Preparation of citrus pectin gels by power ultrasound and its application as an edible coating in strawberries

[Background]: Pectin is heteropolysaccharide found in cell walls originating mainly from by-products, as well as citrus peels, apple and sugar beet pulp, and presenting biological and techno-functional properties. In the present study, a general and structural characterisation of industrial citrus p...

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Bibliographic Details
Authors: Muñoz Labrador, Ana, Moreno, Rodrigo, Villamiel, Mar, Montilla, Antonia
Format: article
Status:Versión enviada para evaluación y publicación
Publication Date:2018
Country:España
Institution:Consejo Superior de Investigaciones Científicas (CSIC)
Repository:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/174151
Online Access:http://hdl.handle.net/10261/174151
Access Level:Open access
Keyword:Citrus pectin
Edible coating
Rheological properties
Strawberry
Ultrasound
Characterisation
Description
Summary:[Background]: Pectin is heteropolysaccharide found in cell walls originating mainly from by-products, as well as citrus peels, apple and sugar beet pulp, and presenting biological and techno-functional properties. In the present study, a general and structural characterisation of industrial citrus pectins was performed together with a study of impact of power ultrasound (US) on their rheological properties, with the aim of using them as edible coatings for fresh strawberries. [Results]: The results obtained indicated that pure pectin showed a methylesterification degree greater than 50% and galacturonic acid content > 65%, supporting its consideration as additive E-440; such conditions were not achieved in pectin with sugar addition. Furthermore, in the rheological study, pectin gels showed a non-Newtonian flow and pseudoplastic behaviour and presented different viscosity ranges depending on the preparation methods, including power US. Gels were used as edible coatings for fresh strawberries aiming to improve their quality during storage over a period of 5 days, controlling quality characteristics such as humidity loss, acidity and colour parameters (L*, a*, b*, C, h°, ΔE). [Conclusion]: The results obtained demonstrate that US treatments give rise to pectin gels that can improve the quality of strawberries over their lifetime.