Yield behavior of gelled waxy oil in water-in-oil emulsion at temperatures below ice formation

► The viscosities and the yield stress values of emulsified oils were compared with a water-free waxy model oil at temperatures below pour point, with some measurements well below the ice point. In viscosity measurements, water-free and emulsified oils showed the shear thinning behavior at temperatures below their WAT, as shown in previous literature. ► In water-free oil, the yield stresses increased more or less linearly as the temperature decreased. Lower yield stress values compared to the water-free oil were measured for the 10 wt.% w/o and 30 wt.% w/o at temperatures between pour point and ice point. This trend is opposite to the one reported in the literature, most likely due to the much lower amount of wax in the model oil. ► The yield stress values of the 10% w/o emulsion crossed over to values higher than those of the water-free oil below the ice point, while those of the 30% w/o emulsion continued to increase but stay below the values for the water-free oil. It is possible that the small amount of water in the 10% w/o emulsion strengthens the gels at temperatures below the ice point while the larger amount of water in the 30% w/o emulsion disrupts networks, effectively acting as an inhibitor. ► Yield stress of the gel once broken and subsequently cooled never did reach the initial yield stress values for the same samples at the same temperature. ► This study shows that the yield behavior of water oil emulsions depends on a number of factors including but not limited to wax and water content, and temperature and shear history.