The purpose of this research was to produce size-controlled polyunsaturated fatty acids (PUFA)-loaded oil-in-water (O/W) emulsions using refined palm oil rich in β-carotene, by microchannel (MC) emulsification. A commercial mixture of long-chain PUFA extracted from Menhaden oil was added to palm oil at a concentration of 45 g/L and used as the to-be-dispersed phase. The continuous phase consisted of a water dispersion of two different emulsifiers, in order to improve droplet stabilization and β-carotene bioavailability: sucrose laurate and β-lactoglobulin (1 wt %, respectively). The effect of various levels of to-be-dispersed phase flux (Jd) (10, 20, 40, and 80 L/(m2·h)) and continuous phase flow velocity (Vc) (ranging from 0.23 to 2.33 mm/s) on the behavior of droplet formation, average droplet size (dav) and coefficient of variation (CV) were evaluated. The fine carotenoid O/W emulsions loaded with PUFA were prepared using an MC emulsification device. Protein-stabilized monodispersed PUFA-loaded emulsi...