Modelado de la cinética de secado e isoterma de adsorción de agua de oca blanca (Oxalis tuberosa variedad Blanca) y zanahoria blanca (Arracacia xanthorrhiza Bancr.)

Abstract

The present work focused on studying the drying kinetics of Oca blanca and Zanahoria blanca in a drying process carried out at a temperature of 65 Celcius degrees for 8 hours. The determination of the critical humidity yielded the values of 0.06 kg wáter per-kg dry solid and 0.07 kg wáter per-kg dry solid for Oca blanca and Zanahoria blanca, respectively. In addition, the kinetics data were fitted to the mathematical models of Newton, Page, modified Page, Henderson and Pabis, Logarithmic, Thomson, and Fick. Through the determination coefficient (R2), the estimated mean error (SE), and the relative mean deviation percentage (P), it was determined that the Page model presented a better fit. On the other hand, the adsorption isotherms were built using supersaturated salts, allowing them to maintain environments with a relative humidity of 11 to 80 percent. The isotherms showed a type II sigmoidal shape, and the values were fitted to the GAB and BET mathematical models. Through the coefficient of determination (R2), a better fit with the GAB model was determined. The monolayer moisture content for the two matrices yielded values of 0.055 kg wáter per-kg dry solid and 0.057 kg wáter per-kg dry solid for Oca blanca and Zanahoria blanca, respectively. This constant is related to the humidity limit that the sample must have to remain stable during storage.