Division E 160 b (ii) ANNATTO NORBIXIN

Solvent-extracted norbixin is obtained from the outer coating of the seeds of the annatto tree (Bixa orellana L.) by washing with one or more of the following food grade solvents: acetone, methanol, hexane, ethanol, isopropyl alcohol, ethyl acetate, alkaline alcohol or supercritical carbon dioxide followed by solvent removal, crystallization and drying. Aqueous alkali is added to the resultant powder, which is then heated to hydrolyse the colouring matter and cooled. The aqueous solution is filtered, and acidified to precipitate the norbixin. The precipitate is filtered, washed, dried and milled, to give a granular powder.

Solvent-extracted norbixin contains several coloured components; the major colouring principle is cis-norbixin, a minor colouring principle is trans-norbixin; thermal degradation products of norbixin may also be present as a result of processing.

cis-Norbixin: 6,6'-Diapo-Ψ,Ψ-carotenedioic acid

cis-Norbixin dipotassium salt: Dipotassium 6,6'-diapo-Ψ,Ψ-carotenedioate

cis-Norbixin disodium salt: Disodium 6,6'-diapo-Ψ,Ψ-carotenedioate

cis-Norbixin: C₂₄H₂₈O₄

cis-Norbixin dipotassium salt: C₂₄H₂₆K₂O₄

cis-Norbixin disodium salt: C₂₄H₂₆Na₂O₄

Not less than 85 % colouring matter (expressed as norbixin)

E^{1 %} _1cm 2870 at ca. 482 nm in 0,5 % potassium hydroxide solution

Acetone: Not more than 30 mg/kg

Methanol: Not more than 50 mg/kg

Hexane: Not more than 25 mg/kg

Ethanol:

Isopropyl alcohol:

Ethyl acetate:

Alkali-processed norbixin (acid-precipitated) is prepared by the extraction of the outer coating of the seeds of the annatto tree (Bixa orellana L.) with aqueous alkali. The bixin is hydrolysed to norbixin in hot alkaline solution and is acidified to precipitate the norbixin. The precipitate is filtered, dried and milled to give a granular powder.

Alkali-processed norbixin contains several coloured components; the major colouring principle is cis-norbixin, a minor colouring principle is trans-norbixin; thermal degradation products of norbixin may also be present as a result of processing.

cis-Norbixin: 6,6'-Diapo-Ψ,Ψ-carotenedioic acid

cis-Norbixin dipotassium salt: Dipotassium 6,6'-diapo-Ψ,Ψ-carotenedioate

cis-Norbixin disodium salt: Disodium 6,6'-diapo-Ψ,Ψ-carotenedioate

cis-Norbixin: C₂₄H₂₈O₄

cis-Norbixin dipotassium salt: C₂₄H₂₆K₂O₄

cis-Norbixin disodium salt: C₂₄H₂₆Na₂O₄

Not less than 35 % colouring matter (expressed as norbixin)

E^{1 %} _1cm 2870 at ca. 482 nm in 0,5 % potassium hydroxide solution

Alkali-processed norbixin (not acid-precipitated) is prepared by the extraction of the outer coating of the seeds of the annatto tree (Bixa orellana L.) with aqueous alkali. The bixin is hydrolysed to norbixin in hot alkaline solution. The precipitate is filtered, dried and milled to give a granular powder. Extracts contain mainly the potassium or sodium salt of norbixin as the major colouring matter.

Alkali-processed norbixin (not acid-precipitated) contains several coloured components; the major colouring principle is cis-norbixin, a minor colouring principle is trans-norbixin; thermal degradation products of norbixin may also be present as a result of processing.

cis-Norbixin: 6,6'-Diapo-Ψ,Ψ-carotenedioic acid

cis-Norbixin dipotassium salt: Dipotassium 6,6'-diapo-Ψ,Ψ-carotenedioate

cis-Norbixin disodium salt: Disodium 6,6'-diapo-Ψ,Ψ-carotenedioate

cis-Norbixin: C₂₄H₂₈O₄

cis-Norbixin dipotassium salt: C₂₄H₂₆K₂O₄

cis-Norbixin disodium salt: C₂₄H₂₆Na₂O₄

Not less than 15 % colouring matter (expressed as norbixin)

E^{1 %} _1cm 2870 at ca. 482 nm in 0,5 % potassium hydroxide solution