title: Stability of anthocyanins from red grape skins under pressurized liquid extraction and ultrasound-assisted extraction conditions.
abstract: The stability of anthocyanins from grape skins after applying different extraction techniques has been determined. The following compounds, previously extracted from real samples, were assessed: delphinidin 3-glucoside, cyanidin 3-glucoside, petunidin 3-glucoside, peonidin 3-glucoside, malvidin 3-glucoside, peonidin 3-acetylglucoside, malvidin 3-acetylglucoside, malvidin 3-caffeoylglucoside, petunidin 3-p-coumaroylglucoside and malvidin 3-p-coumaroylglucoside (trans). The techniques used were ultrasound-assisted extraction and pressurized liquid extraction. In ultrasound-assisted extraction, temperatures up to 75 °C can be applied without degradation of the aforementioned compounds. In pressurized liquid extraction the anthocyanins were found to be stable up to 100 °C. The relative stabilities of both the glycosidic and acylated forms were evaluated. Acylated derivatives were more stable than non-acylated forms. The differences between the two groups of compounds became more marked on working at higher temperatures and on using extraction techniques with higher levels of oxygen in the extraction media.
authors.affiliation: Department of Analytical Chemistry, University of Cadiz, Puerto Real 11510, Spain. ali.liazid@uca.es.
authors.forename: Ali
authors.initials: A
authors.lastname: Liazid
authors.affiliation: Department of Analytical Chemistry, University of Cadiz, Puerto Real 11510, Spain. gerardo.fernandez@uca.es.
authors.forename: Gerardo F
authors.initials: GF
authors.lastname: Barbero
authors.affiliation: Faculty of Sciences, Abdelmalek Essaâdi University, Tetouan 93000, Morocco. latifaazaroual@gmail.com.
authors.forename: Latifa
authors.initials: L
authors.lastname: Azaroual
authors.affiliation: Department of Analytical Chemistry, University of Cadiz, Puerto Real 11510, Spain. miguel.palma@uca.es.
authors.forename: Miguel
authors.initials: M
authors.lastname: Palma
authors.affiliation: Department of Analytical Chemistry, University of Cadiz, Puerto Real 11510, Spain. carmelo.garcia@uca.es.
authors.forename: Carmelo G
authors.initials: CG
authors.lastname: Barroso
mesh_terms: D000872:Anthocyanins / Q000737:chemistry* / Q000302:isolation & purification; D003080:Cold Temperature; D004355:Drug Stability; D005638:Fruit / Q000737:chemistry*; D006358:Hot Temperature; D059625:Liquid-Liquid Extraction; D008872:Microwaves; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification; D011312:Pressure; D013010:Sonication; D027843:Vitis / Q000737:chemistry*
chemical_list: D000872:Anthocyanins; D010936:Plant Extracts