STABILITY OF SOYBEAN OIL-WATER EMULSIONS CONTAINING MONOGLYCERIDES AND DIGLYCERIDES

The stability of 5.0 to 20.0% soybean oil/water emulsions containing KA-2017 (a monoglyceride emulsifier) and KA-2018 (a di/triglyceride emulsifier) were studied. There is a critical molar ratio of fatty acid groups in the monoglyceride compared to the fatty acid groups in the diglyceride at which the stability of the oil globule coalescence reaches a maximum. The electrophoretic data also suggests that some remarkable changes on the oil globule surface occur at this molar ratio of 7 3. The films of KA-2017-KA-2018 at the oil-water interface show viscoelasticity. This critical molar ratio coincides with the molar ratio at which the interfacial films have the highest instantaneous elasticity. From this point of view, KA-2017 and KA-2018 seem to enter some form of association at the oil-water interface, and make up mechanical strong protective films covering oil globules. © 1979.