The effect of sucrose on phase behavior and droplet size in an aqueous phase/surfactant (Tween (R))/vegetable oil system was studied to prepare food nano-emulsions using low-energy emulsification methods. There was minimal difference in the phase behavior between water and sucrose solution/Tween20/vegetable oil systems. The phase transition during emulsification was the main mechanism for preparing a nano-emulsion in Tween20 systems. On the other hand, sucrose caused phase behavior changes in the aqueous phase/Tween40 and Tween80/vegetable oil systems. The sponge phase (L-3) region expanded by adding sucrose to both systems. The cubic (I-1) and hexagonal (H-1) phases decreased and the coexisting liquid crystalline (L-c), micellar (W-m), and oil (O) phases were formed. Adding sucrose facilitated the preparation of nano-emulsions using low-energy method from aqueous phase/Tween40 or Tween80/vegetable oil systems because of the expansion of the L-3 phase and reduction of I-1 and H-1, hence leading to the formation of smaller droplet sized emulsions. (C) 2015 Elsevier Ltd. All rights reserved.