Excessive consumption of saturated and trans fatty acids is positively correlated with an increased risk of cardiovascular disease, metabolic syndrome and Type II diabetes. The search for new materials able to replace and/or reduce saturated/hydrogenated fats using structural design principles is a timely topic. A novel strategy consists on gelation of oil using small molecules (organogelators) that are able to self-assemble in liquid oils. The resulting material, an organogel or oleogel, has similar physical properties to those of fats. Different molecules have been proposed as organogelators such as monoglycerides, fatty acids, fatty alcohols, 12-hydroxystearic acid, waxes, phytosterols, etc. However, among them, fatty alcohols have received little attention in literature.
The aim of this research was to study the ability of saturated fatty alcohols with different even carbon chain length (1-tetradecanol, 1-hexadecanol, 1-octadecanol, 1-eicosanol, and 1-docosanol) to gel peanut oil under different cooling rates. To this aim, minimum gelling concentrations, oil release, solid fat content, back extrusion firmness, microstructure by polarized light microscopy and scanning electron microscopy, differential scanning calorimetry, X-ray diffraction, and ultra-small X-ray scattering analysis were carried out.
Results highlighted that organogels were composed of monotectic phases where fatty alcohols crystals aggregated forming a network that entrapped the oil. The gelling ability of fatty alcohols increased increasing the chain length and decreasing the cooling rate. During storage, fatty alcohol crystals showed a reduction of the lamella thickness that was accompanied to an increase of oil release and a reduction of organonel firmness. The results acquired are interesting in the attempt to tailor fatty alcohol organogels characteristics.
