Xanthan and locust bean gum (LBG) were added in a white "model-sauce". The following samples were prepared: control samples containing gelatinized corn starch, casein, and olive oil and samples containing additionally 0.09%, 0.15% and 0.25% (w/w) xanthan gum, or 0.09% (w/w) LBG. The samples were stored at 5 degreesC for 15 days, and during storage, static and dynamic rheological experiments were performed, their stability was observed and they were investigated microscopically. Gums' addition reduces the viscosity of the control sauce. According to "Ostwald-de Wacle" model (sigma = ky(n)) the consistency (k) of these samples decreases and the flow index (n) increases. All samples behave as weak gels (G', G" values), but control samples were more structured. In these samples an aqueous upper phase separated during storage, while in samples containing hydrocolloids, oil, granules and gum were also observed. Gum aggregates were locally concentrated in a continuous starch polymers network. (C) 2003 Elsevier Ltd. All rights reserved.