SEARCH · PubMed Health
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Amaranth and Sunset Yellow FCF, added to the basic diet of rats at concentrations of 1 200, 2 000, 10 000 and 20 000 mg/kg, do not affect, after administration for ten days, either the percentage of ingested vitamin A' stored in the liver, nor the "liver reserve" of vitamin A (expressed in IU/g/liver).
Vaccinium myrtillus or bilberry fruit is a commonly used herbal product. The usual method of determining the anthocyanin content is a single-wavelength spectrophotometric assay. Using this method, anthocyanin levels of two extracts were found to be 25% as claimed by the manufacturers. When high-performance liquid chromatography (HPLC) was used, however, one extract was found to contain 9% anthocyanins probably not derived from V. myrtillus but from an adulterant. This adulterant was subsequently identified, using HPLC, mass spectroscopy, and nuclear magnetic resonance, as amaranth, that is, 3-hydroxy-4-[(4-sulfo-1-naphthalenyl)azo]-2,7-naphthalenedisulfonic acid trisodium salt-a synthetic dark red sulfonic acid based naphthylazo dye. As described in this study, if deliberate adulteration occurs in an extract, a single-wavelength spectrophotometric assay is inadequate to accurately determine the levels of compounds such as anthocyanins. Detection of deliberate adulteration in commercial samples thus requires the use of alternative, more sophisticated, methods of analysis such as HPLC with photodiode array detection as a minimum.
A teratology study on amaranth and Ponceau 4R was carried out in NMRI mice. The substances were given by gavage either from day 0 through day 7 or from day 6 through day 18 in doses of 7.5, 30 or 100 mg/kg. Distilled water was given by gavage to the control dams from day 0 through day 18. The foetuses were removed on day 18 for detailed examinations. No effect of treatment with the dyes could be observed with regard to number of implantations, frequency of foetal death and resorptions, gross malformations, skeletal or internal malformations or retarded growth as judged by foetal weight. The results are discussed with particular reference to the evaluation of teratologic studies on food colouring in general and the various regulation proposals from the National Food Administration.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Semiconductor-mediated photocatalysed degradation of two selected azo dye derivatives such as amaranth (1) and bismarck brown (2) has been investigated in aqueous suspension by monitoring the change in substrate concentration employing UV spectroscopic analysis technique as a function of irradiation time. The degradation was studied under different conditions such as types of TiO(2), pH, substrate concentration, catalyst concentration, and in the presence of electron acceptors such as hydrogen peroxide (H(2)O(2)), potassium bromate (KBrO(3)) and ammonium persulphate (NH(4))(2)S(2)O(8) besides air. The degradation rates were found to be strongly influenced by all the above parameters. The photocatalyst Degussa P25 showed comparatively highest photocatalytic activity. The dye derivative, bismarck brown (2) was found to degrade faster than amaranth dye (1).
Microsomal NADPH-cytochrome c (P-450) reductase and cytochrome P-450 were purified from the livers of phenobarbitone-treated rats. Purified NADPH-cytochrome c (P-450) reductase effected the NADPH-dependent reduction of FMN and FAD under anaerobic conditions in a non-enzymic manner, but was unable to reduce directly the azo dye, amaranth. In the presence of FMN, the purified reductase effected reduction of amaranth through the production of reduced FMN. Incorporation of NADPH-cytochrome c (P-450) reductase into the microsomal fraction increased the azoreductase activity of liver preparations from phenobarbitone-treated rats, but had no effect on azoreductase activity in preparations from control animals. Azoreductase activity was reconstituted into dilauroyl phosphatidylcholine vesicles containing purified cytochrome P-450 and purified NADPH-cytochrome c (P-450) reductase. In the absence of supplementary FMN, amaranth reduction was completely dependent upon all three components, but in the presence of FMN, the omission of any one component failed to abolish completely azoreductase activity.
The reduction of the azo dye, amaranth, by rat liver microsomes is inhibited about 90% by carbon monoxide, suggesting that the reaction largely depends on cytochrome P-450. Reducing equivalents for this reaction are supplied by NADPH. This reaction is stimulated by riboflavin, FMN and FAD, as well as by methylviologen. A large fraction of the stimulated reaction is not blocked by CO, indicating that there is a pathway of electron transfer which is independent of cytochrome P-450. Rat liver microsomes can reduce FAD, with reducing equivalents supplied by NADPH. The FADH2 thus produced is quickly oxidized by amaranth so that two FADH2 are oxidized for every amaranth reduced. The same stoichiometry is observed with photochemically prepared FADH2, formed in the absence of microsomes.
On an example of definition of the forbidden red dye amaranth E123 in a mix with other red food dyes (azorubin E122 and ponso 4R E124) the method of quantitative processing think level chromatograms was developed. The method includes transfer of chromatogram in a digital kind by scanning and processing of the received image with the help of the program Adobe Photoshop 5.0. The average values of detection of dyes on the developed method make for azorubin, amaranth and ponso 4R accordingly 95.6, 97.1 and 99.4% with correlation coefficients 0.98, 0.98 and 0.99.
The anaerobic reduction of azo dyes by Sphingomonas sp. strain BN6 was analyzed. Aerobic conversion of 2-naphthalenesulfonate (2NS) by cells of strain BN6 stimulated the subsequent anaerobic reduction of the sulfonated azo dye amaranth at least 10-fold. In contrast, in crude extracts, the azo reductase activity was not stimulated. A mutant of strain BN6 which was not able to metabolize 2NS showed increased amaranth reduction rates only when the cells were resuspended in the culture supernatant of 2NS-grown BN6 wild-type cells. The same increase could be observed with different bacterial strains. This suggested the presence of an extracellular factor which was formed during the degradation of 2NS by strain BN6. The addition of 1,2-dihydroxynaphthalene, the first intermediate of the degradation pathway of 2NS, or its decomposition products to cell suspensions of the mutant of strain BN6 (2NS-) increased the activity of amaranth reduction. The presence of bacterial cells was needed to maintain the reduction process. Thus, the decomposition products of 1,2-dihydroxynaphthalene are suggested to act as redox mediators which are able to anaerobically shuttle reduction equivalents from the cells to the extracellular azo dye.
The aim was to devise a method for the measurement of total surface area and weight, as well as saliva weight, for a gelatin-based confectionery gel over the course of human mastication for input into separate modelling of flavour release. The method is based on an alcohol rinse to remove saliva, followed by immersion in amaranth dye to give a thin surface dye layer coating the gel fragments. Total surface area is then found by measurement of quantity of absorbed dye. The resulting time profiles for the six panellists showed that surface area reached a maximum of 3000 mm2 with the 4.28 g gel weight being consumed over 41 to 64 sec with differing numbers of swallows (4-6) and chews (52-103). Calculated total relative saliva weights, 498-993 g kg-1, and flow rates, 2.8-5.6 g min-1, were towards the upper range of those reported in the literature.
Use of the dye amaranth (Color Index 16185) as a supravital stain for ram sperm is described. At a concentration of 0.4% in diluted semen, the dye was completely excluded by motile sperm and had no effect on sperm motility. The nuclei of immotile sperm were stained pink by amaranth. The decrease in sperm motility during 24-h storage at 5 degrees C was accompanied by a corresponding increase in stained sperm nuclei. The presence of the dye during freezing had no effect on sperm cryosurvival but tended to reduce sperm motility during post-thaw incubation. Insemination of ewes with fresh semen containing amaranth or with semen frozen in the presence of amaranth resulted in pregnancies in 7/10 ewes in each group, compared to 6/9 in the case of ewes inseminated with fresh semen without dye.
Bottom Ash, a power plan t waste material and De-Oiled Soya, an agriculture waste product were successfully utilized in removing trisodium 2-hydroxy-1-(4-sulphonato-1-naphthylazo)naphthalene-3,6-disulphonate--a water-soluble hazardous azo dye (Amaranth). The paper incorporates thermodynamic and kinetic studies for the adsorption of the dye on these two waste materials as adsorbents. Characterization of each adsorbent was carried out by I.R. and D.T.A. curves. Batch adsorption studies were made by measuring effects of pH, adsorbate concentration, sieve size, adsorbent dosage, contact time, temperature etc. Specific rate constants for the processes were calculated by kinetic measurements and a first order adsorption kinetics was observed in each case. Langmuir and Freundlich adsorption isotherms were applied to calculate thermodynamic parameters. The adsorption on Bottom Ash takes place via film diffusion process at lower concentrations and via particle diffusion process at higher concentrations, while in the case of De-Oiled Soya process only particle diffusion takes place in the entire concentration range.
A simple spectrophotometric method is described for resolving binary mixtures of some food dyes: Amaranth, Brilliant Blue, Sunset Yellow and Tartrazine, using the first-derivative spectra with measurements at zero-crossing wavelengths. Analytical curves are linear up to 20 mg L(-1). Standard deviations of 1.30, 2.22, 1.93 and 0.81% were obtained for synthetic binary mixtures of 2 mg L(-1) of Amaranth, Brilliant Blue, Sunset Yellow and Tartrazine, respectively. Before the spectrophotometric measurements, the dyes were sorbed onto polyurethane foam and recovered in sodium dodecyl benzene sulfonate solution. Therefore, matrix complexity was eliminated and simple spectra were obtained. The method was very satisfactorily used for determining the colorants in synthetic mixtures, with recoveries in the 96 - 101% range. Detection limit values were dependent on the colorant combination investigated. Commercial products containing binary combinations of these dyes in different ratios (from 1:1 to 1:8) were analyzed. The results were compared with those obtained by HPLC; very similar values were found by the two methods.
During dye decoloration by Trametes versicolor ATCC 20869 in modified Kirk's medium, manganese peroxidase (MnP) and laccase were produced, but not lignin peroxidase, cellobiose dehydrogenase or manganese-independent peroxidase. Purified MnP decolorized azo dyes [amaranth, reactive black 5 (RB5) and Cibacron brilliant yellow] in Mn(2+)-dependent reactions but did not decolorize an anthraquinone dye [Remazol brilliant blue R (RBBR)]. However, the purified laccase decolorized RBBR five to ten times faster than the azo dyes and the addition of a redox mediator, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid), did not alter decoloration rates. Amaranth and RB5 were decolorized the most rapidly by MnP since they have a hydroxyl group in an ortho position and a sulfonate group in the meta position relative to the azo bond. During a typical batch decoloration with the fungal culture, the ratio of laccase:MnP was 10:1 to 20:1 (based on enzyme activity) and increased to greater than 30:1 after decoloration was complete. Since MnP decolorized amaranth about 30 times more rapidly than laccase per unit of enzyme activity, MnP should have contributed more to decoloration than laccase in batch cultures.