Abstract:

Mixts. of polyols (glycerol, propylene glycol, glucose) and water were emulsified in oil (iso-Pr myristate (IPM), medium chain triglycerides (MCT), long chain triglycerides (LCT), and d-limonene) under elevated pressures and homogenization, in the presence of polyglycerol polyricinoleate (PGPR), glycerol monooleate (GMO), and their mixt. as emulsifiers to form water-in-oil emulsions. High pressures was applied to: (a) the emulsion, (b) the aq. phase and (c) the oil phase in the presence of the emulsifiers (PGPR and GMO). Under optimal pressure (2000 atms) applied to the ready-made emulsion or to the aq. phase prior to its emulsification, and with optimal compn. (30wt% polyol in the aq. phase and MCT as the oil phase), the aq. droplets were stable for months and submicron in size (0.1 $μ$m). Moreover, due to equalization of the oil and the aq. phases refractive indexes, the emulsions were almost transparent. Pressure and polyols have synergistic effects on the emulsions stability. During prepn., surface tensions and interfacial tensions were dramatically reduced until an optimal water/polyols ratio was achieved, which allows rupturing of the droplets to submicronal size (0.1 $μ$m) without recoalescence and fast diffusion to the interface. These unique W/O emulsions are suitable for prepg. W/O/W double emulsions for sustained release of active materials for food applications. [on SciFinder(R)]