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Browsing Revistas científicas by Subject "Aceite vegetal"
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Item Comparación del aceite de aguacate variedad Hass cultivado en Colombia, obtenido por fluidos supercríticos y métodos convencionales: una perspectiva desde la calidad(Corporación Universitaria Lasallista, 2012) Restrepo Duque, Ana María; Londoño Londoño, Julián Alberto; González Álvarez, Dubán; Benavides Paz, Yara Licceth; Cardona Salazar, Blanca LucíaIntroduction. Oil is the most important component of avocado, achieving levels up to 25% depending on the variety and the maturity. Such oil is known as a very beneficial product for health. Objective. Compare the avocado oil (Persea americana Mill), Hass variety, cultivated in Colombia and obtained by supercritical fluids, with those obtained by coldpressing and soxhlet, under quality terms. Materials and methods. The physical-chemical, bromatological and microbiological characterizations of the fresh avocado was performed and, before the extraction process, the dehydration of the raw material was made by three methods. The first one was an application of liophylization at -25 ºC, 0,05 mbar and a velocity of 0,04 °C/mín. The second was a convective drying at 45ºC and the third was a controlled drying with sunlight, with an interior temperature under 45°C. Then, the oil was extracted by supercritical fluids at 25 MPa, 313K, cold-pressing and soxhlet, respectively. The oils obtained were tested under terms of acidity index, peroxide index, iodine index, saponification index and specific gravity according to AOCS regulations. Results. There were statistically significant differences with a value of (p˃ 0,05) in the acidity, peroxide, iodine and saponification indexes, when different methods were applied to extract the avocado oil. The opposite happened with the specific gravity. The avocado oil extracted with supercritical fluids had values of 90,18±0,78; 16,87±1,15; 0,48±0,35; 226,18±1,11 and 0,915±0,04 for peroxide index, acidity index, saponification index and specific gravity, respectively. Conclusion. The extraction with supercritical fluids is the best technique to produce avocado oil, because it is useful to obtain the highest yield, the lowest acidity index, a low oxidation of unsaturated fatty acids and a higher iodine index, if compared with conventional extraction methods such as cold pressing and soxhlet.Item Estudio del proceso de transesterificación para la obtención de biodiesel a partir del aceite de palma en un reactor por lotes(Corporación Universitaria Lasallista, 2013-10-26) Reategui Romero, Warren; Salas Barrera, Fernando JavierIntroduction. Theoretically, for producing three moles of ethyl-ester (biodiesel) there must be a reaction between one mole of triglyceride and three moles of ethyl alcohol, but this process is developed in three stages: considering the same stoichiometric relationship, in first place a fatty acid chain is separated from the triglyceride and is combined with the first mole of ethyl alcohol, forming an ethyl-ester mole and a diglyceride mole. Then, a fatty acid chain is separated from the diglyceride previously formed and is combined with the second mole of ethyl alcohol, forming an ethyl-ester molecule and a glycerine molecule, thus finishing the transesterification process. Objective. To study transesterification process in palm tree oil in order to obtain biodiesel in a batch reactor. Materials and methods. In order to perform the study aforementioned, a batch reactor with a volume control has been selected and a general equation of mass transfer has been applied. The equation was simplified taking into account certain considerations pertinent for the case. After the simplification, the equation was applied to every component that intervene in the transesterification process (mole balance for each component), obtaining a differential equations system (phenomena modeling) which was solved by following the finite differences method, thus obtaining the equations that relate concentration vs the time for ecah component. Results. The solution of the model is shown graphically, and the graphic clearly shows the concentration curves vs the time for each component. In these curves it can be observed the approximate time required by each chemical eactions to reach balance. Conclusion. By the use of the phenomenological modeling, a simplified form of the mass transference general equation was obtained for each component of the transesterification process in a batch reactor.Item Evaluación del proceso de extracción de aceite de aguacate hass (Persea americana Mill) utilizando tratamiento enzimático(Corporación Universitaria Lasallista, 2012) Buelvas Salgado, Gustavo Andrés; Patiño Gómez, J. H.; Cano Salazar, J. A.Introduction. Avocado oil is rich in vitamins A, B, C and E, and is mainly composed by monounsaturated fat acids, which effectively reduce cholesterol levels in blood, thus helping to prevent cardiovascular diseases. Objective. Evaluating the performance of Hass avocado (Persea americana Mill) oil extraction in E3-M (mature) from the East of Antioquia, by the use of commercial enzymatic complexes. Materials and methods. To develop this research work, a physical-chemical characterization was performed, determining the pertinent maturity state to extract the oil. The enzymatic extraction was performed with three enzymatic complexes, Pectinex Novozym nd Ultrazym, and three enzyme concentration levels (150, 200 and 250 mL/t. of mixture) to evaluate the quantity of extracted oil. Results. The best performance was achieved with the pectinex enzyme, in a concentration of 200 ml of enzima/t, mixture in which an oil extraction performance of 60% was obtained in the E3-M maturity state (mature). Conclusion. The treatment with enzymatic complexes is a feasible alternative to extract the oil, because it is possible to degrade the galacturonic acid chains and free the oil contained in the idioblasts of the Hass avocado´s (Persea american Mill) mesocarp.