Ethanol Based Extraction of Annatto (Bixa Orellana L.) and Characterisation of the Bixin and Norbixin

Bixa orellana dye was extracted from the seed by method of Soxhlet extraction using ethanol and a percentage yield of 4.3 was obtained. Recrystallisation of the dye was performed using chloroform and ethanol. TLC was used to separate the dye into Bixin and Norbixin with Rf values of 0.56 and 0.42 respectively. The extracted dye was pH sensitive, insoluble in water but soluble in some organic solvents like ethanol and acetic acid . Characterisation by UV-spectroscopy showed maximum absorption for Bixin and Norbixin at 457nm and 453nm respectively. FTIR spectrum of Bixin and Norbixin showed bands confirming similar functional groups for both Bixin and Norbixin except for –CO- stretching and methylene vibration which was absent in Norbixin.