Formulation of controlled size PUFA-loaded oil-in-water emulsions by microchannel emulsification using β-carotene-rich palm oil

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 P-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 beta-carotene bioavailability: sucrose laurate and beta-lactoglobulin (1 wt %, respectively). The effect of various levels of to-be-dispersed phase flux (J(d)) (10, 20, 40, and 80 L/(m(2)center dot h)) and continuous phase flow velocity ((V) over bar (c) (ranging from 0.23 to 2.33 mm/s) on the behavior of droplet formation, average droplet size (d(av)) 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 emulsions were successfully produced, with a d(av) of 27.9 mu m and a CV of less than 4%. The d(av) and CV increased with Jd especially above 40 L/(m(2)center dot h), and were independent of (V) over bar (c), within the velocity range applied in this study. Analysis of the dimensionless Ca indicated that on increasing the Jd up to the critical Ca (0.075), the flow is based on spontaneous transformation, resulting in monodispersed droplets. If Ca. exceeds the critical value, viscous force is dominant, the flow is similar to laminar flow, and the to-be-dispersed phase flows out continuously from the MC.