PREPARATION AND THE CHEMISTRY OF NATURAL FOOD COLOURS FROM ANNATTO PLANT

LIM BON TONG

SUMMARY

Oil-soluble annatto colours were developed by extracting the annatto seeds with corn oil or propylene glycol, whereas water-soluble annatto colour was developed by extracting with 0.1 M potassium hydroxide. Analysis of the annatto colour extracts showed that annatto colour in corn oil has 0.06% total pigment content and six spots on TLC studies. Annatto colour in propylene glycol has a total pigment content of 0.05% and also six spots  on TLC studies. Results also s howed that annatto colour in potassium hydroxide has 0.17% a total pigment content and six spots on TLC studies. Alkaline extraction was found to be more efficient than aqueous extraction in the production of crude pigment powder. Annatto colour in corn oil prepared from crude pigment powder has 0.06% total pigment content. On the other hand, annatto colour in potassium hydroxide prepared from crude pigment powder has 0.58% total pigment content. Annatto colour in corn oil and propylene glycol developed were stable for at least six months, where as annatto colour in potassium hydroxide was found to be stable for at least three months.

 Full Text (417 KB)