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Supercritical fluid extraction (SFE) from aniseed using carbon dioxide was performed at 30 degrees C and pressures of 80-180 bar. The chemical composition of the SFE extract was determined by GC-MS; the quantitative analysis was done by GC-FID and TLC. The total amount of extractable substances or global yield (mass of extract/mass of feed) for the SFE process varied from 3.13 to 10.67% (mass). The solubilities of the anise essential oil in CO(2) were 0.0110, 0.0277, 0.0143, and 0.0182 kg of solute/kg of CO(2) at 80, 100, 140, and 180 bar, respectively. The major compounds identified and quantified in the extracts were anethole ( approximately 90%), gamma-himachalene (2-4%), p-anisaldehyde (<1%), methylchavicol (0.9-1.5%), cis-pseudoisoeugenyl 2-methylbutyrate ( approximately 3%), and trans-pseudoisoeugenyl 2-methylbutyrate ( approximately 1.3%). The Sovová model described quite well the experimental overall extraction curves.

The kinetics of supercritical fluid extraction from vegetable raw materials in fixed beds was studied. The operational conditions used in the extraction of ginger oleoresin were pressures of 150, 200, and 250 bar, temperatures of 20, 30, and 40 °C, and a solvent flow rate of (5.6 ( 0.3) × 10 -5 kg/s of CO 2 . A mathematical model obtained from the differential mass balance in the extraction bed was presented. This model considers the extract as a mixture of various groups of compounds, classified according to their chemical characteristics. The interfacial mass flux of each group of compounds was assumed to be described by one of the solutions of the logistic equation. The model was able to describe quite well the experimental results for ginger oleoresin extraction, considering the extract either as a single pseudocompound or as the sum of three groups of compounds. The overall extraction curves were fitted by both the proposed model and Sovova ´'s model; the sum of square deviations was lower for the proposed model.

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The valorization of extracts from Brazilian vetiver (Vetiveria zizanioides (L.) Nash ex Small) roots was studied. This study took into account the extraction method, the chemical composition of the extracts, their sensorial characteristics, and the possibility of chemical transformations of the product. The performed extraction methods were hydrodistillation and extraction with supercritical carbon dioxide. Some pretreatment methods were tested on the vetiver roots and evaluated in terms of extraction yield, process time, chemical composition, and sensorial properties. Supercritical carbon dioxide extraction resulted in high yield (3.2%) in significantly less time than the other methods. The chemical compositions of the extracts obtained by the different methods were also compared to those of commercial vetiver oils from other sources, showing that Brazilian samples had a greater acid amount. An extraction in basic medium from Brazilian vetiver oil was done to remove its main acid (zizanoic acid), which was chemically transformed into an alcohol (khusimol) of desirable sensorial properties. Sensory evaluation indicated that the Brazilian volatile oil without acid could be used in perfumery and the extract obtained with supercritical carbon dioxide could have application in food.

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