The purpose of this study was to produce an oil-in-water (O/W) emulsion of δ-tocotrienol-rich oil obtained from annatto seeds by a supercritical fluid extraction process. The effects of emulsification by ultrasound (US) were evaluated and compared to emulsification by dispax reactor (DR) at similar energy densities. Saponin-rich extract from Brazilian ginseng roots (BGR) was obtained from BGR by pressurized liquid extraction and used as a biosurfactant. A model O/W emulsion system was prepared with soybean oil and commercial saponin. The influence of the emulsification process, energy density, oil type, biosurfactant type and biosurfactant concentration on the size and stability of the resulting droplets was examined through the experimental design and proper statistical analysis. The results showed that US produced more stable emulsion with smaller droplet sizes in comparison with the DR device at the same energy density. 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