Thermal reversibility of vitamin E-enriched emulsion-based delivery systems produced using spontaneous emulsification

The temperature scanning rate had a major influence on the thermal reversibility of the emulsions. Slow heating of emulsion above the PIT followed by rapid cooling led to thermoreversibility while slow heating followed by slow cooling resulted in thermo-irreversibility of emulsion. [Display omitted] •The temperature scanning rate had a major influence on the thermal reversibility of the emulsions.•Slow heating above the PIT followed by quench cooling led to thermoreversibility of emulsion.•Slow heating above the PIT followed by slow cooling resulted in thermo-irreversibility of emulsion. The influence of temperature scanning and isothermal storage conditions on turbidity, particle size, and thermal reversibility of vitamin E-enriched emulsions produced by spontaneous emulsification was examined. Initially, the mini-emulsions formed were optically transparent and contained small droplets (d≈44nm). When heated (20–90°C), emulsions exhibited a complex turbidity–temperature profile with a phase inversion temperature (PIT) at ≈75–80°C. Temperature scanning rate had a major influence on emulsion thermal reversibility. Slow heating (0.5°C/min) above the PIT followed by quench cooling (≈67°Cmin−1) to 30°C did not appreciably increase turbidity or droplet diameter (d≈50nm), suggesting these systems were thermo-reversible. However, slow heating to temperatures below the PIT followed by rapid cooling appreciably increased droplet size and turbidity (thermo-irreversible). Cooling rate also affected emulsion thermo-reversibility: the turbidity and droplet size after heating above the PIT decreased with increasing cooling rate.