Interactions between modified starch and carrageenan during pasting

This study focused on starch/carrageenan blends. Its aim was to develop a method to evaluate if carrageenan was trapped or excluded by starch granules during pasting, and quantify the amount of interacting polysaccharide in the case of trapping. Four carrageenan samples and a modified waxy maize starch were used, where starch was pasted in carrageenan solutions. The set up method permitted, using an indirect titration, to evaluate the concentration of carrageenan in the supernatants of those 'pasted blends'. The quantity of carrageenan trapped by starch granules could then be obtained. The percentage of trapped kappa-carrageenan was higher than for iota-carrageenan. Increasing the rigidity of kappa-carrageenan chains decreases the amount of trapped carrageenan. To the contrary, decreasing the molecular weight leads to an increase in carrageenan trapping. (C) 2013 Elsevier Ltd. All rights reserved.