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Jokić S., Velić D., Bilić M., Bucić-Kojić A., Planinić M., Tomas S. (2010): Modelling of the process of solid-liquid extraction of total polyphenols from soybeans. Czech J. Food Sci., 28: 206-212.The influence of the solvent, temperature, and extraction time on the extractability of total polyphenols from milled soybeans variety Ika was investigated. The study was performed in order to select the most suitable solvent (water; 50, 60, 70, and 80% aqueous ethanol) for achieving the highest yield of total polyphenols. The most effective solvent (50% aqueous ethanol solution) was used for monitoring the kinetics and modelling of solid-liquid extraction of total polyphenols from soybeans, average particle size 0.459 mm, at solid-liquid ratio of 20 ml/g (ratio of the solvent volume per g of raw material). The total polyphenols content in the soybean extract was determined spectrophotometrically using Folin-Ciocalteu micro-methods at 765 nm. The applicability of different mathematical models (Peleg, Page, and Logarithmic models) to describe the kinetics of the solid-liquid extraction process of total polyphenols from soybeans was studied as well. The results exhibited a significant influence of the solvent and temperature on the kinetics and extraction yield of total polyphenols from soybeans. The best extraction yield of total polyphenols was obtained using 50% aqueous ethanol solution at 80°C after 120 min (4.322 mg GAE/g db ). The extraction yield of total polyphenols in soybean extracts increased by increasing the extraction temperature and extending the duration of the extraction process. The mathematical models applied showed a good agreement with the experimental results, which allows their application in modelling and optimisation of solid-liquid extraction process for the extraction of total polyphenols from soybeans.

In this work the infl uence of 50-80% (v/v) aqueous ethanol and the temperature of extraction (25-80°C) on the extractability of total phenolics, total fl avonoids and total proanthocyanidins from different fi g fruits was investigated. The best extraction conditions (80%, v/v aqueous ethanol, 80°C) obtained in the experiments with lyophilised Ficus carica L. cv. Šaraguja were used while performing the extraction of phenolic compounds from other fi g varieties (Bružetka bijela, Crnica, Bjelica and Termenjača). The antioxidant capacity was measured in all fi g fruits as well.It has been shown that the temperature of extraction and ethanol to water ratio have a statistically signifi cant infl uence on the extraction of phenolic compounds from fi g fruits variety Šaraguja. The highest content of phenolic compounds was found in fi g variety Crnica while the lowest one in fi g variety Bjelica. According to the results obtained in this study, fi g fruits can be considered as a natural source of phenolic compounds with good antioxidant capacity.

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Jokić S., Sudar R., Svilović S., Vidović S., Bilić M., Velić D., Jurković V. (2013): Fatty acid composition of oil obtained from soybeans by extraction with supercritical carbon dioxide. Czech J. Food Sci., 31: 116-125.

Supercritical CO 2 extraction of soybean oil was performed. Response surface methodology was applied to evaluate the effects of pressure, temperature and extraction time on soybean oil yield. The analysis of variance showed that pressure and extraction time followed by the quadratic term of pressure and interaction between pressure and time had the significant effect on the oil yield. The maximum extraction yield (6.59 ⁄ 100 g soybeans) at constant CO 2 flow rate of 1.629 L per min was achieved at 50°C, 300 bar and 4 h. The experimental values agreed well with those predicted by regression model. One-stage diffusion model was successfully applied for modelling the kinetics of soybean oil. The main triacylglycerols of soybean oil were trilinolein, dilinoleoolein, dilinoleopalmitin and linoleooleopalmitin. Soybean oil extracted by supercritical CO 2 had higher levels of linoleic and linolenic acids and lower levels of palmitic and stearic acids compared to oil extracted by organic solvent.