title: Green extraction of grape skin phenolics by using deep eutectic solvents.
abstract: Conventional extraction techniques for plant phenolics are usually associated with high organic solvent consumption and long extraction times. In order to establish an environmentally friendly extraction method for grape skin phenolics, deep eutectic solvents (DES) as a green alternative to conventional solvents coupled with highly efficient microwave-assisted and ultrasound-assisted extraction methods (MAE and UAE, respectively) have been considered. Initially, screening of five different DES for proposed extraction was performed and choline chloride-based DES containing oxalic acid as a hydrogen bond donor with 25% of water was selected as the most promising one, resulting in more effective extraction of grape skin phenolic compounds compared to conventional solvents. Additionally, in our study, UAE proved to be the best extraction method with extraction efficiency superior to both MAE and conventional extraction method. The knowledge acquired in this study will contribute to further DES implementation in extraction of biologically active compounds from various plant sources.
authors.affiliation: Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10000 Zagreb, Croatia.
authors.forename: Marina
authors.initials: M
authors.lastname: Cvjetko Bubalo
authors.affiliation: Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10000 Zagreb, Croatia.
authors.forename: Natka
authors.initials: N
authors.lastname: Ćurko
authors.affiliation: Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10000 Zagreb, Croatia.
authors.forename: Marina
authors.initials: M
authors.lastname: Tomašević
authors.affiliation: Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10000 Zagreb, Croatia.
authors.forename: Karin
authors.initials: K
authors.lastname: Kovačević Ganić
authors.affiliation: Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10000 Zagreb, Croatia. Electronic address: irredovnikovic@pbf.hr.
authors.forename: Ivana
authors.initials: I
authors.lastname: Radojčić Redovniković
mesh_terms: D003116:Color; D008872:Microwaves; D010636:Phenols / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry*; D012997:Solvents; D014465:Ultrasonics / Q000379:methods*; D027843:Vitis / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D010636:Phenols; D010936:Plant Extracts; D012997:Solvents; D014867:Water
keywords: Anthocyanins; Deep eutectic solvent; Grape skin; Green extraction; Microwave; Phenolics; Ultrasound