TRIGLYCERIDE MICROEMULSIONS - EFFECT OF NONIONIC SURFACTANTS AND THE NATURE OF THE OIL

The phase behavior of mixtures of food grade surfactants and various triglycerides was investigated to prepare oil-in-water microemulsions (L(1)) for food uses. Water-in-oil microemulsions (L(2)) were easily formed at a ratio of 75/25 wt % ethoxylated monodiglycerides/monoglyceride. This ratio was found to be optimal for the formation of an extended triglyceride microemulsion area which approached the aqueous corner of the phase diagram where oil-in-water microemulsions (L(1)) are present. Blue-phase regions, which are extremely stable emulsions, were identified. These regions consisted of droplets separated by layers of lamellar liquid crystals. Sucrose enhanced the formation of the L(1) phase while destroying the L(2) phase. Triglycerides containing unsaturated or short-chain fatty acids had improved solubility in L(1)-type microemulsions compared to triglycerides with saturated or long-chain fatty acids.