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1.
Photochem Photobiol Sci ; 23(5): 941-955, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38643418

RESUMO

The identification of more efficient, clean, secure, and competitive energy supply is necessary to align with the needs of sustainable devices. For this reason, a study for developing innovative dye-sensitized solar cells (DSSCs) based on microbial pigments is reported starting from Talaromyces atroroseus GH2. The fungus was cultivated by fermentation and the extracellular pigment extract was characterized by HPLC-DAD-ESI-MS analyses. The most abundant compound among the 22 azaphilone-type pigments identified was represented by PP-O. The device's behavior was investigated in relation to electrolyte and pH for verifying the stability on time and the photovoltaic performance. Devices obtained were characterized by UV-vis measurements to verify the absorbance intensity and transmittance percentage. Moreover, photovoltaic parameters through photo-electrochemical measurements (I-V curves) and impedance characteristics by Electrochemical Impedance Spectroscopy (EIS) were determined. The best microbial device showed a short-circuit current density (Jsc) of 0.69 mA/cm2, an open-circuit photo-voltage (Voc) of 0.27 V and a Fill Factor (FF) of 0.60. Furthermore, the power conversion efficiency (PCE) of the device was 0.11%. Thus, the present study demonstrated the potential of microbial origin pigments for developing DSSCs.


Assuntos
Corantes , Energia Solar , Talaromyces , Talaromyces/química , Talaromyces/metabolismo , Corantes/química , Pigmentos Biológicos/química
2.
Chem Biodivers ; 21(1): e202301357, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38072912

RESUMO

The use of natural dyes in several areas is regulated by current European and non-European legislation, due to various problems with synthetic dyes. The analysis revealed that the lichen studied: Xanthoria parietina has potential natural dye sources and provides bright colors for extraction solvents. Furthermore, dyed wool and toile fabric have good fastness properties in ammonia fermentation and boiling water, both with and without mordants. The sample dyes with Xanthoria parietina were characterized by several analytical techniques: high-performance liquid chromatography with diode array detection (HPLC-DAD) and electrospray ionization with tandem mass spectrometry (HPLC-ESI-Q-ToF). As compounds from Xanthoria parietina form a complex with mordants and tissues, it is impossible to identify the molecules responsible for coloring using chromatographic techniques. However, we have evaluated the dyeing power of their major molecule, parietin. To further confirm the coloring power of the isolated parietin molecule, we performed a dye test with pure parietin. Thus, CIALAB analyses have shown parietin is the molecule responsible for the coloring obtained by Xanthoria parietina. The utilization of parietin derived from lichens facilitates the development of sustainable dyes for textile coloring, presenting an environmentally friendly alternative to synthetic dyes while simultaneously enriching lichen biodiversity.


Assuntos
Ascomicetos , Emodina/análogos & derivados , Líquens , Animais , Líquens/química , Ascomicetos/química , Corantes
3.
Molecules ; 28(16)2023 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-37630206

RESUMO

The dyeing and finishing step represents a clear hotspot in the textile supply chain as the wet processing stages require significant amounts of water, energy, and chemicals. In order to tackle environmental issues, natural dyes are gaining attention from researchers as more sustainable alternatives to synthetic ones. This review discusses the topic of natural dyes, providing a description of their main features and differences compared to synthetic dyes, and encompasses a summary of recent research in the field of natural dyes with specific reference to the following areas of sustainable innovation: extraction techniques, the preparation of substrates, the mordanting process, and the dyeing process. The literature review showed that promising new technologies and techniques have been successfully employed to improve the performance and sustainability of natural dyeing processes, but several limitations such as the poor fastness properties of natural dyes, their low affinity with textiles substrates, difficulties in the reproducibility of shades, as well as other factors such as cost-effectiveness considerations, still prevent industry from adopting natural dyes on a larger scale and will require further research in order to expand their use beyond niche applications.

4.
Molecules ; 28(8)2023 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-37110783

RESUMO

Among the vegetables that stand out for their high concentration of anthocyanins, red cabbage appears as one of the most-used sources of these pigments in food production and it is considered a suitable raw material for the extraction of natural dye. Therefore, the objective was to carry out the production of natural extracts from red cabbage, under different conditions, varying the solvent, type of pre-treatment, pH range, and processing temperature during the concentration of the extracts. The anthocyanins were extracted from red cabbage using the following solvents: distilled water, 25% ethyl alcohol, and 70% ethyl alcohol. The raw material was divided into two groups, the first was subjected to a drying pre-treatment at 70 °C for 1 h and for the second group, the extraction was performed with the raw material in natura. Two pH ranges of 4.0 and 6.0 and extraction temperatures of 25 °C and 75 °C were used in the extracts, resulting in 24 formulations. The extracts obtained were analyzed for colorimetric parameters and anthocyanins. The results of anthocyanins show that the methodology that uses 25% alcohol, pH 4.0, and processing temperature of 25 °C produces a reddish extract and better results in the extraction, presenting average values of 191.37 mg/100 g of anthocyanins, being 74% higher compared to the highest values obtained in the other extracts where the same raw material was used and the solvents differed.


Assuntos
Antocianinas , Brassica , Solventes , Etanol , Extratos Vegetais
5.
Molecules ; 29(1)2023 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-38202776

RESUMO

The subjects of this research are the burial clothes of Polish King Sigismund III Vasa and his wife Constance, which were woven and embroidered with silk and metal threads. Fragments of the textiles underwent spectroscopic, spectrometric, and thermogravimetric analyses. The hydrofluoric acid extraction method was improved to isolate various classes of dyes from the textile samples that had direct contact with human remains. High-performance liquid chromatography, coupled with diode array and tandem mass spectrometry detectors with electrospray ionization (HPLC-DAD-ESI-MS/MS) facilitated the detection and identification of colorants present in the textiles. Cochineal, indigo-, madder-, orchil-, and tannin-producing plants were identified as the sources of dyes used. Scanning electron microscopy with an energy-dispersive X-ray detector (SEM-EDS) was employed to identify and characterize the silk fibers and mordants and the metal threads. The presence of iron, aluminum, sodium, and calcium in the silk threads suggests their potential use as mordants. The analysis of the metal threads revealed that most of them were made from flattened gilded silver wire, with only a few being cut from a sheet of metal. Typical degradation mechanisms of metal threads were shown, resulting from both burial environment and earlier manufacturing process, and the use of the textiles in clothing, i.e., a significant loss of the gold layer was observed in most of silver gilt threads, caused by abrasion and delamination. The results of the thermal analysis confirmed the presence of silk and silver threads in the examined textiles.

6.
J Fluoresc ; 32(1): 203-213, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34694548

RESUMO

In this work, the optoelectronic parameters of natural dyes extracted from beetroot, red cabbage, walnut leaves, and henna were comprehensively investigated, namely the optical energy gap (Eg), extinction coefficient (k), refractive index (n), dielectric constant ([Formula: see text], and optical conductivity ([Formula: see text]. Results showed a high refractive index, dielectric constant and optical conductivity ([Formula: see text] and [Formula: see text]) for the dye extracted from red cabbage, while minimum values of [Formula: see text] and [Formula: see text] were obtained for the henna dye. The transition type of the optical absorption of the dyes was found to be a direct allowed transition, which is taken place between the bonding and antibonding molecular energy levels. The reported results herein are essential in revealing the viability of these natural dyes for potential applications in organic electronics, including organic photovoltaics, photodiodes, and sensors.


Assuntos
Beta vulgaris/química , Brassica/química , Corantes/isolamento & purificação , Eletrônica/métodos , Juglans/química , Lawsonia (Planta)/química
7.
Int J Mol Sci ; 23(17)2022 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-36077071

RESUMO

Concerns about the health of the planet have grown dramatically, and the dyeing sector of the textile industry is one of the most polluting of all industries. Nanoclays can clean dyeing wastewater using their adsorption capacities. In this study, as a new finding, it was possible to analyze and quantify the amount of metal ions substituted by anionic dyes when adsorbed, and to determine the optimal amount of nanoclay to be used to adsorb all the dye. The tests demonstrated the specific amount of nanoclay that must be used and how to optimize the subsequent processes of separation and processing of the nanoclay. Hydrotalcite was used as the adsorbent material. Direct dyes were used in this research. X-ray diffraction (XRD) patterns allowed the shape recovery of the hydrotalcite to be checked and confirmed the adsorption of the dyes. An FTIR analysis was used to check the presence of characteristic groups of the dyes in the resulting hybrids. The thermogravimetric (TGA) tests corroborated the dye adsorption and the thermal fastness improvement. Total solar reflectance (TSR) showed increased radiation protection for UV-VIS-NIR. Through the work carried out, it has been possible to establish the maximum adsorption point of hydrotalcite.


Assuntos
Hidróxido de Magnésio , Poluentes Químicos da Água , Adsorção , Hidróxido de Alumínio , Corantes , Têxteis
8.
Molecules ; 27(10)2022 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-35630767

RESUMO

(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.


Assuntos
Corantes , Corantes de Alimentos , Antocianinas , Betalaínas , Carotenoides , Corantes de Alimentos/química , Humanos
9.
Molecules ; 27(14)2022 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-35889420

RESUMO

In this paper the possibility of applying natural dyes on cellulose fibres were researched with respect to the impact of cotton material pre-treatment (scouring, chemical bleaching, mercerization and mordanting), using renewable sources of natural dyes (waste as a source). As mordants, metal salts of copper, aluminium and ferrum were used, and the influence on colour change as well as on fastness properties were analysed. The natural dyes were extracted from onion peel (Allium cepa L.) and pomegranate peel (Punica granatum L.). In spectrophotometric analysis performed of the plant extracts, the onion extract has peaks at 400 and 500 nm, resulting in red-orange colourations and the pomegranate extract shows a maximum at 400 nm, i.e., in the yellow region, which is characteristic of punicalin. Results show significant influence of cotton pre-treatments on colour appearance and fastness properties, caused by pre-treatments affecting the properties and structure of the cotton itself. The positive effect of mercerization on dye absorption and bonding is confirmed. For wash and light fastness properties, more satisfactory results have been obtained for yarns dyed with pomegranate peel natural dye, and the key importance of mordants for fastness properties has been confirmed.


Assuntos
Corantes , Punica granatum , Corantes/química , Gossypium , Cebolas , Extratos Vegetais/química , Têxteis
10.
Molecules ; 27(3)2022 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-35164187

RESUMO

Flowers are a natural source of bioactive compounds that not only have antioxidant, anti-inflammatory, and anti-aging properties, but can also be used as natural dyes. For this reason, nowadays plants are widely used to produce natural cosmetics and foods. In these studies, the properties of the water extracts of Papaver rhoeas L., Punica granatum L., Clitoria ternatea L., Carthamus tinctorius L., and Gomphrena globosa L., as bioactive, natural dyes, were investigated. Plant flower extracts were tested for their antioxidant (ABTS and DPPH radical methods) and anti-inflammatory effects by determining the ability to inhibit the activity of lipoxygenase and proteinase. The extracts were tested for their cytotoxic effect on skin cells, using Alamar Blue and Neutral Red tests. The ability to inhibit the activity of enzymes responsible for the destruction of elastin and collagen was also studied. Research has shown that extracts have no toxic effect on skin cells, are a rich source of antioxidants and show the ability to inhibit the activity of elastase and collagenase enzymes. P. rhoeas extract showed the strongest antioxidant properties with IC50 value of 24.8 ± 0.42 µg/mL and 47.5 ± 1.01 µg/mL in ABTS and DPPH tests, respectively. The tested plants are also characterized by an anti-inflammatory property, for which the ability to inhibit lipoxygenase at a level above 80% and proteinase at the level of about 55% was noted. Extracts from P. rhoeas, C. ternatea, and C. tinctorius show the strongest coloring ability and can permanently dye cosmetic products, without significant color changes during the storage of the product.


Assuntos
Corantes/química , Cosméticos/química , Flores/química , Extratos Vegetais/farmacologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Cor , Fibroblastos/efeitos dos fármacos , Humanos , Queratinócitos/efeitos dos fármacos , Extratos Vegetais/química
11.
Cutan Ocul Toxicol ; 41(3): 215-220, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35771736

RESUMO

BACKGROUND: Occupational contact dermatitis (OCD) is a skin disorder caused by contact with any substances found in the workplace. Occupational contact dermatitis is second most common occupational disease (15% of all cases of occupational disease). Occupational contact dermatitis is divided into allergic contact dermatitis (ACD) and irritant contact dermatitis (ICD) which is 80% of cases that affects hands. Batik is an art that is painted on cloth, it is one of Indonesian cultural heritage. Batik workers have a higher risk of obtaining OCD due to exposure to chemicals and fluids used during work. Natural dyes used in the dyeing process are less likely to cause ACD than standard allergens. Some of the natural dyes used in the dyeing process in batik industries are Indigofera tinctoria, sappan wood (Caesalpinia sappan), and Mahagony (Swietenia mahagoni) cause skin sensitisation. OBJECTIVE: To compare the results of patch testing between natural dyes (Indigofera tinctoria, sappan wood (Caesalpinia sappan), and Mahagony (Swietenia mahagoni) with standard allergens (p-phneyldiamine 0.1%, potassium dichromate 0.5% and formaldehyde 0.1%) as a cause of ACD in batik workers in Surakarta, East Java, Indonesia. METHOD: A cross-sectional study was conducted on 63 subjects batik workers with OCD in Surakarta, East Java, Indonesia. Subjects were patch tested with three standard allergens (p-phenylenediamine 0.1%, potassium dichromate 0.5%, and formaldehyde 1%) and natural dyes (Indigofera tinctoria, sappan wood (Caesalpinia sappan), and Mahagony (Swietenia mahagoni). A closed patch test was evaluated 48 and 96 hour later. Screening of OCD in batik workers in Surakarta, East Java, Indonesia was based on Nordic Occupational Skin Questionnaire NOSQ-2002, and diagnosis of OCD was based on Mathias criteria (at least 4 out of 7 criteria were met). Data were analysed using a non-parametric Chi-square test with SPSS 21 with a significant difference if the p-value < 0.05. RESULT: Natural dyes significantly caused allergic contact dermatitis in batik workers in Surakarta, East Java, Indonesia than standard allergens (p = 0.016). A positive patch test was found in 11 patients, standard allergen p-phenylenediamine (PPD) 0.1% was seen on one patient, potassium dichromate 0.5% on two patients, and formaldehyde 1% on two patients. A positive patch test using Indigofera tinctoria was found at one patient, sappan wood (Caesalpinia sappan) in three patients, and Mahagony (Swietenia mahagoni) in five patients. CONCLUSION: Natural dyes cause more positive patch test results in batik workers.


Assuntos
Dermatite Alérgica de Contato , Dermatite Irritante , Dermatite Ocupacional , Alérgenos , Corantes/efeitos adversos , Estudos Transversais , Dermatite Alérgica de Contato/diagnóstico , Dermatite Alérgica de Contato/etiologia , Dermatite Irritante/etiologia , Dermatite Ocupacional/diagnóstico , Dermatite Ocupacional/etiologia , Formaldeído , Humanos , Testes do Emplastro/efeitos adversos , Dicromato de Potássio/toxicidade
12.
Molecules ; 26(9)2021 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-34068613

RESUMO

Nowadays, natural dyes are expected by the cosmetic and food industries. In contrast to synthetic dyes, colorants derived from natural sources are more environmentally friendly and safer for human health. In this work, plant extracts from Gomphrena globasa L., Clitoria ternatea L., Carthamus tinctorius L., Punica granatum L. and Papaver rhoeas L. as the natural and functional dyes for the cosmetics industry were assessed. Cytotoxicity on keratinocyte and fibroblast cell lines was determined as well as antioxidant and anti-aging properties by determining their ability to inhibit the activity of collagenase and elastase enzymes. In addition, the composition of the extracts was determined. The obtained extracts were also applied in face cream formulation and color analyses were performed. It has been shown that the obtained extracts were characterized by no cytotoxicity and a high antioxidant potential. The extracts also show strong ability to inhibit the activity of collagenase and moderate ability to inhibit elastase and provide effective and long-lasting hydration after their application on the skin. Application analyses showed that the extracts of P. rhoeas L., C. ternatea L. and C. tinctorius L. can be used as effective cosmetic dyes that allow for attainment of an intense and stable color during the storage of the product. The extracts of P. granatum L. and G. globasa L., despite their beneficial effects as active ingredients, did not work effectively as cosmetic dyes, because cosmetic emulsions with these extracts did not differ significantly in color from emulsions without the extract.


Assuntos
Antioxidantes/farmacologia , Corantes/farmacologia , Cosméticos/farmacologia , Citoproteção , Dessecação , Flores/química , Extratos Vegetais/farmacologia , Benzotiazóis/química , Compostos de Bifenilo/química , Morte Celular/efeitos dos fármacos , Colagenases/metabolismo , Cor , Citoproteção/efeitos dos fármacos , Células HaCaT , Humanos , Cinética , Inibidores de Metaloproteinases de Matriz/farmacologia , Oxazinas/metabolismo , Elastase Pancreática/antagonistas & inibidores , Elastase Pancreática/metabolismo , Picratos/química , Plantas/química , Creme para a Pele/farmacologia , Ácidos Sulfônicos/química , Raios Ultravioleta , Perda Insensível de Água/efeitos dos fármacos , Xantenos/metabolismo
13.
Molecules ; 25(14)2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32679693

RESUMO

Effective analytical approaches for the identification of natural dyes in historical textiles are mainly based on high-performance liquid chromatography coupled with spectrophotometric detection and tandem mass spectrometric detection with electrospray ionization (HPLC-UV-Vis-ESI MS/MS). Due to the wide variety of dyes, the developed method should include an adequate number of reference color compounds, but not all of them are commercially available. Thus, the present study was focused on extending of the universal analytical HPLC-UV-Vis-ESI MS/MS approach to commercially unavailable markers of red, purple, and blue dyes. In the present study, HPLC-UV-Vis-ESI MS/MS was used to characterize the colorants in ten natural dyes (American cochineal, brazilwood, indigo, kermes, lac dye, logwood, madder, orchil, Polish cochineal, and sandalwood) and, hence, to extend the analytical method for the identification of natural dyes used in historical objects to new compounds. Dye markers were identified mostly on the basis of triple quadrupole MS/MS spectra. In consequence, the HPLC-UV-Vis-ESI MS/MS method with dynamic multiple reaction monitoring (dMRM) was extended to the next 49 commercially unavailable colorants (anthraquinones and flavonoids) in negative ion mode and to 11 (indigoids and orceins) in positive ion mode. These include protosappanin B, protosappanin E, erythrolaccin, deoxyerythrolaccin, nordamnacanthal, lucidin, santalin A, santalin B, santarubin A, and many others. Moreover, high-resolution QToF MS data led to the establishment of the complex fragmentation pathways of α-, ß-, and γ- aminoorceins, hydroxyorceins, and aminoorceinimines extracted from wool dyed with Roccella tinctoria DC. The developed approach has been tested in the identification of natural dyes used in 223 red, purple, and blue fibers from 15th- to 17th-century silk textiles. These European and Near Eastern textiles have been used in vestments from the collections of twenty Krakow churches.


Assuntos
Cor , Corantes/análise , Corantes/química , Espectrometria de Massas , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem , Madeira/química
14.
Molecules ; 25(9)2020 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-32397593

RESUMO

The possibility of obtaining a carmine or pink color on ordinary cooked ham by applying natural dyes from three plant species, namely red radish (Raphanus sativus L.), hibiscus (Roselle sabdariffa L.) and red beetroot (Beta vulgaris L.), was investigated. The extracts were evaluated for the stability at physical-chemical parameters and subjected to cytotoxicity assays in the gastric cell line AGS Encapsulation of the extracts in soybean lecithin liposomes and maltodextrin microcapsules was performed. Lyophilized extracts before and after encapsulation in maltodextrin were applied in the formulation of ordinary cooked ham and used in a pilot scale of production. The color of cooked ham samples from different assays was evaluated visually and by colorimetry. The results suggest that the coloration of ordinary cooked ham obtained with extracts of red beetroot is very promising for future applications in this type of meat product.


Assuntos
Beta vulgaris/química , Betalaínas/análise , Culinária/métodos , Produtos da Carne/normas , Extratos Vegetais/análise , Carne de Porco/normas , Betacianinas/análise , Betacianinas/química , Betacianinas/toxicidade , Betalaínas/química , Betalaínas/isolamento & purificação , Betalaínas/toxicidade , Cápsulas/química , Linhagem Celular , Cor , Colorimetria , Corantes/química , Corantes/isolamento & purificação , Hibiscus/química , Humanos , Lecitinas/química , Lipossomos/química , Espectrometria de Massas , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/toxicidade , Polissacarídeos/química , Raphanus/química , Glycine max/química
15.
Molecules ; 24(20)2019 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-31635425

RESUMO

When the imagination conjures up an image of an Egyptian mummy, it is normally one of a human body wrapped with undyed linen bandages. However, the reality was much more colourful, as shown by the set of red mummy shrouds and textile fragments from Pharaonic Egypt considered in this work. The textiles were subjected to scientific investigation with the main aim of shedding light on the sources of red colour and on the possible reasons for the different levels of colour fading. The red colourants were investigated using various non-invasive and micro-invasive approaches. The results pointed towards the presence of three sources of red colour, which, in increasing order of lightfastness, are safflower (Carthamus tinctorius), madder (Rubia spp.), and red ochre. Micro-morphological observations and elemental analyses also enabled some hypotheses to be formulated regarding the application of these colourants to the textiles. The results not only deepen our knowledge of dyeing technologies in ancient Egypt and shed new light on the function of red shrouds and textiles as part of the funerary practices of Pharaonic Egypt, but are also essential in planning the display and future preservation of these mummies and their associated textiles.


Assuntos
Carthamus tinctorius/química , Corantes/análise , Rubia/química , Têxteis/história , Argila/química , Corantes/classificação , Antigo Egito , História Antiga , Humanos , Múmias , Têxteis/análise
16.
J Food Sci Technol ; 56(8): 3677-3686, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31413395

RESUMO

Betalains are vacuolar pigments present in tubers, flowers or fruits. Their use in the food industry is significant because they are considered bioactive completely safe to consume. However, betalains are susceptible to temperature which affects their stability. The most of the available methods that determine stability involve high costs, are destructive and generate waste. In this work was evaluated the thermal degradation of betalain at 75 °C for several intervals of time, by using different techniques. Colorimetry showed a change in the tone angle (h°) from 359.76° to 20.54° after the heat-treatment, suggesting thermal degradation by changing the color from violet to red-orange. High-pressure liquid chromatography, shows the decrease of the concentration of betanin in addition to the formation of neobetanin, the main degradation product in betalains. UV-visible spectrophotometry suggest also thermal degradation of betanin, by the decrease of the absorption at 538 nm caused by the heat treatment. Finally, Fourier transform infrared spectroscopy (FTIR) showed a decrease in the intensity of two absorption bands at 1243 and 879 cm-1, corresponding to the C-O and C-C vibrations of the carboxylic acid respectively after heat treatment. These results suggest that the main route of degradation corresponds to decarboxylation. We propose the use of FTIR spectroscopy as a practical alternative for the analysis of the degradation of natural dyes during storage, making evident the possible use of this methodology for industrial applications.

17.
J Food Sci Technol ; 56(9): 4147-4157, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31477986

RESUMO

Color is a sensory attribute that influences the acceptance of food and dyes are added into food products to provide them attractiveness. In this context, anthocyanins have merged as an alternative to synthetic dyes. This study aimed to develop food model systems of fermented or unfermented dairy beverages containing added microencapsulated anthocyanin-rich extracts from juçara palm fruit. The stabilities of both pigment and beverage throughout storage in opaque or transparent packaging have been evaluated. Acidity, pH and anthocyanin content in both beverages did not vary during 28 days of storage, and the content of bioactive compounds did not decrease over time. A slight overall color difference that is probably invisible to naked eyes was detected between the beverages analyzed at days 0 and 28. The potential of applying microencapsulated natural pigments into dairy matrices is an effort to increase their nutritional and sensorial values.

18.
Molecules ; 23(2)2018 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-29415495

RESUMO

A multi-tool analytical practice was used for the characterisation of a 16th century carpet manufactured in Cairo. A mild extraction method with hydrofluoric acid has been evaluated in order to isolate intact flavonoids and their glycosides, anthraquinones, tannins, and indigoids from fibre samples. High-performance liquid chromatography coupled to spectroscopic and mass spectrometric detectors was used for the identification of possible marker compounds with special attention paid to natural dyes present in the historical samples. Weld, young fustic, and soluble redwood dye were identified as the dye sources in yellow thread samples. Based on the developed method, it was possible to establish that red fibres were coloured with lac dye, whereas green fibre shades were obtained with indigo and weld. Tannin-containing plant material in combination with indigo and weld were used to obtain the brown hue of the thread. Hyphenation of high-performance liquid chromatography (HPLC) with quadrupole time-of-flight mass spectrometry (QTOF MS) and triple-quadrupole mass spectrometry (QqQ MS) enabled us to recognise four uncommon and thus-far unknown dye components that were also found in the historical samples. These compounds probably represent a unique fingerprint of dyed threads manufactured in a Turkish workshop. Scanning electron microscopy with energy-dispersive X-ray detector (SEM-EDS) and Fourier transform infrared spectroscopy (FT-IR) were used for the identification and characterisation of substrates and mordants present in the historical carpet. Carbon and oxygen were detected in large quantities as a part of the wool protein. The presence of aluminium, iron, and calcium indicated their usage as mordants. Trace amounts of copper, silica, and magnesium might originate from the contaminants. FT-IR analysis showed bands characteristic for woollen fibres and SEM micrographs defined the structure of the wool.


Assuntos
Cromatografia , Corantes/análise , Corantes/química , Análise Espectral , Animais , Cromatografia/métodos , Cromatografia Líquida de Alta Pressão , Corantes/isolamento & purificação , Pisos e Cobertura de Pisos , Extração Líquido-Líquido , Espectrometria de Massas , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral/métodos , Têxteis ,
19.
Chemistry ; 23(58): 14454-14461, 2017 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-28815818

RESUMO

Guided by a "chemistry first" approach using molecular networking, eight new bright-blue colored natural compounds, namely dactylocyanines A-H (3-10), were isolated from the Polynesian marine sponge Dactylospongia metachromia. Starting from ilimaquinone (1), an hemisynthetic phishing probe (2) was prepared for annotating and matching structurally related natural substances in D. metachromia crude extract network. This strategy allowed characterizing for the first time in Nature the blue zwitterionic quinonoid chromophore. The solvatochromic properties of the latter are reported.


Assuntos
Clortetraciclina/análogos & derivados , Poríferos/química , Animais , Produtos Biológicos/síntese química , Produtos Biológicos/química , Produtos Biológicos/isolamento & purificação , Clortetraciclina/síntese química , Clortetraciclina/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Cristalografia por Raios X , Espectroscopia de Ressonância Magnética , Conformação Molecular , Poríferos/metabolismo , Quinonas/química , Sesquiterpenos/química , Espectrometria de Massas em Tandem
20.
Anal Bioanal Chem ; 408(12): 3349-58, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26935929

RESUMO

The present work reports a method for identification of Polish cochineal (Porphyrophora polonica L.) in historical fabrics by the use of high-performance liquid chromatography coupled with diode array and tandem mass spectrometric detection with electrospray ionization (HPLC-DAD-ESI MS/MS). This hyphened technique allows detection and identification of 16 new minor colorants present in the discussed scale insect (including two previously observed by Wouters and Verhecken (Ann Soc Entomol Fr. 1989;25:393-410), but specified only as compounds of unknown structures) that do not occur (e.g., in American cochineal). The MS/MS experiments, complemented with UV-VIS data, enable identification of mono- and di-, C- and O-hexosides of kermesic and flavokermesic acids or their derivatives. The present paper introduces a fingerprint of color compounds present in Polish cochineal and defines them, particularly pp6 (ppI, O-hexoside of flavokermesic acid), as its markers allow distinguishing of Polish-cochineal reds from the American ones. Usefulness of the selected set of markers for identification of Polish cochineal has been demonstrated in the examination of textiles from the collection of the National Museum in Warsaw using the multiple reaction monitoring (MRM) method, originally elaborated on the basis of this study.

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