Safety issues related to the employment of synthetic colorants in different industrial segments have increased the interest in the production of colorants from natural sources, such as microorganisms. Improved cultivation technologies have allowed the use of microorganisms as an alternative source of natural colorants. The objective of this work was to evaluate the influence of some factors on ...

A method for the simultaneous determination of the colorants Sunset Yellow FCF and Quinoline Yellow using solid-phase spectrophotometry is proposed. The colorants were isolated in Sephadex DEAE A-25 gel at pH 5.0, the gel-colorants system was packed in a 1 mm silica cell and spectra were recorded between 400 and 600 nm against a blank. Statistical results were obtained by partial least squares ...

Consumers are avoiding foods containing synthetic colourants, which lead food industries to replace them by natural pigments. Food colorants may be classified into synthetic, nature-identical, inorganic and natural colorants. Natural colorants for food are made from renewable sources. Most often, the colorants are extracted from plant material, but other sources such as insects, algae, cyanobac...

Research has been initiated to determine a set of six basis colorants which are the best representation of artwork such as paintings. That is, their spectral information can be accurately reconstructed by linear combinations of the six estimated colorants. Since each painting is possibly created by different colorants, the six estimated colorants are image dependent. The clue leading to the six...

OBJECTIVE To investigate the surfaces and principal elements of the colorants of cosmetically tinted contact lenses (Cos-CLs). METHODS We analyzed the surfaces and principal elements of the colorants of five commercially available Cos-CLs using scanning electron microscopy with energy-dispersive x-ray analysis. RESULTS In two Cos-CLs, the anterior and posterior surfaces were smooth, and col...

Duotone refers to an image with various shades of a hue mapped in an vector or wedge through a color space. The colorant, the gradient curve, and the number of colorants used define the slice through the color space. The image is printed with two or more analogue colorants. The colorants may be custom formulated or selected from a named color system. Typically two colorants are placed on a subs...

The reflectance model developed by Kubelka and Munk was evaluated for agreement in color prediction of thick pigmented samples and for linearity of optical absorption and scattering coefficients with concentration of colorant in maxillofacial elastomer. The colorants tested were generic opacifiers, dry mineral earth pigments, and fibrous colorants. Significant linear relationships were commonly...

We tested synthetic food colorants for their antioxidative potential by the in vitro superoxide generation assay in differentiated HL-60 cells in response to phorbol ester. Among the 12 colorants tested, such fluorescein-type red colorants as rose bengal showed potent inhibitory activity without any cytotoxicity under dark conditions. The intracellular accumulation and superoxide anion scavengi...

A novel marine bacterium strain effectively produced prodiginine type pigments. These colorants could dye wool, silk and synthetic fabrics such as polyester and polyacrylic and also show antibacterial properties against Escherichia coli and Staphylococcus aureus bacteria on the dyed products. Methyl nitrosoguanidine was used as a mutation agent to increase the genetic diversity and the producti...