Encapsulation of vitamin E in edible emulsions fabricated using a natural surfactant

Vitamin E is a fat-soluble vitamin widely used in pharmaceutical, supplement, food, and cosmetic preparations that must be encapsulated before it can be dispersed into aqueous-based products. The purpose of this study was to develop all-natural oil-in-water emulsions that could be used to incorporate vitamin E into functional food and beverage products. These emulsions were stabilized by a natural food-grade surfactant (Q-Naturale (R)) isolated from the bark of the Quillaja saponaria Molina tree. The influence of oil phase composition (vitamin E to medium chain triglyceride (MCT) ratio), aqueous phase composition (glycerol to water ratio), and surfactant type (Q-Naturale (R) versus Tween 80) on the size of the droplets produced by high pressure homogenization was examined. Small droplets could not be formed using only vitamin E acetate as the oil phase because of its very high viscosity, but they could be formed when >= 20% MCT was incorporated into the oil phase prior to homogenization. In the absence of glycerol, Q-Naturale (R) was capable of forming emulsions containing relatively small droplets (d < 400 nm) from oil phases containing relatively high vitamin levels (60-80%). This droplet size could be decreased (d < 250 nm) by incorporating 50% glycerol in the aqueous phase prior to homogenization to increase its viscosity and decrease its interfacial tension. Tween 80 was more effective than Q-Naturale (R) at producing small droplets when the oil phase contained low levels of vitamin E acetate (<= 40%), but the opposite was true at higher vitamin levels. These results indicate that a natural surfactant (Q-Naturale (R)) is effective at forming edible Vitamin E delivery systems that could be used in functional food and beverage applications. (c) 2012 Elsevier Ltd. All rights reserved.