The objective of this study was to develop a simple and reproducible method for the qualitative and quantitative analysis of betalains in plasma samples, based on Solid Phase Extraction (SPE) and micro-high performance liquid chromatography coupled with mass spectrometry (micro-HPLC-MS/MS). The eight betalain compounds detected and quantified were characterized in the fortified rat blood plasma...

Monascorubrin and its derivatives are polyketides used as natural colorants for a wide range of food for more than one thousand years. Since the biosynthetic pathway for this ancient chemical compound is unknown and genome sequence unavailable for any Monascus species, monascorubrin production has relied on extraction from fungal cultures of Monascus species. In vitro synthesis and genetic mani...

There is a current need to develop low-cost strategies to degrade and eliminate industrially used colorants discharged into the environment. Colorants discharged into natural water streams pose various threats, including: toxicity, degradation of aesthetics and inhibiting sunlight penetration into aquatic ecosystems. Dyes and colorants usually have complex aromatic molecular structures, which m...

The underlying non-linearity of how print colorants combine makes color control in printing significantly more complex than for other color imaging devices. While in additive systems a measurement of their few primaries and per-channel nonlinearities versus luminance is a sufficient basis for predicting color output, printing typically requires the measurement of a large number of colorant comb...

PURPOSE To evaluate the individual contributions of pigment colorant and packing solution containing polyvinyl pyrrolidone (PVP) on the oxygen permeability (Dk) of a cosmetic printed etafilcon A daily disposable contact lens packaged with PVP. METHOD The oxygen transport of a contact lens is evaluated through the central optical zone of the lens. Cosmetic printed contact lenses contain pigmen...

STATEMENT OF PROBLEM The average clinical life span of a maxillofacial prosthesis is approximately 6 months, at which point it needs to be refabricated, mainly because of degradation of the color and physical properties of the prosthesis. PURPOSE This first part of a 3-part study evaluated the effect of coloring agents on the physical properties of maxillofacial elastomers. METHODS AND MATE...

Non-destructive tests (NDT) of historical artifacts are the ideal scientific tools for the analyses of culturally important heritage objects. However, for the investigations of certain materials, especially natural organic dyes and pigments, it is important for curators, conservators, and scientists to be aware that such analyses are not always practical or prudent. At best, NDT can definitivel...

In this study, dyeing of two regenerated polyester fibers, poly-trimethylene terephthalate (PTT) and poly-lactic acid (PLA), with natural dyes were compared with that of poly-ethylene terephthalate (PET) fiber. Lac was used as the primary natural colorant while Catechu was chosen as a natural color that can also act as a biomordant. The effects of temperature, initial pH of dye bath and dyeing ...