Application of deep eutectic solvents in extraction of phenolic compounds from grape skin by microwaved and ultrasound assistant extraction

Eutektična otapala su otopine sintetizirane iz dva ili više spoja koji se međusobno mogu povezati vodikovim vezama te stvarati eutektičnu otopinu s točkom ledišta nižom od one koju imaju supstrati. Područja njihove primjene su mnogobrojna, a među njima je i ekstrakcija bioaktivnih spojeva iz biljnog materijala. U istraživanju je ispitana ekstrakcija fenola iz pokožice Plavca malog eutektičnim otapalom kolin- klorida i oksalne kiseline s različitim udjelima vode. Najučinkovitijom se pokazalo eutektično otapalo sa 25% vode te je s njim ispitan utjecaj procesnih parametara, temperature i vremena, na ektrakciju fenola pomoću aktivacije mikrovalovima ili ultrazvukom. Ekstrakcija pomoću aktivacije ultrazvukom pokazala se najboljom jer je njome ekstrahirano 34,61 ± 0,73 mg g-1 s.t. fenola na temperaturi od 65 tijekom 50 minuta, odnosno 21,04 ± 0,36 mg g-1 s.t. antocijana na 90 °C tijekom 50 minuta. Rezultati su pokazali da je moguće razviti ekološki prihvatljivu metodu optimiranjem procesa ekstrakcije fenola upotrebom eutektičnih otapala.Deep eutectic solvents are fluids generally composed of two or tree cheap and safe components that are capable of self-association, often through hydrogen bond interactions, to form a eutectic mixture with a melting point lower than that of each individual component. They have many fields of application, and among them is extraction of bioactive compounds from plants. In study is extracted phenols from the skin of grape Plavac mali with 75% eutectic solvent made with choline cloride and oxalic acid in water and with it investigate the impact of process parametars, temperature and time, in extraction of phenols using microwaved or ultrasound assistant extraction. The most effective extraction was ultrasound assistant extraction because it extracted 34,61 ± 0,73 mg g-1 dw of phenols at 65 °C for 50 minutes, and 21,04 ± 0,36 mg g-1 dw anthocyanins at 90 °C for 50 minutes. The results showed that it is possible to develop an environmentally friendly method of optimizing the extraction of phenols using a eutectic solvent