Effect of formulation and processing conditions on the rheological and textural properties of a semi-liquid syrup model

The effect of two hydrocolloids, the overall composition and stirring rate of a confectionery semi-liquid syrup model, were studied by means of the measure of rheological properties, instrumental texture evaluation and turbidity. A syrup model was made with sucrose, high fructose corn syrup, gum (dextran or carrageenan), citric acid and water. An experimental design based on Taguchi’s method was employed to evaluate the influence of sugar concentration, gum type, gum concentration, citric acid concentration and stirring rate. An analysis of variance was performed. From all evaluated properties (except turbidity), °Brix was the factor that showed the maximum influence, with higher values on textural properties (adhesive force, cohesive work and stringiness). The gum type had influence over viscosity, hardness, adhesive force and turbidity. The Newtonian behavior predominated in the syrups and viscosity of samples was affected by the variables studied. The mean values of viscosity, hardness and adhesive force for all samples with carrageenan were higher than those obtained with dextran (at both °Brix levels).