Preparation and Characterization of Functional Compounds Encapsulated Microemulsion with Nonionic Surfactants

FANG ZHONG*, WENTING XU, TINGTING FU AND YUE LI

State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, China

ABSTRACT

Influence of hydrophobic chain lengths of surfactant, co-surfactant, oil and different surfactant to co-surfactant ratios on phase behavior of Tween/alcohol/alkane/H2O was investigated with pseudo-ternary phase diagrams. The total areas of the microemulsion (ME) regions were determined. The largest ME region was formed when the ratio of surfactant: co-surfactant was 2 : 1 (w/w). The capacity for formation of MEs increased with an increase of hydrophobic chain length of the Tween, which was opposite to the trend for alkane (oil). N-butanol formed the largest ME region among the alcohols tested as co-surfactants. Sub-ME phases were identified by conductivity measurements. O/W MEs were observed when the water content was higher than 62 - 68%. The O/W sub-phase regions had significantly lower particle sizes and viscosities than either the W/O or bi-continuous sub-phases.

Key words: Microemulsion, Phase behavior, Surfactant, Microemulsion region, Particle size, Viscosity