Ethanol-Based Extraction of Annatto (<i>Bixa Orellana L.)</i> and Characterization of the Bixin and Norbixin

Abstract

<i>Bixa orellana</i> dye was extracted from the seeds by the method of Soxhlet extraction using ethanol where a percentage yield of 31.4 was obtained. Recrystallization of the dye was performed using chloroform and ethanol to increase the degree of purity. Thin layer chromatography was used to separate the dye into Bixin and Norbixin with <i>R</i>_f 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. Characterization by UV-vis spectroscopy showed maximum absorption for Bixin and Norbixin at 457 and 453 nm, respectively. Fourier transform infrared spectra 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. With the yield, purity level, and other properties of the extracted dye, the comparative advantages of ethanol-based Soxhlet extraction of the dye were well established.