Modelación, simulación y escalado de la obtención de 1-kestosa a partir de sacarosa por vía enzimática
Fecha
2014-06-25
Autores
Cabrera Carrazana, Roberto Jesús
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Editor
Universidad Central "Marta Abreu" de las Villas
Resumen
La 1-kestosa es el fructooligosacárido de mayor valor comercial debido a sus propiedades prebióticas y puede obtenerse a partir de la sacarosa por la acción de enzimas como la sacarosa:sacarosa 1-fructosiltrasnferasa (1-SST). En el presente trabajo se modeló la cinética de reacción de la 1-SST donde la velocidad inicial de transfructosilación se ajustó a una función lineal de la actividad de la sacarosa cuyo coeficiente de actividad fue una función decreciente exponencial de la concentración de sacarosa. La desactivación térmica de esta enzima fue descrita a través de un modelo cinético de primer orden. La introducción de estos modelos en la plataforma Matlab 2010a permitió optimizar el proceso de producción de 1-kestosa, utilizando además ecuaciones que describen el comportamiento de la transferencia de calor en biorreactores discontinuos tipo tanque agitado. En el trabajo se establecieron como mejores condiciones de reacción de la 1-SST: 100 rpm, 45ºC y 800 g/L de sacarosa inicial. Basados en la simulación se realizaron corridas experimentales que ajustaron en más de un 95% respecto a los modelos teóricos. Estos experimentos permitieron obtener rendimientos de más de 400 g/L de 1-kestosa, los que resultan superiores a los reportados en la literatura para sistemas discontinuos. Se escaló el proceso a 1 y 6 L utilizando como criterio de escalado igual velocidad en la punta del impelente con ajustes superiores al 95%, esto demostró la aplicabilidad del modelo ante los cambios de escala y la factibilidad del proceso establecido para la obtención de 1-kestosa con fines comerciales.
The 1-kestose is the fructooligosaccharide of higher economic value due to their prebiotic properties and can be obtained from sucrose by the action of enzymes such as sucrose:sucrose 1-fructosyltrasnferase (1-SST). In this study was modeled the 1-SST reaction kinetic, the initial transfructosylation rate was well fitted with a linear function of the sucrose activity where the activity coefficient was an exponential decreasing function of the sucrose concentration. The enzyme heat deactivation was described by a first-order kinetic model. The introduction of these models in the Matlab 2010a platform allowed optimizing the process of 1-kestose production; also heat transfer rate equations for stirred tank bioreactors were used. The best 1-SST reaction conditions established in this work were: 100 rpm, 45ºC and 800 g/L of initial sucrose. Based on the simulation results were performed experimental runs that fitted in more than 95 % when compared to the theoretical models. These experiments enabled yields of over 400 g/L of 1-kestose, which are higher than those reported in the literature for batch systems. The process was scaled up to 1 and 6 L with over 95 % fit, considering as scale up criteria equal speed on the impeller tip, this demonstrated the potential application of the model at different scales and the feasibility of the established process to obtain 1-kestose for commercial purposes
The 1-kestose is the fructooligosaccharide of higher economic value due to their prebiotic properties and can be obtained from sucrose by the action of enzymes such as sucrose:sucrose 1-fructosyltrasnferase (1-SST). In this study was modeled the 1-SST reaction kinetic, the initial transfructosylation rate was well fitted with a linear function of the sucrose activity where the activity coefficient was an exponential decreasing function of the sucrose concentration. The enzyme heat deactivation was described by a first-order kinetic model. The introduction of these models in the Matlab 2010a platform allowed optimizing the process of 1-kestose production; also heat transfer rate equations for stirred tank bioreactors were used. The best 1-SST reaction conditions established in this work were: 100 rpm, 45ºC and 800 g/L of initial sucrose. Based on the simulation results were performed experimental runs that fitted in more than 95 % when compared to the theoretical models. These experiments enabled yields of over 400 g/L of 1-kestose, which are higher than those reported in the literature for batch systems. The process was scaled up to 1 and 6 L with over 95 % fit, considering as scale up criteria equal speed on the impeller tip, this demonstrated the potential application of the model at different scales and the feasibility of the established process to obtain 1-kestose for commercial purposes
Descripción
Palabras clave
Sacarosa, Sucrose, Fructosa, Fructose, 1-Kestosa - Fructooligosacárido, Proceso de Producción, Proceso Químico, Chemical Processes, Cinética, Cinética Química, Chemical Kinetics