Supercritical extraction of carotenoids and lipids from buriti (Mauritia flexuosa), a fruit from the Amazon region

Pulp of the buriti fruit (Mauritia flexuosa, Mart.) was extracted with supe rcritical CO, to obtain oil fractions with a high concentration of vitamins , especially p-carotene. The raw material consisted of a mixture of pulp an d peel that was scraped off the immature fruit. The extracted oil was analy zed by gas chromatography and spectrophotometry, and results were compared with those obtained by extraction using hexane as solvent. The oil extracte d with hexane showed a content of about 1% carotene. Extraction with superc ritical CO2 was capable of removing about 80% of the initial carotene conte nt. Extraction experiments were carried out at pressures of 20 and 30 MPa a nd temperatures of 313 and 328 K. The extraction curves typically showed th e three regions found in supercritical fluid extraction of natural products , i.e. beginning with a straight line characteristic of the constant rate e xtraction period, followed by the falling rate period, and ending with the diffusion rate period. Experimental data were correlated using the model pr oposed by Sovova. The model showed good agreement with experimental data. T he mass transfer coefficients of the solid phase were obtained by adjusting the model equation. The solubility values calculated are within the range for common vegetable oils. (C) 1999 Elsevier Science B.V. All rights reserv ed.