title: Antioxidant activity of grape skin aqueous extracts from pressurized hot water extraction combined with electron paramagnetic resonance spectroscopy.
abstract: Pressurized hot water extraction (PHWE) was employed to prepare extracts from dried grape skin of two wine grape varieties (St. Laurent and Alibernet) at various temperatures (from 40 up to 120°C) and amounts of sample (0.5, 1.0 and 1.5 g). To assess the antioxidant activity of the extracts, electron paramagnetic resonance (EPR) spectroscopy was applied involving DPPH and ABTS(+) assays. Other extract characteristics including HPLC profile of anthocyanins and total phenolic compound content were obtained as well. PHWE has also been compared with earlier results of extractions of the same grape skin samples with compressed methanol and compressed ethanol under the conditions of pressurized fluid extraction (PFE). From this comparison, PHWE emerges as the more benign and efficient extraction method to recover valuable phenolic antioxidants from grape skins for the prospective use in functional food supplements.
authors.affiliation: Institute of Analytical Chemistry of ASCR, v.v.i., Veveří 97, CZ-602 00 Brno, Czech Republic. stavikova@iach.cz
authors.forename: Lenka
authors.initials: L
authors.lastname: Sťavíková
authors.forename: Martin
authors.initials: M
authors.lastname: Polovka
authors.forename: Barbora
authors.initials: B
authors.lastname: Hohnová
authors.forename: Pavel
authors.initials: P
authors.lastname: Karásek
authors.forename: Michal
authors.initials: M
authors.lastname: Roth
mesh_terms: D000975:Antioxidants / Q000737:chemistry; D005591:Chemical Fractionation / Q000379:methods*; D002851:Chromatography, High Pressure Liquid; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D006358:Hot Temperature; D019441:Plant Epidermis / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry*; D011312:Pressure; D013056:Spectrophotometry, Ultraviolet; D027843:Vitis / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D010936:Plant Extracts; D014867:Water