The Binary System Rapeseed Phosphatidylcholine (RPC) - Water and Behaviour of RPC at an Oil/Water Interface

ABSTRACT

The phase behaviour of aqueous rapeseed phosphatidylcholine (RPC) has been studied by low-angle X-ray diffraction and polarization microscopy between 20° and 70°C. Only an La phase was observed

The surface tension of RPC at an oil /water interface has been measured by the drop volume technique at 25°C. In the presence of water an La phase was formed at the interface between oil and excess water, complicating the measurements. From surface tension measurements a plateau value of 9 mN/m was obtained for 0.1 % (w/w) RPC initially dissolved in the oil. In the binary system of RPC and oil, an oil continous solution (L2) was formed up to 0.5% (w/w) RPC. If the amount of RPC was further increased, phase separation occurred and a liquid crystalline phase was found to co-exist with the L2 phase.