An apparatus for frying food, such as pork loin, tenderloin, sirloin or potatoes was presented. In order to design such a fryer, a general mathematical model was formulated for heat energy consumption during the process of frying food. On the basis of a general mathematical model, a model of heat energy consumption was developed using an example the production of French fries. The problem was investigated both theoretically and empirically. The theoretical studies involved computer simulation of heat energy consumption, whereas experiments were conducted to measure heat energy consumption during French fries frying in the apparatus designed by the author. The theoretical heat energy consumption was 14.5-15.7% lower than the actual one. (C) 2002 Elsevier Science Ltd. All rights reserved.