Drying behavior and mathematical modeling of Tenebrio molitor using a closed system heat pump dryer

Abstract

Abstract The main purpose of this paper was to investigate the influence of air temperatures (T), air velocity (v) and blanching time (ô) on the behavior of Tenebrio molitor when a closed-system heat pump dryer is used to dry the sample to equilibrium water content (dry basis water content is 12.5%). The T was 40°C, 50°C and 60°C; the v was 2, 3 and 4 m/s; and the ô was 15, 30 and 45 s. And the quality of T. molitor was measured every 15 minutes. We also established a mathematical model to predict the drying process. Altogether, six selected thin-layer mathematical drying models were compared to assess the drying process based on the coefficients of determination (R2), root mean square error and the sum of the squared error. The results showed that the drying time can be shortened as T, v and ô increased and T and v had greater effects on the drying time compared with the ô. There are three stages throughout the drying process—the constant speed stage was the shortest and the decelerated stage played a leading role. Among six selected thin-layer mathematical drying models, the Midilli model (R2 = 0.9997) was superior to others in describing the drying curves of T. molitor. The experimental data of MR was in agreement with the prediction results of Mildilli model.