Coloring preparations from Hylocereus polyrhizus have recently received attention because peel and/or aril of the fruit exhibit a high content of betacyanins. These pigments are of special interest due to their potential as a red food colorants with a high stability at neutral pH. To improve production yield and to obtain a concentrated Hylocereus fruit extract, Pectinex Ultra SP–L in various d...

Betalains replace anthocyanins as color pigments in most families of Caryophyllales. Unlike anthocyanins, betalains are derived from tyrosine via three enzymatic steps: hydroxylation of L-tyrosine to L-3,4-dihydroxyphenylalanine (L-DOPA; step 1), and conversion of L-DOPA to betalamic acid (step 2), and to cyclo-DOPA (cDOPA; step 3). The principal enzymes responsible for these reactions have bee...

Purslane (Portulaca oleracea) is a globally-distributed plant with a long history of use in folk medicine and cooking. We have developed purslane as a model system for exploring plant responses to stress. We exposed two varieties of purslane to saline stress with the objective of identifying differences between the varieties in the plasticity of morphological and physiological traits. The varie...

It is a common practice to prepare tint ladders of each colorant consisting of five or more concentrations in order to develop a colorant database for instrumental-based color matching, characterization of optical properties of a coloration system, and pigment mapping. For two-constant Kubelka-Munk theory, the unit absorption and scattering coefficients for each colorant can be solved by the li...

Introduction The transformation of a digital image from a three-dimensional color space, such as RGB, XYZ, L*u*v*, etc., to four-dimensional colorant space (typically cyan, magenta, yellow, and black) is in general underdetermined. (The reasons for the addition of a black colorant are detailed in Yule. [1]) We therefore have a degree of freedom for colors within the three-colorant gamut; withou...

The current study is aimed to utilize the microwave for isolation of colorant from neem bark and its application onto chemical & bio-mordanted cotton fabric. For the purpose, aqueous, acid and organic media have been employed to isolate the colorant and to make its application onto surface modified and bio-mordanted cotton fabric followed by microwave treatment up to 6min....

Total anthocyanins in different cultivars of mulberry were measured and a process for the industrial preparation of mulberry anthocyanins as a natural food colorant was studied. In 31 cultivars of mulberry, the total anthocyanins, calculated as cyanidin 3-glucoside, ranged from $147.68$ to $2725.46$ mg/L juice. Extracting and purifying with macroporous resins was found to be an efficient potent...