Non-ionic sucrose esters microemulsions for food applications. Part 1. Water solubilization

Factors affecting water solubilization in four-component nonionic microemul sion systems stabilized by polyol nonionic surfactants (sucrose esters) hav e been investigated. The effect of changing the chain length of alcohol (us ed as cosurfactant) and the lipophilic moiety of surfactant have been explo red. The maximum water solubilization in the isotropic region (at oil/n-but anol ratio of 1) was 47, 23 and 55 wt.% for sucrose stearate (S-1570), sucr ose laurate (L-1695) and sucrose palmitate (P-1570), respectively. Replacin g the triglyceride oil (MCT) by dodecane caused a decrease in the water sol ubilization (40 wt.%) for sucrose stearate with an oil/n-butanol ratio of 1 . The empirical BSO (Bansal, Shah, O'Connell) [1] equation which was derive d as an empirical condition for maximum water solubilization in microemulsi ons stabilized by anionic surfactants, in relation to the cosurfactant (alc ohol) and oil chain lengths, i.e. N-S = N-O + N-A, where N-S, N-O, N-A are the surfactant chain lengths, oil and alcohol, respectively, was re-examine d for this type of surfactants. This study demonstrates that a maximum wate r solubilization is obtained when the N-S = (N-O +/- 3) + N-A for N-S is gr eater than 14; when N-S is less than 14, this equation cannot predict the m aximum water solubilization. (C) 2000 Elsevier Science Ireland Ltd. All rig hts reserved.