Effects of calcium pH, and blockiness on kinetic rheological behaviour and microstructure of HM pectin gels

C. Lofgren, S.E. Guillotin, E. Evenbratt, H.A. Schols, A.M. Hermansson

Research output: Contribution to journalArticleAcademicpeer-review

76 Citations (Scopus)

Abstract

The kinetic behavior during gel formation and the microstructure of 0.75% high methoxyl (HM) pectin gels in 60% sucrose have been investigated by oscillatory measurements and transmission electron microscopy for three comparable citrus pectin samples differing in their degree of blockiness (DB). Ca2+ addition at pH 3.0 resulted in faster gel formation and a lower storage modulus after 3 h for gels of the blockwise pectin A. For gels of the randomly esterified pectin B, the Ca2+ addition resulted in faster gel formation and a higher storage modulus at pH 3.0. At pH 3.5, both pectins A and B were reinforced by the addition of Ca2+. In the absence of Ca2+, the shortest gelation time was obtained for the sample with the highest DB. Microstructural characterization of the gel network, 4 and 20 h after gel preparation, showed no visible changes on a nanometer scale. The microstructure of pectins A and B without Ca2+ was similar, whereas the presence of Ca2+ in pectin A resulted in an inhomogeneous structure.
Original languageEnglish
Pages (from-to)646-652
JournalBiomacromolecules
Volume6
Issue number2
DOIs
Publication statusPublished - 2005

Keywords

  • atomic-force microscopy
  • galacturonic acid distribution
  • chain association
  • gelation
  • endopolygalacturonase
  • polysaccharides

Fingerprint Dive into the research topics of 'Effects of calcium pH, and blockiness on kinetic rheological behaviour and microstructure of HM pectin gels'. Together they form a unique fingerprint.

  • Cite this