Canadian Journal of Chemical Engineering, Vol.92, No.7, 1189-1196, 2014
Optimization of the formulation of water in oil emulsions entrapping polysaccharide by increasing the amount of water and the stability
Water in oil emulsions entrapping a polysaccharide have been formulated and the purpose of this study is first to increase the amount of dispersed water and the amount of polysaccharide. The second part of the study is devoted to check the stability of the obtained emulsion over 2 years. Encapsulation of polysaccharide was realized by introducing the aqueous phase (containing the required polysaccharide and glycerol) into a stirred oil phase (wherein the polyglycerol polyricinoleate (PGPR) as the surfactant has been previously dissolved). Emulsion stability tests were carried out immediately after preparation and after ageing tests. For that purpose the emulsions were submitted to cooling and heating cycles performed in a calorimeter in order to detect the freezing and melting temperatures of the dispersed water. Due to nucleation phenomena, the delay between freezing and melting is correlated to the way the water is dispersed within the emulsion and therefore gives information about the stability of the emulsions. To complete these tests other ones were performed such as bottle test, laser diffraction granulometry and rheometry. It was shown that it is possible to get emulsions containing 75% of water, showing the required stability and flow ability.