Efecto de temperatura sobre los parámetros termodinámicos de la isoterma de adsorción de harina de arveja (Pisum sativum L.) entera, descascarada e hidrolizada
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Date
2024
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Universidad Nacional de Trujillo
Abstract
Las isotermas de sorción de humedad y sus parámetros termodinámicos son de gran importancia en el desarrollo de nuevos productos y procesos alimentarios. En tal sentido, esta investigación tuvo como objetivo evaluar el efecto de la temperatura (20, 30 y 40 °C) sobre los parámetros termodinámicos de la isoterma de adsorción de harina de arveja (Pisum sativum L.) entera, descascarada e hidrolizada. Para ello se establecieron tres tipos de harina: Tipo A (harina de grano de arveja sin pelar y sin hidrolizar, denominada entera), Tipo B (harina de arveja sin cáscara) y tipo C (harina de arveja sin cáscara e hidrolizada con alfa amilasa). Las muestras fueron dispuestas en ambientes con actividad de agua entre 0.1 y 0.9. Por un periodo de 7 días. El ajuste a los datos experimentales de humedad de equilibrio se realizó con el modelo de GAB. Se determinó el calor isostérico, entropía de adsorción, energía libre de Gibbs, área de adsorción y energía de activación, encontrándose variaciones importantes en cada tipo de harina entre las tres temperaturas evaluadas. El tipo de isoterma en todos los casos fue sigmoideo de tipo II según la clasificación de Brunauer. La temperatura ejerció efecto significativo (p < 0.05) sobre el valor de monocapa de las harinas de arveja, disminuyendo al incrementar la temperatura. Tanto el calor isostérico como la energía libre de Gibbs y el área de adsorción disminuyeron con la temperatura. Los valores más altos de entropía y energía de activación se encontraron en la harina tipo B. Los valores negativos de energía libre de Gibbs sugieren que el proceso de adsorción en la superficie de la harina de arveja es espontáneo.
ABSTRACT Moisture sorption isotherms and their thermodynamic parameters are of great importance in the development of new food products and processes. In this sense, this research aimed to evaluate the effect of temperature (20, 30 and 40 °C) on the thermodynamic parameters of the adsorption isotherm of whole, shelled and hydrolyzed pea flour (Pisum sativum L.). For this, three types of flour were established: Type A (unpeeled and unhydrolyzed pea grain flour, called integer), Type B (shelled pea flour) and type C (shelled pea flour and hydrolyzed with alpha amylase). The samples were placed in environments with activity between 0.1 and 0.9 for a period of 7 days. The adjustment to the experimental data of equilibrium humidity was carried out with the GAB model. The isosteric heat, adsorption entropy, Gibbs free energy, adsorption area and activation energy were determined, finding important variations in each type of flour between the three temperatures evaluated. The type of isotherm in all cases was type II sigmoid according to Brunauer's classification. Temperature had a significant effect (p < 0.05) on the monolayer value of pea flours, decreasing with increasing temperature. Both isosteric heat, Gibbs free energy and adsorption area decreased with temperature. The highest values of entropy and activation energy were found in type B flour. The negative values of Gibbs free energy suggest that the adsorption process on the surface of pea flour is spontaneous.
ABSTRACT Moisture sorption isotherms and their thermodynamic parameters are of great importance in the development of new food products and processes. In this sense, this research aimed to evaluate the effect of temperature (20, 30 and 40 °C) on the thermodynamic parameters of the adsorption isotherm of whole, shelled and hydrolyzed pea flour (Pisum sativum L.). For this, three types of flour were established: Type A (unpeeled and unhydrolyzed pea grain flour, called integer), Type B (shelled pea flour) and type C (shelled pea flour and hydrolyzed with alpha amylase). The samples were placed in environments with activity between 0.1 and 0.9 for a period of 7 days. The adjustment to the experimental data of equilibrium humidity was carried out with the GAB model. The isosteric heat, adsorption entropy, Gibbs free energy, adsorption area and activation energy were determined, finding important variations in each type of flour between the three temperatures evaluated. The type of isotherm in all cases was type II sigmoid according to Brunauer's classification. Temperature had a significant effect (p < 0.05) on the monolayer value of pea flours, decreasing with increasing temperature. Both isosteric heat, Gibbs free energy and adsorption area decreased with temperature. The highest values of entropy and activation energy were found in type B flour. The negative values of Gibbs free energy suggest that the adsorption process on the surface of pea flour is spontaneous.
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Keywords
Arveja, Hidrólisis, Monocapa, GAB, Parámetros termodinámicos