title: Microencapsulation of pulp and ultrafiltered cactus pear (Opuntia ficus-indica) extracts and betanin stability during storage.
abstract: Pulp (CP) and ultrafiltered (UF) cactus pear extracts were encapsulated with Capsul (C) by applying a central composite design (CP-C and UF-C systems) by spray-drying. To evaluate the effect of the extract, microparticles obtained under optimal conditions were characterised and stored at 60 °C. Betacyanin and betaxanthin encapsulation efficiency reached values above 98% for both systems studied. This efficiency was attributed to strong interactions between betalains and the polymer. Betalain degradation in CP-C and UF-C microparticles followed pseudo-first order kinetics. The betacyanin degradation rate constant was significantly higher for CP-C than for UF-C. These results suggested that the mucilage or higher sugar content of CP increased the hygroscopicity of the CP-C microparticles, leading to the degradation of betalain. The hydrolysis pathway was the main mechanism of betanin degradation during microparticle storage. These results demonstrate the potential utility of both CP-C and UF-C microparticles as natural colourants for healthy foods.
authors.affiliation: Departamento de Ciencia de los Alimentos y Tecnología Química, Facultad de Ciencias Químicas y Farmacéuticas, Casilla 133, Universidad de Chile, Santiago, Chile.
authors.forename: Cristina
authors.initials: C
authors.lastname: Vergara
authors.affiliation: Escuela de Ingeniería de Alimentos, Pontificia Universidad Católica de Valparaíso, Waddington 716, Playa Ancha, Valparaíso, Chile; DATACHEM Agrofood: Data Analysis and Applied Chemometrics Research Group, Chile.
authors.forename: Jorge
authors.initials: J
authors.lastname: Saavedra
authors.affiliation: Departamento de Agroindustria y Enología, Facultad de Ciencias Agronómicas, Casilla 1004, Universidad de Chile, Santiago, Chile.
authors.forename: Carmen
authors.initials: C
authors.lastname: Sáenz
authors.affiliation: Departamento de Ciencia de los Alimentos y Tecnología Química, Facultad de Ciencias Químicas y Farmacéuticas, Casilla 133, Universidad de Chile, Santiago, Chile.
authors.forename: Paula
authors.initials: P
authors.lastname: García
authors.affiliation: Departamento de Ciencia de los Alimentos y Tecnología Química, Facultad de Ciencias Químicas y Farmacéuticas, Casilla 133, Universidad de Chile, Santiago, Chile. Electronic address: proberts@uchile.cl.
authors.forename: Paz
authors.initials: P
authors.lastname: Robert
mesh_terms: D050859:Betacyanins / Q000737:chemistry*; D050858:Betalains / Q000737:chemistry*; D061353:Food Storage; D005638:Fruit; D006801:Humans; D029747:Opuntia / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry*; D014462:Ultrafiltration
chemical_list: D050859:Betacyanins; D010936:Plant Extracts; D050858:Betalains; C020228:betanin
keywords: Betalains; Betanin; Prickly pear; Spray-drying; Ultrafiltration