EMULSION-STABILIZING EFFECT OF BACTERIAL CELLULOSE

The bacterial cellulose produced in an agitated culture (Ag-BC) showed the highest emulsion-stabilizing effect among the examined cellulosic materials, It was clarified that a mechanical barrier and a scaffoldi ng structure composed of fine fibrils of bacterial cellulose interrupt ed the coalescence of oil droplets to stabilize the emulsion without r educing the interfacial tension as occurred with sorbitan monolaurate. Since Ag-BC consists of thinner fibrils and smaller flocs than any ot her cellulosic material, Ag-BC would cover a larger surface area of th e oil droplet as a mechanical barrier. The emulsion containing Ag-BC w as stable against the addition of salt, and changes in pH and temperat ure in comparison with xanthan gum and sorbitan monolaurate. This stab ility would have been due to the stability of the mechanical barrier a nd a scaffolding structure composed of stable crystalline cellulose. I n contrast, instability in the conformation of xanthan gum and a reduc tion in the interfacial tension of the surfactant would lead to instab ility of the emulsion.