Evaluation of different drying models for freeze drying of ripe mangabas with different diameters through of performance indicators

Abstract

Drying mathematic models are used to characterize the drying process by estimating important parameters to the processes. Mangaba (Hancornia speciosa Gomes) is a tropical climate fruit with high perishability. Due to this fact, it is necessary alternative processes to increase its shelf life, such as freeze-drying. The objective of this work was to analyze several models in order to evaluate the best model according to the process conditions through the indices of the performance of models which are: accuracy factor (A_f), bias factor (B_f), root mean square error (RMSE) and standard error of prediction (%SEP). The fruits were frozen at -20 °C in conventional freezer, and then freeze-dried at -50 °C and 38 μmHg for 1380 min. The results showed that the model of Page was precise independent of the diameter, with: A_f: 1.9198, B_f: 1.8446, RMSE: 0.0275 e %SEP: 5.6298 and A_f: 1.7334 B_f: 1.6735; RMSE: 0.0221 e %SEP: 3.5545 for the small and large mangabas, respectively. It was noted that the model of Page resulted in a better correlation between the experimental and estimated data.