Difference in dispersed properties of O/W emulsion prepared with polyoxyethylene[20] sorbitan monopalmitate (Tween 40) or polyoxyethylene[20] sorbitan trioleate (Tween 85)

O/W emulsion is used for many food materials and its stability is important to improve new food functionality such as tastes, and flavors, or to retain healthy materials. Because surfactants are usually mixed as stabilizers, selection of surfactants is a dominant factor for the stabilization of O/W emulsion. In the present paper, the characterization and stability of O/W emulsion prepared with polyoxyethylene [20] sorbitan monopalmitate (Tween 40) or polyoxyethylene [20] sorbitan trioleate (Tween 85) were evaluated physico-chemically by a dynamic light scattering method, turbidimetry and electrochemical measurements of oil droplet. Moreover, surface tension was measured for the surfactants, oil and their mixtures. It was observed that there were some differences between Tween 40 and Tween 85, in particle size distribution and the aggregation behavior of oil droplets, and adsorption on their surface, on the contrary, ζ-potential of oil droplet and the fraction of surface coverage with the surfactants were identical. It was concluded from the time courses of turbidity changes that Tween 40 was superior to Tween 85 in the stabilization of the oil droplets.