Effect of temperature on low-energy nano-emulsification and phase behavior in water/polyoxyethylene sorbitan fatty acid ester (Tweens®)/vegetable oil systems

• Increasing temperature caused phase changes; La → H1, L3; H1 → L3; L3→S + O, Wm; I1 → Wm.
• Emulsion droplet sizes depended on phase behavior along preparation course.
• L3 phase promotes emulsification with production of small and homogeneous droplets.
• H1 and I1 phases lead to formation of big and polydisperse emulsion droplets.
• Low-energy prepared emulsions exhibited high stability over storage time.

The effect of temperature (25, 40, and 60 °C) on food nano-emulsification using low-energy method in water/Tweens®/vegetable oil systems was studied. Increasing temperature resulted in a disappearance of solid Tween60 existing at 25 °C and phase transformations in Tween40, 60, and 80 systems; lamellar phase (La) transformed to hexagonal (H1) or sponge (L3) phase, H1 to L3, L3 to coexisting surfactant and oil (S + O) phase or micellar (Wm) phase, and cubic phase (I1) to Wm phase. Phase behavior along the preparation process resulted in differences in droplet size and homogeneity of prepared emulsions. The L3 structure promotes the formation of small droplet sized emulsions with low polydispersity, while H1 and I1 structures lead to the formation of highly polydisperse and/or big droplet sizes. The low-energy method prepared emulsions exhibited high stability over storage. Careful consideration of phase behaviors may lead to the production of tailor-made emulsions for specific industrial uses.