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Supercritical carbon dioxide extraction, as a relatively new separation technique, can be used as a very efficient process in the production of essential oils and oleoresins from many of plant materials. The extracts from these materials are a good basis for the new pharmaceutical products and ingredients in the functional foods. This paper deals with supercritical carbon dioxide extraction of selected oil seeds which are of little interest in classical extraction in the food industry. In this article the process parameters in the supercritical carbon dioxide extraction, such as pressure, temperature, solvent flow rate, diameter of gound materials, and moisture of oil seed were presented for the following seeds: almond fruits, borage seed, corn germ, grape seed, evening primrose, hazelnut, linseed, pumpkin seed, walnut, and wheat germ. The values of investigated parameters in supercritical extraction were: pressure from 100 to 600 bar, temperature from 10 to 70oC, diameter of grinding material from 0.16 to 2.0 mm, solvent flow used from 0.06 to 30.0 kg/h, amount of oil in the feed from 10.0 to 74.0%, and moisture of oil seed from 1.1 to 7.5%. The yield and quality of the extracts of all the oil seeds as well as the possibility of their application in the pharmaceutical and food, industries were analyzed

Phytosterols in Cucurbita pepo convar. citrullina seed oil were analyzed by GC-MS after extraction by the organic solvents, hexane and petroleum ether, and by supercritical carbon dioxide at 400 bar and 408C. Desmosterol, campesterol, stigmasterol, spinasterol, D7,22, D7stigmastenol, D7,, and D7-avenasterol were identified mass spectrometrically via detection of the parent molecular ions and fragmentation patterns of corresponding trimethylsilyl derivatives. The used derivatizing agents N-methyl-N-(trimethylsilyl)trifluoroacetamide (MSTFA) and N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) are equally effective for phytosterol content determination. As expected, the predominant phytosterols were D7-sterols that ranged from 91.0 to 94.2% of the total phytosterol content given as sum of free sterols and steryl esters. Comparison of extraction methods revealed that, although the oil yields obtained by extraction with hexane, petroleum ether and supercritical CO 2 were 43.37, 44.65, and 36.17%, respectively, the total phytosterol content in supercritical CO 2 extract (294 mg/100 g oil, for both MSTFA and BSTFA) was about 30% higher than in hexane and about 20% higher than in petroleum ether extract.Practical applications: Extraction with the application of fluids in supercritical state opens a new approach to the production of edible vegetable oils. Many economical, health, and environmental aspects are interlaced in this modern approach. By applying the supercritical extraction, the selectivity of the extraction can be significantly improved compared to traditional methods of extraction. Thus, depending on the operating conditions of supercritical CO 2 extraction higher total phytosterol content can be achieved resulting in improved nutritional value of the pumpkin seed oil.

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Ground fruits of the common juniper (Juniperus communis L.), with a particle size range from 0.250-0.400 mm, forming a bed of around 20.00 +/- 0.05 g, were extracted with supercritical CO(2) at pressures of 80, 90, and 100 bars and at a temperature of 40 degrees C. The total amount of extractable substances or global yield (mass of extract/mass of raw material) for the supercritical fluid extraction process varied from 0.65 to 4.00% (wt). At each investigated pressure, supercritical CO(2) extract fractions collected in successive time intervals over the course of the extraction were analyzed by capillary gas chromatography, using flame ionization (GC-FID) and mass spectrometric detection (GC-MS). More than 200 constituents were detected in the extracts, and the contents of 50 compounds were reported in the work. Dependence of the percentage yields of monoterpene, sesquiterpene, oxygenated monoterpene, and oxygenated sesquiterpene hydrocarbon groups on the extraction time was investigated, and conditions that favored the yielding of each terpene groups were emphasized. At all pressures, monoterpene hydrocarbons were almost completely extracted from the berries in the first 0.6 h. It was possible to extract oxygenated monoterpenes at 100 bar in 0.5 h and at 90 bar in 1.2 h. Contrary to that, during an extraction period of 4 h at 80 bar, it was possible to extract only 75% of the maximum yielded value of oxygenated monoterpene at 100 bar. Intensive extraction of sesquiterpenes could be by no means avoided at any pressure, but at the beginning of the process (the first 0.5 h) at 80 bar, they were extracted about 8 and 3 times slower than at 100 and 90 bar, respectively. Oxygenated sesquiterpenes were yielded at fast, constant extraction rates at 100 and 90 bar in 1.2 and 3 h, respectively. This initial fast extraction period was consequently followed by much slower extraction of oxygenated sesquiterpenes.

Supercritical fluid extraction (SFE) is one of the relatively new efficient separation method for the extraction of essential oils from different plant materials. The new products, extracts, can be used as a good base for the production of pharmaceutical drugs and additives in the perfume, cosmetic, and food industries. The aim of this work was to analyze the supercritical carbon dioxide extraction (SC-CO2) of oils from the selected spice plant materials. In this paper the process parameters such as pressure, temperature, solvent flow rate, size of grinding materials, and ratio of the co-solvent were presented for the selected spice plant materials: black pepper, caraway, celery, cinnamon, clove, coriander, daphne, fennel, ginger, hyssop, juniper, lavender, oregano, pennyroyal, red pepper, safflower, sage, turmeric, and vanilla. The values of operating conditions were: pressure from 7.5 to 68 MPa, temperature from 293 to 363 K, solvent flow rate from 0.003 to 30.0 kg/h, and diameter of grinding material from 0.17 to 3.90 mm. The global yield and quality of the extracts all of the plant material investigated, as well as the possibility of their application in the food, cosmetics and pharmaceutical industries were analyzed. The composition of the extracts was wery complex, and in every case the extract was composed of more than 200 components. All the compounds from the CO2 extracts were classified in the following groups: monoterpene, sesquiterpene, oxygenated monoterpene, and oxygenated sesquiterpene and other hydrocarbon groups. In some of the systems investigated the different mathematical models (Sovová, Hong), which have taken from the literature, were used to correlate the experimental data.

The hydrodynamic characteristics of the air-water-toluene three-phase system in a spray extraction column at 20 °C were examined. The average and local hold-up data of the dispersed phase were determined in dependence on the flow rates of the continuous, dispersed and gaseous phases. The average gas phase hold-up was also measured and analyzed. A comparison was made of the hydrodynamic characteristics of the two-phase (water-toluene) and three-phase (air-water-toluene) systems.With respect to the dispersed phase hold-up, a spray extraction column can operate in three modes of packing of the dispersed phase drops 1,2 : dispersed, restrained, and dense. The efficiency is relatively low when the column is operated in the dispersed or restrained drop packing mode, mainly due to a high axial mixing in the continuous phase. An increased efficiency of the spray extraction column is attained with the dense packing of the dispersed phase drops, where the axial mixing in the two phases is significantly decreased.The efficiency of non-mechanically agitated extraction columns with different packings can be considerably increased by introducing an inert gas as a mixing agent in the two-phase system 3-5 . The energy thus introduced increases the turbulence within the now three-phase, gas-liquid-liquid (G-L-L) system, which brings about improved dispersion of the droplets and, consequently, a higher hold-up and a larger mass transfer area 3 . Priestley and Ellis 5 observed that the dispersed phase droplets were smaller and there was more backmixing in the continuous phase when a gas was introduced into the packed extraction column. Galkin et al. 6 found the largest reduction of the height equivalent to a theoretical stage (HETS) in plate extraction columns with superficial gas velocities of 0.02 -0.03 m s −1 . The authors concluded that this way of energy introduction was more efficient than by stirring or pulsation of the column.Gas-Agitated Liquid-Liquid Extraction