Banca de QUALIFICAÇÃO: GEOVANE CHACON DE CARVALHO

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : GEOVANE CHACON DE CARVALHO
DATA : 11/04/2018
HORA: 15:00
LOCAL: Auditório do NUPPRAR
TÍTULO:

Characterization of vegetable oils by means of thermal and chromatographic

PALAVRAS-CHAVES:

vegetable oils, quality parameters, thermogravimetry, CG-MS, rheological study

PÁGINAS: 120
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Química
SUBÁREA: Química Analítica
ESPECIALIDADE: Análise de Traços e Química Ambiental
RESUMO:

Global production of vegetable oils has been expanding rapidly in recent years, driven by demand from the pharmaceutical industry, and increasingly by the use of fuels and other non-food uses such as oleochemicals. Based on this, this work proposes the characterization of vegetable oils extracted from Bixa orellana (urucum - OU), caryodendron orinocense K. (cacay - OC), Chenopodium quinoa Willd (quinoa - OQ), Coffea robusta L. (OCV), Syzygium cumini (jamelão - OJ) and Moringa oleifera Lamarck, which were extracted from seeds and leaves and flowers, respectively, WHO and OMFF. The quality of vegetable oils is characterized by various physical and chemical parameters that depend on various conditions, such as: oil source, geographical origins, climatic and agronomic growth conditions, as well as processing and storage conditions. This work was carried out to determine the following parameters: acidity index (IA), saponification index (IS), peroxide index (PI), iodine (II) index, refractive index (IR), relative density ), viscosity (ƞ), composition and distribution of fatty acids by gas chromatography according to the Association of Official Analytical Chemists (AOAC). The present work also carried out the analysis of the infrared spectrum, a thermogravimetric and rheological study of vegetable oils in order to evaluate their behavior as a function of temperature. For I.A. only the samples of OU and OCV are above the values established by resolution DRC - No. 270, dated September 22, 2005. Regarding the saponification indices according to the standards of the Codex Alimentarius - Food and Agriculture Organization of the United Nations, the only sample whose value is above that proposed is WHO. In relation to I.P. the OQ and OCV samples are in accordance with the DRC resolution. The other oils presented values above the value required by the DRC. In relation to I.I. the OMFF sample had the lowest value, while the OCV sample had the highest value. Refractive indexes and densities presented similar values for all the oils analyzed. The rheological study was carried out in order to obtain the values for the viscous activation energy (Eav) and the adjustment parameter (η0), the results obtained in this study were consistent with other studies carried out on other vegetable oils. The thermogravimetric study was performed in the heating ratios of 5 and 10 ° C / min in the atmospheres of N2 and synthetic air up to 600 ° C, thus obtaining the TG / DTG / DSC curves. In the thermoanalytical studies, it can be verified that each oil analyzed is peculiar to the proposed thermal decompositions, it was observed that the most thermally stable oil at a heating rate of 10 ° C / min is the quinoa oil, while the least In this study the infrared spectra were obtained for thermoanalytical decompositions and the kinetic studies of the thermal decompositions were carried out in order to calculate the order of reaction (n), the activation energy (Ea ) and the frequency factor (A) by the approximation and integral methods, using kinetic equations proposed by Coats and Redfern, Horowitz and Meltzger, Madhusudanan and Van Krevelen. In relation to the average infrared spectra it was observed that all spectra of the samples were similar. Finally, fatty acid composition was performed by GC-MS, the samples in studies showed seven well-defined major peaks. These peaks were identified with the help of a NILTES 14.L database spectrum. The quantification of fatty acids was obtained using the peak area ratio. These fatty acids were identified as: C13: 0 with retention time of 29.72 min, C15: 0 with retention time of 35.84 min, C16: 1 with a retention time of 42.35 min, C16: 0 with a retention time of 43.06 min, C17: 0 with a retention time of 45.82 min, C18: 1 with a retention time of 48.69 min, C18: 1 with a retention time of 48, 71 min, C18: 2 with a retention time of 48.54 min, and finally C18: 0 with a retention time of 49.39 min.

MEMBROS DA BANCA:
Presidente - 7350310 - MARIA DE FATIMA VITORIA DE MOURA
Interno - 348475 - DJALMA RIBEIRO DA SILVA
Externo ao Programa - 3149615 - HENRIQUE EDUARDO BEZERRA DA SILVA
Externo ao Programa - 1412709 - NEDJA SUELY FERNANDES
Externo ao Programa - 2413537 - POLLYANA SOUZA CASTRO