Browsing by Subject "Dairy Proteins"

To study the feasibility of replacing dairy proteins with plant proteins to stabilise emulsions, 9 emulsions were prepared at pH= 3 with sunflower oil and 1% protein solutions containing WPI, SC, PPI individual proteins and their blends (3:1, 1:1, 1:3). Changes in droplet size and zeta-potential were measured to investigate the emulsion stability. The interfacial composition, surface loads, and the protein adsorption behaviour were studied to analyse the interface. Furthermore, the dilatational rheology of the interface was studied as the interfacial properties play a critical role in emulsion stability. All proteins showed good emulsifying and stabilising abilities at pH=3, as they contributed to form emulsions with relatively small droplets (0.355-0.411µm), and prevented destabilisation for 2 weeks. Such results were related to the strong electrostatic repulsion between the droplets and the viscoelastic film formed by proteins. No synergistic or antagonistic effect was observed by using dairy and pea protein blends, indicating pea proteins could be used to partially replace the dairy proteins. A preferential adsorption of dairy proteins over pea proteins was found, with SC being the most dominating type at the interface due to the higher diffusion rate and structural flexibility. However, globular WPI and PPI formed stronger interfacial films than SC and its blend owing to the extensive intermolecular interactions.