Efecto del Recubrimiento Comestible en las Propiedades de Trozos de Batata (Ipomoea Batatas Lam) Fritos por Inmersión: Parte 2: Propiedades Termofísicas y de Transporte

Abstract

ResumenSe estudió el efecto de la carboximetilcelulosa y la temperatura en las propiedades termofísicas, los coeficientes de transferencia de calor y masa, pérdida de humedad y ganancia de aceite durante la fritura de trozos de batata. El calor específico, conductividad térmica y densidad se determinaron mediante ecuaciones experimentales y la difusividad térmica se determinó según su definición física a partir de los valores de las otras propiedades termofísicas. Los coeficientes de transferencia de calor y masa se determinaron gráficamente basados en las soluciones de las ecuaciones diferenciales de conducción de calor y de concentración de humedad, en una dimensión y utilizando la regla de la superposición para ajustarla a un plato finito. Los resultados indicaron que las propiedades termofísicas de la batata varían significativamente durante la etapa de freído. El coeficiente de transferencia de calor h es mayor cuando aumenta la temperatura del aceite y se utiliza recubrimiento. El coeficiente de transferencia de masa kc es mayor cuando aumenta la temperatura del aceite y no se utiliza recubrimiento comestible. Además, se observó que el recubrimiento comestible disminuye más del 30 % el contenido de aceite final para todas las temperaturas de freído utilizadas, lo que hace que sea una excelente elección para mejorar la calidad nutricional de los productos fritos. ABSTRACTThe effect of temperature on Carboxymethylcellulose and thermophysical properties, heat transfer coefficients and mass, moisture loss and oil uptake during frying of potato chips was studied. The specific heat, thermal conductivity and density were determined using experimental equations and the thermal diffusivity was determined by their physical definition from the values of other thermophysical properties. The heat transfer coefficients and mass were determined graphically based on the solutions of the differential equations of heat conduction and high moisture, and using one-dimensional overlap rule to conform to a finite plate. The results indicated that the thermophysical properties of sweet potatoes vary significantly during the frying stage. The heat transfer coefficient h is greater when the oil temperature increases and coating used. The mass transfer coefficient kc is greater as the temperature increases and no edible oil is used. Moreover, the edible coating decreases more than 30% oil content for all end frying temperatures used, which makes it an excellent choice for improving the nutritional quality of the fried products.

Mass transfer during the vacuum frying of Malanga slices (Colocasiaesculenta)

“…In the Table 2 can be observed the diffusivity coefficient of water in the fried samples at 130 °C and 150 °C was higher than those fried at 110 °C due to exist a major ) mobility of the water molecules as the temperature increases; also when the oil content is high, diffusion coefficient enhance in the Malanga slices. Alviset al, [16] stated the rate of moisture loss is higher with the enhancing of the oil temperature, the same thing occurs with the effective diffusivity due to higher temperature is produced more porosity and consequently greater water diffusivity. These obtained values are into the range reported by Troncoso and Pedreschi (2009) [17] for water diffusion in the potato issue during vacuum frying (8.57 × 10 -9 and 1.21 × 10 -8 m 2 s -1 for a temperature range between 120 °C and 140 °C).…”

Determination of the Moisture and Oil Thermal Diffusivity Coefficients in Breadfruit (Artocarpus altilis) During Vacuum Frying

“…That is, there was a phase in which the moisture rate came out with greater speed than the other samples. Alviset al, [20]stated that rate of moisture lossis greater with the increase in oil temperature, as well as the effective diffusivity, since at higher temperature, higher porosity and consequently greater water diffusivity occur. Among the moisture transporting properties of the moisture diffusivity in a product, frying is the one that controls, since it defines the velocity of diffusion of liquid or steam in the product and also the velocity of evaporation and condensation.…”

“…It has been found considerably that the moisture of various foods has varied due to the complex structure of the polymers in them (starch and protein) and their interaction with water [21]. Average values obtained for D eff in the study by Alviset al, [20] In research conducted it has been found that the effective moisture diffusivity in the industrial cake dough system during baking of a cake was 9.9 × 10 -11 m 2 s -1 -3.8 × 10 -8 m 2 s -1 for the temperature of products from 33.1 to 126 °C [22], different from those reported in this study. But very similar to those reported by Dincer and Yildiz [23] for sausages, fried at 180 °C (1.31 × 10 -7 m 2 s -1 ).…”

SECADO DE ARENCA (Triportheus magdalenae): INFLUENCIA DEL SALADO EN PILA SECA Y HÚMEDA

“…Pero se aleja de los datos reportados por Alvis y colaboradores [18], quienes en su trabajo de recubrimiento comestible en las propiedades de trozos de Batata (Ipomoea Batatas lam) fritos por Inmersión a diferentes temperaturas obtuvieron valores de 9,19x10 -7 a 13,9x10 -7 m 2 /s para muestras sin recubrimiento. las diferencias entre los coeficientes encontrados en el presente trabajo y los reportados en la literatura, pueden ser explicadas por la diferencia entre las características de los productos trabajados, los métodos utilizados para la medición de los contenidos de y el método de solución de las ecuaciones de transferencia de masa [17,19].…”