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

Abstract

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 tristearate-GT; sorbitan tristearate-ST; sorbitan monostearate-SM 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.

Modulation and Characterization of Wax-Based Olive Oil Organogels in View of Their Application in the Food Industry

“…The observed changes in this variable were possibly caused due to the use of extra virgin olive oil exhibiting a long carbon chain, instead of the medium chain triglyceride (MCT) used in the mentioned works. The use of an oil phase with longer chain triglycerides (LCT), in conjugation with lower polarity and higher degree of unsaturation, may have steered to lower gelation concentrations when compared to reports using MCT oils [ 10 , 16 , 23 ].…”

“…In order to provide a three-dimensional structure to these edible natural oils, different groups of gelators can be used, namely, low-molecular-weight organogelators (LMOGs) and polymers [ 8 , 9 ]. Several LMOGs have been explored as gelling agents for vegetable oils [ 10 , 11 , 12 ]. Polymeric organogels are mainly formed through the cross-linked networks established by covalent interactions, while LMOGs are based mainly on non-covalent interactions (e.g., van der Waals interactions, H-bonding, π-π stacking) [ 13 , 14 , 15 ].…”

Moisture sorption and thermodynamic properties of Camellia oleifera seeds as influenced by oil content

“…Further analysis of sorption behavior by the application of thermodynamic principles can exhibit important information that provides an understanding of moisture properties and associated energy requirements of heat and mass transfer, food physicochemical and microbiological stability [10,11] . Thermodynamic parameters such as differential enthalpy and entropy, integral enthalpy and entropy, equilibrium spreading pressure, binding energy, sorption activity and average capacity per unit mass have been studied individually or jointly in previous reports of walnut [12] , chestnut [13] , peanut [14] , Zanthoxylum bungeanum seeds [15] and wheat [16,17] .…”

Preparation of Protein Oleogels: Effect on Structure and Functionality

“…LMWOGs are often amphiphilic and self-assemble into supramolecular structures, building space-spanning networks [9]. Examples of LMWOGs that have been shown to form oleogels are monoglycerides [10][11][12][13][14][15][16][17][18], natural waxes [17,[19][20][21][22][23], enzymatically synthesized wax esters [24], ceramides [25], hydroxylated fatty acids [26,27], lecithin [28,29], and oligopeptides [30]. Additionally, combinations of LMWOGs have been studied, such as fatty acids and fatty alcohols [31,32], oleic acid and sodium oleate [33], sorbitan tri-stearate, tocopherol, phytosterol, β-citosterol or ceramide in combination with lecithin [34][35][36][37][38], γ-oryzanol and β-sitosterol [39][40][41][42][43], monoglycerides and phytosterols [44], beeswax and β-carotene [45], wax and monoglycerides [46], and combinations of fully hydrogenated oil, candedilla wax and monoglycerides [47].…”