Thermo-Reversible Oleogels Formulated with Monoglycerides or Beeswax as Oleogelator for Food Applications

Nowadays, consumers are increasingly concerned about the effects of diet on health. In this context, oleogelation has been suggested as an interesting strategy to substitute unhealthy fats and may even allow encapsulation of bioactive substances in food matrices. This suggests that the development of thermo-reversible oleogels could have a significant impact on the bioavailability and biostability of functional foods, as well as the associated beneficial outcomes. The purpose of this study was to compare oleogels using two food additives as gelling agents: E471, which consists mainly of fatty acids monoglycerides, and beeswax (E-901). To achieve this, a rheological characterization of oleogels was carried out by using Small Amplitude Oscillatory Shear tests (SAOS). Systems containing distilled commercial monoglycerides of fatty acids showed a typical gel behaviour at 20 °C, while the behaviour of beeswax oil systems corresponded to weak gels at this temperature. This was also reflected in an increase in the temperature at which the gel-sol transition occurred when the systems were heated. The transition took place at higher temperatures for the monoglyceride gels, which indicates that they are stronger gels. An increase in the elastic component of the oleogels was noted as the concentration of gelling agent increased. Oleogels with 4% distilled commercial monoglycerides and 4% beeswax show stability at body temperature, although the latter shows reversibility during heating. Conversely, systems with 2% of both gel-ling agents undergo the gel-sol transition before reaching body temperature.