Method development and survey of Sudan I-IV in palm oil and chilli spices in the Washington, DC, area

Hues of risk: investigating genotoxicity and environmental impacts of azo textile dyes

The textile industry, with its extensive use of dyes and chemicals, stands out as a significant source of water pollution. Exposure to certain textile dyes, such as azo dyes and their breakdown products like aromatic amines, has been associated with health concerns like skin sensitization, allergic reactions, and even cancer in humans. Annually, the worldwide production of synthetic dyes approximates 7 × 107 tons, of which the textile industry accounts for over 10,000 tons. Inefficient dyeing procedures result in the discharge of 15-50% of azo dyes, which do not adequately bind to fibers, into wastewater. This review delves into the genotoxic impact of azo dyes, prevalent in the textile industry, on aquatic ecosystems and human health. Examining different families of textile dye which contain azo group in their structure such as Sudan I and Sudan III Sudan IV, Basic Red 51, Basic Violet 14, Disperse Yellow 7, Congo Red, Acid Red 26, and Acid Blue 113 reveals their carcinogenic potential, which may affect both industrial workers and aquatic life. Genotoxic and carcinogenic characteristics, chromosomal abnormalities, induced physiological and neurobehavioral changes, and disruptions to spermatogenesis are evident, underscoring the harmful effects of these dyes. The review calls for comprehensive investigations into the toxic profile of azo dyes, providing essential insights to safeguard the aquatic ecosystem and human well-being. The importance of effective effluent treatment systems is underscored to mitigate adverse impacts on agricultural lands, water resources, and the environment, particularly in regions heavily reliant on wastewater irrigation for food production.

Multifunctional Carbon Dots-Based Fluorescence Detection for Sudan I, Sudan IV and Tetracycline Hydrochloride in Foods

Sudan dyes are strictly prohibited from being added to edible products as carcinogens and tetracycline hydrochloride (TC) remaining in animal-derived food may cause harm to the human body. Therefore, it is necessary to establish a high-sensitivity, simple and convenient method for the detection of Sudan dyes and TC in foods for safety purposes. In this work, multifunctional blue fluorescent carbon dots (B-CDs) were prepared by a one-step hydrothermal synthesis using glucose as the carbon source. The results show that the fluorescence intensity of B-CDs was significantly affected by the acidity of the solution and can be quenched by Sudan I, IV and TC through selective studies. Interestingly, the fluorescence quenching intensities of B-CDs have a good linear relationship with the concentration of Sudan I and IV at pH = 3-7. The wide range of pH is beneficial to broaden the application of B-CDs in a practical samples analysis. The method has been successfully applied to real food samples of tomato paste, palm oil and honey, and the detection limits are 26.3 nM, 54.2 nM and 31.1 nM for Sudan I, Sudan IV and TC, respectively. This method integrates Sudan dyes and TC into the same multifunctional B-CDs, which shows that the sensor has a great potential in food safety detection.

Plant Metabolomics as a Tool for Detecting Adulterants in Edible Plant: A Case Study of Allium ursinum

Allium ursinum and poisonous adulterants Convallaria majalis and Arum maculatum were used as a model for detection of adulterants in edible plant. A. ursinum samples were spiked with C. majalis and A. maculatum to mimic adulteration. Metabolomic fingerprinting of all samples was performed using ¹H NMR spectroscopy, and the resulting data sets were subjected to multivariate data analysis. As a result of this analysis, signals of adulterants were extracted from the data, and the structures of biomarkers of adulteration from partially purified samples were elucidated using 2D NMR and LC-MS techniques. Thus, isovitexin and vicenin II, azetidine-2-carboxylic acid, and trigonelline indicated adulteration of A. ursinum samples with C. majalis. Isovitexin was also recognized to be an indicator of adulteration of A. ursinum with A. maculatum. In conclusion, the case study of A. ursinum suggested that plant metabolomics approach could be utilized for identification of low molecular weight biomarkers of adulteration in edible plants.

A simple method to quantify azo dyes in spices based on flow injection chromatography combined with chemometric tools

Para Red (PR) and Sudan dyes have been illegally used as colorants to adulterate certain foods by enhancing their red/orange colour. In addition, they are toxic and carcinogenic. This work presents the development of a simple flow injection chromatographic method combined with chemometric tools to perform the determination of PR, Sudan I (SI) and Sudan II (SII) in food samples. The flow chromatographic system consisted of a low-pressure manifold coupled to a reverse phase monolithic column. A Partial Least Square (PLS) model was applied to resolve overlapped absorption spectra registered for each dye at the corresponding retention time. The relative errors of calibration (RMSECV, %) were 0.49, 0.85 and 0.23, and the relative errors of prediction (RMSEP, %) were 1.12, 0.75 and 0.33 for PR, SI and SII, respectively. The residual predictive deviation (RPD) values obtained were higher than 3.00 for all analytes. The method was successfully applied to quantify the dyes in six different commercial spices samples. The results were compared with the HPLC reference method concluding that there were no significant differences at the studied confidence level (α = 0.05). The proposed method can be used to rapidly determine the analytes in a simple, reliable, low-cost and environmentally-friendly manner.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13197-021-05299-8.

Authentication of Herbal Medicines Based on Modern Analytical Technology Combined with Chemometrics Approach: A Review

Since ancient times, herbal medicines (HMs) have been widely popular with consumers as a "natural" drug for health care and disease treatment. With the emergence of problems, such as increasing demand for HMs and shortage of resources, it often occurs the phenomenon of shoddy exceed and mixing the false with the genuine in the market. There is an urgent need to evaluate the quality of HMs to ensure their important role in health care and disease treatment, and to reduce the possibility of threat to human health. Modern analytical technology is can be analyzed for analyzing chemical components of HMs or their preparations. Reflecting complex chemical components' characteristic curves in the analysis sample, and the comprehensive effect of active ingredients of HMs. In this review, modern analytical technology (chromatography, spectroscopy, mass spectrometry), chemometrics methods (unsupervised, supervised) and their advantages, disadvantages, and applicability were introduced and summarized. In addition, the authentication application of modern analytical technology combined with chemometrics methods in four aspects, including origin, processing methods, cultivation methods, and adulteration of HMs have also been discussed and illustrated by a few typical studies. This article offers a general workflow of analytical methods that have been applied for HMs authentication and explains that the accuracy of authentication in favor of the quality assurance of HMs. It was provided reference value for the development and application of modern HMs.

Sub-acute exposure to Sudan IV-adulterated palm oil induces oxidative stress and represses the expression of Nrf2 and antioxidant genes in male albino rats

This study investigated the effects of Sudan IV dye (S4D) on antioxidant biomarkers using palm oil adulterated with S4D. Thirty male albino rats were grouped into five (n = 6); Normal control, palm oil (PO), PO + S4D (100 mg/kg), PO + S4D (250 mg/kg), and S4D (250 mg/kg) for 21 days. Oxidative stress biomarkers were assessed in the serum, liver, and kidneys. Exposure to S4D (alone and in adulterated PO) occasioned significant depletions in the activities of SOD, CAT, and GPx, as well as GSH levels in the assessed compartments. Contrastingly, the levels of NO and MDA were significantly (p < 0.05) increased in the serum, liver, and kidney of rats exposed to PO + S4D (both doses) and S4D (250 mg/kg) when compared to control rats. Further, the expressions of the genes coding for CAT, GPx-1, GSR, and Nrf-2 were significantly (p < 0.05) down-regulated, relative to β-actin, in groups exposed to S4D compared to the control. Interestingly, these parameters were not significantly different (p > 0.05) in the unadulterated PO-exposed rats compared to the control. These results show that S4D depleted the antioxidant capacities, while potentiating the generation of reactive species and oxidative damage. This study provides useful information on the oxidative mechanisms associated with consumption of S4D-containing consumer products.

Fast, easy, cheap, robust and safe method of analysis of Sudan dyes in chilli pepper powder

Illicit use of Sudan dyes, a group of harmful and carcinogenic azo dyes, in the food industry has taken a surge in various parts of the world, especially in Africa. Their use in food as additives pose a dire health risk to consumers and have been banned by various food regulatory bodies worldwide. To help increase surveillance, various methods have been proposed for their analysis in literature. This study also sought to experiment and propose an alternative method for quick, easy, cheap, robust and ecologically safe analysis of Sudan dyes in chilli pepper powder and similar matrices. The optimized method used a 6.0 mL mixture of acetone:acetonitrile (1:5 v/v) solvent in a modified QuEChERs method for extraction of Sudan dyes I-IV. The simultaneous analysis of the dyes were achieved on Shimadzu prominence UFLC 20AD coupled with SPD 20AX UV detector operated at dual wavelength of 500 and 480 nm. A total of twenty four (24) chilli pepper powder samples from eight different vendors on the Ghana market were analysed using the optimized method. Quantitation of analytes were done using the external standard calibration method with determination coefficient, R² > 0.9999. The limit of detection (LOD) and limit of quantitation (LOQ) of the method were 0.02–0.04 mg/kg and 0.05–0.13 mg/kg respectively. A good recovery range between 85.3 – 121.2% were obtained for a spike level of 1.0 mg/kg in real samples. ANOVA analysis at 95% CL showed statistically no significant difference (p > 0.05) in the recoveries between samples and also between the individual compounds. The method experimented and proposed in this study is fast, easy, cheap, robust and ecologically safe, presenting an alternative method for routine analysis for increased rate of surveillance against the illicit use of Sudan dyes as food additives.

Fatty Acid Ethyl Esters in Virgin Olive Oils: In-House Validation of a Revised Method

The content of fatty acid ethyl esters (FAEEs) is one of the quality parameters to define if an olive oil can be classified as extra virgin as these compounds are considered markers for virgin olive oils obtained from poor-quality olives. In addition, FAEEs can also be indirect markers to detect soft deodorization treatment. In this study, an off-line HPLC-GC-FID method for determination of FAEEs is presented, revising the preparative step and the GC injector required by the official method (EU Reg. 61/2011). After optimization, the method was validated in-house by analyzing several parameters (linearity, limit of detection LOD, limit of quantification LOQ, robustness, recovery, precision, and accuracy) to determine its effectiveness. Linearity was measured in the 2.5-50 mg/L range; furthermore, intra-day and inter-day precision values were lower than 15%, while the LOD and LOQ were lower than 1 and 1.5 mg/kg, respectively, for all compounds considered. The main advantages of this revised protocol are: (i) significant reduction in time and solvents needed for each analytical determination; (ii) application of HPLC as an alternative to traditional LC, carried with manually packed glass columns, thus simplifying the separation step.

SWATH-MS screening strategy for the determination of food dyes in spices by UHPLC-HRMS

A multi-class wide-scope screening method for the detection and identification of artificial colours and illegal dyes in spices was developed for regulatory purposes. The screening was carried out by ultra-high performance liquid chromatography hyphenated with a quadrupole/time-of-flight mass spectrometry (UHPLC-QTOF-MS) with sequential window acquisition of all theoretical fragment-ion spectra (SWATH) and was validated with forty-one compounds by spiking experiments in curry and paprika extracts. In order to detect and identify the compounds with a high level of confidence, a home-made tandem mass spectrometry (QTOF-MS/MS) database of approximately one hundred illegal dyes and artificial colours was created. The procedure was then used to screen field samples of spices and spice blends purchased from Swiss markets. Sudan IV, Sudan I, bixin (E160b) and Ponceau 4R (E124) were all detected among the eight non-compliant samples.