Identification of Natural and Artificial Colorants in Industrial Products Marketed in Senegal

Food colorants are widely used in the food industry to maintain or enhance product color. However, as the use of these colorants can have negative impacts on health, it is essential to analyze the risks associated with their consumption. This analysis requires, among other things, obtaining sufficient data on the presence of these colorants in foods, as well as their level of consumption. However, data on these colorants is often virtually non-existent in developing countries. The aim of this study was to determine the colorant profile of industrial products marketed in Senegal. Information on food additives was collected on 399 labels of different food product categories in shops located in Dakar. Data is recorded and processed using Excel software. Based on the Codex classification, analysis of the profile of additives identified on the labels of food samples revealed the presence of 31 colorants. The natural colorants identified are dominated by beta-carotene, widely present in beverages and dairy products, and paprika extract identified on cookies and industrial sauces. Artificial colors are dominated caramels present in several foods including bouillons, vinegars, sauces and hard candies. Secondly, there was a strong presence of the azo dye Sunset yellow FCF, widely found in samples of beverages, confectionery and cookies. The results of this case study enable us to appreciate the wide presence and diversity of colorants on the Senegalese market, and the importance of controlling them to guarantee consumer safety.

Natural hydroxyanthraquinoid pigments as potent food grade colorants:an overview

Natural pigments and colorants are widely used in the world in many industries such as textile dying,food processing or cosmetic manufacturing.Among the natural products of interest are various compounds belonging to carotenoids,anthocyanins,chlorophylls,melanins,betalains...The review emphasizes pigments with anthraquinoid skeleton and gives an overview on hydroxyanthraquinoids described in Nature,the first one ever published.Trends in consumption,production and regulation of natural food grade colorants are given,in the current global market.The second part focuses on the description of the chemical structures of the main anthraquinoid colouring compounds,their properties and their biosynthetic pathways.Main natural sources of such pigments are summarized,followed by discussion about toxicity and carcinogenicity observed in some cases.As a conclusion,current industrial applications of natural hydroxyanthraquinoids are described with two examples,carminic acid from an insect and Arpink red^(™)from a filamentous fungus.

Natural Colorants:Historical,Processing and Sustainable Prospects

With the public’s mature demand in recent times pressurized the textile industry for use of natural colorants,without any harmful effects on environment and aquatic ecosystem,and with more developed functionalities simultaneously.Advanced developments for the natural bio-resources and their sustainable use for multifunctional clothing are gaining pace now.Present review highlights historical overview of natural colorants,classification and predominantly processing of colorants from sources,application on textiles surfaces with the functionalities provided by them.Chemistry of natural colorants on textiles also discussed with relevance to adsorption isotherms and kinetic models for dyeing of textiles.

EFFECTS OF ORGANIC COLORANTS ON PHOTO-INITIATED CROSSLINKING AND PHOTO-OXIDATION DEGRADATION OF POLYETHYLENE AND RELATED MECHANISM

The effects of three organic colorants on photo-initiated crosslinking and photo-oxidation degradation of polyethylene (PE) samples irradiated by microwave excited (MWE) UV lamp in the melt and the related mechanism have been studied by gel content and thermal extension rate determinations,X-ray photoelectron spectroscopy (XPS),mechanical property tests,UV spectroscopy,and light microscope.The data from the gel content and thermal extension rate determinations of photo-crosslinked polyethylene (XLPE) sample...

Colorant Formulation Using 3 - layer Artificial Neural Networks

The colorant formulation using artificial neural networks (ANN) was investigated in this study. A simple 3 -layer, input - hidden - output system was constructed for the recipe formulation of one - , two - , and three -dye mixtures. Comprehensive tests were carried out to explore the properties of a 3 - layer simple ANN systematically . These properties include number of neurons in the hidden layer, learning rate of the network, momentum factor of the network, as well as the number of epochs for the learning process. The tests show accurate results for one - and two - dye mixtures while less accurate but comparable results to conventional colorant formulation systems for three - dye mixtures. It is also found that the optimum values of the neural network parameters are important towards the accuracy of the colorant formulation.

The feasibility study of natural pigments as food colorants and seasonings pigments safety on dried tofu coloring

In order to improve appetite,attract consumers and even conform to the food culture,food coloring has become one of the necessary links in modern food processing.For example,dried-tofu will be colored by adding artificial food colors(AFCs)such as sunset yellow,cochineal red A or other seasonings like soy sauce.However,the dispute persists about whether AFCs are harmful to health.Some studies indicate AFCs affect children’s intelligence and attention,cause hyperactivity,and allergy when children consumed≥50 mg.In addition,researches showed that chemical soy sauce produces a trace of methylglyoxal(MGO)in the manufacturing process,which is related to diseases such as oxidative stress,diabetes,and cognitive deterioration.Therefore,natural pigments are relatively new and promising strategy for replacing high-risk AFCs.Thus,the objective of this study was to use dried-tofu as a natural colorants coloring screening platform,through the concept of three primary colors to discuss the coloring effects of natural colorants in Taiwan in double–phase(liquid phase to solid phase)food coloring system and assess the effects of MGO on PC12 neuron cellular morphology and cell cycle at the dietary exposure in soy sauce.Our results showed that formula G:R=0.2:0.8 and C:R=0.08:0.92 were coloring by combined natural colorants had the same eye sensory quality acceptance of consumer and had the intention to purchase.Furthermore,the results from the PC12 cell suggested that dietary exposure of methylglyoxal(<50M)in soy sauce did not affect neuron cellular morphology and cell cycle significantly.Overall,Gardenia Yellow,Curcumin,and Radish Red could overcome the application restrictions in multiplephase food coloring system and simultaneously soy sauce as a coloring agent was safety.It showed the possibility of them as food colorants on dried-tofu.

Genotoxicity of Synthetic Food Colorants

A study was conducted to evaluate the genotoxicity, if any, of the permitted synthetic food colorants used in India. Eight synthetic food colorants namely Erythrosine （E 127）, Tartrazine （E 102）, Ponceau 4R （E 124）, Sunset Yellow FCF （E 110）, Brilliant Blue FCF （E133）, Fast Green FCF （E143）, Carmoisine （E122） and Indigo Carmine （E132） and their combination are used in sweets namely Ladu, Jilebi and Halwa in Calicut and suburban areas of Kerala, in India. The genotoxicity of the colorants alone and in combinations at different concentrations were evaluated by Cytokinesis Block Micronucleus （CBMN） Assay. It was observed that all the above colorants and their combinations could cause genotoxicity to human lymphocytes even at the permissible concentration of 100 ppm as per PFA （Prevention of Food Adulteration） Act of India. The toxicity varied from dye to dye and was proportional to their concentration. Combination of colors showed more toxicity than the individual components. Toxicity could be reduced drastically by reducing the concentration of the dyes at least 50% below the permissible limit. Permitted synthetic food colorants even at the permissible limit should be used with caution. This study demonstrated the need for redefining the permissible limit of the food colorants based on Admissible Daily Intake （ADI） as being practiced in developed countries.

Rare earth colorants to start production

Nontoxic colorant from rare earths is expected to be put into full production in the current year in Baotou, the biggest city in the Inner Mongolia autonomous region, following a decision by the local government to upgrade the rare earths industry to value-added processes against previously mining the raw materials. "Due to its perfect coloring and nontoxic properties the coloring agent, mainly for plastics and leathers, can replace most existing dyes in the market," said Zhang Hongjie, inventor of the colorant and member of the Chinese Academy of Sciences.

Synthesis and characterization of yellow water-borne polyurethane using a diol colorant as extender

A novel and facile method toward a series of yellow water-borne polyurethane was developed by using an intrinsically colored diol in this paper.The yellow aqueous dispersion PCLD-HENA-PU was synthesized based on isophorone diisocyanate(IPDI), polycaprolactonediol(PCLD) and 2,2-dimethylol propionic acid(DMPA) using a yellow diol N,N-bis(2-hydroxyethyl)-4-nitroaniline (HENA) as a chain extender.Due to the complete reaction of OH group in colorant HENA with NCO group in diisocyanate,a series of stable yellow p...

Harnessing Microalgae Biomass from Lake Taihu as a Natural Biocolorant Source for Sustainable Eco-Friendly Dyeing of Cotton with Ultrasonication

Most water bodies worldwide are infested with algae bloom and Lake Taihu is no exception, various techniques have been developed to harvest microalgae from Lake Taihu as part of the lake cleaning program and this results in a large algae biomass to deal with. This study made use of the algae biomass harvested as a biocolorants source for textile application and also evaluated its dyeing characteristics with mercerized and bleached cotton. The fabrics were dyed with either ultrasound or water bath method. The ultrasound method improved dye extraction yield from 17.8% for the conventional method to 26.7%, which was also enhanced to 33.2% with the addition of HCl (1 cm). The ultrasound dyeing method was effective at improving dye uptake at a reduced dyeing temperature when compared to the conventional method and also produced different shades of color after dyeing with different mordants. The dyed fabrics had good fastness properties for laundry, crocking and light. The dyed fabrics also showed a good ultraviolet protection factor. The use of algae biomass as a potential source of colorants for textile application will provide an alternate dye source that is environmentally friendly.

Non-volatile dynamically switchable color display via chalcogenide stepwise cavity resonators

High-resolution multi-color printing relies upon pixelated optical nanostructures,which is crucial to promote color display by producing nonbleaching colors,yet requires simplicity in fabrication and dynamic switching.Antimony trisulfide(Sb_(2)S_(3))is a newly rising chalcogenide material that possesses prompt and significant transition of its optical characteristics in the visible region between amorphous and crystalline phases,which holds the key to color-varying devices.Herein,we proposed a dynamically switchable color printing method using Sb_(2)S_(3)-based stepwise pixelated Fabry-Pérot(FP)cavities with various cavity lengths.The device was fabricated by employing a direct laser patterning that is a less timeconsuming,more approachable,and low-cost technique.As switching the state of Sb_(2)S_(3) between amorphous and crystalline,the multi-color of stepwise pixelated FP cavities can be actively changed.The color variation is due to the profound change in the refractive index of Sb_(2)S_(3) over the visible spectrum during its phase transition.Moreover,we directly fabricated sub-50 nm nano-grating on ultrathin Sb_(2)S_(3) laminate via microsphere 800-nm femtosecond laser irradiation in far field.The minimum feature size can be further decreased down to~45 nm(λ/17)by varying the thickness of Sb_(2)S_(3) film.Ultrafast switchable Sb_(2)S_(3) photonic devices can take one step toward the next generation of inkless erasable papers or displays and enable information encryption,camouflaging surfaces,anticounterfeiting,etc.Importantly,our work explores the prospects of rapid and rewritable fabrication of periodic structures with nano-scale resolution and can serve as a guideline for further development of chalcogenide-based photonics components.

Coupling of reduced inorganic fertilizer with plant-based organic fertilizer as a promising fertilizer management strategy for colored rice in tropical regions

Colored rice is a type of high-quality,high-added-value rice that has attracted increasing attention in recent years.The use of large amounts of inorganic nitrogen fertilizer in rice fields results in low fertilizer use efficiency and high environmental pollution.Organic fertilizer is a promising way to improve soil quality and sustain high yields.However,most studies focus on the effect of animal-based organic fertilizers.The effects of different ratios of plantbased organic fertilizer and inorganic fertilizer on the grain yield and quality of colored rice have rarely been reported.Therefore,a two-year field experiment was conducted in 2020 and 2021 to study the effects of replacing inorganic N fertilizers with plant-based organic fertilizers on the yield,nitrogen use efficiency(NUE),and anthocyanin content of two colored rice varieties in a tropical region in China.The experimental treatments included no nitrogen fertilization(T1),100% inorganic nitrogen fertilizer(T2),30%inorganic nitrogen fertilizer substitution with plant-based organic fertilizer(T3),60%inorganic nitrogen fertilizer substitution with plant-based organic fertilizer(T4),and 100% plantbased organic fertilizer(T5).The total nitrogen provided to all the treatments except T1 was the same at 120 kg ha-1.Our results showed that the T3 treatment enhanced the grain yield and anthocyanin content of colored rice by increasing nitrogen use efficiency compared with T2.On average,grain yields were increased by 9 and 8%,while the anthocyanin content increased by 16 and 10% in the two colored rice varieties under T3 across the two years,respectively,as compared with T2.Further study of the residual effect of partial substitution of inorganic fertilizers showed that the substitution of inorganic fertilizer with plant-based organic fertilizer improved the soil physiochemical properties,and thus increased the rice grain yield,in the subsequent seasons.The highest grain yield of the subsequent rice crop was observed under the T5 treatment.Our results suggested that the application of plantbased organic fertilizers can sustain the production of colored rice with high anthocyanin content in tropical regions,which is beneficial in reconciling the relationship between rice production and environmental protection.

The protective effect of cyclodextrin on the color quality and stability of Cabernet Sauvignon red wine

The impact of cyclodextrins(CDs)on wine quality and stability remains largely unknown.This study systematically assessed the protective effect of the post-fermentation addition of CDs on color stability of red wine from the viewpoints of color characteristics,copigmentation and phenolic profiles.The grey relational analysis(GRA)and principal component analysis(PCA)methods were employed to dissect the key effective determinants related to color quality.The addition of CDs induced a significant hyperchromic effect of 8.19-25.40%,a significant bathochromic effect and an enhancement of the color intensity.Furthermore,the evolution of anthocyanin forms and the content of monomeric anthocyanins revealed that β-CD is a superior favorable cofactor during wine aging,but for long-term aging,2-HP-β-CD and 2-HP-γ-CD are more beneficial in promoting the formation of polymerized anthocyanins and color stability.This work provides an important reference for the use of CDs to enhance the color quality and stability of red wines.

OptoGPT: A foundation model for inverse design in optical multilayer thin film structures

Optical multilayer thin film structures have been widely used in numerous photonic applications.However,existing inverse design methods have many drawbacks because they either fail to quickly adapt to different design targets,or are difficult to suit for different types of structures,e.g.,designing for different materials at each layer.These methods also cannot accommodate versatile design situations under different angles and polarizations.In addition,how to benefit practical fabrications and manufacturing has not been extensively considered yet.In this work,we introduce OptoGPT(Opto Generative Pretrained Transformer),a decoder-only transformer,to solve all these drawbacks and issues simultaneously.

Intelligent diagnosis of retinal vein occlusion based on color fundus photographs

AIM:To develop an artificial intelligence(AI)diagnosis model based on deep learning(DL)algorithm to diagnose different types of retinal vein occlusion(RVO)by recognizing color fundus photographs(CFPs).METHODS:Totally 914 CFPs of healthy people and patients with RVO were collected as experimental data sets,and used to train,verify and test the diagnostic model of RVO.All the images were divided into four categories[normal,central retinal vein occlusion(CRVO),branch retinal vein occlusion(BRVO),and macular retinal vein occlusion(MRVO)]by three fundus disease experts.Swin Transformer was used to build the RVO diagnosis model,and different types of RVO diagnosis experiments were conducted.The model’s performance was compared to that of the experts.RESULTS:The accuracy of the model in the diagnosis of normal,CRVO,BRVO,and MRVO reached 1.000,0.978,0.957,and 0.978;the specificity reached 1.000,0.986,0.982,and 0.976;the sensitivity reached 1.000,0.955,0.917,and 1.000;the F1-Sore reached 1.000,0.9550.943,and 0.887 respectively.In addition,the area under curve of normal,CRVO,BRVO,and MRVO diagnosed by the diagnostic model were 1.000,0.900,0.959 and 0.970,respectively.The diagnostic results were highly consistent with those of fundus disease experts,and the diagnostic performance was superior.CONCLUSION:The diagnostic model developed in this study can well diagnose different types of RVO,effectively relieve the work pressure of clinicians,and provide help for the follow-up clinical diagnosis and treatment of RVO patients.

Synthesis of γ-Ce_2S_3 colorant under low temperature and its coloring properties for PE and PVC

A series of cerium sulfides were successfully prepared using commercially available nanoscale CeO_2 as precursor, anhydrous Na_2CO_3 as dopants, CS_2 as sulfur source, under 600–800 oC, respectively. Properties of samples were investigated by means of X-ray diffraction（XRD）, scanning electron microscopy（SEM） and spectrophotometry. The results showed that corresponding γ-Ce_2S_3 with small size was obtained by using nanoscale CeO_2 as precursor; pure phase γ-Ce_2S_3 could be obtained under low temperature of 700 oC. Coloring properties of γ-Ce_2S_3 obtained under 800 oC were studied by researching γ-Ce_2S_3/PE and γ-Ce_2S_3/PVC composites, respectively. The results showed that satisfied coloring effects to PE and PVC were obtained by using 0.5 phr and 0.2 phr γ-Ce_2S_3, respectively.

Physiological and psychological responses to tended plant communities with varying color characteristics

Exposure to plants has been reported to promote health and reduce stress,and plant color has direct impacts on physical and mental health.We used images of common types of tended plant communities in Shenyang,China,with combinations of yellow,green,and red foliage,as experimental stimuli.A total of 27 images were used as visual stimuli.We used electroencephalography to measureαwave activity(8-13 Hz)in 40 subjects while they viewed visual stimuli.These data were combined with subjective questionnaire data to analyze the relaxing effect of images of tended plant communities with different color types and proportions on people.The results revealed that,although there were slight differences between the electroencephalography and psychological findings,women were significantly more relaxed than men after viewing the images.Physiological and psychological responses varied with the types and proportions of colors in the tended plant communities:those of foliage with combinations of two or three colors induced stronger responses than images with a single color.Specifically,(1)for one-color plant communities,green or yellow plant communities induced a stronger relaxation effect than red plant communities;(2)for two-color plant communities,the optimal color proportion was 55%+45%,and the green+yellow and green+red color combinations induced a stronger relaxation effect;(3)for three-color plant communities,the relaxation effect was strongest when the color proportion was 55%green+25%yellow+20%red.These data would provide a plant color matching in future plant landscape design,which may be helpful for creating healthy and relaxing environments.

Facile preparation of nano-g-C_(3)N_(4)/UiO-66-NH_(2) composite as sorbent for high-efficient extraction and preconcentration of food colorants prior to HPLC analysis

In this work,the nano-g-C_(3)N_(4)/Ui O-66-NH_(2)composite was prepared by one-step solvothermal method.The as-prepared composite was characterized by scanning electron microscopy,Brunner-Emmet-Teller measurement,energy dispersive spectrometer,X-ray diffraction,and Fourier transform infrared spectroscopy.By using nano-g-C_(3)N_(4)/Ui O-66-NH_(2)composite as sorbent,a dispersive solid-phase extraction coupled with high-performance liquid chromatography was developed to sensitive analysis of food colorants including tartrazine,amaranth,carmine,sunset yellow,allura red and bright blue.The experiment parameters including the amount of sorbent,adsorption time,the p H of adsorption solution,desorption time,desorption solvent,the p H of desorption solution as well as the proportion between desorption solvent and buffer solvent were investigated.Under the optimized conditions,the limits of detection(S/N=3) and limits of quantitation (S/N=10) were determined in the ranges of 0.08-0.8 and 0.2-2.0 ng/m L,respectively.With the developed sample pretreatment method,carmine and brilliant blue were determined from blueberry juice by HPLC-DAD.The contents were calculated as 1.53μg/m L and0.17μg/mL,respectively.

Unsupervised Color Segmentation with Reconstructed Spatial Weighted Gaussian Mixture Model and Random Color Histogram

Image classification and unsupervised image segmentation can be achieved using the Gaussian mixture model.Although the Gaussian mixture model enhances the flexibility of image segmentation,it does not reflect spatial information and is sensitive to the segmentation parameter.In this study,we first present an efficient algorithm that incorporates spatial information into the Gaussian mixture model(GMM)without parameter estimation.The proposed model highlights the residual region with considerable information and constructs color saliency.Second,we incorporate the content-based color saliency as spatial information in the Gaussian mixture model.The segmentation is performed by clustering each pixel into an appropriate component according to the expectation maximization and maximum criteria.Finally,the random color histogram assigns a unique color to each cluster and creates an attractive color by default for segmentation.A random color histogram serves as an effective tool for data visualization and is instrumental in the creation of generative art,facilitating both analytical and aesthetic objectives.For experiments,we have used the Berkeley segmentation dataset BSDS-500 and Microsoft Research in Cambridge dataset.In the study,the proposed model showcases notable advancements in unsupervised image segmentation,with probabilistic rand index(PRI)values reaching 0.80,BDE scores as low as 12.25 and 12.02,compactness variations at 0.59 and 0.7,and variation of information(VI)reduced to 2.0 and 1.49 for the BSDS-500 and MSRC datasets,respectively,outperforming current leading-edge methods and yielding more precise segmentations.

Identification and effective regulation of scarb1 gene involved in pigmentation change in autotetraploid Carassius auratus

The autotetraploid Carassius auratus(4nRR,4n=200,RRRR)is derived from whole-genome duplication of Carassius auratus red var.(RCC,2n=100,RR).In the current study,we demonstrated that chromatophores and pigment changes directly caused the coloration and variation of 4nRR skin(red in RCC,brownish-yellow in4nRR).To further explore the molecular mechanisms underlying coloration formation and variation in 4nRR,we performed transcriptome profiling and molecular functional verification in RCC and 4nRR.Results revealed that scarb1,associated with carotenoid metabolism,underwent significant down-regulation in 4nRR.Efficient editing of this candidate pigment gene provided clear evidence of its significant role in RCC coloration.Subsequently,we identified four divergent scarb1 homeologs in 4nRR:two original scarb1 homeologs from RCC and two duplicated ones.Notably,three of these homeologs possessed two highly conserved alleles,exhibiting biased and allelespecific expression in the skin.Remarkably,after precise editing of both the original and duplicated scarb1homeologs and/or alleles,4nRR individuals,whether singly or multiply mutated,displayed a transition from brownishyellow skin to a cyan-gray phenotype.Concurrently,the proportional areas of the cyan-gray regions displayed a gene-dose correlation.These findings illustrate the subfunctionalization of duplicated scarb1,with all scarb1genes synergistically and equally contributing to the pigmentation of 4nRR.This is the first report concerning the functional differentiation of duplicated homeologs in an autopolyploidfish,substantiallyenrichingour understanding of coloration formation and change within this group of organisms.