Search

In this present work, photocatalysts based on a new pyrochlore-type solid solution were prepared using the ceramic method at 1000°C. X-ray diffraction (XRD) analysis shows the existence of a solid solution with pyrochlore structure Bi1.5Sb1.5Zn1–xCuxO7 (0 ≤ x ≤ 1). Scanning Electron Microscope (SEM) images exhibited a slight difference in the external morphology of the samples. The UV-diffuse measurement revealed a change in the absorbance from the UV part for the zinc-rich compound to the visible part for the copper-rich compound. The Energy band gap values were between 3.15 and 1.84 eV. The photocatalytic activity of these prepared mixed oxides was studied for the photo-degradation of the dye Orange II (ORII) as an organic pollutant, in the presence of hydrogen peroxide (H2O2) as an oxidising agent, under sunlight irradiation, by varying different parameters such as the catalysts mass, the oxidant volume, the concentration of the pollutant and the pH. The experimental results obtained by UV-visible spectroscopy revealed that the removal efficiency of ORII increased with increasing the irradiation time for all tested photocatalysts. The pseudo-first-order kinetic model gave the best fit, with the highest correlation coefficients (R2 = 0.99). The results of this study revealed the potential and various advantages of these new efficient photocatalysts. [ABSTRACT FROM AUTHOR]

(1) Background: In this study, bioactive compounds (phenolics and betalains) extracted from beetroot were stabilized by encapsulation with maltodextrin and soy protein by the freeze drying method. Stability of bioactive compounds and bioactivities in a beetroot extract and encapsulates during 60 days of storage at 4 °C (without light) and at 25 °C (with and without light) were investigated. (2) Methods: Contents of bioactive compounds and bioactivity (antioxidant activity by DPPH, RP, and ABTS tests; anti-inflammatory and antihyperglycemic activity) were determined. Improvement in stability of bioactives' content and bioactivity of prepared encapsulates in relation to the extract was observed after storage at room temperature under light conditions. (3) Results: Encapsulation with maltodextrin showed improvement in stability of all studied bioactive parameters, while an encapsulate with soy protein improved stability of bioactives and antioxidant activity compared to the extract. The encapsulated beetroot extract represents a promising food additive for functional foods due to their content of bioactive compounds and consequent bioactivities. [ABSTRACT FROM AUTHOR]

AbstractFood additives are essential constituents of food products in the modern world. The necessity of food processing went up rapidly as to meet requirements including, imparting desirable properties like preservation, enhancement and regulation of color and taste. The methods of identification and analysis of such substances are crucial. With the advancement of technology, a variety of techniques are emerging for this purpose which have many advantages over the existing conventional ways. This review is on different kinds of additives used in the food industry and few prominent methods for their determination ranging from conventional chromatographic techniques to the recently evolved nano-sensor techniques. [ABSTRACT FROM AUTHOR]

Copyright of Cameroon Academy of Sciences Journal is the property of Cameroon Academy of Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A systematic and extensive analytical study was carried out on the loose inlays discovered in the Ptolemaic workshop of Tebtynis (Fayum oasis, Egypt). This paper presents data derived from the multi‐methodological archaeometric investigations (optical microscopy, scanning electron microscopy–energy‐dispersive spectroscopy, electron probe microanalysis, micro‐Raman spectroscopy) performed on a set of intentionally colored and opacified glasses. In particular, we will discuss the textural, chemical, and mineralogical results related to the study of the yellow, yellowish‐orange, red, and brown inlays and semi‐finished/waste products now preserved at the Museo Egizio, Torino. The results highlight the presence of natron (low‐magnesium glasses, LMG) and plant ash (high‐magnesium glasses, HMG) base glass, coexisting with intermediate composition. Yellow samples are opacified using lead antimonates doped with iron and sometimes tin; conversely, yellowish‐orange specimens and the only brown sample are characterized by nanocrystals of cuprite. Red glasses are found in two variants: Dull reds are HMG with colloidal metallic copper particles, while sealing‐wax reds show LMG composition, associated with dendritic cuprite dispersed in a transparent, greenish matrix. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the production, stability and applicability of colorants produced by filamentous fungi isolated from soil samples from the Amazon. Initially, the isolates were evaluated in a screening for the production of colorants. The influences of cultivation and nutritional conditions on the production of colorants by fungal isolates were investigated. The colorants produced by selected fungal isolates were chemically characterized using the Liquid Chromatography‐Mass Spectrometry technique. The antimicrobial and cytotoxic activities, stability evaluation and applicability of the colorants were investigated. As results, we observed that the isolates Penicillium sclerotiorum P3SO224, Clonostachys rosea P2SO329 and Penicillium gravinicasei P3SO332 stood out since they produced the most intense colorants. Compounds produced by Penicillium sclerotiorum P3SO224 and Clonostachys rosea P2SO329 were identified as sclerotiorin and penicillic acid. The colorant fraction (EtOAc) produced by these species has antimicrobial activity, stability at temperature and at different pHs, stability when exposure to light and UV, and when exposed to different concentrations of salts, as well as being nontoxic and having the ability to dye fabrics and be used as a pigment in creams and soap. Considering the results found in this study, it was concluded that fungi from the soil in the Amazon have the potential to produce colorants with applications in the textile and pharmaceutical industries. [ABSTRACT FROM AUTHOR]

This study was focused on the identification and quantification of betaxanthins using high-performance liquid chromatography with a diode array detector coupled to electrospray ionisation mass spectrometry (HPLC-DAD-ESI-MS) in leaves of various cultivars of Beta vulgaris (beet) and Gymnocalycium mihanovichi i grafted cacti. In G. mihanovichii grafted cacti, four betaxanthins, namely histidine-Bx, histamine-Bx, serine-Bx, and proline-Bx, were tentatively identified in the yellow, orange, pink, and red varieties, with contents ranging from 0.09 to 1.55 mg/kg fresh weight (FW). Betaxanthins were not detected in the green cactus. Histidine-Bx was the prevailing betaxanthin compound in the majority of cultivars. Fifteen betaxanthins were successfully identified in the leaves of five B. vulgaris cultivars (cv.): Snow Ball, Boldor, Cylindra, Rhubarb, and Round Dark Red. Leaves of yellow beet (cv. Boldor) had the highest total betaxanthin content (20.4 mg/kg FW), while white beet (cv. Snow Ball) had the lowest one (3.43 mg/kg FW). The leaves of red cultivars had comparable betaxanthin contents, ranging from 13.4 to 18.8 mg/kg FW, similary to the yellow cultivar, indicating their potential as valuable sources of betaxanthins. There was no single dominant betaxanthin in B. vulgaris leaves. The leaves of B. vulgaris were found to be a richer source of betaxanthin than the grafted cactus G. mihanovichii , which opens up new prospects for research into the potential utilization of these compounds in the industry.

Due to the high stability of azo-type dyes, conventional treatment processes such as adsorption, flocculation, and activated sludge are not efficient for decolorizing wastewater effluents. An alternative to traditional wastewater treatment is photocatalysis, which has gained significant interest because research has shown it to be a viable and cost-effective process that uses sunlight as an inexhaustible energy source. In heterogeneous photocatalysis, a photocatalyst is required, such as TiO2, ZnO, composite materials, and, more recently, metal–organic frameworks (MOFs). MOFs, also known as “coordination polymers”, exhibit photocatalytic properties and have been proven to be promising materials in the photocatalytic degradation of dyes. This study presents recent advances in using MOFs as photocatalysts to degrade recalcitrant contaminants like azo-type dyes. Recent advancements in developing photocatalysts based on MOFs are focused on two strategies. Firstly, the development of new MOFs composed of complex ligands or a mixed ligand system, and secondly, the synthesis of composite materials based on MOFs and metal oxides, metals, sulfides, nitrides, etc. Both strategies have significantly contributed to the search for new semiconductors to degrade some recalcitrate contaminants in wastewater.

Anthocyanins are water-soluble pigments found in plants. They exist in various colors, including red, purple, and blue, and are utilized as natural colorants in the food and cosmetics industries. The pharmaceutical industry uses anthocyanins as therapeutic compounds because they have several medicinal qualities, including anti-obesity, anti-cancer, antidiabetic, neuroprotective, and cardioprotective effects. Anthocyanins are conventionally procured from colored fruits and vegetables and are utilized in the food, pharmaceutical, and cosmetic industries. However, the composition and concentration of anthocyanins from natural sources vary quantitively and qualitatively; therefore, plant cell and organ cultures have been explored for many decades to understand the production of these valuable compounds. A great deal of research has been carried out on plant cell cultures using varied methods, such as the selection of suitable cell lines, medium optimization, optimization culture conditions, precursor feeding, and elicitation for the production of anthocyanin pigments. In addition, metabolic engineering technologies have been applied for the hyperaccumulation of these compounds in varied plants, including tobacco and arabidopsis. In this review, we describe various strategies applied in plant cell and organ cultures for the production of anthocyanins. [ABSTRACT FROM AUTHOR]

Fabric is a commonly found piece of physical evidence at most crime scenes. Forensic analysis of fabric is typically performed via microscopic examination. This subjective approach is primarily based on pattern recognition and, therefore, is often inconclusive. Most of the fabric material found at crime scenes is colored. One may expect that a confirmatory identification of dyes can be used to enhance the reliability of the forensic analysis of fabric. In this study, we investigated the potential of near-infrared Raman spectroscopy (NIRS) in the confirmatory, non-invasive, and non-destructive identification of 15 different dyes on cotton. We found that NIRS was able to resolve the vibrational fingerprints of all 15 colorants. Using partial-squared discriminant analysis (PLS-DA), we showed that NIRS enabled ~100% accurate identification of dyes based on their vibrational signatures. These findings open a new avenue for the robust and reliable forensic analysis of dyes on fabric directly at crime scenes. Main conclusion: a hand-held Raman spectrometer and partial least square discriminant analysis (PLS-DA) approaches enable highly accurate identification of dyes on fabric. [ABSTRACT FROM AUTHOR]

The present study aimed to identify adulteration of honey with sugar syrups and colorants using UV–Vis spectroscopy, combined with multivariate statistical analysis. A total of 209 honeys were used, including 151 commercial honey samples (thyme, pine, and polyfloral honeys) collected from different countries of Mediterranean (Greece, Malta, Spain, Tunisia, and Turkey) and 58 adulterated Greek thyme honey samples by adding syrups and colorants. Honey adulteration was identified using Principal Component Analysis (PCA) along with Random Forest (RF), Partial Least Squares – Discriminant Analysis (PLS-DA), and Data Driven-Soft Independent Modelling of Class Analogies (DD-SIMCA) using the spectral range of 220–550 nm. Comparatively, DD-SIMCA models produced better results in terms of accuracy and sensitivity in most cases evaluated. The results support the good predictive capability of UV–Vis spectroscopy combined with chemometrics for the determination of honey adulteration, and thus, it could be utilized as a rapid, inexpensive, and simple method. [ABSTRACT FROM AUTHOR]

Due to the high stability of azo-type dyes, conventional treatment processes such as adsorption, flocculation, and activated sludge are not efficient for decolorizing wastewater effluents. An alternative to traditional wastewater treatment is photocatalysis, which has gained significant interest because research has shown it to be a viable and cost-effective process that uses sunlight as an inexhaustible energy source. In heterogeneous photocatalysis, a photocatalyst is required, such as TiO2, ZnO, composite materials, and, more recently, metal–organic frameworks (MOFs). MOFs, also known as "coordination polymers", exhibit photocatalytic properties and have been proven to be promising materials in the photocatalytic degradation of dyes. This study presents recent advances in using MOFs as photocatalysts to degrade recalcitrant contaminants like azo-type dyes. Recent advancements in developing photocatalysts based on MOFs are focused on two strategies. Firstly, the development of new MOFs composed of complex ligands or a mixed ligand system, and secondly, the synthesis of composite materials based on MOFs and metal oxides, metals, sulfides, nitrides, etc. Both strategies have significantly contributed to the search for new semiconductors to degrade some recalcitrate contaminants in wastewater. [ABSTRACT FROM AUTHOR]

Natural additives are a core topic of food science due to their food safety aspects, and among the natural additives, colorants and antioxidants stand out. The aim of this study was to verify the potential effect of naturally colored antioxidants extracted from Moringa oleifera leaves, propolis and grape pomace on the shelf life of chicken paté. The parameters of TBARS, total volatile basic nitrogen (TVB-N), pH and color were monitored in the paté during 35 days of cold storage at a temperature of 4 ± 1 °C. Moringa extracts, which produced the highest yields, provided a more colorful food product. Grape pomace showed the greatest antioxidant potential and was more efficient in inhibiting lipid oxidation. TVB-N levels remained within the limit considered safe for food in all applications. The total color difference was greater in the first weeks in all treatments, emphasizing that the red grape pomace showed greater color stability.

Natural ingredients have been used for centuries for skin treatment and care. Interest in the health effects of plants has recently increased due to their safety and applicability in the formulation of pharmaceuticals and cosmetics. Long-known plant materials as well as newly discovered ones are increasingly being used in natural products of plant origin. This review highlights the beneficial effects of plants and plant constituents on the skin, including moisturizing (e.g., Cannabis sativa, Hydrangea serrata, Pradosia mutisii and Carthamus tinctorius), anti-aging (e.g., Aegopodium podagraria, Euphorbia characias, Premna odorata and Warburgia salutaris), antimicrobial (e.g., Betula pendula and Epilobium angustifolium), antioxidant (e.g., Kadsura coccinea, Rosmarinus officinalis, Rubus idaeus and Spatholobus suberectus), anti-inflammatory (e.g., Antidesma thwaitesianum, Helianthus annuus, Oenanthe javanica, Penthorum chinense, Ranunculus bulumei and Zanthoxylum bungeanum), regenerative (e.g., Aloe vera, Angelica polymorpha, Digitaria ciliaris, Glycyrrihza glabra and Marantodes pumilum), wound healing (e.g., Agrimonia eupatoria, Astragalus floccosus, Bursera morelensis, Jatropha neopauciflora and Sapindus mukorossi), photoprotective (e.g., Astragalus gombiformis, Calea fruticose, Euphorbia characias and Posoqueria latifolia) and anti-tyrosinase activity (e.g., Aerva lanata, Bruguiera gymnorhiza, Dodonaea viscosa, Lonicera japonica and Schisandra chinensis), as well as their role as excipients in cosmetics (coloring (e.g., Beta vulgaris, Centaurea cyanus, Hibiscus sabdariffa and Rubia tinctiorum), protective and aromatic agents (e.g., Hyssopus officinalis, Melaleuca alternifolia, Pelargonium graveolens and Verbena officinalis)). [ABSTRACT FROM AUTHOR]

This study was focused on the identification and quantification of betaxanthins using high-performance liquid chromatography with a diode array detector coupled to electrospray ionisation mass spectrometry (HPLC-DAD-ESI-MS) in leaves of various cultivars of Beta vulgaris (beet) and Gymnocalycium mihanovichii grafted cacti. In G. mihanovichii grafted cacti, four betaxanthins, namely histidine-Bx, histamine-Bx, serine-Bx, and proline-Bx, were tentatively identified in the yellow, orange, pink, and red varieties, with contents ranging from 0.09 to 1.55 mg/kg fresh weight (FW). Betaxanthins were not detected in the green cactus. Histidine-Bx was the prevailing betaxanthin compound in the majority of cultivars. Fifteen betaxanthins were successfully identified in the leaves of five B. vulgaris cultivars (cv.): Snow Ball, Boldor, Cylindra, Rhubarb, and Round Dark Red. Leaves of yellow beet (cv. Boldor) had the highest total betaxanthin content (20.4 mg/kg FW), while white beet (cv. Snow Ball) had the lowest one (3.43 mg/kg FW). The leaves of red cultivars had comparable betaxanthin contents, ranging from 13.4 to 18.8 mg/kg FW, similarly to the yellow cultivar, indicating their potential as valuable sources of betaxanthins. There was no single dominant betaxanthin in B. vulgaris leaves. The leaves of B. vulgaris were found to be a richer source of betaxanthin than the grafted cactus G. mihanovichii. [ABSTRACT FROM AUTHOR]

The perception of light and color is an omnipresent phenomenon of everyday life. Therefore, students develop their own concepts or ideas about the nature of these phenomena at an early age. These concepts or ideas influence the way students perceive and understand light and color. Pre‐existing concepts have a significant influence on the learning process. Hence, it is important to take these into account when designing teaching and learning materials in order to address these concepts specifically. One method to support the learning process is the use of interactive visualizations that enable students to experience phenomena in a more targeted way and to question and/or extend their existing concepts. This article therefore, deals with the conception and development of interactive visualizations on the topic of light and color and presents possible implementations into the chemistry classroom. [ABSTRACT FROM AUTHOR]

In this study, rice straw (RS) and cow dung (CD) waste were hydrothermally processed for the recovery of bio-oil and biochar. The hydrothermal experiments were performed in a 5 L capacity reactor under the following process conditions: temperature (240–340 °C), solvent to biomass ratios of 1:1, 1:2, 2:1, 1:3 and 3:1, a time of 1 h and a pressure of 15 bar. The HTL products were characterized via FTIR, SEM and GC–MS (gas chromatography mass spectrometry). It was seen that the maximum bio-oil yield was 32.5 wt% and the biochar yield was 18.5 wt% for the 2:1 RS:CD mixture at a temperature of 320 °C. The bio-oil contained hexadecane, heptadecane, octadecane and other hydrocarbons, and their presence was confirmed by GC–MS. The biochar was analyzed, and it was used in wastewater treatment to remove the colorants. The biochar also showed some promising results in the colorants removal study, with an efficiency of more than 76%. [ABSTRACT FROM AUTHOR]

Drying the biomass produced is one of the critical steps to avoid cell degradation; however, its high energy cost is a significant technological barrier to improving this type of bioprocess's technical and economic feasibility. This work explores the impact of the biomass drying method of a strain of Potamosiphon sp. on the extraction efficiency of a phycoerythrin-rich protein extract. To achieve the above, the effect of time (12–24 h), temperature (40–70 °C), and drying method (convection oven and dehydrator) were determined using an I-best design with a response surface. According to the statistical results, the factors that most influence the extraction and purity of phycoerythrin are temperature and moisture removal by dehydration. The latter demonstrates that gentle drying of the biomass allows removing the most significant amount of moisture from the biomass without affecting the concentration or quality of temperature-sensitive proteins. [ABSTRACT FROM AUTHOR]

Natural colorants, mostly of plant and fungal origins, offer advantages over chemically synthetic colorants in terms of alleviating environmental pollution and promoting human health. The market value of natural colorants has been increasing significantly across the globe. Due to the ease of artificially culturing most fungi in the laboratory and in industrial settings, fungi have emerged as the organisms of choice for producing many natural colorants. Indeed, there is a wide variety of colorful fungi and a diversity in the structure and bioactivity of fungal colorants. Such broad diversities have spurred significant research efforts in fungi to search for natural alternatives to synthetic colorants. Here, we review recent research on the genetic and environmental factors influencing the production of three major types of natural fungal colorants: carotenoids, melanins, and polyketide-derived colorants. We highlight how molecular genetic studies and environmental condition manipulations are helping to overcome some of the challenges associated with value-added and large-scale productions of these colorants. We finish by discussing potential future trends, including synthetic biology approaches, in the commercial production of fungal colorants. [ABSTRACT FROM AUTHOR]

This study aims to take advantage of the wine industry by-products and extract bioactive compounds from grape pomace by applying methodologies susceptible to be integrated easily into industrial workflows because of the association with standard instrumentation and facilities, while the main factors affecting the efficiency of the process have been optimized. The sampling consisted of two grape varieties: 'Touriga Nacional' and 'Sousão'. A response surface methodology (RSM) method was used to optimize the extraction conditions based on three independent variables according to the chemical characteristics and stability/lability traits associated with polyphenols; the main bioactive phytochemical in grape pomace: solvent (50%, 70%, and 90% ethanol); temperature (20 °C, 40 °C, and 60 °C); and pH (0.5% HCl, 2% HCl, and 3.5% HCl). The phytochemical profile, as well as the radical scavenging and reducing powers were determined on 27 different samples. The highest yield and antioxidant activity corresponded to extracts obtained at 60 °C using 3.5% HCl and 70% ethanol. The values for total phenols and flavonoids were 44.93 mg of gallic acid equivalents (GAE) and 22.95 mg of catechins equivalents (CE) per gram, respectively. Concerning the evaluation of antioxidant capacity using various assays such as ABTS, DPPH, and FRAP, the results obtained were 0.30, 0.43, and 0.36 mmol of Trolox equivalent antioxidant capacity (TEAC) per gram, correspondingly. The analysis of the extract obtained with the best extraction performance using these parameters via High-Performance Liquid Chromatography–Mass Spectrometry has been also performed, allowing us to identify fourteen (14) compounds, including phenolic acids (n = 3), flavonols (n = 7), and anthocyanins (n = 4). As a result of this process, the best conditions for the production of a natural and environmentally friendly dye, not only avoiding waste but also reusing these by-products, were achieved. [ABSTRACT FROM AUTHOR]

Confirmatory identification of hair colorants can be used to establish a connection between a suspect and the crime science or demonstrate the absence of such connections. A growing body of evidence shows that surface‐enhanced Raman spectroscopy (SERS) could be a confirmatory, minimally destructive, and fully noninvasive analysis of hair colorants. In SERS, a signal that provide the information about the chemical structure of both permanent and semipermanent dyes present on hair is enhanced by a million‐fold using noble metal nanostructures. However, it is unclear whether the information of hair colorants can be revealed if hair was contaminated or exposed to harsh environments such as sunlight and heat. In this work, we determine the effect of a short‐ and long‐term heat exposure on SERS‐based analysis of hair colored with blue and red permanent and semipermanent dyes. We found that short and especially long‐term heat exposure at 220°C could alter chemical structure, and consequently SERS spectra, of permanent and semipermanent colorants. This thermal degradation of permanent dyes complicates their direct identification using SERS. We also found that partial least squares discriminant analysis can be used to overcome this issue allowing for highly accurate identification of both permanent and semipermanent dyes on colored hair that was exposed to 220°C for 6–12 min. These results show that heat exposure of colored hair should be strongly considered upon their SERS‐based examination to avoid both false positive or false negative identification of chemical dyes. [ABSTRACT FROM AUTHOR]

Biotechnologically produced carotenoids occupy an important place in the scientific research. Owing to their role as natural pigments and their high antioxidant properties, microbial carotenoids have been proposed as alternatives to their synthetic counterparts. To this end, many studies are focusing on their efficient and sustainable production from renewable substrates. Besides the development of an efficient upstream process, their separation and purification as well as their analysis from the microbial biomass confers another important aspect. Currently, the use of organic solvents constitutes the main extraction process; however, environmental concerns along with potential toxicity towards human health necessitate the employment of "greener" techniques. Hence, many research groups are focusing on applying emerging technologies such as ultrasounds, microwaves, ionic liquids or eutectic solvents for the separation of carotenoids from microbial cells. This review aims to summarize the progress on both the biotechnological production of carotenoids and the methods for their effective extraction. In the framework of circular economy and sustainability, the focus is given on green recovery methods targeting high-value applications such as novel functional foods and pharmaceuticals. Finally, methods for carotenoids identification and quantification are also discussed in order to create a roadmap for successful carotenoids analysis. [ABSTRACT FROM AUTHOR]

The concept of the presented research was to assess the applicability of natural colorants in dyeing biocomposites filled with natural fillers. As dyes, ground coffee, turmeric, couscous and ground paprika were used. Additionally, wood flour and walnut shell flour were added to improve strength parameters. The fillers were not dyed prior to processing, but the pigments were processed with the matrix and the filler. The optical observation and the influence of steam sterilization on mechanical properties were carried out, taking into consideration esthetics and performance of the product. The results showed that natural colorants can be successfully used to dye composites. Low-density biocomposites with increased rigidity were obtained. Composites were characterized by lower tensile strength than neat green polyethylene which was approximately 18 MPa. The high result for tensile modulus was obtained for composition with coffee – it increased to 2045 MPa.

Natural pigments and colorants have seen a substantial increase in use over the last few decades due to their eco-friendly and safe properties. Currently, customer preferences for more natural products are driving the substitution of natural pigments for synthetic colorants. Filamentous fungi, particularly ascomycetous fungi (Monascus, Fusarium, Penicillium, and Aspergillus), have been shown to produce secondary metabolites containing a wide variety of pigments, including β-carotene, melanins, azaphilones, quinones, flavins, ankaflavin, monascin, anthraquinone, and naphthoquinone. These pigments produce a variety of colors and tints, including yellow, orange, red, green, purple, brown, and blue. Additionally, these pigments have a broad spectrum of pharmacological activities, including immunomodulatory, anticancer, antioxidant, antibacterial, and antiproliferative activities. This review provides an in-depth overview of fungi gathered from diverse sources and lists several probable fungi capable of producing a variety of color hues. The second section discusses how to classify coloring compounds according to their chemical structure, characteristics, biosynthetic processes, application, and present state. Once again, we investigate the possibility of employing fungal polyketide pigments as food coloring, as well as the toxicity and carcinogenicity of particular pigments. This review explores how advanced technologies such as metabolic engineering and nanotechnology can be employed to overcome obstacles associated with the manufacture of mycotoxin-free, food-grade fungal pigments. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Limited information was available on the quality and safety profile of tea in China, even though food quality and safety of tea is an issue of great concern to consumers and the public. Stochastic Bayesian modeling was employed in this study to investigate food quality and safety profile of tea in China market. Results indicated that the overall nonconforming rate (95 % CI, confidence interval) of tea was 2.6 ‰ (1.3 ‰ to 4.5 ‰), indicating a high level for the quality and safety status of tea in market. Pesticide residues exceeding maximal limit (MRLs) was the major cause leading to nonconformity of tea, with estimated incidences (95 % CI) of 11.7 ‰ (0.5 ‰ to 53.2 ‰), 1.1 ‰ (0.4 ‰ to 2.0 ‰), 2.3 ‰ (0.6 ‰ to 5.5 ‰), and 0.55 ‰ (0.06 ‰ to 1.51 ‰), respectively, for Yellow tea, Green tea, and Oolong tea; whereas illegal application of additives was more likely to occur in black tea, with an incidence of 1.1 ‰ (0.4 ‰ to 2.7 ‰), despite that an estimated incidence of 2.9 ‰ (0.4 ‰ to 16.1 ‰) was generated for Yellow tea due to fewer inspects and small sample sizes involved for analysis. The difference in quality and safety status of tea between provinces was statistically insignificant, as indicated by overlapped 95 % CIs of nonconforming rates. Results of this study provided reliable information on quality and safety profile of tea in China market, and suggested that application of pesticides during tea plantation and illegal use of additives during black tea production worth more attention in respect of quality and safety of tea. [ABSTRACT FROM AUTHOR]

Anthocyanins are water-soluble pigments found in plants. They exist in various colors, including red, purple, and blue, and are utilized as natural colorants in the food and cosmetics industries. The pharmaceutical industry uses anthocyanins as therapeutic compounds because they have several medicinal qualities, including anti-obesity, anti-cancer, antidiabetic, neuroprotective, and cardioprotective effects. Anthocyanins are conventionally procured from colored fruits and vegetables and are utilized in the food, pharmaceutical, and cosmetic industries. However, the composition and concentration of anthocyanins from natural sources vary quantitively and qualitatively; therefore, plant cell and organ cultures have been explored for many decades to understand the production of these valuable compounds. A great deal of research has been carried out on plant cell cultures using varied methods, such as the selection of suitable cell lines, medium optimization, optimization culture conditions, precursor feeding, and elicitation for the production of anthocyanin pigments. In addition, metabolic engineering technologies have been applied for the hyperaccumulation of these compounds in varied plants, including tobacco and arabidopsis. In this review, we describe various strategies applied in plant cell and organ cultures for the production of anthocyanins.

Fabric is a commonly found piece of physical evidence at most crime scenes. Forensic analysis of fabric is typically performed via microscopic examination. This subjective approach is primarily based on pattern recognition and, therefore, is often inconclusive. Most of the fabric material found at crime scenes is colored. One may expect that a confirmatory identification of dyes can be used to enhance the reliability of the forensic analysis of fabric. In this study, we investigated the potential of near-infrared Raman spectroscopy (NIRS) in the confirmatory, non-invasive, and non-destructive identification of 15 different dyes on cotton. We found that NIRS was able to resolve the vibrational fingerprints of all 15 colorants. Using partial-squared discriminant analysis (PLS-DA), we showed that NIRS enabled ~100% accurate identification of dyes based on their vibrational signatures. These findings open a new avenue for the robust and reliable forensic analysis of dyes on fabric directly at crime scenes. Main conclusion: a hand-held Raman spectrometer and partial least square discriminant analysis (PLS-DA) approaches enable highly accurate identification of dyes on fabric.

Forensic analysis of hair is important as hair is one of the most commonly examined forms of trace evidence found at crime scenes. A growing body of evidence suggests that surface‐enhanced Raman spectroscopy (SERS), a label‐free and non‐destructive analytical technique, can be used to detect and identify artificial colorants present on hair. However, hair collected at crime scenes is often contaminated by substances of biological and non‐biological origin present at such locations. In this study, we investigate the extent to which four contaminants, saliva, blood, dirt, and bleach can alter the accuracy of SERS‐based detection and identification of both permanent and semi‐permanent colorants present on hair. Our findings show that saliva and dirt reduce the intensity of the colorants' signals but do not obscure their detection and identification. At the same time, an exposure of the colored hair to bleach or the presence of blood eliminates SERS‐based analysis of artificial dyes present on such samples. We identified the procedure that can be used to remove blood contamination, which, in turn, enables identification of the hair colorants on such pre‐cleaned samples. However, bleach treatment irreversibly eliminates SERS‐based detection of artificial colorants on hair. These findings expand our understandings about the potential of SERS in forensic investigation of colorants on trace hair evidence. [ABSTRACT FROM AUTHOR]

Copyright of Revista Ciencia y Tecnología Agropecuaria is the property of Agrosavia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The influence of stabilizing activity of citric buffers on betacyanins, as well as their thermal dehydrogenation and decarboxylation in a beetroot betalain-rich extract (BRE), was studied at pH 3–8 and temperature 30, 50 and 85 °C with an additional effect of EDTA. In acetate/phosphate buffers, the highest stability is observed at pH 5 and it decreases toward pH 3 as well as pH 8, which is more remarkable at 85 °C. For the citrates, a contradictory effect was observed. Citric buffers tend to stabilize the substrate pigments and their intermediary products in acidic solutions, although increase their reactivity at pH 6–8. The highest impact of EDTA addition on pigment retention in acetate buffers is observed at 85 °C and pH 3–5 as well as 8, reflecting the preserving activity of EDTA at the most unfavorable conditions. At lower temperatures, pigment stability in more acidic conditions is still at higher levels even without addition of citrates or EDTA. The most striking effect on generation of betanin derivatives during heating is 2-decarboxylation which preferentially proceeds in the most acidic environment and this generation rate at 85 °C is much higher in the citrate buffers compared to acetates. [ABSTRACT FROM AUTHOR]

The public expected color from the early photographic images, yet, daguerreotypes—the first commercially available photographic process—failed to register the natural colors. Daguerreotypists developed several coloring methods to solve this inconvenience after 1840. Scientific analyses of the hand-colored daguerreotypes are limited, and the primary information sources available are manuals and patents. This study aims to contribute to the knowledge of hand-coloring techniques, which impacts conservation practices, mainly the cleaning procedures and complements technical art history investigations. We studied nine colored daguerreotypes with a non-invasive methodology based on three spectroscopic techniques: X-ray fluorescence (XRF), micro-Raman spectroscopy (μ-Raman), and micro-Fourier-transform infrared spectroscopy in reflection mode (μ-rFTIR). The results revealed the different colorants and some of their mixtures employed by the colorist. It also adds information regarding the photographic production of three studios: Désiré François Millet, active in Paris between 1840 and 1868; Antoine Claudet (1797–1867), active in London; and the James E. McClees and Washington Lafayette Germon studio, operative between 1846 and 1855 in Philadelphia, USA. These technical details constitute a helpful comparison to future studies on Daguerreian studios and colored daguerreotypes. [ABSTRACT FROM AUTHOR]

Balancing physicochemical properties and sensory properties is one of the key points in expanding edible packaging applications. The work consisted of two parts, one was to investigate the effects of cellulose nanocrystals (CNC) on the packaging-related properties of whey protein isolate films with natural colorants (curcumin, phycocyanin, and lycopene) under freeze-thaw (FT) conditions; the other was to test oral tactility and visual sensory properties of the edible films and their overall acceptability in packed ice cream. FT treatment reduced the mechanical strength and moisture content and increased the water vapor permeability of the films, as water-phase transformation not only disrupted hydrogen bonds but also the film network structure through physical stress. The oral tactility produced by CNC and the visual effect produced by colorants could affect participants' preference for edible films. This study provides a good reference for the consumer-driven product development of packaged low-temperature products. [ABSTRACT FROM AUTHOR]

During antiquity, it is known that glass was produced in specialized primary workshops in Levant and Egypt, and this glass was melted and formed into objects in secondary workshops, and distributed in most cities and towns of the Roman Empire. Great efforts, although it is difficult, have been made to distinguish where it was produced. In this study, we perform chemical analysis on 48 glass samples (22 moils and 26 glass artefacts) dated to the 6th century CE from Vasileos Irakleiou Street, 45, Thessaloniki in northern Greece by using Scanning Electron Microscopy (SEM) with Energy–Dispersive X-ray microanalysis (EDX). All glasses were produced with natron as a flux and based on the sodium oxide content we divided them into two groups. Most of the glasses' chemical analysis indicates that they originated from Egypt, and can be categorized as HIMT and others as Roman Mn or Roman Mn-Sb. MnO is the main decolorizer, while in some samples MnO coexists with Sb2O3. Finally, recycling processes are evident in most of the samples. [ABSTRACT FROM AUTHOR]

Titanium dioxide (in the form of E171) is a ubiquitous excipient in tablets and capsules for oral use. In the coating of a tablet or in the shell of a capsule the material disperses visible and UV light so that the contents are protected from the effects of light, and the patient or caregiver cannot see the contents within. It facilitates elegant methods of identification for oral solid dosage forms, thus aiding in the battle against counterfeit products. Titanium dioxide ensures homogeneity of appearance from batch to batch fostering patient confidence. The ability of commercial titanium dioxide to disperse light is a function of the natural properties of the anatase polymorph of titanium dioxide, and the manufacturing processes used to produce the material utilized in pharmaceuticals. In some jurisdictions E171 is being considered for removal from pharmaceutical products, as a consequence of it being delisted as an approved colorant for foods. At the time of writing, in the view of the authors, no system or material which could address both current and future toxicological concerns of Regulators and the functional needs of the pharmaceutical industry and patients has been identified. This takes into account the assessment of materials such as calcium carbonate, talc, isomalt, starch and calcium phosphates. In this paper an IQ Consortium team outlines the properties of titanium dioxide and criteria to which new replacement materials should be held. [ABSTRACT FROM AUTHOR]

Use of dyes as well as colorants in industrial processes has extensively increased. Effluents from various industries such as textile, paint, food, etc. are reported to have a diverse range of colorants. The effluents from these industries are often released into natural water bodies, causing serious water and environmental pollution, to which humans and other species are constantly exposed. Continued changes in climate have also affected water availability for people around the world. Thus, advanced treatments and removal of harmful contaminants from municipal and industrial wastewater are becoming increasingly important. Removal of dyes and colorants from wastewater can be done in a variety of ways, including physical, chemical, and biological treatments. These technologies, however, differ in terms of efficiency, cost, and environmental effect. There are many technological and economic challenges for the wastewater treatment methods currently available. The search for the most suitable strategy for successful degradation or removal of dyes from effluents is an urgent requirement. Previously published research suggests that the use of enzymes for dye removal is a more economic and effective strategy as compared to traditional techniques. Nanoparticles, with their exceptional physicochemical features, have the potential to tackle the problem of wastewater purification in a less energy-intensive way. However, extensive standardization would be a necessity for the use of different nanoparticles. Therefore, intense research in the use of enzymes and nanoparticle-based technologies may provide much needed technological solution for the remediation of a diverse range of dyes from wastewater. [ABSTRACT FROM AUTHOR]

The concept of the presented research was to assess the applicability of natural colorants in dyeing biocomposites filled with natural fillers. As dyes, ground coffee, turmeric, couscous and ground paprika were used. Additionally, wood flour and walnut shell flour were added to improve strength parameters. The fillers were not dyed prior to processing, but the pigments were processed with the matrix and the filler. The optical observation and the influence of steam sterilization on mechanical properties were carried out, taking into consideration esthetics and performance of the product. The results showed that natural colorants can be successfully used to dye composites. Low-density biocomposites with increased rigidity were obtained. Composites were characterized by lower tensile strength than neat green polyethylene which was approximately 18 MPa. The high result for tensile modulus was obtained for composition with coffee – it increased to 2045 MPa. [ABSTRACT FROM AUTHOR]

This work aimed to study petiole palm tree wastes (PTW) efficiency in removing two basic dyes: Rhodamine B (RB) and Victoria blue B (VBB) from aqueous solutions in single and binary systems under various experimental conditions including the effect of contact time, pH, initial concentration, and temperature. The PTW characterization shows that the PTW is a lingo-cellulosic material. The experimental results indicate that the removal of both dyes was relatively fast, spontaneous, exothermic and occurred on monolayers. Moreover, the adsorption competition between these two dyes on the adsorbent particles surface was important since the Langmuir's adsorption capacities were evaluated to 260.1; 440.1; 168.0; and 417.4 mg/g for RB and VBB in single and binary systems, respectively. These adsorption capacities, even in binary systems, are interesting compared to other raw materials and prove that this abundant agricultural waste can be considered as a promising material for an efficient dyes removal from aqueous effluents. [ABSTRACT FROM AUTHOR]

Betalains in bracts of Bougainvillea are of great application potential as natural food colorants and antioxidants. This study explored the color, spectra, composition, storage stability, and antioxidant properties of betalain-based Bougainvillea bracts extracts (BBEs) to verify their application value. The results showed that Bougainvillea bract color variance is due to varied contents and proportions of betacyanins (Bc) and betaxanthins (Bx). Bc or Bx alone determined hues of purple or yellow, respectively; the co-existence of Bc and Bx would produce varied hues of red. BBEs showed bright color and good antioxidant properties under a wide pH range. The pH range of 5–6 was optimal for the highest color stability, and pHs 3–8 were optimal for stronger antioxidants. Bc mainly underwent color fading during storage, while Bx easily produced dark precipitates or melanism under strong acidic (pH < 4) or alkaline conditions (pH > 8). However, Bougainvillea Bx showed 3–4 times higher antioxidant ability than Bc. Different considerations for Bc and Bx are needed for varied application purposes. The purple bracts containing only Bc would be more suitable as colorant sources, while additional Bx can bring enhancement of antioxidant ability and richness of Bougainvillea extract color. [ABSTRACT FROM AUTHOR]

Natural colorants, mostly of plant and fungal origins, offer advantages over chemically synthetic colorants in terms of alleviating environmental pollution and promoting human health. The market value of natural colorants has been increasing significantly across the globe. Due to the ease of artificially culturing most fungi in the laboratory and in industrial settings, fungi have emerged as the organisms of choice for producing many natural colorants. Indeed, there is a wide variety of colorful fungi and a diversity in the structure and bioactivity of fungal colorants. Such broad diversities have spurred significant research efforts in fungi to search for natural alternatives to synthetic colorants. Here, we review recent research on the genetic and environmental factors influencing the production of three major types of natural fungal colorants: carotenoids, melanins, and polyketide-derived colorants. We highlight how molecular genetic studies and environmental condition manipulations are helping to overcome some of the challenges associated with value-added and large-scale productions of these colorants. We finish by discussing potential future trends, including synthetic biology approaches, in the commercial production of fungal colorants.

This study aims to take advantage of the wine industry by-products and extract bioactive compounds from grape pomace by applying methodologies susceptible to be integrated easily into industrial workflows because of the association with standard instrumentation and facilities, while the main factors affecting the efficiency of the process have been optimized. The sampling consisted of two grape varieties: ‘Touriga Nacional’ and ‘Sousão’. A response surface methodology (RSM) method was used to optimize the extraction conditions based on three independent variables according to the chemical characteristics and stability/lability traits associated with polyphenols; the main bioactive phytochemical in grape pomace: solvent (50%, 70%, and 90% ethanol); temperature (20 °C, 40 °C, and 60 °C); and pH (0.5% HCl, 2% HCl, and 3.5% HCl). The phytochemical profile, as well as the radical scavenging and reducing powers were determined on 27 different samples. The highest yield and antioxidant activity corresponded to extracts obtained at 60 °C using 3.5% HCl and 70% ethanol. The values for total phenols and flavonoids were 44.93 mg of gallic acid equivalents (GAE) and 22.95 mg of catechins equivalents (CE) per gram, respectively. Concerning the evaluation of antioxidant capacity using various assays such as ABTS, DPPH, and FRAP, the results obtained were 0.30, 0.43, and 0.36 mmol of Trolox equivalent antioxidant capacity (TEAC) per gram, correspondingly. The analysis of the extract obtained with the best extraction performance using these parameters via High-Performance Liquid Chromatography–Mass Spectrometry has been also performed, allowing us to identify fourteen (14) compounds, including phenolic acids (n = 3), flavonols (n = 7), and anthocyanins (n = 4). As a result of this process, the best conditions for the production of a natural and environmentally friendly dye, not only avoiding waste but also reusing these by-products, were achieved.