Moura, Maria de Fátima Vitória deCarvalho, Geovane Chacon de2019-11-292019-11-292019-07-17CARVALHO, Geovane Chacon de. Composição de ácidos graxos em óleos vegetais obtida por cromatografia gasosa e sua correlação com propriedades térmicas, reológicas, espectroscópicas e outras propriedades físico-químicas. 2019. 143f. Tese (Doutorado em Química) - Centro de Ciências Exatas e da Terra, Universidade Federal do Rio Grande do Norte, Natal, 2019.https://repositorio.ufrn.br/jspui/handle/123456789/28085This work determined the fatty acid composition in vegetable oils obtained by gas chromatography and correlated them with the thermal, rheological, spectroscopic and other physicochemical properties such as the acidity, saponification, peroxide, iodine and refraction indices. relative density and viscosity. Vegetable oils were extracted from the following species: annatto (OU), cacay (OC), quinoa (OQ), green coffee (OCV), jamelão (OJ) and moringa (OMS and OMFF, respectively to seeds / leaves and flowers). The fatty acid composition was obtained by gas chromatography (CG-FID) according to the Association of Official Analytical Chemists (AOAC) and the physicochemical determinations were performed according to the manual of PhysicalChemical Methods for Food Analysis of the Institution. Adolf Lutz. Thermal characterization was performed using TG, DTG and DSC and analysis of the volatiles released during their thermal decomposition by TG-FTIR. The rheological study was performed using a rheometer. Chromatograms indicated the presence of 13 fatty acids with linoleic acid (C18: 2n6c) being the most abundant fatty acid in all samples. From the rheological study we obtained for the activation energy (Ea) the following order OJ> OQ> OC> OMS> OMFF> OCV> OU, which indicates the viscosity. From the obtained TG / DTG / DSC curves, it was verified that each oil analyzed presented peculiarities in its thermal decomposition and the proposed stability order is OQ> OMFF> OCV> OMS> OJ> OC> OU. A similar profile was observed for the thermal decomposition curves for most of the oils studied, except for the OU, which presents a high amount of pigments. Infrared spectra indicated the evolution of volatiles during the thermal decomposition of oils under synthetic air and N2 atmospheres; In these, different intensities were verified for the thermal decomposition products, but following the same assignment profile.Acesso AbertoÓleos vegetaisParâmetros de qualidadeTermogravimetriaCG-MSEstudo reológicoAnálise físico-química de óleos vegetaisdoctoralThesisCNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA