Anais do Simpósio Latino Americano de Ciências de Alimentos
Anais do 14 SLACA - Simpósio Latino Americano de Ciência de Alimentos

Palm oil is the most produced oil in the world, despite being related to cardiovascular diseases. Coconut oil is also believed to raise blood cholesterol because it is made up of medium-chain fatty acids (MCT). On the other hand, MCTs are digested faster, as they do not require the presence of bile and pancreatic lipase due to their high content of low-chain fatty acids. So, the aim of this work was to study the crystallization and melting behavior of cholesterol in mixtures with coconut oil and palm oil. For this purpose, the thermodynamic phase equilibrium systems composed of these lipids and cholesterol were experimentally measured and evaluated by the solid-liquid equilibrium theory. Mixtures were formulated from 0 to 100% cholesterol, crystallization and melting were evaluated by differential scanning calorimetry (DSC) and some microscopies taken to evaluate more complex behaviors. Results showed that despite its high melting temperature and molecular complexity, cholesterol could be solubilized in both oils, promoting a classical eutectic behavior. It means that cholesterol melting point were decreased up to the melting point of the oil and there is a limit temperature (called as eutectic temperature), close to oil melting point, in which above, the system is biphasic and below, the system is solid. Several solid-solid transitions could be seen during melting, showing that other phenomena were probably affecting cholesterol crystal profile, such as polymorphism and solid solution formation, common in mixtures of triacylglycerols. Palm oil, in particular, presented the formation of liquid crystalline structures when mixed with cholesterol in some concentration. This could be probably promoted by the long chain triacylglycerols of palm oil composition. All these phenomena observed can probably affect the solubility of cholesterol in lipid media, being a factor that can influence its absorption in the gastrointestinal tract in the presence of these oils.