Microstructure, Rheology and Stability of Vegetable Cream-Like Emulsions Prepared with Natural Oils: Effects of Homogenization Speed and Polyglycerol Polyricinoleate Concentration

Abstract

The aim of this work is to analyze the microstructure, rheology and stability of vegetable cream-like emulsions prepared with polysorbate 80 (Tween 80) as hydrophilic emulsifier and coconut oil (CO), palm oil (PO) or sunflower oil (SO) in dispersed lipid phase. The effects of homogenization speed and polyglycerol polyricinoleate (PGPR) concentration in lipid phase were studied. Aggregation of oil globules by partial coalescence was observed in emulsions prepared with CO and PO due to the partial crystallization of the lipid phase, showing higher viscoelastic parameters and higher creaming stability in comparison to the systems with SO. The increase of homogenization speed led to the formation of smaller globules, reducing the partial coalescence degree in emulsions with CO due to the decrease of capture efficiency, but favoring the same process in systems with PO, presumably because of the increase of collision frequency. The addition of PGPR increased the partial coalescence degree in emulsions with CO and PO, which would be attributed to the modification of the crystallization behavior of the lipid phase. However, smaller aggregates were observed in the presence of PGPR, probably because of the formation of a more packed, less hydrated structure. In the long term, the inclusion of PGPR in systems with CO and PO was more effective to increase creaming stability than the increase of homogenization speed. The findings of this work could be relevant for the formulation and stabilization of whipped dairy cream simulators prepared with vegetable components.