title: CZE separation of strawberry anthocyanins with acidic buffer and comparison with HPLC.
abstract: Anthocyanins, the major colourants of strawberries, are polar pigments that are positively charged at low pH. Herein, we have assessed a new analytical method for the separation of anthocyanins using CZE. Acidic buffer solutions (pH <2) were employed in order to maintain pigments in the cation flavylium form and achieve high molar absorptivity at 510 nm. These spectral properties enabled us to identify strawberry anthocyanins in a preliminary stage by detection in the visible range, although the method was optimised at 280 nm to obtain the best S/N. The effects of buffer composition highlighted the necessity of adding an organic modifier to the running buffer to obtain a suitable separation. The electrophoretic method permitted the separation of the three main anthocyanins of strawberry extracts, namely pelargonidin 3-glucoside (Pg-glu), pelargonidin 3-rutinoside and cyanidin 3-glucoside. The electrophoretic results, expressed as retention time and separation efficiency of the major anthocyanin (Pg-glu), were compared to those achieved in HPLC, the analytical technique traditionally used for the investigation of anthocyanins in vegetable matrix. The content of Pg-glu in strawberries (cv. Camarosa), calculated with HPCE and HPLC methods, resulted respectively in 11.41 mg/L and 11.37 mg/L.
authors.affiliation: Dipartimento di Scienze degli Alimenti, Università di Bologna, Cesena (FC), Italy.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Comandini
authors.forename: Giampaolo
authors.initials: G
authors.lastname: Blanda
authors.forename: Andrea
authors.initials: A
authors.lastname: Cardinali
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Cerretani
authors.forename: Alessandra
authors.initials: A
authors.lastname: Bendini
authors.forename: Maria Fiorenza
authors.initials: MF
authors.lastname: Caboni
mesh_terms: D000143:Acids / Q000737:chemistry*; D000872:Anthocyanins / Q000032:analysis*; D002021:Buffers; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D019075:Electrophoresis, Capillary / Q000379:methods*; D005504:Food Analysis / Q000379:methods; D031985:Fragaria / Q000737:chemistry*; D005638:Fruit / Q000737:chemistry*
chemical_list: D000143:Acids; D000872:Anthocyanins; D002021:Buffers