The impact of oil type and fatty acid chain length on the development of food-grade microemulsions for
the entrapment of b-carotene was investigated. The microemulsion region of a ternary phase diagram containing
short chain monoglycerides was larger than for di- and triglycerides when Tween 80 was used as
surfactant. The cytotoxicity of microemulsions composed of a 30% monoglyceride oil, 20% Tween 80 and
50% aqueous buffer were evaluated using an in vitro cell culture model (human epithelial colorectal adenocarcinoma,
Caco-2). The cytotoxicity test showed that the viability of Caco-2 cells against b-carotene
microemulsions at concentrations of 0.03125% (v/v) was higher than 90%. This study suggests that short
chain monoglycerides could be used with Tween 80 to prepare transparent b-carotene-encapsulated O/W
microemulsions in the particle size range of 12–100 nm.
