The microstructure, melting and crystallization behavior, rheological properties and oil binding capacity of crystalline networks of plant-derived waxes in edible oil were studied and then compared amongst different wax types. The critical concentrations for oleogelation of canola oil by rice bran wax (RBX), sunflower wax, candelilla wax, and carnauba wax were 1, 1, 2, and 4 %, respectively, suggesting RBX and sunflower wax are more efficient structurants. A phenomenological two-phase exponential decay model was implemented to quantify the oil-binding capacity of these oleogels. Parameters obtained from this empirical model were then evaluated against microscale structural attributes such as crystal size, mass distribution and porosity to determine the structural dependence of oilbinding capacity. Gels containing candelilla wax exhibited the greatest oil-binding capacity, as they retained nearly 90 % of their oil. This is due to the small crystal size as well as the spatial distribution of these crystals. Using a microscopic to macroscopic approach, this study examines how the structural characteristics unique to each wax and resulting oleogel system affect functionality and macroscopic behavior.

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The aim of the present research was to study the effect of shear on the crystallization behavior of monoglyceride organogels. To this end, organogels were prepared by mixing cod liver oil and saturated monoglycerides at 80°C and then crystallizing them at 20°C under shear rates ranging from 0 to 2,000 s −1 . The organogels were characterized using polarized light microscopy, Cryo-SEM, and X-ray diffraction. The rheological properties and the oil binding capacity of the different systems were also evaluated. Results obtained in this study showed that the introduction of shear during organogel formation greatly affects structure at the nano, micro, and macro levels. Solidification of the organogel under static conditions led to the formation of a strong gel network, with a high oil binding capacity. On the contrary, shear processing during crystallization led to the formation of a weak gel network with a low oil binding capacity.

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A molecular interpretation of the eutectic behavior of a binary mixture of tristearin (SSS) and tripalmitin (PPP) triglycerides was formulated using computer simulations and experimental techniques (calorimetry and X-ray scattering). A eutectic composition was identified using both experimental and computer simulation techniques at a composition of 70% PPP and 30% SSS, in agreement with previous findings in the literature. The decrease in the melting temperature at the eutectic composition can be ascribed to an interplay between enthalpic and entropic effects. In particular, a lower global melting enthalpy at the eutectic composition was detected here, caused by a less efficient packing of the triglycerides in the crystal. On the other hand, a higher crystalline disorder is reflected in a lower change in the entropy of melting. The simultaneous decrease in global enthalpy and entropy has a contrasting effect on the melting temperature, with a slight melting point depression found in both experiment and simulations, resulting from a combination of enthalpic and entropic factors. Computer simulations showed, in fact, that the eutectic effect can be ascribed to the reduction of crystalline order when SSS molecules are incorporated into the PPP crystal structure. This decrease of the crystalline order is due to the protrusion of SSS end-chains (last three carbons of each alkyl chain) into the interlamellar space between adjacent lamella. These end-chains disturb the orderly stacking of the lamella, as evidenced by low-density regions in the interlamellar space. Thus, the greater disorder of the last atoms of the SSS alkyl chains is consequently due to the greater conformational freedom. At molecular level, in fact, the conformational freedom of terminal atoms of SSS surrounded by shorter PPP molecules is larger than the conformational freedom of longer SSS in the neighborhood of short PPP.