engleski

Effects of supercritical fluid extraction parameters on yield and tocopherol composition of soybean oil

For many applications supercritical fluid extraction has several advantages compared to extraction with classical solvents (e.g. hexane). There are no solvent residues in the extract and the low process temperatures are used. Fragrances and aromas remain unchanged. The extraction agent CO2 is nontoxic, nonexplosive, inflammable, cheap, readily available and easily removed from extracted products. Supercritical fluid extraction of soybean oil at different conditions of temperature and pressure was studied. Soybean oil was fractionated into few fractions collected at different time intervals during extraction. Fractionation was performed at following temperatures: 40, 50 and 60 °C and at pressures 300, 400 and 500 bar. The composition of tocopherols in different fraction of soybean oil obtained at different extraction process conditions was determined. The results show that the extraction yields are significantly affected by applied extraction pressures. In order to describe the extraction process, the Sovová model was used and very good agreement with experimental results was obtained. The extraction was successfully scaled-up to pilot plant maintaining the ratio solvent flow rate/raw material mass and ratio packed column height/packed column diameter constant between small and large scales. The extraction conditions statistically significant influenced the tocopherols composition. In all obtained extracts, the content of γ-tocopherol was significantly higher compared to content of α- and δ-tocopherol, while the content of β-tocopherol was low or not detected in obtained fractions. Furthermore, the total tocopherol content extracted from soybean oil by n-hexane was less than that extracted by the supercritical CO2.

supercritical fluid extraction; soybean oil; tocopherol; modelling

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