The objective of this study was to optimise the spray drying conditions for the encapsulation of Gac oil using response surface methodology. Results indicated that the corresponding response surface model was sufficient to describe and predict encapsulation efficiencies (EEs) in terms of the oil, beta-carotene, lycopene, encapsulation yield (EY), moisture content (MC), water solubility index (WSI) and peroxide value (PV) with R-2 of 0.92, 0.91, 0.89, 0.85, 0.89, 0.98 and 0.97, respectively. Under optimal conditions (inlet and outlet temperatures of 154 and 80 degrees C), the response variables including the EEs of the oil, beta-carotene, lycopene, EY, MC, WSI and PV were predicted and validated as 87.22%, 82.76%, 84.29%, 52.78%, 4.90%, 90.29% and 4.06 meq/kg, respectively. Furthermore, physicochemical, reconstitution and colour properties of the optimally encapsulated powder were also determined. It was concluded that this powder containing high content of unsaturated fatty acids, beta-carotene and lycopene, and having the attractive red-yellow colour can be used as nutrient supplement and natural food colourant. (C) 2014 Elsevier B.V. All rights reserved.