Rapid Screening Technique To Identify Sudan Dyes (I to IV) in Adulterated Tomato Sauce, Chilli Powder, and Palm Oil by Innovative High-Resolution Mass Spectrometry

Evaluating aflatoxins and Sudan dyes contamination in red chili and turmeric and its health impacts on consumer safety of Lahore, Pakistan

Spices are contaminated with aflatoxins (AFs) and Sudan dyes which are classified as class Group 1 and Group 3 human carcinogens by the International Agency for Research on Cancer (IARC) respectively and their prolonged exposure may raise a human health concern. A total of 474 samples of red chili and turmeric were collected from Lahore city and were subjected to quantitative and qualitative AFs and Sudan dyes analysis by thin layer chromatography (TLC) respectively. The number of red chili and turmeric samples with ≥10 μg/kg of total AFs (European Union standard limit) were 70% and 33% respectively and considered unfit for human consumption. The presence of Sudan dyes in red chili and turmeric samples was 67% and 27% respectively. The mean estimated daily intake (EDI) among females and males was 0.0019 μg/kg bw/day, 0.0012 μg/kg bw/day for red chili, and 0.0008 μg/kg bw/day, 0.0006 μg/kg bw/day for turmeric respectively. The mean value of margin of exposure (MOE) among females and males for ingestion of AFs-contaminated red chili and turmeric was 210.25, 332.13, 501.02, and 699.31 respectively. Therefore, the current study demands a continuous monitoring plan and the implementation of novel techniques to enhance the product's quality and protect public health.

Banned Sudan dyes in spices available at markets in Karachi, Pakistan

Sudan dyes were investigated in branded and non-branded spices, commonly available in the markets of Karachi, Pakistan. High performance liquid chromatography (HPLC) with a variable wavelength detector (VWD) was applied to determine Sudan dyes I-IV. The non-branded samples had higher concentrations of Sudan dyes than the maximum limits of 0.1 mg/kg. The highest concentration of Sudan dye (I) was found in turmeric powder (8460 mg/kg) and the lowest concentration (1.50 mg/kg) of Sudan (IV) in Chaat Masala. This indicates that the use of non-branded spices is not safe, whereas no Sudan dye was found in the branded spice samples. Further studies regarding the higher carcinogenic risk posed by Sudan dye adulterated spices in Pakistan is strongly advised.

Fraud detection in crude palm oil using SERS combined with chemometrics

Edible crude palm oil (CPO) is a vital oil utilized in various industries, including food, pharmaceuticals, and domestic cooking. Unfortunately, reports of CPO adulteration with harmful Sudan dyes have surfaced over the years. Surface-enhanced Raman spectroscopy (SERS) and chemometrics were employed to detect Sudan dyes adulteration in CPO within 900 - 1800 cm^{- 1} Raman peak. The concentration of Sudan dyes detected in CPO samples ranged between 0.005 and 4 ppm. The principal component analysis (PCA) model detected Sudan II and Sudan IV in CPO with 99.88 and 99.90% accuracy. Linear discriminant analysis (LDA) and K-Nearest Neighbors (KNN) also recorded high detection rates of Sudan II and IV dyes in CPO. Sudan II and IV dyes could be detected at 0.0028 ppm and 0.0019 ppm by this sensor. The performance of the Au@Ag SERS sensor was comparable to that of HPLC. This study proved SERS and chemometrics can be used to authenticate edible CPO.

Quirks of dye nomenclature. 16. Dyes, and a pigment, named after places

Many dyes produced during the 19^th century were named after locations. Manufacturers proliferated the number of synonyms used and in time, the original names were forgotten. Therefore, in the headings below, the original names are followed by the current name(s) in parentheses. The stories of some of these dyes that survived into the 21^st century are recounted here. Numerical identity data are provided. Chemical structures also are provided and for simplicity, ionic structures, which can be multiple and pH variable, are presented as their parents.

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.

Optical screening for presence of banned Sudan III and Sudan IV dyes in edible palm oils

Due to the proven carcinogenicity of Sudan III and IV dyes, they are considered global public health issues. They are banned in all forms as food colourants. We propose the monitoring of simple and easy-to-measure optical properties of palm oils, such as the refractive indices and spectrophotometric properties, as efficient indicators to detect adulteration. Coupling these results with principal component analysis, excess refractive index, and integration of transmittance introduces a novel detection tool for the authentication of edible palm oil. This opens a new opportunity for accurate handheld devices to detect adulteration and provide control in the field. This work assessed in total of 49 samples, some collected from different parts of Ghana and others, in-house adulterated samples. The Ghana Food and Drugs Authority, who performed a complex and expensive chemical analysis of the samples, confirmed our results with good agreement.

Development of a Novel Method for Rapid Discrimination between Wild and Farmed Sea Bream

A simple method based on direct sampling analysis, coupled with a time of flight mass spectrometer, was developed to discriminate between wild and farmed sea bream on the basis of the docosahexaenoic and arachidonic fatty acid ratio. Good precision in repeatability and reproducibility (relative standard deviation < 15%) was obtained. The fatty acid ratios of the two types of fish were statistically significant (Student's t < 0.001). The use of a simple, rapid, and cost-effective tool could aid in the detection of commercial fish fraud, increase the number of controlled samples, and strengthen control along the entire commercial chain.

Rapid and nondestructive fraud detection of palm oil adulteration with Sudan dyes using portable NIR spectroscopic techniques

Non-destructive, simple and fast techniques for identifying authentic palm oil and those adulterated with Sudan dyes using portable NIR spectroscopy would be very beneficial to West Africa countries and the world at large. In this study, a portable NIR spectroscopy coupled with multivariate models were developed for detecting palm oil adulteration. A total of 520 samples of palm oil were used comprising; 40 authentic samples together with 480 adulterated samples containing Sudan dyes (I, II, III, IV of 120 samples each). Multiplicative scatter correction (MSC) preprocessing technique plus Principal component analysis (PCA) was used to extract relevant spectral information which gave visible cluster trends for authentic samples and adulterated ones. The performance of Linear discriminant analysis (LDA) and Support vector machine (SVM) were compared, and SVM showed superiority over LDA. The optimised results by cross-validation revealed that MSC-PCA + SVM gave an identification rate above 95% for both calibration and prediction sets. The overall results show that portable NIR spectroscopy together with MSC-PCA + SVM model could be used successfully to identify authentic palm oils from adulterated ones. This would be useful for quality control officers and consumers to manage and control Sudan dyes adulteration in red palm oil.

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.

A simple assay platform for sensitive detection of Sudan I-IV in chilli powder based on CsPbBr3 quantum dots

Sudan dyes are phenyl-azoic derivatives widely used in industry. Classified as carcinogenic and are strictly forbidden in foodstuffs; however, some unscrupulous businessmen adopted it for coloring foodstuffs. Here, a simple and effective fluorescence (FL) assay platform has been developed for the detection of Sudan I-IV based on CsPbBr₃ perovskite quantum dots (QDs). It was found that the fluorescent emission of CsPbBr₃ QDs can be effectively quenched by Sudan I-IV. Under the optimized conditions, the FL quenching efficiency of CsPbBr₃ QDs was quantitatively correlated to the logarithmic concentrations of Sudan I-IV over the ranges of 100-10,000, 0.1-1000, 0.1-2000 and 0.4-1000 ng mL^-1 for Sudan I-IV, and the corresponding limits of detection were 3.33, 0.03, 0.03 and 0.04 ng mL^-1 (at 3σ/slope), respectively. CsPbX₃ QDs (X = Cl, Br, and I or mixed halide systems Cl/Br and Br/I) was utilized as sensor in FL assay, which have unique optical properties of high FL quantum yields (up to 90%), narrow half peak width (26 nm) and tunable FL emissions spectra (410-700 nm). Meanwhile, the practical use of this assay platform for Sudan I-IV detection in chilli powder samples was also demonstrated, which indicated the potential in practical applications.