Physical Properties of Monoglycerides Oleogels Modified by Concentration, Cooling Rate, and High-Intensity Ultrasound

Abstract

The aim of this study was to investigate the effects of monoglycerides (MG) concentration (3, 4.5, and 6 wt%), cooling rate (0.1 and 10 °C/min), and high‐intensity ultrasound (HIU) application on physical properties of oleogels from MG and high oleic sunflower oil. Microstructure, melting profile, elasticity (G′), and solid fat content (SFC) were measured immediately after preparation of samples (t = 0) and after 24 hr of storage at 25 °C. Samples’ textural properties (hardness, adhesiveness, and cohesiveness) and oil binding capacity (OBC) were evaluated after 24 hr at 25 °C. In general, samples became less elastic over time. Slow cooling rate resulted in lower G′ after 24 hr compared to the ones obtained using 10 °C/min. Network OBC was improved by increasing MG concentration and cooling rate, and by applying HIU. After storage, oleogel melting enthalpy increased with MG concentration. In general, this behavior was not correlated with an increase in SFC. An improvement in the network structure was generally reached with the increase in cooling rate, according to texture and rheology results, for both sonicated and nonsonicated conditions. At the highest MG concentration, HIU application was more efficient at increasing OBC and hardness of the network at 0.1 °C/min. Microscopy images showed that the oleogels microstructure was changed as a consequence of HIU application and cooling rate, evidencing smaller crystals both in sonicated and faster cooled samples. Obtained results demonstrate that cooling rate, MG concentration, and HIU can be used satisfactorily to tailor physical properties of MG oleogels.