Identification Of Natural Dyes Research Articles

Identification of natural dyes with halochromic properties and their potential use as food spoilage indicators

Purpose The purpose of this research is to identify and investigate some natural dyes with halochromic properties for potential use as food spoilage indicators to reduce waste and curve the negative effects of food borne diseases. Design/methodology/approach Exactly 10 potential dye-yielding plants were selected based on their colour (mostly purple, red, maroon and pink). Solvent extraction was used to extract the dyes and pH differential method was used to determine the concentrations of anthocyanin in the extracted dyes. Different concentrations of hydrochloric acid and sodium hydroxide (0.1 M, 1 M and 2 M) in drops and in excess as acidic and basic solution, respectively, were used to test the halochromicity of the extracted dyes. Methyl red (a synthetic dye) was used as a reference standard/control. The pH of the dyes was recorded before and after addition of both NaOH and HCl solutions. Findings Five out of the 10 dyes extracted (labelled as dye A–E for Ti plant (green Cordyline fruticosa), coleus (Coleus blumei), paper flower (Bougainvillea glabra), painted nettle (Palisandra coleus) and purple heart (Setcresea purpurea), respectively, were found to be halochromic (even at low doses) by changing its colour when exposed to both acidic and basic solutions. While other dyes labelled F–J for red acalypha (Acalypha wilkesiana), golden shower (Cassia fistula), golden dew drop (Duranta repens), wild sage (Lantana camara var Aculeata) and pink oleander (Apocynaceae Nerium oleander), respectively, were either completely insensitive to the solutions in drops, slightly sensitive at high doses or the colour change is insignificant. Although some dyes were found to be more sensitive than others but in most cases, the colour changes in halochromic dyes were more stable in acidic conditions than in basic making it more sensitive to the basic than the acidic solution with the exception of dye A and E (to some extent) which was sensitive to both acidic and basic solution. The anthocyanin contents of dye A–J were found to be between the range of 2.28–10.35 mg/l with dye E having the lowest and dye J with the highest anthocyanin concentration, respectively. The initial pH of all the dyes falls within the range of 4.8–7.3 with most found within the acidic range. Originality/value Halochromic dye research studies are still at the infancy stage in developing world despite the vast available and abundant potential natural halochromic dye-yielding plants. The study explored this area of research and gives an opportunity for the development of smart packaging for pH-sensitive foods using natural dyes as an alternative to conventional synthetic dyes to reduce cost and also curve the negative effect of synthetic dyes as well as food borne diseases.

Identification of natural dyes in historical tapestries, a LC-MS/MS approach.

Abstract The present study concerns the identification of the colouring matter in ancient tapestries of different historical periods. The investigation was performed using HPLC-DAD-ESI-MS and the results were compared with a previously created reference database. Furthermore, the characteristic fragmentation pathway provided additional information for the identification of the dyes employed.

Dataset supporting the identification of natural dyes in yellow, orange, brown and green fibres from Krakow liturgical vestments.

This data article provides an extensive and complete description of the colorants and dyes identified in fibre samples taken from the historical textiles that were described in the article "Universal analytical method for characterization of yellow and related natural dyes in liturgical vestments from Krakow” by K. Lech [1]. Natural organic dyes, for centuries used to dye fibres, contain usually from a few to several dyeing compounds. The correct identification of the dye requires at first the identification of their colouring components using sensitive and selective analytical techniques. One of this technique is high-performance liquid chromatography combined with spectrophotometric detection and detection using tandem mass spectrometry with electrospray ionization (HPLC-UV-Vis-ESI MS/MS). The HPLC-UV-Vis-ESI MS/MS protocol was used to identify natural dyes present in 89 yellow, orange, brown and green fibres taken from 15th- to 17th-century silk textiles used in vestments belonging to the collections of seventeen churches in Krakow, Poland.

An SERS analytical protocol for characterizing native Japanese plant extracts

AbstractThe identification of natural dyes in ancient textiles is a longstanding challenge for scientists; yet, the effort honours the skill and knowledge of master dyers by retracing traditional dyeing methods and assisting in conserving historical treasures for future generations. Here, the main constituents of selected native Japanese extracts from the roots of Lithospermum erythrorhizon and Scutellaria baicalensis, the barks of Phellodendron amurense and Morella rubra, the dried flower bud of Syzygium aromataticum, and the fruit of Terminalia chebula are determined by surface‐enhanced Raman spectroscopy following traditional Japanese extraction methods. The analytical amalgamation of data from SERS examinations on crude extracts and on subsequently refiltered and diluted extracts provides further effective and sensitive results for the combined identification of napthoquinones (shikonin and alkanin), alkaloid (berberine), polyhydroxyflavonoids (baicalin/baicalein, myricetin/myricitrin), diarylheptanoids, allylbenzene (eugenol), and tannins (gallic/ellagic acid). The comparison of results from this analytical protocol with those achieved by the more traditional chromatographic and mass spectrometric method provides and questions data regarding generally accepted marker components and enantioselective discriminations that serve to enrich the database of biological sources of colouring materials to be used in determining historically important Japanese colorants and dyestuffs.

Identification of natural dyes in rare Coptic textile using HPLC- DAD and mass spectroscopy in museum of Faculty of Arts, Alexandria University, Egypt

Rare Coptic dyed textile samples, collected from the studied museum, were identified with A High Performance Liquid Chromatographic method coupled to a Diode-Array-Detector (HPLC-DAD) and Liquid chromatography coupled with tandem mass spectrometry (LC–MS-MS). In addition, this study attempts to evaluate the efficacy of an improved extraction method using two solvents compared with the conventional hydrolysis method. The results indicated that mixtures of organic dyes were used in these objects in order to produce different colors. Various natural dyes such as indigo and madder, etc. were identified. Dyes identification can be very helpful in dating these archeological textiles depending on the sort of dye and its manufacturing or discovery date. Furthermore, the identification of dyes, used for historical textiles, can help in elucidating their place of origin and time of production. Moreover, dyes identification will be used in developing a plan for conservation and restoration of the valuable textile collection in this museum.

Identification of Natural Dyes on 18th Century Liturgical Textiles from Dubrovnik

In this paper researches were carried out on fragments of textiles from the 18[sup]th[/sup] century from Dubrovnik, for which, based on the design and art-historical analysis, it was determined that it was a part of an object (pluvial, cope) from liturgical vestments (ecclesiastical textiles) of the Dubrovnik diocese. Using modern non-destructive and micro-destructive methods we conducted the identification of green, blue and red as the dominant tones on the artefacts of historical textiles from Dubrovnik. The identification was based on the application of modern complementary techniques: UV / VIS, HPLC, SEM-EDX and FTIR-ATR. We analysed samples of coloured fiber, as well as ones obtained by the extraction of dyes from the dyed fibers. Archival data on natural dyes used in the Dubrovnik region in the period 14-19th century was taken into account in the identification of the historical textile dyes.

Identification of Natural Dyes in Ancient Textiles by Time-of-Flight Secondary Ion Mass Spectrometry and Surface-Enhanced Raman Spectroscopy.

The identification of dyes in archaeological remains is a long standing challenge. Major problems include contamination by environmental conditions over long periods of time, small amounts and limited availability of excavated samples, and low concentrations of dyestuff in the obtained samples. To address these issues, highly sensitive and non-destructive techniques are required. In response, in this work, two non-destructive analytical techniques, Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) and Surface-Enhanced Raman Spectroscopy (SERS), were used for dye detection and the analysis results are compared. TOF-SIMS provides high detection efficiency for the analysis of organic materials whereas SERS is a useful technique for the detection of dyes in ancient textiles. An Ag colloid was employed to surmount the limitations of normal Raman measurement such as background fluorescence and weak Raman signals in small amounts of components. To identify the dyes used in ancient textiles, standard samples prepared using various dyestuffs and historical samples were analyzed with TOF-SIMS and Raman techniques. From the TOF-SIMS and the SERS spectra, dyestuffs such as alizarin, berberine, an indigo were identified in ancient textiles. The results suggest that TOF-SIMS and SERS are efficient non-destructive techniques for the characterization of archaeological textiles.

Identification of Natural Dyes on Laboratory-Dyed Wool and Ancient Wool, Silk, and Cotton Fibers Using Attenuated Total Reflection (ATR) Fourier Transform Infrared (FT-IR) Spectroscopy and Fourier Transform Raman Spectroscopy

Attenuated total reflection (ATR) infrared and Fourier transform (FT) Raman spectra were obtained from wool threads dyed in the laboratory with natural dyes used in antiquity, following a procedure similar to ancient methods for dyeing wool. The ATR spectra were primarily dominated by the signals of the wool, making it difficult to identify the dye on the fibers only by visual inspection of the infrared spectrum. However, the Raman spectra showed more significant characteristics attributable to the dyes as previously studied in the literature on modern synthetic dyes. A library-search method was thus applied to the second derivatives of both the ATR and Raman spectra to verify the possibility of identifying the dye. Two libraries were constructed, one consisting of the ATR spectra of undyed wool (raw, washed, and mordanted) and the transmission spectra of pure dyes and the other consisting of the Raman spectra of undyed wool and of pure dyes. Correlation and first-derivative correlation search algorithms were used. The results presented here suggest that the two types of spectroscopy are complementary in this kind of work, allowing the almost complete identification of historic dyes on wool. In fact, through the combined use of the two searches, most dyes were identified with a good index of similarity and within the first five hits. Only for annatto was identification totally impossible using either technique. Subsequently the same method was applied to wool, silk, and cotton threads taken from ancient Caucasian and Chinese textiles.

Identification of natural dyes in historical textiles from Romanian collections by LC-DAD and LC-MS (single stage and tandem MS)

Abstract In this study, the dyes present in five 17th- to 18th-century textiles from the National Museum of Art of Romania, three religious embroideries and two brocaded velvets, are characterized and discussed, together with earlier results on textiles from Romanian collections obtained by the same research group. Dye analyses were performed using two methods: the well-established liquid chromatography-diode array detection (LC–DAD) and a recently developed liquid chromatography-mass spectrometry (LC–MS) analytical protocol. The examination of very small historical samples by both techniques allows a better insight in the advantages and limitations of the two approaches to real analyses to be obtained. LC–MS data interpretation is based entirely on the results accumulated for dye standards. Electrospray ionization (ESI) was used in the negative ion mode and an ion trap served as mass analyzer. Both single stage (MS) and tandem (MS/MS) mass spectrometric approaches were considered. The dyes and natural sources identified by both analytical techniques are discussed in the historical context of the textiles, with respect to earlier results collected for similar Romanian objects. The study showed that the dye sources found in the 17th- and 18th-century Romanian velvets and embroideries were produced using a wide variety of dye sources, suggesting influences from Europe as well as from Asia Minor. Dye sources imported from New World have been also detected. The range of biological sources is in very good correspondence with earlier results obtained from textiles in the Romanian Collections. LC-MS (single stage and tandem MS) approaches have been demonstrated to be valuable tools for dye identification in small-scaled samples from historical textile objects only if sufficient knowledge on the dyes and their biological sources is first accumulated within experiments performed on standard dyes and standard dyed fibers.

Identification of Natural Dyes in Selected Museum Textiles Using High Performance Liquid Chromatography with Photodiode Array Detection (HPLC-PDA)

The present study has employed a high performance liquid chromatographic method coupled with a diode array detector (HPLC-DAD) to identify the dyestuffs in textile samples collected from the Coptic Museum in Cairo and the Museum of Jordanian Heritage. The results indicate that mixtures of organic dyes are used in dyeing these samples to produce different colours. The most dominantly identified colourants in samples collected from the Museum of Jordanian Heritage are laccaic acid, kermesic acid, munjistin and indigotin. The most dominantly identified dyestuffs are lac dye (Kerria lacca, Kerr), kermes (Kermes vermilio), madder (Rubia) species and indigoid dye source, either indigo (Indigofera species) or woad (Isatis tinctoria L.). These results confirm the historical information in the Museum of Jordanian Heritage in that the tested textile objects date back to the end of the 19th century or the beginning of the 20th century. The most dominantly identified colourants in samples collected from the Coptic Museum are alizarin, purpurin, and indigotin. The most dominantly identified dyestuffs are madder and indigotin. Based on this investigation, it is concluded that the tested dyed samples collected from the Coptic Museum belong to the 6-7th centuries. This conclusion is in agreement with the initial dating of samples according to the style of the decorations.

Identification of natural dyes used in works of art by pyrolysis–gas chromatography/mass spectrometry combined with in situ trimethylsilylation

Samples of four natural dyes from different organic families--natural madder (anthraquinonoid), curcuma (curcuminoid), saffron (carotenoid) and indigo (indigotic)--were analysed using a new procedure based on pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), which includes the on-line derivatisation of the natural dyes using hexamethyldisilazane (HMDS). In addition, a previous procedure involving the addition of a 10% H2SO4 aqueous solution to the dye and further separation with ethyl acetate has been tested. This procedure enhances the sensitivity of the method by extracting the colouring compounds from the rest of the compounds present in the natural dye. Two possible derivatising reagents--HMDS and tetramethylammonium hydroxide (TMAH)--were compared in order to assess their effectiveness in the proposed method. Characteristic peaks from trimethylsilyl derivatives of alizarin, quinizarin, xanthopurpurin and purpurin were obtained for madder; peaks from safranal, isophorone and trimethylsilyl derivative of crocetin for saffron; peaks from 4-(4-hydroxy-3-methoxy)phenyl-3-buten-2-one and 4-(4-hydroxy-3-methoxy)phenyl-2-butanone, which are primary pyrolysis products of curcuma, and peaks from indole, 2-methylindole and 2,3-dihydroindol-2-one, which are primary pyrolysis products of indigo, among others, were obtained. The reported procedure leads to the unambiguous identification of the four studied dyes from solid samples formed by individual dyes.

Detection of Natural Dyes in Kamaboko Prepared as Imitation Crab

A method for the extraction and identification of natural dyes in Kamaboko (fish paste products) prepared as imitation crab was developed.A sample (5g) cut into small pieces was incubated with sodium dodecyl sulfate (0.3g) and 50ml of 0.2% protease solution (Pronase P) at 37°C for 2 hours, then the mixture was centrifuged. The supernatant fluid was extracted with ether. DEAE-Sephadex was added to the lower aqueous layer, and this mixture was stirred for 10min. The DEAE-Sephadex was filtered off and washed with water and 0.1% hydrochloric acid, then the dyes were eluted with 5% sodium chloride solution-ethanol (1:3). The eluate was evaporated to dryness on a steam bath and the dyes were extracted with ethyl acetate from the residue. The extract was filtered, the solvent was evaporated off and the residue was dissolved in ethyl alcohol.The dyes from the ether and aqueous layers were identified by thin-layer chromatography. The recoveries of monascus pigments, cochineal, laccaic acid and norbixin added to Kamaboko prepared as imitation crab were over 80%.The method was applied for the detection of natural dyes in commercial imitation crab products prepared from Kamaboko, and monascus pigments, laccaic acid and norbixin were found.