Influence of galactomannan addition on the viscoelastic properties of pectin-calcium systems

• Type: Chapter or Part of a Book
• Date: 1994

Authors

J. Silva (Author) Other; Maria do Pilar Gonçalves (Author) FEUP; J. Doublier (Author) Other; M. Axelos (Author) Other

Book

Title: Gums and Stabilisers for the Food Industry 7

Pages: 301-305

ISBN: 0-19-963465-3

Publisher: Oxford University Press

Other information

Resumo (PT): The influence of galactomanuan addition on the formation of low methoxyl pectin/calcium networks, with different density of crosslinks, was studied through the changes in the mechanical spectrum obtained from dynamic shear measurements. The mixed gels showed an increase in the storage and loss moduli with the increase of galactomannan concentration, especially at high frequency. The pectin/calciam network remains the continuous gel matrix con-trolling the viscoelastic behaviour of these systems at low frequency. The effect of galactomannan addition on the viscoelastic behaviour of the mixed gels at "equilibrium" depends on the structure of the pectin/calcium net-work. We suggest that there is no specific interaction and that the changes in the mechanical properties of the pectin gels are due to the entrapment of the galactomannan macromolecules in the pectin-calcium network. One inter-esting aspect is the decrease of the tendency for the pectin/calcium gels to undergo syneresis, by the addition of the galactomannan.

Abstract (EN): The influence of galactomanuan addition on the formation of low methoxyl pectin/calcium networks, with different density of crosslinks, was studied through the changes in the mechanical spectrum obtained from dynamic shear measurements. The mixed gels showed an increase in the storage and loss moduli with the increase of galactomannan concentration, especially at high frequency. The pectin/calciam network remains the continuous gel matrix con-trolling the viscoelastic behaviour of these systems at low frequency. The effect of galactomannan addition on the viscoelastic behaviour of the mixed gels at "equilibrium" depends on the structure of the pectin/calcium net-work. We suggest that there is no specific interaction and that the changes in the mechanical properties of the pectin gels are due to the entrapment of the galactomannan macromolecules in the pectin-calcium network. One inter-esting aspect is the decrease of the tendency for the pectin/calcium gels to undergo syneresis, by the addition of the galactomannan.

Language: Portuguese

Type (Professor's evaluation): Scientific

No. of pages: 5