Effect of guar gum on the rheological, thermal and textural properties of soybean β‐conglycinin gel

Abstract

SummaryThe effect of guar gum, a non‐gelling neutral polysaccharide, on the thermal gelation of soybean β‐conglycinin was analysed using the dynamic oscillatory rheological measurement, differential scanning calorimetry and texture profile analysis. The endothermic peak temperature of β‐conglycinin in the presence of 0.5% guar gum was about 89.1 °C. However, the endothermic peaks shifted to higher temperatures as the guar gum concentration increased from 0.05% to 0.5%, which could be attributed to the thermodynamic incompatibility with guar gum, resulting in a promoted aggregation of the thermally denatured β‐conglycinin. Furthermore, the elastic modulus increased with increasing concentration of guar gum, with a less frequency dependence. In addition, the springiness, cohesiveness and fracturability enhanced but the hardness decreased, as the guar gum concentration increased. The study demonstrated that incorporation of guar gum improved markedly the thermal and functional properties of soybean β‐conglycinin thermal‐induced gel, which can help better to design new food formulations.