Butternut and beetroot pectins: characterization and functional properties

Authors
Fissore, Eliana Noemi; Rojas, Ana Maria Luisa; Gerschenson, Lia Noemi; Williams, Peter A.
Publication Year
2013
Language
English
Format
article
Status
Published version
Description
The physicochemical characteristics and functional properties of butternut (Cucumis moschata Duch. ex Poiret) and beetroot (Beta vulgaris L. var. conditiva) pectins obtained by enzymatic extraction from by-products of vegetable processing have been evaluated. The molecular mass distribution was determined using Gel Permeation Chromatography using light scattering, refractive index and UV detectors and the samples were found to be highly heterogeneous and polydisperse. Mw values of 136,000 and 1,309,000 g/mol were determined for butternut and beetroot pectins respectively. Butternut pectin had a high degree of methyl esterification. In the presence of high concentrations of sugar and at low pH, this pectin did not form gels but instead produced viscous solutions. Solutions showed pseudoplastic flow behaviour with a shear thinning index of 0.68 as determined from the Power law model. Beetroot pectin had a low degree of methyl esterification and formed gels with addition of Ca2+ at concentrations of 10 mg/g pectin or higher. The maximum value of the storage modulus was obtained at a Ca2+/GalA ratio of 0.25. The thermal stability of gels suggested that hydrogen bond interactions prevailed in the absence of Ca2+, whereas electrostatic junction zones increasingly developed between pectin chains as the calcium concentration increased. Aqueous solutions of butternut and beetroot pectins significantly reduced surface tension and both samples were able to form stable oil-in-water emulsions. It was found that protein and/or polyphenol – rich fractions present in the pectins adsorbed at the oil–water interface and were responsible for the emulsification properties.
Fil: Fissore, Eliana Noemi. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Fil: Rojas, Ana Maria Luisa. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Fil: Gerschenson, Lia Noemi. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Fil: Williams, Peter A.. Glyndwr University Wrexham; Reino Unido
Subject
Butternut pectin
Beetroot pectina
Functional properties
Alimentos y Bebidas
Otras Ingenierías y Tecnologías
INGENIERÍAS Y TECNOLOGÍAS
Access level
Restricted access
License
https://creativecommons.org/licenses/by-nc-nd/2.5/ar/
Repository
CONICET Digital (CONICET)
Institution
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identifier
oai:ri.conicet.gov.ar:11336/15860