Relationship Between Oil Uptake and Water Content During Deep-Fat Frying of Potato Particulates Under Isothermal Temperature

The purpose of this study is to correlate water content and oil uptake with the structural changes of potato particulates during deep-fat frying. Raw potato particulates were sliced to form cylinders of 0.006 m diameter x 0.006 m length and subjected to deep-fat frying at isothermal oil temperatures of 160, 190 and 220 A degrees C. The microstructure properties were assessed using a field emission scanning electron microscope (FESEM). Previous results showed that a simultaneous two first-order kinetic model adequately predicted water loss of potato particulates during isothermal frying. In this study, a simple rational model with two parameters in which regression squared (Rsqr) reaches 0.983 shows that oil uptake can be expressed by water content. The cross-sectional structure of potato particulates observed using FESEM is different from the surface structure. Regardless of the frying temperature, pores not only become larger but also increase in number after the transition time. The observations of structural changes at the surface and inner section of potato particulates through the pictures of FESEM are critical. This physical evidence supports our previous assumption that the mechanisms of water loss (two-stage rate processes) before and after transition time are different.