Vitrification of κ-carrageenan in the presence of high levels of glucose syrup

Gel-forming structures and stages of red algal galactans of different sulfation levels

“…It has been reported that at a high level of co-solutes, galactans are severely water deficient, resulting in the occurrence of polysaccharide chains as a sparsely cross-linked network (Evageliou et al 1998;Whittaker et al 1997). Other studies suggest that, under such conditions, the polymeric chains are present as small, ordered gel particulates embedded within viscous solution (Richardson and Norton 1998; Fig.…”

Critical Assessment of the Application of the WLF/Free Volume Theory to the Structural Properties of High Solids Systems: A Review

“…obtained by treating a set of frequency sweeps taken at different temperatures with the WLF equation, are reproduced with an accuracy of ±2 degrees centigrade by the cooling/heating profiles of the same samples as the cross over of G and G traces passing from the glass transition region to the glassy state and, hence, are experimentally verified (Evageliou et al, 1998;Kasapis et al, 1999). The massive changes in the nature or the glassy behaviour of sugar cannot be explained on the basis of the simple mixing rule implemented by the Couchman-Karasz equation (1978) but should be the result of molecular interactions between the polymer and co-solute at high levels of solids (>70%).…”

“…Similar transformation from free-volume derived effects in the glass transition region to the process of an energetic barrier to rotation in the solid-like environment of the glassy state was observed for high sugar/κ-carrageenan, gellan, locust bean gum and guar gum mixtures. The phenomenon appears to be universal, thus prompting us to assign physical significance to the rheological T g as the threshold of two distinct molecular processes (Evageliou et al, 1998;Sworn and Kasapis, 1998;Kasapis et al, 1999;. The temperature function in the glass transition can be compared directly with the activation energy in the glassy state using a modification of the WLF equation.…”

The effect of pressure on the glass transition of biopolymer/co-solute

“…The water content of the glucose syrup was considered in calculating the composition of samples, and the glucose syrup content in this paper refers to dry solids. The material has been thoroughly characterised and details of its composition have been published earlier [19]. Sucrose was AnalaR grade from Sigma-Aldrich Corp., St. Louis, MO, USA.…”