Fig. 3 shows the air velocity effect on the drying of papaya seeds. It was found in Fig. 3a and b that the kinetic curves were similar, but, the time necessary to attain the equilibrium was higher at high air velocities. Since papaya seeds contain lipids carbohydrates and proteins, the use of high air velocities coupled with high temperatures (higher than 60 ◦C) can cause structural modifications in these compounds, hindering the drying operation (Donadon et al., 2013; Mocelin et al., 2014). On the other hand, at low temperatures (Fig. 3c), the air velocity increase caused a decrease in the time necessary to attain the equilibrium. This fact can be attributed to the higher heat and mass transfer rates. Similar behavior was found by Gazor and Minaei (2005), studying the influence of air velocity (1.5–2.5 m s−1) on the drying time of pistachio.