Chili seeds, which are a byproduct of the production of chili powder and chili paste, contain a variety of substances that can lead to useful products. The oxidation of the unsaturated fatty acids in chili seed oil can lead to off flavor for these products, so it is important to develop procedures for reducing the oxidation. In this paper, we analyzed the quality of chili seed oil extracted with supercritical fluid CO2, studied the viscosity and stability of different emulsion formulations, and investigated a way of protecting the chili seed oil by microencapsulation with a composite wall material composed of starch sodium octenylsuccinate and maltodextrin. The oil, which was extracted with supercritical carbon dioxide, CO2, was of high quality with an iodine value (IV) of 130.50 +/- 1.75 g/100 g and a peroxide value (PV) of 2.81 +/- 0.29 mmol/kg. Gas chromatography was used to identify ten different fatty acids in the chili seed oil, and 82.84% of them were found to be unsaturated. An emulsion containing 30% oil was stabilized by 10% composite wall material and spray drying using an inlet air temperature of 160 +/- 2 degrees C and an outlet air temperature of 80 +/- 2 degrees C Scanning electron microscopy revealed a particle size of polyhedral microcapsules from 3 to 20 mu m. The loading efficiency of the microcapsules was up to 9435%, which suggested good liquidity and uniformity. We found that using starch sodium octenylsuccinate and maltodextrin as a composite wall material with spray drying is an effective way to encapsulate and protect chili seed oil. (C) 2017 Elsevier B.V. All rights reserved.