Search Results (345)

Safflower (Carthamus tinctorius L.) is increasingly attracting the attention of Mediterranean farmers due to its broad environmental adaptability and low input requirements. Although still relatively underexplored, this species holds remarkable potential as a source of natural dyes and bioactive phytochemicals with recognized health-promoting and phytotherapeutic properties. In this study, the effects of genotype and sowing time on safflower’s productive and qualitative traits were investigated by testing six genotypes and two sowing times (autumn and spring) in an open-field trial conducted in central Tuscany. The Pieve genotype achieved the highest floret dry yield per head, number of heads per plant, and total floret yield per plant, whereas the Montola 2000 genotype was distinguished by its elevated polyphenol concentration and pronounced antioxidant activity. Autumn sowing resulted in higher yields of bioactive pigments, including carthamin and yellow quinochalcones, alongside greater total phenolic content and antioxidant capacity. Conversely, spring sowing appeared to limit pigment biosynthesis, likely due to environmental stressors such as elevated temperature and excessive light exposure. Overall, these findings highlight the strong influence of genotype and sowing time on the accumulation of health-beneficial compounds in safflower. By optimizing these factors, safflower can be strategically valorized as a multipurpose crop in the Mediterranean region, combining economic and environmental sustainability with the production of natural compounds of high nutraceutical and phytotherapeutic value. Full article

Beer is a drink that has been a staple in human history, evolving from its beginning in antiquity to the present day. Nowadays, large breweries and other companies have set up laboratories focused on finding and developing new yeast strains for the brewing sector to meet consumers’ demand for new beer styles. Monascus spp. are ascomycota that have been known for hundreds of years. They are widely popular in Asian cuisine, especially in fermented foods. Studies show that Monascus spp. produce numerous food dyes and substances that positively influence human health. In the presented work, Monascus ruber was tested as a potential microorganism for the beer industry. Experiments included fermentation trials with Monascus ruber in four regimes: in aerobic condition, anaerobic condition, anaerobic condition with pH kept above 4.5, and in anaerobic condition with pH set to 4.5. As a reference, commercial Saccharomyces cerevisiae and Saccharomyces pastorianus were used. Fermentation parameters were evaluated by measurements of ethanol and extract level. The final product was tested for its colour in order to evaluate if monascus-derived pigments were present in the beverage. Moreover, a qualitative analysis of lovastatin and citrinin was performed in order to check if those monascus metabolites were present. Finally, small-scale consumer tests were performed in order to check the organoleptic properties of the obtained beverage. Results show that Monascus ruber is able to ferment beer wort in a similar manner as Saccharomyces strains, reaching a slightly lower degree of attenuation. Nevertheless, a longer lag phase was observed in monascus trials, except for the trial with preset pH at 4.5. The most visible change in the product was a reddish colour that appeared in the sample in aerobic conditions. The qualitative analysis showed that lovastatin and citrinin were present in the tested samples. Consumer tests show that experimental beer has a different taste than Saccharomyces-fermented products. Although the presented results are preliminary, they could be a good starting point for further research on monascus-based beverages. Full article

The massive influx of pelagic Sargassum in the Caribbean poses a serious environmental, social, and economic problem, as the stranded biomass is often treated as waste and deposited in landfills. This literature review synthesizes recent research highlighting its potential for valorization in various industries, turning this challenge into an opportunity. Sargassum has low levels of protein and lipids. Still, it is particularly rich in carbohydrates, such as alginates, fucoidans, mannitol, and cellulose, as well as secondary metabolites, including phenolic compounds, flavonoids, pigments, and phytosterols with antioxidant and bioactive properties. These biochemical characteristics allow for its application in renewable energy (bioethanol, biogas, biodiesel, and combustion), agriculture (fertilizers and biostimulants), construction (composite materials, cement additives, and insulation), bioremediation (adsorption of heavy metals and dyes), and in the health sector (antioxidants, anti-inflammatories, and pharmacological uses). A major limitation is its high bioaccumulation capacity for heavy metals, particularly arsenic, which increases environmental and health risks and limits its direct use in food and feed. Therefore, innovative pretreatment and bioprocessing are essential to mitigate these risks. The most promising approach for its utilization is a biorefinery model, which allows for the sequential extraction of multiple high-value compounds and energy products to maximize benefits, reduce costs, and sustainably transform Sargassum from a coastal pest into a valuable industrial resource. Full article

Michler’s Ketone (MK) is widely utilized as an additive in pigments, dyes, and other colorants, and has become a non-negligible environmental presence. Currently, environmental monitoring data and toxicity data for MK are extremely limited, and its specific mechanisms of neurotoxicity remain poorly characterized. A zebrafish model was employed to systematically delineate the neurotoxic mechanisms of MK through the integration of network toxicology predictions, transcriptomic profiling, and RT-qPCR validation. The results demonstrated that MK exposure was found to induce oxidative stress in zebrafish larvae, which subsequently disrupted the calcium signaling pathway and triggered apoptosis, ultimately leading to neurodevelopmental and locomotor behavioral impairments. This study provides a fundamental basis for elucidating MK’s developmental neurotoxicity mechanisms, while also holding significant value for its ecological risk assessment. Full article

Natural dyes have emerged as a promising alternative to synthetic dyes for industrial applications due to their advantages, namely, easy availability, low cost, and environmental friendliness. In this sense, natural dyes, due to their potential to react over the pH range, could offer an alternative to conventional pH measuring techniques for industrial products, such as potentiometers, sensors, or indicator drops. Therefore, this project aims to evaluate the potential of several natural organic dyes in response to changes in pH and develop an indicator for determining pH grades. We extracted and analyzed the pigments of forty natural vegetable species using two extraction methods with a mixture of solvents, specifically 70% MeOH/30% H₂O. The results find that pigments of cabbage, hibiscus flower, radish, and turmeric in their dry state exhibit the best reaction over a broad pH range, and color can be easily distinguished according to its level. These findings demonstrate the potential of natural dyes as a novel approach for pH verification, providing a sustainable and cost-effective alternative to conventional techniques. Full article

The study and preservation of illuminated manuscripts, particularly miniatures on parchment, are crucial for understanding the artistic, cultural, and technological history of the past. This research investigates the materials used in a 16th-century illuminated scroll, analyzing both the miniatures and the written text through non-invasive techniques. A multi-analytical approach was applied, including optical microscopy, Hypercolorimetric Multispectral Imaging (HMI), infrared reflectography in the 950–1700 nm range, Fiber Optics Reflectance Spectroscopy (FORS), macro X-ray fluorescence (MA-XRF) spectroscopy, Raman spectroscopy, and External Reflection Fourier Transform Infrared (ER-FTIR) spectroscopy. These methods provided a comprehensive characterization of the painting materials’ chemical composition and the artistic techniques utilized, revealing new information on Renaissance materials and practices. The detected mineral pigments primarily include smalt, vermilion, lead white, and minium, which are consistent with materials commonly found in illuminated manuscripts. Aluminosilicate and calcite were identified as fillers or substrates utilized for organic dyes, particularly those generating pink hues. An uncommon finding was the green pigment, which was identified as copper hydroxynitrate. Furthermore, gold and silver were extensively employed in the decorative elements, both as metal foils and in shell pigment form. Finally, the capital letters were executed using smalt and vermilion, while the black text ink was characterized as iron gall ink, a composition typically employed on parchment supports. Full article

Brilliant blue, as a pigment food additive, has all the characteristics of printing and dyeing wastewater and belongs to persistent and refractory organic compounds. The photocatalysis–Fenton reaction system consists of two parts: photocatalytic reaction and Fenton reaction. Electrons promote the decomposition of H₂O₂ to produce •OH. In addition, the effective separation of e- and h⁺ by light strengthens the direct oxidation of h⁺, and h⁺ reacts directly with OH⁻ to produce •OH, which can further promote the removal of organic pollutants. In this paper, g-C₃N₄ and Fe/g-C₃N₄ photocatalysts were prepared by the thermal polycondensation method. Fe/g-C₃N₄ of 15 wt% can reach 98.59% under the best degradation environment, and the degradation rate of g-C₃N₄ is only 7.6% under the same conditions. The photocatalytic activity of the catalysts was further studied. Through active species capture experiments, it is known that •OH and •O₂⁻ are the main active species in the system, and the action intensity of •OH is greater than that of •O₂⁻. The degradation reaction mechanism is that H₂O₂ combines with Fe²⁺ in Fe/g-C₃N₄ to generate a large amount of •OH and Fe³⁺, and the combination of Fe-N bonds accelerates the cycle of Fe³⁺/Fe²⁺ and promotes the formation of •OH, thereby accelerating the degradation of target pollutants. •O₂⁻ can reduce Fe³⁺ to Fe²⁺, Fe²⁺ reacts with H₂O₂ to produce •OH, which promotes degradation, and •O₂⁻ itself also plays a role in degradation. In addition, under the optimal experimental conditions obtained by response surface experiments, the fitting degree of first-order reaction kinetics is 0.96642, and the fitting degree of second-order reaction kinetics is 0.57884. Therefore, this reaction is more in line with first-order reaction kinetics. The adsorption rate is only proportional to the concentration of Fe/g-C₃N₄. Full article

A comparative study was performed between some waste materials to assess their ability to produce natural pigment from Bacillus subtilis KU710517 isolated from the marine sponge Pseudoceratina arabica. Bacillus subtilis KU710517 was able to produce a yellowish-brown pigment with wheat bran and molokhia stems in both water and synthetic media. Some factors affecting the pigment production by Bacillus subtilis KU710517 were studied. The pigments produced had been assessed for their use in dyeing wool fabrics (at a liquor ratio of 50:1 across various pH levels), and the color strength values of samples were examined. The highest color strength value of dyed wool fabrics was obtained when using water containing 6% molokhia stems (K/S 6.98) for 2 days at pH 9. Also, good fastness properties were obtained with molokhia stems. Therefore, the yellowish-brown pigment produced from Bacillus subtilis KU710517 is highly appropriate for dyeing and printing wool textiles and serves as a safe alternative to synthetic dyes that create environmental issues. Moreover, using waste materials and water in the production of dye is an economical and ecofriendly method. HPLC analysis of the pigment produced from molokhia stems in a water medium indicated the presence of rutin and syringic acid, which are responsible for the yellowish-brown color. The antimicrobial properties of the produced pigment were examined with the cup agar diffusion technique. Nutrient agar plates were inoculated with 0.1 mL of 105–106 cells/mL of yeast and bacteria. Czapek-Dox agar plates were heavily inoculated with 0.1 mL (106 cells/mL) of fungal culture. 100 microliters of the dye sample were added to each cup. The pigment showed considerable antimicrobial activity against bacteria, yeast, and fungi and displayed the strongest antimicrobial activity against E. coli (28 mm zone of inhibition). Therefore, the produced pigment can be used in the pharmaceutical field, especially in the dyeing of surgical dressings and clothing. Full article

Bigels are promising delivery systems for bioactive compounds, combining the properties of hydrogels and oleogels. Pequi carotenoids, characterized by their natural yellow fluorescence, hold potential to replace the artificial dye tartrazine in foods while simultaneously enhancing their functional properties. This study developed food-grade bigels with varying oleogel-to-hydrogel ratios (40%, 60%, 80% OG) to assess the pigmentation capacity of pequi carotenoid extracts. Hydrogel contained agar and xanthan gum, while oleogel comprised beeswax, lecithin, sunflower oil, and 400 μg/100 g carotenoid extract. Bigel color was analyzed using the CIELAB system. Linear and multiple regression models were applied to assess the influence of crosslinking time (1 vs. 12 h), extraction solvent (acetone vs. [BMIM][BF4]), saponification, and oleogel ratio on color parameters. The color of the carotenoid-enriched bigels was mainly influenced by the extraction solvent and the oleogel ratio, while saponification and crosslinking time had only minor impacts. Although changes in L*, a*, and b* were observed across samples, ΔE* values generally reflected low perceptibility. Notably, more evident color differences were associated with variations in solvent type and oleogel ratio. These findings contribute to a better understanding of how formulation parameters influence the pigmentation behavior and support the development of natural, visually appealing functional foods. Full article

We systematically investigated the parent anthracene (abbreviated as en-1, C₁₄H₁₀) and three N,N′-disubstituted derivatives: the 1,5-diethylanthracene (en-2, C₁₈H₁₈), the 1,5-divinylanthracene (en-3, C₁₈H₁₄), and the 1,5-diphenylanthracene (en-4, C₂₆H₁₈), using a rigorous density functional theory (DFT)/time-dependent density functional theory (TD-DFT) approach. Following full geometric optimization and frequency validation (no imaginary frequencies), frontier molecular orbital analysis revealed an inverse correlation between conjugation extent and the HOMO-LUMO energy gap. Electrostatic potential (ESP) analysis further indicated a progressive increase in surface potential variance upon substitution, reflecting charge redistribution. TD-DFT calculations yielded vertical excitation wavelengths of 438 nm, 441 nm, 464 nm, and 496 nm for en-1, en-2, en-3, and en-4, respectively. Complementary color theory predicts visual colors of yellow, yellow, red, and orange for these compounds based on their absorption characteristics. This work establishes a closed-loop “computation-spectra-color” model for anthracene-based dyes, providing a transferable design paradigm for novel functional pigments with high molar extinction coefficients. Full article

The relevance of well-structured mitochondria in sustaining the integrity of the retinal pigment epithelium (RPE) is increasingly evident. Conversely, altered mitochondria are a culprit of age-related macular degeneration (AMD), which is influenced by the activity of mechanistic target of rapamycin (mTOR). In the present manuscript, the mitochondrial status of RPE cells was investigated by light and electron microscopy following the administration of various doses of compounds, which modulate mTOR. The study combines MitoTracker dyes and mitochondrial immunohistochemistry with in situ mitochondrial morphometry. Various doses of 3-methyladenine (3-MA), curcumin, and rapamycin were administered alone or in combination. The activity of autophagy and mTOR was quantified following each treatment. Administration of 3-MA led to activation of mTOR, which was associated with severe cell death, altered membrane permeability, and altered ZO-1 expression. In this condition, mitochondrial mass was reduced, despite a dramatic increase in damaged mitochondria being reported. The decrease in healthy mitochondria was concomitant with alterations in key mitochondria-related antigens such as Tomm20, Pink1, and Parkin. Specific mitochondrial alterations were quantified through in situ ultrastructural morphometry. Both curcumin and rapamycin counteract mTOR activation and rescue mitochondrial status, while preventing RPE cell loss and misplacement of decreased ZO-1 expression. Mitigation of mTOR may protect mitochondria in retinal degeneration. Full article

This study explores the dual functionality of cadmium-based pigments (CdS, CdSe, and CdS_1−xSe_x solid solutions) as historical colorants and visible-light photocatalysts. Synthesized pigments here replicated hues of traditional cadmium reds. At the same time, their photocatalytic efficiency was evaluated using model dyes, such as indigo carmine (anionic) and fuchsine (cationic), as a representative of heritage materials. Structural and optical characterization confirmed tunable bandgaps (1.63–2.28 eV) and phase-dependent microstructures, with CdS_1−xSe_x composites exhibiting compositional heterogeneity. Photocatalytic tests revealed specific degradation mechanisms. Indigo carmine degradation was dominated by superoxide radicals (O₂^•−), while fuchsine degradation relied on photogenerated electrons (e′). Scavenger experiments highlighted the synergistic role of reactive oxygen species (ROS) and charge carriers, with CdS and CdSe showing the highest activity. Intermediate composites displayed selective reactivity, suggesting trade-offs between phase homogeneity and surface interactions. Reduced photocatalytic efficiency in composites aligns with cultural heritage needs, where pigment stability under light exposure is critical. This work bridges material science and conservation, demonstrating how the compositional tuning of CdS_1−xSe_x can balance color fidelity, photocatalytic activity, and longevity in art preservation. Full article

Due to the large amount of plastic waste that is currently produced, the demand for ecological solutions to this situation has been growing. Many research studies in recent years have focused on polylactic acid (PLA) as a biodegradable material made from renewable resources. The individual components of biodegradable materials should comply with the EN 13432 standard, which defines the properties of a “compostable” material. Careful selection of dyes and pigments is therefore important in terms of maintaining the biodegradability of the finished products. In this article, we focus on evaluating the flow properties of color masterbatches modified with inorganic biodegradable pigments. Two types of PLA were used as polymer pigment carriers, and titanium dioxide, carbon black, and two iron oxides were used as inorganic pigments. We monitored the effect of the type and concentration of pigments on the processability and rheological properties of the prepared color PLA masterbatches. The capillary viscometer and rotary rheoviscometer were used to determine rheological properties. The flow properties of color masterbatches containing 1 and 3 wt.% inorganic pigments with two types of pure polymers, PLA6100 and PLA175, were compared. We found that the color PLA masterbatches had good processability and satisfactory rheological properties, and therefore they are usable for further processing. Full article

The fashion industry is facing increasing challenges related to textile waste and environmental pollution, driving the need for sustainable material innovations. Bacterial cellulose (BC), a biodegradable and non-polluting biomaterial, has emerged as a promising alternative for the sustainable transformation of fashion materials. Investigations into printing and dyeing techniques are expected to provide methodological frameworks for the design and functional application of BC materials, promoting their adoption and development in the fashion sector. This study, using the kombucha culture method, systematically investigated the cultivation, purification, plasticization, and drying processes of BC as a fashion material, examined its color characteristics using plant and reactive dyeing, and evaluated the effects of pattern printing and the feasibility of traditional plant pigment stencil printing, digital printing, and cyanotype printing on BC. Based on these printing and dyeing methods, digital printing combined with reactive dyeing—offering richer print effects, a wider color gamut, and higher rubbing fastness—was selected to realize the fashion design series Photosynthesis using BC as the primary material. This research contributes methodological insights into the integration of bio-based materials in fashion design and promotes the advancement of sustainable practices within the textile and apparel industries. Full article

Nitrogen-containing heterocycles are essential compounds in nature, and their structural and functional diversity inspired the synthesis of a wide range of derivatives with diverse applications as pharmaceuticals, agrochemicals, dyes, polymers, cosmetics, etc. Among them, N-fused heterocycles represent an important category, due to their high potential as biologically active agents. Pyrazolo[5,1-c][1,2,4]triazoles, a class of nitrogen heterobicycles, have multiple applications as dyes and pigments. Also, a number of compounds containing this structure have been investigated for their biological activities. All the main experimental results published in the literature (both articles and patents) regarding the latter are summarized in this review. Full article