release in ALG-LBG microbeads. This study fills a gap in understanding how the incorporation of different natural hydrocolloids influences both the encapsulation efficiency and release dynamics of alginate-based microbeads, providing valuable insights for applications in food and pharmaceutical industries. Full article

This study presents the development and application of a batch-type photoelectrochemical reactor employing advanced oxidation processes (AOPs) with in situ generated TiO₂ particles for the efficient degradation of azo dyes. The reactor uses titanium sheets as electrodes, facilitating the electrochemical generation of TiO₂, which acts as a photocatalyst under UV light. This study specifically targets azo dyes frequently encountered in industrial wastewater, focusing on Brilliant Blue, Erythrosine, and Tartrazine, which together form the Navy Blue dye composition. The experimental methodology replicates real-world conditions, ensuring the results are representative of practical scenarios. Key findings demonstrate that the in situ production of TiO₂ enables effective heterogeneous photocatalysis, achieving significant dye degradation rates. This research highlights the novelty of combining in situ TiO₂ generation with a batch-type reactor, offering advantages in cost-effectiveness, scalability, and environmental impact. Comparative analysis with existing methods underscores the reactor’s potential for industrial applications, particularly in wastewater treatment. Furthermore, this study outlines the mechanistic insights into dye degradation and provides a foundation for optimizing photocatalytic processes to address environmental challenges. Full article

The suitability of steel shavings (SS) as a low-cost waste catalyst in catalytic ozonation and the heterogeneous Fenton process was evaluated. Three dyes were selected for the research: Indigo Carmine, Tartrazine, and Allura Red AC. Single processes (oxidation by H₂O₂, O₃, and heterogeneous Fenton process) and hybrid processes (O₃ + Fenton) were applied. The Fenton process had the highest efficiency at pH = 3 and with the highest dose of catalyst (5 mg of SS) and hydrogen peroxide (30 µL). More than 98% discoloration of the solution was observed in 10 min. Analyzing ozone-based processes, they can be ranked with the highest efficiency as follows: (O₃ + H₂O₂ + SS) > (O₃ + H₂O₂) > O₃ > (O₃ + SS). The combination of the Fenton process (5 mg of SS + 15 µL of H₂O₂) with ozonation accelerated the reaction rate in the case of Indigo Carmine. In the hybrid process, only 5 min were enough for complete decolorization, while more than 98% in the Fenton process was reached after 30 min. Kinetic studies revealed that the degradation of dyes in an aqueous solution through advanced oxidation processes followed first- and second-order reaction kinetics. The calculation of the energy requirement confirmed that the most economic process for removing Indigo Carmine was the O₃+Fenton process (SS dose = 5 mg, H₂O₂ dose = 15 µL, pH = 3). Full article

Technical and economic criteria were used to evaluate the feasibility of the treatment of an industrial effluent (10 m³/h) for water recovery and reuse. The treatment evaluation included the following: (1) effluent characteristic determination; (2) selection and evaluation of the effluent treatment at lab scale, establishing operating conditions and process efficiency; (3) scaling up the treatment process to the industrial level; (4) treatment plant design and commercial availability analysis of the required equipment; and (5) the costs of the inversion and operation of the plant treatment, cost/m³ for water recovery, and time of investment recovery. The physicochemical characteristics of the effluent exposed the polluted wastewater with sodium chloride salts and colourants, predominating a mixture of tartrazine, Red 40, and brilliant blue from the synthesis of food additives. Other contributions of organic compounds and salts could be in minor content. According to the effluent conditions, a coupled process, integrated with ozonation and reverse osmosis, was indicated to be a treatment for water recovery. Scaling up the plant treatment design resulted in 130 m² of area, producing 7.7 m³/h of clean water. The cost of the effluent treatment was 1.4 USD/m³, with an inversion return of 3.4 years and cost investment of USD 860,407. The treatment process resulted a viable project for water recovery. Full article

Globalization has increased production in various industries, including textiles, food, and pharmaceuticals. These industries employ different dyes in production, leading to undesired discharge, which conventional treatment fails to remove from the water. The present study aims to synthesize, characterize, and use different pure catalysts (TiO₂ and Zn₂SnO₄) and their compounds doped with CoFe₂O₄ together with ozone (O₃) for the degradation of the azo dye yellow tartrazine (TZ), evaluating the process. For this characterization, N₂ porosimeter, zeta potential, X-ray diffraction, SEM-EDS, and diffuse reflectance spectra were used. Specific surface areas (m² g⁻¹) of 109, 106, 65, and 83 were used for TiO₂, CoFe₂O₄/TiO₂, Zn₂SnO₄, and CoFe₂O₄/Zn₂SnO₄, respectively. Both compounds are characterized as nanocatalysts as they have a band gap of 2.75 and 2.83 eV and average particle size of 98 and 85 nm for CoFe₂O₄/TiO₂ and Zn₂SnO₄, respectively. We employed a reactional model, which was able to describe the catalytic ozonation for all cases, with a low R² of 0.9731. The combination of processes increased TZ degradation from 57% to 74% compared to O₃ alone, achieving a maximum degradation of 98.5% within 50 min of catalysis at a low ozone flow rate. This highlights the potential of the produced catalysts for energy-efficient effluent treatment. Full article

The MAP process involved placing acid-pretreated biomass (CPH) in a domestic microwave oven at 600 W for 15 min. This was followed by a doping process with iron salts (+2, +3) to obtain BCCPH-Fe. Characterization of BCCPH-Fe was carried out using surface analysis (BET), TGA analysis and FTIR. Subsequently, the photodegradation process was performed using three different light sources (solar, UV 254 nm and UV 356 nm), with tartrazine as the adsorbate. The effect of pH on photodegradation was studied, and the percentage of degradation was evaluated through equilibrium and kinetic studies. The amount of BCCPH-Fe, tartrazine concentration, and exposure time to the light source were also evaluated. The best conditions for the photodegradation process were: light source was 254 nm, pH of 5, 1 g of BCCPH-Fe over 100 mL of tartrazine, 25 ppm tartrazine concentration, and 40 h exposure time. Under these conditions, a 93.45% removal of tartrazine was achieved. The experimental data of the adsorption equilibrium best fit the Langmuir-Hinshelwood model, while the adsorption kinetics best fit the pseudo-first-order model. The apparent kinetic constant was 0.04053 [h⁻¹], and the correlation coefficient was 0.98667. In conclusion, photodegradation using BCCPH-Fe can be an effective method for the removal of tartrazine from wastewater, offering a sustainable alternative to traditional methods. Full article