Selective extraction of bioactive compounds from annatto seeds by sequential supercritical CO2 process

The present work proposed a two-step sequential scCO(2) extraction process to selectively extract the main bioactive compounds from annatto seeds, geranylgeraniol and tocols, aiming to diversify and to improve the added-value of annatto seeds products. Firstly, pressure (10,17, 24 and 31 MPa) and temperature (40 and 60 degrees C) conditions resulting CO2 densities ranging from 290 kg/m(3) to 915 kg/m(3) were investigated to verify its effect on the chemical composition of the extracts. Extracts obtained at 290 kg/m(3) presented the highest geranylgeraniol content (39 +/- 9%) and the lowest tocotrienols content (0.95 +/- 0.04%). CO2 densities higher than 629 kg/m(3) were needed to recover tocotrienols-rich fractions. Therefore, a two-step sequential scCO(2) extraction process was carried out using 60 degrees C and 10 MPa (290 kg/m(3)) in the first step to recover the geranylgeraniol-rich fraction, and 40 degrees C and 20 MPa (840 kg/m(3)) in the second step to recover the tocotrienols-rich fraction. (C) 2019 Elsevier B.V. All rights reserved.