Balangu (Lallemantia royleana) seed contains valuable gum (BSG) which has good thickening property. The influence of L. royleana seed gum (0e0.3%) on characteristics of soybean oil (20e50%) in water emulsions stabilized by whey protein concentrate (WPC) (0.5e5%) was investigated using response surface methodology. For each response, a second-order polynomial model was developed using multiple linear regression analysis. Increasing the gum concentration to a critical level decreased droplet particle size, creaming index and zeta potential while increased the emulsion polydispersity index and viscosity. Although WPC improved the fresh emulsion characteristics while after 28 of storage it had no stabilizing properties. Optimum formulation for a stable emulsion was found to be 0.15% BSG, 5% WPC and 50% oil content. At this point emulsion had lower particle size and creaming index.

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