Mathematical Modeling of Cooling Rates of Mango Fruits during Unsteady State Cooling in an Artificial Ripening Chamber

Abstract

Mango fruits need to be ripened artificially using ethylene in thermally insulated refrigerated chambers. The present experiments were conducted to determine the kinetics of cooling rates (with respect to time) of mangoes during unsteady state cooling before ripening the fruits. Ethylene based ripening systems becoming popular due to safe and healthy ripening unlike ripening using calcium carbide. Three different lots 4, 6 and 10 Metric Tons of mangoes placed in perforated plastic crates were cooled first to the desired optimum temperature for ripening. Temperature profiles of mangoes were monitored and recorded with a data logger. Time taken for the mangoes to reach the optimum set temperature of 16.80C is 16, 20 and 26 hours for 4, 6 and 10 MT respectively. During the unsteady state cooling (from approximately 300C to 160C), rate of cooling is modeled using three mathematical equations, viz. linear, exponential and polynomial. Experimental data of pre-cooling is fitted to the predicted values. Best fitting models are proposed based on highest R2 values for all three different quantities of mangoes pre-cooled. The results will be helpful for deciding the timing for ethylene injection and design of refrigeration equipment for part loads of the ripening chambers.