Formulation of water-in-oil-in-water (W/O/W) emulsions containing trans-resveratrol

Resveratrol is a high-value bioactive polyphenolic compound with vast applications in functional foods; as such, effective and scalable delivery strategies for this compound are worthy of study. In this research, W/O/ W emulsions were successfully prepared using polyglycerol polyricinoleate (PGPR) as a lipophilic emulsifier and Tween 80 as a hydrophilic emulsifier with the goal of developing biocompatible carriers to improve the bioavailability of resveratrol. The effects of the type of emulsifier, the concentration of emulsifier, the ratio of the oil phase to the internal water phase, and homogeneous pressure on the physical properties of the W/ O/W emulsions (such as microstructure, droplet size, distribution, zeta potential, viscosity and encapsulation efficiency) were investigated. The optimum processing conditions for preparing W/O/W emulsions are as follows: the ratio of the oil phase to the internal water phase is 80 : 20, the concentrations of lipophilic and hydrophilic emulsifiers are 10 wt% and 5 wt%, and the homogeneous pressures in the first and second steps are 30 MPa and 10 MPa. The optimal preparation process of the W/O/W emulsions was used to encapsulate resveratrol. The results showed that at up to 0.040 wt% in the internal water phase (ethanol), resveratrol could be successfully encapsulated in W/O/W emulsions with an encapsulation efficiency of 99.97 +/- 0.001%. Moreover, resveratrol was successfully encapsulated in the internal water phase and oil phase together; thus, it was not necessary to increase the amount of carrier materials. This study provides a novel encapsulation formulation to increase the delivery efficacy of resveratrol.