Phase behavior and SANS investigations of edible sugar–limonene microemulsions

We have studied the phase behavior and microstructure of edible microemulsions of d-limonene with concentrated aqueous sugar solutions (>65 wt%) using sucrose laurate and sucrose oleate as surfactants. The phase behavior of these mixtures was systematically studied as a function of temperature and surfactant composition, identifying the specific effects of sugar concentration, surfactant chain length, and oil loading on the formation of microemulsion and lamellar phases. Small-angle neutron scattering experiments confirm the presence of well-structured microemulsions with domain sizes ranging from ∼35 to 60 nm. With few exceptions, the patterns of microemulsion phase behavior with concentrated sugar solutions are very similar to that of aqueous systems.