Regulatory alerts regarding unauthorized use of colorants in food are frequently issued, often involving excessive concentration, improper declaration, or prohibited dyes. The illegal use of reactive textile dyes in food-related coloring preparations remains largely unrecognized, but confirmed cases have been reported in 2016 and 2020 and most recently in May 2025. This work presents the qualitative analyses’ results of a blue coloring powder for food use with regard to reactive dyes. The sample was labeled as a natural product, although it exhibited the color stability typical of artificial dyes. Prompting further investigation, combined spectroscopic, chromatographic and mass spectrometric methods were applied for the characterization and comparison with reference samples. In agreement with all analyses performed, strong evidence was found that the blue coloring powder contained several identical constituents with a reference sample of Reactive Blue 21. The overall composition suggests that both are complex mixtures of different phthalocyanines, suspected byproducts of synthesis, and various unknown compounds, rendering the powder unsuitable for human consumption. These findings emphasize the importance of tightened analytical controls regarding the unauthorized addition of textile dyes to food in order to maintain consumer safety.

The detection of reactive dyes in food matrices is crucial for food safety and compliance with regulations, especially since the use of such in food products is not approved. This study investigates the potential of using tin(II)chloride and laccase to cleave anthraquinone reactive dyes and to detect their characteristic degradation products as markers for the presence of dye in food. Nine reactive blue anthraquinone dyes and one green anthraquinone dye were cleaved using tin(II)chloride and laccase. Reactions with reactive dyes bound to maize starch were also carried out to evaluate the suitability of these methods for detecting matrix-bound dyes. Model food matrices, including gummy candy, hard candy, and maize chips, were spiked with the reactive dyes, and the presence of degradation products was analysed using LC-ESI-MS/MS. Two common cleavage products were formed from each sample, namely 1,4-diaminoanthrahydroquinone-2-sulphonic acid (DAHS) and 1-aminoanthraquinone-2-sulphonic acid (AAS). In all examined cases, at least one of the characteristic cleavage products could be detected. Laccase showed lower effectiveness with matrix-bound dyes, whereas treatment with acidic tin(II)chloride was effective even in complex food matrices. These findings suggest that the analysis of cleavage products could be a valuable tool for the detection of reactive dyes in food matrices.

Visually appealing foods are often associated by consumers with subjective quality features, such as freshness, palatability, and shelf life. In the past, there have been repeated violations in which regulations on the use of pigments in food were ignored and/or unauthorized or toxic dyes (e.g., Sudan red in paprika powder) were added. Most recently, adulterations by using reactive dyes from the textile sector have been reported. These included, among others, colored spice preparations for use in meat products (e.g., for sausages and meat products), which were advertised to contain natural plant-derived pigments mainly consisting of betalains and/or anthocyanins. In contrast to natural dyes, reactive dyes are very stable toward extreme pH values, heat, and light. Due to their chemical properties, reactive dyes cannot be detected by classical dye analysis as they may be covalently bound to the food matrix. Methods for the analysis of matrix-bound reactive dyes are therefore required. In this study, a reductive cleavage method of bound textile dyes in different food matrices (spice mixtures, fruit juices, and scalded sausages) and the detection of characteristic cleavage products after enrichment by solid phase extraction (SPE) and liquid chromatography-electrospray ionization-tandem mass spectrometric (LC-ESI-MS/MS) analysis is reported. In addition, 13 suspicious samples provided by project partners were analyzed using the newly developed LC-ESI-MS method.

Electrospray mass spectrometry off-line profiling monitored the recovery of targeted indole alkaloids from a fortified crude extract of Catharanthus roseus (790 mg) using semi-preparative high-performance countercurrent chromatography (HPCCC) fractionation. Visualization of selected single-ion traces projected the HPCCC molecular weight elution profile. Experimental partition-ratio values KD and peak widths for detected metabolites were determined. Structural characterization of metabolites and co-elution effects were monitored in the scan range m/z 100–2000. In this study, the biphasic solvent system containing n-hexane–n-butanol–water with 0.5% ion-pair reagent trifluoro-acetic acid [1:1:2, v/v/v] was used based on partition ratio KD-value liquid chromatography–electrospray ionization–mass spectrometry (LC-ESI-MS) analysis prediction. The monitoring of target ions resulted in the isolation of six major concentrated indole alkaloids (akuammicine, catharanthine, perivine, vindoline, vindorosine, and 19R-vindolinine), which were fully elucidated by 1D and 2D nuclear magnetic resonance (NMR) spectroscopy.

Bixa orellana (Bixaceae) seeds are widely used as food colouring and spice, but also as traditional medicine for treatment of several diseases. Terpenoids from Bixa orellana seeds were extracted by n-hexane and separated by semi-preparative high-performance countercurrent chromatography (HPCCC) and then scaled-up to a high speed countercurrent chromatography apparatus (HSCCC) operated in head-to-tail mode. Evaluation of five biphasic solvent systems led to the suitable system consisting of n-hexane, ethyl acetate, methanol and water (8:2:8:2, v/v/v/v). The CCC-experiments were monitored by off-line atmospheric pressure chemical ionisation mass-spectrometry (APCI-MS/MS) in positive ionisation mode to project single ion traces of target compounds. Off-line mass profiles were converted to column-graphs which showed co-elution effects and areas of pure recoverable substances. Four major compounds bixin (1), alismol (2), geranyl-geraniol (3), δ-tocotrienol (4) were targeted and HPCCC and HSCCC experiment performance was compared by their specific partition ratio values KD, the separation factor α, as well as the resolution factor RS.

A‑type procyanidins (PCs) are known for their numerous health benefits. They are produced by oxidative conversion of B‑type PCs such as B1 and B2, induced by oxidative processes during food processing, or by direct transformation via enzymes or radical agents such as 2,2‑diphenyl‑1‑picryl-hydrazyl (DPPH) radicals. In this study, we demonstrated the DPPH radical oxidation of a mixture of dimeric PCs B2 (EC‑(4β→8)‑EC) and B4 (C‑(4α→8)‑EC), obtained by the semi-synthetic acid‑catalysed depolymerisation of Salix alba polymer after (-)‑epicatechin addition. Under reaction conditions of 50.0 °C for 185 min and a molar ratio of 9/31.25 (n/n) of B‑type to DPPH radical, various reaction products like A‑type PCs, spirocyclisation products (m/z 575 [M-H]-), (bis)methylated B‑types and oxidised PCs (m/z 591, 581 and 605 [M-H]-), as well as further oxidised products (m/z 573 [M-H]-) were detected. The aim of this study was to investigate reaction by‑products using high‑speed countercurrent chromatography (HSCCC) followed by sequential off‑line flow‑injection ESI‑MS/MS profiling based on selected single ion traces, and two‑dimensional (2D) HSCCC x LC‑ESI‑MS plots for preparative visualisation of metabolites as a powerful tool for elution profile analysis and monitoring of the co‑elution effects of isomeric and isobaric compounds. HSCCC x LC‑PDA monitoring at λ= 280 nm revealed the presence of oligomeric and polymeric compounds formed by an intermolecular nucleophilic addition. The HSCCC separation in combination with an off‑line ESI‑MS/MS profiling and a 2D‑plot of HSCCC fractions versus LC‑ESI‑MS/LC‑PDA was successfully applied for the semi‑synthetic reaction approach of radical‑induced oxidation of dimeric B‑type PCs.

Endemic in 21 countries, Chagas disease, also known as American Trypanosomiasis, is a neglected tropical disease (NTD) caused by the protozoan parasite Trypanosoma cruzi. The available drugs for the treatment of this disease, benznidazole and nifurtimox, are outdated and display severe side effects. Thus, the discovery of new drugs is crucial. Based on our continuous studies aiming towards the discovery of natural products with anti-T. cruzi potential, the MeOH extract from aerial parts of Baccharis sphenophylla Dusén ex. Malme (Asteraceae) displayed activity against this parasite and was subjected to high-performance countercurrent chromatography (HPCCC), to obtain one unreported syn-labdane diterpene — sphenophyllol (1) — as well as the known compounds gaudichaudol C (2), ent-kaurenoic acid (3), hispidulin (4), eupafolin (5), and one mixture of di-O-caffeoylquinic acids (6–8). Compounds 1–8 were characterized by analysis of nuclear magnetic resonance (NMR) and mass spectrometry (MS) data. When tested against trypomastigote forms, isolated labdane diterpenes 1 and 2 displayed potent activity, with EC50 values of 20.1 μM and 2.9 μM, respectively. The mixture of chlorogenic acids 6–8, as well as the isolated flavones 4 and 5, showed significant activity against the clinically relevant amastigotes, with EC50 values of 24.9, 12.8, and 2.7 μM, respectively. Nonetheless, tested compounds 1–8 displayed no cytotoxicity against mammalian cells (CC50 > 200 μM). These results demonstrate the application of HPCCC as an important tool to isolate bioactive compounds from natural sources, including the antitrypanosomal extract from B. sphenophylla, allowing for the development of novel strategic molecular prototypes against tropical neglected diseases.

BACKGROUND: Growing concern over the potential adverse health effects of synthetic colorants has led to a rising utilization of plant-derived pigments within the food industry. Purple betacyanins from red dragon fruits (Hylocereus polyrhizus) have been subjected to an environmentally sustainable purification process for natural colorants.RESULTS: The violet-hued pigments were absorbed onto preconditioned chitin material, a biodegraded polymer derived from shrimp shells. Liquid chromatographic-electrospray ionization-tandem mass spectrometric analysis was employed to analyze the betalain pigment composition in the raw fruit extract, making comparisons between the adsorbed supernatant and desorbed solutions. Fourier transform infrared analysis, optical microscopy, and scanning electron microscopy were conducted on the resin pre- and post-adsorption stages, revealing distinctive infrared bands (R-NH-R, C-O, CO, -OH) indicative of betacyanin functional groups in the pigmented materials. The uniform adsorption of the colorant onto the adsorbents causes the intense purple color of the resin, with a maximum removal efficiency of 0.29 mg g(-1). Adsorption data were subjected to various kinetic models, with the pseudo-second-order model demonstrating the optimal fit to the kinetic data (R-2 = 0.97), while the Freundlich model proved most suitable for describing the sorption isotherm (R-2 = 0.98). The adsorption energy, as determined by the Dubinin-Radushkevich equation, was 0.23 kJ mol(-1), implying a physical adsorption mechanism on a heterogeneous surface.CONCLUSION: Betacyanins derived from red dragon fruits could be recovered for food colorants through chitin adsorption. This recovery mechanism is attributed to electrostatic interactions among the functional groups, including hydroxyl and carboxyl groups, and hydrogen bonds. (c) 2024 Society of Chemical Industry (SCI).

Grapevine roots, as a side-stream of a vineyard, are a sustainable resource for the recovery of oligomeric stilbenoids, such as the bioactive r-viniferin. The aim of this study is to evaluate an in silico-supported method, based on the Conductor-like Screening Model for Real Solvents (COSMO-RS), for selection of environmentally friendly natural deep eutectic solvents (NADES) with regard to the extraction of grapevine roots. The most suitable NADES system for ultrasonic-assisted extraction of r-viniferin was choline chloride/1,2-propanediol. The optimal extraction parameters for r-viniferin were determined using single-factor experiments as follows: choline chloride/1,2-propanediol 1/2 mol/mol, 10 wt% H2O, biomass/NADES ratio 1/10 g/g, and 10 min extraction time. Under optimized conditions, the extraction yield of r-viniferin from grapevine roots reached 76% of the total r-viniferin content. Regarding stability, stilbenoids in choline chloride/1,2-propanediol remained stable during 128 days of storage at ambient temperature. However, fructose/lactic acid-based NADES were observed to degrade stilbenoids; therefore, the removal of the NADES will be of interest, with a suitable method implemented using Amberlite® XAD-16N resin. As green solvents, the NADES have been used as effective and environmentally friendly extractants of stilbenoid-containing extracts from grapevine roots for potential applications in the cosmetic and pharmaceutical industry or as nutraceuticals in the food industry.

Peanut hulls (Arachis hypogaea, Leguminosae), which are a side stream of global peanut processing, are rich in bioactive flavonoids such as luteolin, eriodictyol, and 5,7-dihydroxychromone. This study aimed to isolate these flavonoid derivatives by liquid-liquid chromatography with as few steps as possible. To this end, luteolin, eriodictyol and 5,7-dihydroxychromone were isolated from peanut hulls using two different techniques, high-performance countercurrent chromatography (HPCCC) and fast-centrifugal partition chromatography (FCPC). The suitability of the biphasic solvent system composed of n-hexane/ethyl acetate/methanol/water (1.0/1.0/1.0/1.5; v/v/v/v) was determined by the Conductor like Screening Model for Real Solvents (COSMO-RS), which allowed the partition ratio KD-values of the three main flavonoids to be calculated. After a one-step HPCCC separation of ~1000 mg of an ethanolic peanut hull extract, 15 mg of luteolin and 8 mg of eriodictyol were isolated with purities over 96%. Furthermore, 3 mg of 5,7-dihydroxychromone could be isolated after purification by semi-preparative reversed-phase liquid chromatography (semi-prep. HPLC) in purity of over 99%. The compounds were identified by electrospray ionization mass spectrometry (ESI-MS) and nuclear magnetic resonance spectroscopy (NMR).

LebensmittelchemieVolume 77, Issue S3 p. S3-102-S3-102 Analytik Identifizierung von Marker-Verbindungen für den Nachweis einer unerlaubten Verwendung von Reactive Blue 19 in Lebensmitteln L. C. Küchner, L. C. Küchner Braunschweig/DSearch for more papers by this authorL. Diers, L. Diers Braunschweig/DSearch for more papers by this authorB. Nguyen Thanh, B. Nguyen Thanh Braunschweig/DSearch for more papers by this authorG. Jerz, G. Jerz Braunschweig/DSearch for more papers by this authorProf. Dr. P. Winterhalter, Prof. Dr. P. Winterhalter Braunschweig/D TU Braunschweig, Schleinitzstr. 20, Braunschweig/DSearch for more papers by this author L. C. Küchner, L. C. Küchner Braunschweig/DSearch for more papers by this authorL. Diers, L. Diers Braunschweig/DSearch for more papers by this authorB. Nguyen Thanh, B. Nguyen Thanh Braunschweig/DSearch for more papers by this authorG. Jerz, G. Jerz Braunschweig/DSearch for more papers by this authorProf. Dr. P. Winterhalter, Prof. Dr. P. Winterhalter Braunschweig/D TU Braunschweig, Schleinitzstr. 20, Braunschweig/DSearch for more papers by this author First published: 01 August 2023 https://doi.org/10.1002/lemi.202359083AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat No abstract is available for this article. References [1]H. Zollinger, Color Chemistry. Syntheses, Properties, and Applications of Organic Dyes and Pigments 2003. [2]J. Müller-Maatsch, R. M. Schweiggert und R. Carle. Food Control, 2016, 70, 333–338. [3]Voyksner, R. D., Straub, R., Keever, J. T., Freeman, H. S., Hsu, W. N. Environ. Sci. Technol. 1993, 27 (8), 1665–1672. [4]Januschewski, E., Nguyen Thanh, B., Bischof, G., Bergmann, P., Jerz, G., Winterhalter, P., Heinz, V. Juadjur, A. Deutsche Lebensmittelrundschau, 2021, 117 (3). Volume77, IssueS3Supplement: Abstracts der Vorträge, Posterflashtalks und Poster von den 51. Deutschen Lebensmittelchemietagen 2023August 2023Pages S3-102-S3-102 ReferencesRelatedInformation