Modelado de la cinética de secado e isotermas de adsorción de agua de oca amarilla (Oxalis tuberosa variedad amarilla) y oca roja (Oxalis tuberosa variedad roja)

Abstract

The Yellow Oca and Red Oca are tubers that contain a large amount of water, which makes them perishable food. Drying is a process where the amount of water in the food is reduced through mass and heat exchange between the matrix and hot air. In this study, these tubers were dried at 65 degrees Celsius for 8 hours. The analysis of the drying kinetics allowed it to determine the critical humidity, which yielded values of 0.059 kg water on kg dry solid and 0.086 kg water on kg dry solid for yellow and red Oca, respectively. In addition, seven mathematical models commonly used for analyzing drying kinetics in foods were used (Newton, Page, modified Page, Henderson, and Pabis, Logarithmic, Thomson, and Fick), and it was observed that the model that best fits is Newton's. On the other hand, adsorption isotherms were built using salts found in a water activity range of 0.11 to 0.8. It was determined that the yellow and red Oca meals generate type II isotherms. The data from these isotherms were adjusted to the mathematical models of BET and GAB. It was determined that the model that best fits the data is GAB due to the range in which it works.