title: Modification of citrus and apple pectin by power ultrasound: Effects of acid and enzymatic treatment.
abstract: Pectin-derived oligosaccharides are emerging as a new generation of functional ingredients with new or improved technological and/or bioactive properties as compared to pectin. This work addresses the impact of power ultrasound (US) on the structure of citrus and apple pectin under different experimental conditions of power, amplitude and pectin concentration in aqueous and acid media, as well as in the presence of a pectinase. Results indicated that depolymerisation of both pectin increased with time and intensity of US in aqueous media and their polydispersity decreased. In general, a higher depolymerisation was observed in pectin treated by US in the presence of nitric and citric acids than in water, and hardly any difference was detected between both types of acids. Most of the assays gave rise to high-methoxylated pectin with a degree of esterification above 50%, pointing out their suitability for potential gelling agents. Finally, US did not have any impact in assisted enzymatic hydrolysis on the degree and/or rate of depolymerisation at low and medium levels of pectin concentration (0.5 and 2%), whereas a higher diversity of pectin fragments was found at 5% which could be indicative of a more controlled depolymerisation. These findings highlight the importance of the selection of appropriate US processing conditions to diversify the applications of modified pectin, as well as the potential of US as a prospective alternative to currently used depolymerisation techniques.
authors.affiliation: Instituto de Investigación en Ciencias de la Alimentación (CIAL) (CSIC-UAM) CEI (CSIC+UAM), Nicolás Cabrera, 9, Campus de la Universidad Autónoma de Madrid, 28049 Madrid, Spain.
authors.forename: Nerea
authors.initials: N
authors.lastname: Muñoz-Almagro
authors.affiliation: Instituto de Investigación en Ciencias de la Alimentación (CIAL) (CSIC-UAM) CEI (CSIC+UAM), Nicolás Cabrera, 9, Campus de la Universidad Autónoma de Madrid, 28049 Madrid, Spain. Electronic address: a.montilla@csic.es.
authors.forename: Antonia
authors.initials: A
authors.lastname: Montilla
authors.affiliation: Instituto de Investigación en Ciencias de la Alimentación (CIAL) (CSIC-UAM) CEI (CSIC+UAM), Nicolás Cabrera, 9, Campus de la Universidad Autónoma de Madrid, 28049 Madrid, Spain.
authors.forename: F Javier
authors.initials: FJ
authors.lastname: Moreno
authors.affiliation: Instituto de Investigación en Ciencias de la Alimentación (CIAL) (CSIC-UAM) CEI (CSIC+UAM), Nicolás Cabrera, 9, Campus de la Universidad Autónoma de Madrid, 28049 Madrid, Spain.
authors.forename: Mar
authors.initials: M
authors.lastname: Villamiel
mesh_terms: D002957:Citrus / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D027845:Malus / Q000737:chemistry*; D010368:Pectins / Q000737:chemistry* / Q000378:metabolism*; D011096:Polygalacturonase / Q000378:metabolism*; D000069453:Ultrasonic Waves
chemical_list: D010368:Pectins; D011096:Polygalacturonase
keywords: Citric; Depolymerisation; Modified pectin; Nitric; Pectinase; Ultrasound