Tesis doctoral de Aline Santana Scotelari De Souza
Hydrogenation is an extremely important process to modify the melting point of vegetable oils and to contribute important textural properties to food. The versatility of the hydrogenation process promotes the industrial development of fats to achieve specific physical and chemical characteristics in processed foods. despite of the fact that isomerization of cis-trans configuration increases the melting point, conflicting conclusions have resulted from studies on trans fatty acids. In several studies, these isomers formed during hydrogenation of fatty edible oils have shown to have similar effects as saturated fats increasing serum cholesterol levels in the blood, believed to be a major cause of heart disease. For this reason, apprehension and public awareness have risen regarding the potential health hazards of trans fatty acids intake in the human diet. the physical and sensory properties of the final product strongly depend on the number of residual double bonds as well as on the cis-trans isomers present in the mixture. From nutritional point of view the cis isomer is more desirable. however, fatty acids with trans configuration affect the textural and melting properties of fat, increasing the stability and serving to extend the plastic range that are characteristics beneficial for margarine production and others products requiring a sharp melting point with good flavor stability while providing the required firmness at room temperature. The consumption of trans fatty acids has been discussed in connection with an elevated risk of developing premature atherosclerosis as well as cardiovascular diseases. The low trans c18:1 content is a desirable objective with respect to food health. melting behaviour of hydrogenated products is an important property for functionality in many prepared food products. the proportion of solid to liquid fat in a shortening, margarine, or specialty product at a given temperature has an important relationship to the performance of the product at that temperature. This proportion cannot be determined from single point melting analysis or other analysis of the physical properties. Estimates of the solids and liquids contents in a fat at different temperatures over the melting range can be made with calorimetric, dilatometric or nuclear magnetic resonance procedures. In this thesis work, this behaviour was monitored mainly by differential scanning calorimetry (dsc). the main aim of the thesis was the characterization of a hydrogenated product under supercritical fluids as reaction solvent. The supercritical hydrogenation is an alternative process for producing a wide variety of end products having different characteristics of industrial foodstuffs interest to be used as low cholesterol precursors for margarine and shortening bases. The purpose of this thesis was to monitor the changes in fatty acid composition and trans fatty acids at different time intervals of hydrogenation process of sunflower oil in supercritical fluids and to determine its effects on solid fat content of the hydrogenated products.
Datos académicos de la tesis doctoral «Vegetable oils hydrogenation technology in supercritical fluids for food applications: characterization of hydrogenated products«
- Título de la tesis: Vegetable oils hydrogenation technology in supercritical fluids for food applications: characterization of hydrogenated products
- Autor: Aline Santana Scotelari De Souza
- Universidad: Politécnica de catalunya
- Fecha de lectura de la tesis: 17/07/2009
Dirección y tribunal
- Director de la tesis
- María ángeles Larrayoz Iriarte
- Tribunal
- Presidente del tribunal: ignasi Casas pons
- philip Jaeger (vocal)
- eliana Ramirez rangel (vocal)
- Ana isabel Castellote bargallo (vocal)