A method of producing organic pigment microparticles includes: Step 1 of precipitating organic pigment microparticles by mixing an organic pigment raw material liquid in which an organic pigment raw material is mixed with a solvent, and a precipitation solvent for precipitating the organic pigment microparticles from the organic pigment raw material liquid in a thin film fluid formed by introducing the organic pigment raw material liquid and the precipitation solvent in a space between at least two processing surfaces which are disposed so as to face each other, being capable of approaching to and separating from each other, at least one of which rotates relatively to the other; and Step 2 of coating at least a part of the organic pigment microparticles with an oxide coating; wherein the oxide coating is optically colorless and transparent, and Step 1 and Step 2 are performed out continuously in the thin film fluid.

The present invention relates to methods for obtaining natural colorants from materials of plant origin. The method comprises a mixing step, a co-pigmentation step, an enzymatic hydrolysis step and various filtration steps carried out under specific conditions.

The present invention relates to near-infrared-absorbing dye-based composite particles which exhibit a photothermal effect and/or photoacoustic signal upon photoirradiation, a preparation method thereof, and a use thereof. The near-infrared-absorbing composite particles comprise: a water-insoluble salt of a near-infrared-absorbing dye, which comprises anions of the near-infrared-absorbing dye and metal cations capable of forming a precipitation product with the anions of the near-infrared-absorbing dye; and particles of a polymeric surfactant, in which a water-insoluble salt of the near-infrared-absorbing dye is supported in the hydrophobic part of the polymeric surfactant.

The invention discloses a gardenia blue pigment with high brightness and low redness and a preparation method therefor, and belongs to the technical field of pigment extraction. Genipin, an enzymolysis product of gardenia extract, is used as a raw material. Genipin and amino acids (phenylalanine, tryptophan, glycine, or tyrosine) are weighed at a molar ratio of 1:(0.375-0.75), and subjected to a polymerization reaction under a conventional condition to generate a gardenia blue precursor. The gardenia blue precursor is oxidized to develop a color, refined by using ultrafiltration membrane, and finally spray-dried to obtain the gardenia blue pigment with high brightness, low redness, and low cost.

The present invention provides a method for preparing a colour-stable preparation of a magnesium chlorophyllin alkali metal salt or alkali earth metal salt from natural sources of chlorophyll. The invention further provides a colour-stable and substantially pure pigment composition comprising a vibrant green magnesium chlorophyllin in the form of an alkali metal or alkali earth metal salt, e.g. those prepared by the methods of the invention, and the use of the salts and compositions of the invention as colouring agents, in particular as food colouring agents, and as medicaments and disinfectants.

The present invention relates to a method of separating betanin from red quinoa by supercritical fluid fractionation, including: mixing an extract of red quinoa with an ethanol/water mixture to obtain a mixture of red quinoa/ethanol/water; and separating betanin from the mixture of red quinoa/ethanol/water by supercritical fluid fractionation, which operates under a pressure between 2300 to 4400 psi at a temperature between 35 to 65 C. for a period of time between 15 to 90 minutes.

A method of preparing paprika red pigment with low polycyclic aromatic hydrocarbons includes (1) drying, crushing and granulating mature peppers to obtain pepper particles; (2) extracting the pepper particles with a vegetable oil in a rotocel extractor to obtain a paprika red pigment solution; (3) extracting the paprika red pigment solution with an ethanol solution in a liquid-liquid extractor to remove spicy substances; (4) running the paprika red pigment solution through a low-pressure chromatography column to remove polycyclic aromatic hydrocarbons; and (5) concentrating the paprika red pigment solution to obtain the paprika red pigment with low polycyclic aromatic hydrocarbons.

Process for preparing disodium 5,5-indigosulfonate, the feedstock being indigo, this process including the following steps: i) the indigo is subjected to a sulfonation treatment resulting in a mixture that contains 5,5-indigosulfonic acid, this process including: ii) a reduction treatment is applied to the mixture obtained in step i), and optionally a purification step, so as to obtain a composition including leuco-5,5-indigosulfonic acid, iii) the leuco-5,5-indigosulfonic acid is isolated from the composition resulting from step ii), iv) the leuco-5,5-indigosulfonic acid resulting from step iii) is oxidized to give disodium 5,5-indigosulfonate.

The invention seeks protection for a novel method for the surface functionalization of solid materials with one or more active ingredients intended to confer specific properties thereon, such as anti-UV, fluorescence or coloring properties.

The present invention provides a method for preparing a colour-stable preparation of a magnesium chlorophyllin alkali metal salt or alkali earth metal salt from natural sources of chlorophyll. The invention further provides a colour-stable and substantially pure pigment composition comprising a vibrant green magnesium chlorophyllin in the form of an alkali metal or alkali earth metal salt, e.g. those prepared by the methods of the invention, and the use of the salts and compositions of the invention as colouring agents, in particular as food colouring agents, and as medicaments and disinfectants.