Pomegranate seed oil nanoemulsion enriched by α-tocopherol; the effect of environmental stresses and long-term storage on its physicochemical properties and oxidation stability

In this study, pomegranate seed oil (PSO) nanoemulsions loading different amounts of alpha-tocopherol (0-40%) were produced. The nanoemulsions were fabricated by ultra-sonication method and the influence of thermal treatment (20-90 degrees C), pH (2-8) and ionic strength (0-500 mM NaCl) were investigated on physicochemical properties of all treatments. Moreover, the oxidative stability and alpha-tocopherol degradation were also assessed on optimal enriched nanoemulsion formulation during 50-day storage. The droplet diameter, viscosity, antioxidant activity, encapsulation efficiency and loading capacity of optimal formulation were 37.5 nm, 514 cp, 92%, 3.45% and 92.5%, respectively. The peroxide value changed in the range of 4.5-5.3 and 6.7-10.5 meq O-2/kg in loaded and unloaded nanoemulsions, respectively. Transmission electron microscopy demonstrated spherical morphology of nanoemulsion droplets with diameter average of 40 nm. This study suggested that PSO nanoemulsion loading alpha-tocopheml could be introduced as delivery system with favorable features under severe environmental conditions.

Automated summary

This study produced pomegranate seed oil nanoemulsions loaded with varying amounts of alpha-tocopherol, with optimal formulation showing favorable features such as small droplet diameter, high encapsulation efficiency, and good oxidative stability. The nanoemulsions demonstrated potential as a delivery system under harsh environmental conditions.