Emulsion Droplets Entering and Spreading at the Air and Water Interface Studied by Drop Shape Tensiometry

EMULSION DROPLETS ENTERING AND SPREADING AT THE AIR AND WATER INTERFACE STUDIED BY DROP SHAPE TENSIOMETRY Jiahui Geng Advisor: University of Guelph, 2016 Professor Milena Corredig Co-advisor: Professor Loong-Tak Lim & Dr. Yuan Fang This research investigated the entering and spreading phenomena of emulsion droplets at the air-water interface, as it relates to ring formation and oil spreading in beverage emulsions. Drop shape tensiometry was employed to observe the adsorption, entering or spreading of oil droplets. A flavor emulsion, resembling a beverage was employed as the model system for this thesis. The spreading coefficient was not an effective indicator for oil spreading at the air-water interface in the complex emulsion systems. In biopolymer based emulsion systems, the dilational elastic modulus is a better parameter than surface tension as a prediction of the entering and spreading events. It was also shown that instability may be prevented by addition of a low molecular weight emulsifier. For the first time, confocal microscopy was employed to observe adsorption and spreading of oil droplets in model beverage emulsions.