RHEOLOGICAL PROPERTIES AND APPLICATIONS OF MESQUITE TREE (PROSOPIS JULIFLORA) GUM. 5. THE RHEOLOGICAL PROPERTIES AND STABILITY OF CORN OIL -IN-WATER EMULSIONS STABILISED BY BLENDS OF MESQUITE GUM AND TWEEN 60.

Corn oil-in-water emulsions were prepared using mesquite gum and Tween 60 in conjunction as emulsifier-stabilisers. The mesquite gum/ Tween 60 ratio influenced the viscoelasticity and stability of the emulsions. The viscoelasticity parameters decreased in magnitude, and the rate of drop coalescence increased, as the mesquite gum/Tween 60 ratio decreased. In addition, this ratio influenced the pattern of change in the viscoelasticity parameters when the emulsions were aged. Mixed films of mesquite gum and Tween 60 adsorbed at a flat corn oil-water interface exhibited viscoelasticity, the parameter magnitudes decreasing as the mesquite gum/ Tween 60 ratio decreased. The influence of the mesquite gum/Tween 60 ratio on both the emulsions and model interfacial films is attributed to the relative proportions of the two emulsifier-stabilisers adsorbed at the oil-water interface, their configuration in the adsorbed state and their ability to interlink to form a network.