Comprehensive chlorophyll composition of commercial green food colorants and coloring foodstuffs by HPLC-ESI-QTOF-MS/MS: Chlorophyllins.

Consumers demand higher levels of food quality and safety, so food legislative organizations need full knowledge of food composition to develop regulations that guarantee quality and safety criteria. This is the context for green natural food colorants and the new category green "coloring foodstuffs". We have exploited the capabilities of targeted metabolomics assisted by powerful software and algorithms to unravel the comprehensive chlorophyll composition in commercial samples of both colorant categories. With the aid of an in-house library, at first, seven new chlorophylls have been identified, among all the samples analyzed, providing data on their structural configuration. Next, taking advantage of an expert-curated database, eight more chlorophylls non-described previously have been found, which will be significant for the chemistry of chlorophylls. Finally, we have deciphered the sequence of chemical reactions that take place during the manufacturing of green food colorants and propose the whole pathway that explains the occurrence of the chlorophylls they contain.

Bioactive Natural Pigments' Extraction, Isolation, and Stability in Food Applications.

Color in food has multiple effects on consumers, since this parameter is related to the quality of a product, its freshness, and even its nutrient content. Each food has a characteristic color; however, this can be affected by the technological treatments that are applied during its manufacturing process, as well as its storage. Therefore, the development of new food products should take into account consumer preferences, the physical properties of a product, food safety standards, the economy, and applications of technology. With all of this, the use of food additives, such as dyes, is increasingly important due to the interest in the natural coloring of foods, strict regulatory pressure, problems with the toxicity of synthetic food colors, and the need for globally approved colors, in addition to current food market trends that focus on the consumption of healthy, organic, and natural products. It is for this reason that there is a growing demand for natural pigments that drives the food industry to seek or improve extraction techniques, as well as to study different stability processes, considering their interactions with the food matrix, in order to meet the needs and expectations of consumers.

Appraising the electrocatalytic performance of beta-cyclodextrin embellished supramolecular recognition system for pernicious food colorants.

The current research presents the evaluation of supramolecular proficiency of the designed platform for electrocatalytic determination of pernicious food colorants, amaranth and fast green. The approach involving surface modification of glassy carbon electrode with beta cyclodextrin decorated strontium ferrite reduced graphene oxide nanocomposite (SFrGO-ßCD) to ensure fast and reversible electro-oxidation of hydroxyl groups of the colorant molecules. The synergy between SF and rGO facilitated the sensor with enhanced surface area and conductivity through faradic redox reaction. Tremendous decrease in the obtained values of peak separation potential and impedance as manifested in CV and EIS analysis, enabled by electrostatic interactions between surface functionalities of rGO and ßCD has resulted in the significant augmentation of sensitivity. The value of charge transfer coefficient, number of electrons involved, nature of electron transport process at electrode electrolyte interface during the analysis of electrochemical detection were explored through CV experiments. Food samples analysis (without spiking) utilizing screen printed electrode manifested the sensor as portable device for real time monitoring. Outstanding detection limit (0.022 nM for amaranth and 0.051 nM for fast green), excellent regenerability (Relative standard deviation less than 3%) and apparent recovery rate (above 90%) of the modified electrode presented a colossal potential for the development of sustainable and commercially competitive electrochemical sensor in food sector.

Multispectroscopic, virtual and in vivo insights into the photoaging defense mediated by the natural food colorant bixin.

An upsurge in early onset of photoaging due to repeated skin exposure to environmental stressors such as UV radiation is a challenge for pharmaceutical and cosmeceutical divisions. Current reports indicate severe side effects because of chemical or synthetic inhibitors of matrix metalloproteases (MMPs) in anti-skin aging cosmeceuticals. We evaluated the adequacy of bixin, a well-known FDA certified food additive, as a scavenger of free radicals and its inhibitory mechanism of action on MMP1, collagenase, elastase, and hyaluronidase. The anti-skin aging potential of bixin was evaluated by several biotechnological tools in silico, in vitro and in vivo. Molecular docking and simulation dynamics studies gave a virtual insight into the robust binding interaction between bixin and skin aging-related enzymes. Absorbance and fluorescence studies, enzyme inhibition assays, enzyme kinetics and in vitro bioassays of human dermal fibroblast (HDF) cells highlighted bixin's role as a potent antioxidant and inhibitor of skin aging-related enzymes. Furthermore, in vivo protocols were carried out to study the impact of bixin administration on UVA induced photoaging in C57BL/6 mice skin. Here, we uncover the UVA shielding effect of bixin and its efficacy as a novel anti-photoaging agent. Furthermore, the findings of this study provide a strong foundation to explore the pharmaceutical applications of bixin in several other biochemical pathways linked to MMP1, collagenase, elastase, and hyaluronidase.

Chronic exposure to synthetic food colorant Allura Red AC promotes susceptibility to experimental colitis via intestinal serotonin in mice.

Chemicals in food are widely used leading to significant human exposure. Allura Red AC (AR) is a highly common synthetic colorant; however, little is known about its impact on colitis. Here, we show chronic exposure of AR at a dose found in commonly consumed dietary products exacerbates experimental models of colitis in mice. While intermittent exposure is more akin to a typical human exposure, intermittent exposure to AR in mice for 12 weeks, does not influence susceptibility to colitis. However, exposure to AR during early life primes mice to heightened susceptibility to colitis. In addition, chronic exposure to AR induces mild colitis, which is associated with elevated colonic serotonin (5-hydroxytryptamine; 5-HT) levels and impairment of the epithelial barrier function via myosin light chain kinase (MLCK). Importantly, chronic exposure to AR does not influence colitis susceptibility in mice lacking tryptophan hydroxylase 1 (TPH1), the rate limiting enzyme for 5-HT biosynthesis. Cecal transfer of the perturbed gut microbiota by AR exposure worsens colitis severity in the recipient germ-free (GF) mice. Furthermore, chronic AR exposure elevates colonic 5-HT levels in naïve GF mice. Though it remains unknown whether AR has similar effects in humans, our study reveals that chronic long-term exposure to a common synthetic colorant promotes experimental colitis via colonic 5-HT in gut microbiota-dependent and -independent pathway in mice.

Effectiveness of denture cleansers on flexible denture base resins in the removal of stains colored by food colorant solution: An in vitro study.

Aim: The aim of the study was to compare the efficiency of three denture cleansers (Valclean, Polident and Clinsodent) in removal of turmeric stains from flexible denture base resins. Settings and Design: In vitro - comparative study. Materials and Methods: A total of 45 specimens of flexible denture base resins were fabricated and subjected to baseline colour measurements using spectrophotometer. Specimens were stained with turmeric and colour measurements of stained specimens were made. All the stained specimens were divided into three groups (n = 15) for removal of stains with three denture cleansers: Valclean, Polident, Clinsodent and colour measurements of cleansed specimens were made. The colour measurements (ΔE) values obtained were collected and statistical analysis was done. Statistical Analysis Used: One-way ANOVA (Analysis of Variance), Tukey's post hoc test. Results: One way ANOVA test revealed that the mean colour difference of three groups were statistically different with P value < 0.001. A further Tukey post hoc test revealed that the Valclean group had lesser mean scores than Polident and Clinsodent group. Conclusion: It was concluded that Valclean showed statistically significant greater stain removal efficiency than Polident followed by Clinsodent.

Riboflavin attenuates tartrazine toxicity in the cerebellar cortex of adult albino rat.

Tartrazine is a synthetic yellowish dye considered one of the most common food colorants. Extensive usage of tartrazine in humans led to harmful health impacts. To investigate the impact of tartrazine administration on the cerebellum and to assess the potential role of riboflavin co-administration in the adult male albino rat. Four groups of adult albino rats were included in this study. Group I was supplied with distilled water. Group II was supplied tartrazine orally at a dose of 7.5 mg/kg BW dissolved in distilled water. Group III was supplied with tartrazine at the same previously mentioned dose and riboflavin orally at a dose of 25 mg/kg BW dissolved in distilled water. Group IV was supplied with riboflavin at the same previously mentioned dose. The study was conducted for 30 days then rats were sacrificed, weighted and the cerebella extracted and handled for light, ultrastructural and immunohistochemical evaluation. It was found with tartrazine treatment focal areas of Purkinje cell loss leaving empty spaces, a broad spread of neuronal affection to the degree of the disappearance of some of the granular cells, reduced the thickness of the molecular and granular layers, and strong positive GFAP immunoreactions. With riboflavin coadministration restored continuous Purkinje layer with normal appeared Purkinje cells, but some cells were still shrunken and vacuolated as well as the molecular and granular cell layers appeared normal. Tartrazine had deleterious effects on the cerebellar cytoarchitecture, and riboflavin co-administration alleviated these neurotoxic effects.

Facile hydrothermal synthesis and purification of fluorescent carbon dots for food colorant tartrazine detection based on a dual-mode nanosensor.

Colorant tartrazine is widely used in the food industry, but its long-term and excessive consumption is harmful to human health. Therefore, it is necessary to establish a sensitive detection method for tartrazine. Blue fluorescent carbon dots with L-arginine and o-phenylenediamine as precursors, namely L-Arg/oPD-CDs, were prepared via the hydrothermal method. Then, L-Arg/oPD-CDs were further purified by dialysis, thin layer chromatography and column chromatography. A dual-mode nanosensor based on fluorescent and UV absorption was successfully developed. Excellent linear ranges of 0-5 µM and 10-50 µM were obtained with a low detection limit of 42.3 nM based on fluorescence. A good linear range of 0-50 µM was obtained with a low detection limit of 130.15 nM based on UV absorption. The quenching mechanism of tartrazine towards L-Arg/oPD-CDs fluorescence was the inner filter effect. In addition, a dual-mode nanosensor was used for tartrazine determination in millet, maize flour, carbonated drink, and sugar samples. This study provides new insight into the detection of tartrazine by applying a dual-mode nanosensor.

Enhanced artificial intelligence for electrochemical sensors in monitoring and removing of azo dyes and food colorant substances.

It is necessary to determine whether synthetic dyes are present in food since their excessive use has detrimental effects on human health. For the simultaneous assessment of tartrazine and Patent Blue V, a novel electrochemical sensing platform was developed. As a result, two artificial azo colorants (Tartrazine and Patent Blue V) with toxic azo groups (-NN-) and other carcinogenic aromatic ring structures were examined. With a low limit of detection of 0.06 µM, a broad linear concentration range 0.09µM to 950µM, and a respectable recovery, scanning electron microscopy (SEM) was able to reveal the excellent sensing performance of the suggested electrode for patent blue V. The electrochemical performance of an electrode can be characterized using cyclic and differential pulse voltammetry, and electrochemical impedance spectroscopy. Moreover, the classification model was created by applying binary classification assessment using enhanced artificial intelligence comprises of support vector machine (SVM) and Genetic Algorithm (GA), respectively, a support vector machine and a genetic algorithm, which was then validated using the 50 dyes test set. The best binary logistic regression model has an accuracy of 83.2% and 81.1%, respectively, while the best SVM model has an accuracy of 90.3% for the training group of samples and 81.1% for the test group (RMSE = 0.644, R2 = 0.873, C = 205.41, and = 5.992). According to the findings, Cu-BTC MOF (copper (II)-benzene-1,3,5-tricarboxylate) has a crystal structure and is tightly packed with hierarchically porous nanomaterials, with each particle's edge measuring between 20 and 37 nm. The suggested electrochemical sensor's analytical performance is suitable for foods like jellies, condiments, soft drinks and candies.

Role of salts and solvents on the defibrillation of food dye "sunset yellow" induced hen egg white lysozyme amyloid fibrils.

Several food dyes are known to induce amyloid fibrillation when interacting with proteins. Here, we studied the role of sunset yellow (SY) in the amyloid fibrillation of hen egg white lysozyme (HEWL) and characterized the changes using spectroscopy techniques. Turbidity results showed that SY dye induces aggregation in HEWL in concentrations dependent manner. The aggregation induced by SY dye is kinetically very fast, no lag phase was detected, and the kinetics process follows an isodesmic kinetics pathway. The SY-dye induce aggregates have cross-ß secondary structure confirmed by far-UV CD measurements. The effect of salts and solvents was also seen on SY-induced aggregates. Turbidity, far-UV CD, and kinetics results suggest that certain concentrations of NaCl and (NH4)2SO4 solubilize the SY-induce amyloid fibrils, but (NH4)2SO4 is more effective. Similarly, solvents are also solubilized the SY-induces HEWL amyloid fibrillation but the order of defibrillation is as follows: Isopropanol> ethanol > methanol which signified that isopropanol is more effective than other solvents. The salts and solvents data suggest that the electrostatic, as well as hydrophobic interaction, is responsible for SY-induced amyloid fibrillation. These conformational changes should be examined, more seriously for the purpose of food safety.

Back to nature, microbial production of pigments and colorants for food use.

Pigments-producing microorganisms are quite common in Nature. However, there is a long journey from the Petri dish to the market place. Twenty-five years ago, scientists wondered if such productions would remain a scientific oddity or become an industrial reality. The answer is not straightforward as processes using fungi, bacteria or yeasts can now indeed provide carotenoids or phycocyanin at an industrial level. Another production factor to consider is peculiar as Monascus red colored food is consumed by more than one billion Asian people; however, still banned in many other countries. European and American consumers will follow as soon as "100%-guaranteed" toxin-free strains (molecular engineered strains, citrinin gene deleted strains) will be developed and commercialized at a world level. For other pigmented biomolecules, some laboratories and companies invested and continue to invest a lot of money as any combination of new source and/or new pigment requires a lot of experimental work, process optimization, toxicological studies, and regulatory approval. Time will tell whether investments in pigments such as azaphilones or anthraquinones were justified. Future trends involve combinatorial engineering, gene knock-out, and the production of niche pigments not found in plants such as C50 carotenoids or aryl carotenoids.

Lycopene-rich watermelon concentrate used as a natural food colorant: Stability during processing and storage.

A lycopene-rich watermelon (Citrullus lanatus) concentrate was incorporated into snack cracker, fusilli pasta, and extruded snacks for coloring purposes. Changes in the L* and a* color coordinates and in the lycopene content were evaluated before and after thermal processes and monitored through 90 days of storage at ambient temperature. The products with the maximum lycopene degradation during processing were snack cracker and extruded snack (between 30 and 45%) whereas no degradation was observed in the fusilli pasta, except during cooking into boiling water (reduction up to 41%). The change in color during processing varied substantially depending on the product, but, in general, thermal treatments applied reduced the a* values (less reddish). The degradation kinetics of the lycopene and the color during storage followed first-order kinetics, with a half-life time of 25 to 315 days for lycopene content and 65 to 210 days for a* coordinate. Snack cracker was the most stable and had more than a 4-month period before losing half of the pigment content.

Improved Stability of Blue Colour of Anthocyanins from Lycium ruthenicum Murr. Based on Copigmentation.

Natural blue food colourant is rare. The aim of this work was to screen compounds from the common copigments that could improve the blue tones of anthocyanins (ACNs) and to investigate the effect of different copigments on the colour stability of anthocyanins in neutral species. International Commission on Illumination (CIE) colour space, UV, IR, NMR, atomic force microscopy (AFM) and computational chemistry methods were utilised to evaluate ACNs from Lycium ruthenicum Murr. (LR), which is complexed with food additives and biological agents. The results indicate that Pro-Xylane (PX), Ectoin (ECT) and dipotassium glycyrrhizinate (DG) enhance the blue colour of the ACNs. ACNs-PX presents a colour close to Oxford Blue and has a surface height of 2.13 ± 0.14 nm and slightly improved stability. The half-life of ACNs-DG is improved 24.5-fold and had the highest complexation energy (-50.63/49.15) kcal/mol, indicating hydrogen bonds and π-π stacking forces enhance stability. These findings offer a new perspective for anthocyanin utilisation as a blue colourant and contribute to the large-scale application of LR.

Impact of ultrasonication applications on color profile of foods.

Food color is a feature that provides preliminary information about their preference or consumption. There are dominant pigments that determine the color of each food; the most important pigments are anthocyanins (red-purple color), chlorophylls (green color), carotenoids (yellow-orange color), and betalains (red color). These pigments can be easily affected by temperature, light, oxygen, or pH, thereby altering their properties. Therefore, while processing, it is necessary to prevent the deterioration of these pigments to the maximum possible extent. Ultrasonication, which is one of the emerging non-thermal methods, has multidimensional applications in the food industry. The present review collates information on various aspects of ultrasonication technology, its mechanism of action, influencing factors, and the competence of different ultrasonication applications (drying, irradiation, extraction, pasteurization, cooking, tempering, etc.) in preserving the color of food. It was concluded that ultrasonication treatments provide low-temperature processing at a short time, which positively influences the color properties. However, selecting optimum ultrasonic processing conditions (frequency, power, time, etc.) is crucial for each food to obtain the best color. The key challenges and limitations of the technique and possible future applications are also covered in the paper, serving as a touchstone for further research in this area.

Effects of acidic beverages on color stability of bulk-fill composites with different viscosities / Efectos de las bebidas ácidas sobre la estabilidad del color de resinas tipo Bulk con diferentes viscosidades

Abstract The aim of this in vitro study is to investigate the effects of acidic beverages on the discoloration of bulk-fill composites with different viscosities. 144 disc-shaped specimens (8mm diameter × 2mm thick) were prepared from four different composite resins including a nanohybrid (Filtek Ultimate), two packable bulk- fill (Filtek Bulk Fill, Tetric N Ceram Bulk Fill), and a flowable bulk-fill composite (Tetric N Flow Bulk Fill). The specimens of each group were divided into 3 subgroups and submerged in distilled water, orange juice and coke (n=12). Color difference (ΔE) were measured using CIELab color space and a compact spectrophotometer (VITA Easyshade) at baseline and after 30 days of immersion. Data were analyzed using two- way ANOVA and Tukeys HSD post-hoc tests (P2.7) was observed for all bulk-fill composites tested. It can be speculated that orange juice has a more negative effect on the color stability compared to coke. Additionally, flowable bulk-fill composite was more prone to discoloration than condensable bulk-fill composites.

Resumen El objetivo de este estudio fue investigar los efectos de las bebidas ácidas en la decoloración de resinas compuestas tipo Bulk con diferentes viscosidades. Se prepararon 144 muestras en forma de disco (8mm de diámetro x 2mm de grosor) a partir de cuatro resinas compuestas diferentes que incluyen un nanohíbrido (Filtek Ultimate), dos de pasta condensables tipo Bulk (Filtek Bulk Fill, Tetric N Ceram Bulk Fill) y una fluida (Tetric N Flow Bulk Fill). Las muestras de cada grupo se dividieron en 3 subgrupos y se sumergieron en agua destilada, jugo de naranja y Coca-Cola (n=12). La diferencia de color (ΔE) se midió utilizando el CIELab y un espectrofotómetro compacto (VITA Easyshade) al inicio y después de 30 días de inmersión. Los datos se analizaron mediante ANOVA bidireccional y pruebas post-hoc HSD de Tukey (P2,7) para todos los materiales resinosos. Se puede especular que el jugo de naranja tiene un efecto más negativo sobre la estabilidad del color en comparación con la Coca-Cola. Además, la resina fluida fue más propensa a la decoloración que las resinas condensables.

Photocatalytic removal of food colorant using NiO/CuO heterojunction nanomaterials.

In recent days, the existence of several food colorants has an impact on human health issue that may induce major carcinogenic effects. Therefore, the removal of food colorants must be made in accordance with the necessity of health awareness in life. Photocatalyst treatment using semiconductors shows a promising way to solve these issues. In this relation, this paper presents the novel nanoflower shaped NiO/CuO (0.9:0.1 M and 0.5:0.5 M) photocatalysts developed via co-precipitation method for the destruction of methyl orange (MO) as a model food colorant under visible light irradiation. The X-ray diffraction result proposed that the composite catalysts consist of mixed heterostructures (cubic and monoclinic) with no other impurities. From the images of transmission electron microscope, the catalyst presents nano spherical and cubical mixed morphologies. Besides, NiO/CuO (0.5:0.5 M) catalyst exhibits agglomeration due to the highly contented CuO. The Energy Dispersive X-ray spectra gave the elemental configuration without other impurity traces. The Brunauer-Emmett-Teller surface area of NiO/CuO (0.9:0.1 M) catalyst occupies higher surface area. Unfortunately, NiO/CuO (0.5:0.5 M) sample has lower surface area due to the agglomerated particles. The UV-vis spectra confirmed that the absorption of the catalyst lies in higher wavelength region occupying small band gap. Moreover, the visible light activity of the catalysts showed 75.3% (0.9:0.1 M) and 40.2% (0.5:0.5 M) degrading efficiencies. At the end, the highly efficient catalyst was experienced photocatalytic activity upto 5 repeated runs and the efficiency remained the same. Therefore, the catalyst NiO/CuO (0.9:0.1 M) has prompted the successful degradation of MO food colorant under visible light.

Electrochemical monitoring sensors of water pollution systems.

Analytical techniques as strong, precise, and expensive are necessary for monitoring food and water safety for contaminants, microorganisms, and allergies that might be harmful if used. Sudan dyes are commonly utilized as an ingredient in food dye substances and a variety of industrial items. These colors are classified as three carcinogens and are linked to liver and bladder cancers. They are not authorized for human consumption by the International Agency for Research on Cancer (IARC) and are not permitted to be used by the Food Standards Agency or the European Union. This article describes electrochemical dye analysis beside the numerous electrochemical sensors utilized to identify these dyes as a food colorant and water. As a result, the qualities, chemistry, and toxicity of dyes as food colorants and industrial goods in Sudan have been investigated in this study. Sudan dyes have been thoroughly studied, and many electrochemical sensors have been developed to define and monitor these dyes in food colorants. As a result, current electrochemical sensors have been found to be neither mass-production nor cost-effective. Mostly, the synthesis of high-performance materials needs high knowledge, and the production of electrode surfaces is remained difficult due to labor-intensive and time-consuming activities.

Ascomycota as a source of natural colorants.

In the last few decades, there has been a great demand for natural colorants. Synthetic colorants are known to be easy to produce, are less expensive, and remain stable when subjected to chemical and physical factors. In addition, only small amounts are required to color any material, and unwanted flavors and aromas are not incorporated into the product. Natural colorants present in food, in addition to providing color, also have biological properties and effects that aid in the prevention and cure of many diseases. The main classes of colorants produced by phylum Ascomycota include polyketides and carotenoids. A promising producer of colorants should be able to assimilate a variety of sources of carbon and nitrogen and also exhibit relative stability. The strain should not be pathogenic, and its product should not be toxic. Production processes should also provide the expected color with a good yield through simple extraction methods. Research that seeks new sources of these compounds should continue to seek products of biotechnological origin in order to be competitive with products of synthetic and plant origin. In this review, we will focus on the recent studies on the main producing species, classes, and metabolic pathways of colorants produced by this phylum, historical background, impact of synthetic colorants on human health and the environment, social demand for natural colorants and also an in-depth approach to bioprocesses (influences on production, optimization of bioprocess, extraction, and identification), and limitations and perspectives for the use of fungal-based dyes.

Semiquantitative naked-eye detection of synthetic food colorants using highly-branched pipette tip as an all-in-one device.

The existing strategies for the determination of synthetic food colorants (FCs) in manufactured foods are highly relied on specialized instruments and skilled personnel which are limited by the high technical threshold and instrumentation cost. Herein, highly branched pipette tips (PTs) were fabricated as a robust all-in-one device for high-performance extraction and visual detection of FCs via handy aspiration and dispensing procedures of pipette controller. The density of extraction groups and inner specific surface area of PTs greatly increased after facile physical coating and subsequent layer-by-layer branching reactions, and the maximum increment in binding capacity of PTs was exceeded 300 times at 8-10 iterations of branching layers, enabling the PTs to be colored just by short-time extraction of FCs and to achieve the instrument-independent visual detection of FCs by virtue of their outstanding PT-SPE performance. As a proof-of-concept, the in-situ PT-based solid phase extraction (PT-SPE) with high recoveries (from 91.73 ± 4.76% to 99.90 ± 4.14%) and semiquantitative naked-eye detection of FCs (Allura red and brilliant blue) in real beverages were experimentally demonstrated to be highly feasible by comparison with classical techniques like spectrophotometry, HPLC, and mass spectrometry.

Insight into the Progress on Natural Dyes: Sources, Structural Features, Health Effects, Challenges, and Potential.

(1) Background: Dyes play an important role in food, medicine, textile, and other industries, which make human life more colorful. With the increasing demand for food safety, the development of natural dyes becomes more and more attractive. (2) Methods: The literature was searched using the electronic databases PubMed, Web of Science, and SciFinder and this scoping review was carried out following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). (3) Results: 248 articles were included in this review. This review summarizes the research progress on natural dyes in the last ten years. According to structural features, natural dyes mainly include carotenoids, polyphenols, porphyrins, and alkaloids, and some of the newest dyes are summarized. Some pharmacological activities of carotenoids, anthocyanin, curcumin, and betalains in the last 10 years are summarized, and the biological effects of dyes regarding illumination conditions. The disadvantages of natural dyes, including sources, cost, stability, and poor bioavailability, limit their application. Here, some feasible strategies (potential resources, biotechnology, new extraction and separation strategies, strategies for improving stability) are described, which will contribute to the development and utilization of natural dyes. (4) Conclusion: Natural dyes show health benefits and potential in food additives. However, it is necessary for natural dyes to pass toxicity tests and quality tests and receive many regulatory approvals before their final entry into the market as food colorants or as drugs.