engleski

Aqueous two-phase extraction of polyphenols using a microchannel system – process optimization and intensification

Polyphenols are one of the most numerous and wide spread group of compounds in the plant world. Nowadays, organic solvents such as methanol, ethanol, acetone, dimethylformamide, ethyl, acetate, diethylether are mainly used for the extraction of polyphenols. Those solvents require special process conditions and special care for disposal of used solvents. In this paper, extraction of polyphenols from the model solution was performed using water-two-phase systems which contains 80 - 90 % water and represents slightly burden on the environment. Aqueous solution of gallic acid was used as a model solution for polyphenols. Extraction was performed in aqueous- two-phase system containing PEG6000 - H2O - (NH4)2SO4 in macroextractor (10 mL) and microextractor (total volume = 14 µL). The influence of the process parameters, the concentration of gallic acid, pH and composition of water-two- phase system was investigated to maximize partition coefficient. A method of multifactor experimental planning was used to optimize extraction process and the results were statistically analysed using the evolutionary operation method (EVOP). Optimal operating conditions of the extraction process were pH = 6.50, γ(gallic acid) = 4.50 g L-1, mass fraction of polyethylene glycol wPEG = 0.1037 and mass fraction of ammonium sulphate (AMS) wAMS = 0.0925. At those conditions maximal partition coefficient of K = 5.54 was achieved and successfully applied in macro and microreactor for total phenols extraction from white wine. Approximately the same partition coefficients were achieved in the microextractor for 60 fold shorter residence times

polyphenols ; gallic acid ; aqueous two-phase systems ; multifactor plan of experiments ; evolutionary operation (EVOP) ; microreactor

Ovaj se tekst temelji na radu koji je financirala Nacionalna zaklada za znanost, visoko školstvo i tehnologijski razvoj Republike Hrvatske.