When the cassava crackers were fried at the temperature of 140 °C at frying time 10 s (Fig. 2 (a)) the fracture pattern shows only one drop in force and a smaller number sound peaks, which indicates the absence of crispy behavior. Crispy products should fracture at a low force with multiple brittle fracture events (Vincent, 1998 and Luyten et al., 2004). In Fig. 2 (b–d) many big force events, followed by some smaller force events can be seen, while the frying temperature at 160 °C (Fig. 2 (g–i)) shows many fracture events roughly similar in size. This can be explained by the high number of small air cells as can be seen later in Fig. 4 (g–i)