Thermodynamic, rheological and structural properties of edible oils structured with LMOGs: Influence of gelator and oil phase

Supplementary data associated with this article can be found, in the online version, at https://doi.org/10.1016/j.foostr.2018.03.003.

The effect of different oil phases and low molecular weight organogelators (LMOGs) structures on edible oils was investigated through differential scanning calorimetry (DSC), rheology and small-angle X-ray scattering (SAXS). Different gelators (glyceryl tristearateGT; sorbitan tristearateST; sorbitan monostearateSM and glyceryl monostearate-GM) were tested in medium-chain triglycerides and high oleic sunflower (named MCT and LCT). Systems were thermoreversible and their thermodynamic properties were dependent on the combined effect of the interactions of structurants polar head with other constituents and the sterical effect of their hydrophobic tails. The crystallization onset temperature was higher for GM and SM, possibly due to the lower sterical effect of their tails. However, the corresponding enthalpy and entropy change values were influenced by the hydrophilic head group: glycerol-based organogelator molecules were able to interact strongly than sorbitans, increasing these values. Rheological studies showed that gels produced with LCT were stronger than with MCT. Moreover, cooling and heating cycles showed more than one transition and shear dependence. Stronger structures were more sensitive to temperature, possibly because of their more organized structure that destabilizes more easily with the increase of molecular mobility. These results were in agreement with the SAXS analyses. At 50°C, the stronger networks lost their initial structure, and at 70°C they collapsed. Thus, molecular interactions and structurant self-assembly were dependent on the structurant+solvent combination, leading to different physicochemical properties and thermal stability. It is expected that these results will allow customizing properties of structured oil for diverse applications, spanning from food to cosmetic and pharmaceutical industries.

LuizH.FasolinthanksthescholarshipCapes/FCTprogram(349/13) for the research exchange and Rosiane Lopes Cunha thanks CNPq (CNPq 307168/2016-6) for the productivity grant. The authors also would like to thank Fapesp (EMU 09/54137-1), CNPq and Capes for their financial support and the Brazilian Synchrotron Light Laboratory (LNLS) for the opportunity to carry out SAXS measurements. This study was also supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/ 04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 – Programa Operacional Regional do Norte. and of the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462).