Extraction and consecutive purification of anthocyanins from grape pomace using ionic liquid solutions

The global wine industry generates approximately 8.5 million tons of waste annually, which contains several biomolecules of high value. The present study focuses on the extraction of anthocyanins from grape pomace via solid/liquid extraction with aqueous solutions of the ionic liquid 1-ethyl-3-methylimidzaolium acetate [(C(2)mim]OAc) and sequential purification in aqueous two-phase systems (ATPS) with additional salts. The optimum conditions for solid/liquid extraction were obtained using response surface methodology and yielded up to 3.58 mg g(-1) anthocyanins. During ATPS formation, the highest purification factor (PF = 16.2 fold) was obtained in the bottom and salt-rich phase using K2CO3 (29.41 wt%) and [C(2)mim]OAc (29.28 wt%) at 35 degrees C and atmospheric pressure. The partition process is exothermic, spontaneous and governed by enthalpy forces. (C) 2017 Elsevier B.V. All rights reserved.