Polyglycerol polyricinoleate stabilised water-in-oil emulsion: Structural characteristics and functional performance

Abstract

In the present work, the relationship between structural characteristics and functional performance in polyglycerol polyricinoleate (PGPR) stabilised water-in-oil (W/O) emulsions was investigated. Novel W/O emulsions with a PGPR concentration of 4%, and oil volume fractions (φO) of 0.7 and 0.8 showed the smallest mean droplet size (~5 μm) and highest emulsification index (~97%). Both W/O emulsions showed shear-thinning and elastic-dominant properties with a weak frequency dependence. Both W/O emulsions possessed superior thixotropic recovery properties with recovery percentages of 131.26% (φO = 0.7) and 114.56% (φO = 0.8). The thermo-responsive properties could be closely related to the PGPR aggregation induced by hydrophobic interaction and interfacial rearrangement. The present work helped to design and develop functional W/O emulsions as alternatives to butter spreads, bio-lubricants, and other thermo-responsive delivery systems.