Effect of oat spelt and beech xylan on the gelling properties of kappa-carrageenan hydrogels

Mixed hydrogel samples of commercially important food hydrocolloid, viz. kappa-carrageeenan (kC) with abundantly available oat spelt (OSX) and beech (BX) xylan were investigated using dynamic oscillatory measurements, thermal (DSC), syneresis measurement in gel samples, moisture content, morphological (SEM), and swelling measurements on the dried samples. At total polymer concentrations of 1% (w/w), a kC concentration in the interval between 10 and 50% (w/w), and OSX or BX concentrations 50-90% (w/w, w.r. to dry kC), were used. Syneresis in kC gels was decreased significantly, while swelling ability was increased radically, after mixing with xylans. Gelling and melting temperatures of kC were increased in kC/BX(50-90) hydrogels, while decreased in kC/OSX(50-90). SEM analysis indicated that kC formed porous and compact hydrogels with OSX and BX, respectively. Frequency dependence result indicated that kC(10) solution behaves like gel materials when mixed with 90% (w/w) OSX or BX. Crown Copyright (C) 2011 Published by Elsevier Ltd. All rights reserved.