Fabrication and characterization of fat crystal-stabilized W/O high internal phase Pickering emulsions (HIPPEs) as a low-fat alternative margarine

Abstract

High internal phase Pickering emulsions (HIPPEs) stabilized by food grade particles are increasingly being utilized as a viable alternative to saturated and trans fats. Fat crystals are of special interest as the pivotal Pickering particles, while their stabilization mechanisms for HIPPEs are uncharted territory. Herein, beeswax (BW) or palm stearin (PS) were used in a simple one-step process to create W/O HIPPEs containing up to 74.05% (v/v) water, as a low-fat substitute to margarine. The effects of concentration (5 wt% and 8 wt%) and glycerol monooleate (GMO) on the microstructure, thermal, interfacial and rheological properties of these HIPPEs were investigated to decipher the different stabilization mechanisms. All GMO-free samples were stable only when fat crystals concentration was 8 wt%, with BW forming dense coating around the droplets while PS forming a thin shell. After the addition of GMO, all BW-based emulsions were stabilized by the combined effect of Pickering (elastic interfacial layer) and network stabilization, while PS-based HIPPEs were stabilized only at 8 wt% and remained in the form of crystal shells. 8BW-G had a G′ close to 105 Pa, which is similar to that of commercial margarine, and remained stable for at least 1 year in a semi-solid state.