Maximum values of heat transfer coefficient were 500 and 265 W/m2-K for high pressure and atmospheric frying, respectively. These values were obtained at the point of maximum mass change for both cases (at 32 s vs 22 s for pressure versus atmospheric frying; Fig. 4). Increase in the apparent heat transfer coefficient value at the earlier stages of frying can be explained by more efficient renewal of the oil boundary layer caused by the incipient bubbling.