Mechanical properties of kappa carrageenan-locust bean gum mixed gels with added sucrose

The mechanical behaviour of kappa carrageenan(C)-locust bean gum (LBG) mixed gels with sucrose added was studied. The total hydrocolloid content (HC) varied between 0.5 and 1.0%, and sucrose content between 0 and 60%. Two series of gels were prepared: one with hydrocolloids in the ratio LBG/C = 1/1, and the other with C only. The maximum rupture force (F(max)), deformability modulus (E(ap)), and resistance to wire cut (W) and knife cut (K) were measured. While values for all parameters increased with the addition of sucrose in C gels, a sharp fall in the values of F(max), Wand K was registered in C-LBG mixed gels at 60% sucrose concentration, which might be attributed to competition for water between sucrose and gum molecules, probably leading to a glassy structure. Sensory non-oral evaluation of gel texture confirmed the instrumental results obtained. In 0.75% HC mixed gels the point of structural change was observed at a concentration of similar to 50% sucrose.