Aakash Patel, Dr. Supratim Ghosh IC-IMPACTS Summer Institute 2016 Formation, Stability and Rheology of food protein-stabilized nanogels from nanoemulsions Aakash Patel, Dr. Supratim Ghosh Department of Food and Bioproduct sciences University of Saskatchewan IC-IMPACTS Summer Institute 2016

Emulsions and Nanoemulsions Oil Water Unique characteristics of nanoemulsions: Stability (Objective) Rheology (Objective) Opacity Bioavailability Emulsion Mixture of two immiscible liquids Conventional Emulsion droplet size: 1-10 µm Nanoemulsions droplet size: <200 nm Experimental details: Whey protein or casein as emulsifier 40% canola oil Homogenization @ 20,000 psi for 8 cycles to reduce the droplet size to nanoscale Laser diffraction particle size analyzer for droplet size Rheology to measure viscosity and viscoelasticity by Rheometer Oil phase Aqueous phase Amphiphilic substances (emulsifiers)

Results and mechanism Shell layer thickness Increase influence of shell layer (emulsifier layer over droplet + electrostatic charge) Increase in effective volume fraction (increase in surface area – increase in protein) Jam packing of droplet leads to gelation

Future studies and Applications Further reduction in droplet size by evaporative ripening Conversion of weak gels in to strong gels by changing pH, ionic strength or temperature to alter protein structure Study of interfacial rheology of protein layer to understand effect on gel formation Application: Preparation of emulsion based food products with longer stability Reduction in dispersed oil phase volume and still obtain same consistency (low fat foods) Suitable for use in pharmaceutical industry as gels for delivery of substances due to easy absorption of nanodroplets

Thank you