Chemical Physical and Physicochemical changes during Frying
E. P. Kalogianni
This work investigates changes occuring in the frying medium (oil or fat) and the food being fried (potatoes) during repeated frying. The changes investigated in the frying medium include chemical changes (polymer and polar compouds) physical changes (density viscosity) and physicochemical changes (dynamic interfacial properties at the oil/air and oil/water interface) and temperature profiles during frying. The changes examined in the potato include water and oil content, crust and pore development as well as with temperature changes in different positions in the.core and crust of the food being fried.
Frying was performed under well-controlled experimental conditions simulating those found in industrial and catering applications. Several variables related to the process the oil and the potatoes were studied. Namely: the effect of potato to oil ratio, of oil temperature profile, of potato specific gravity, potato variety, potato movement in the fryer, of the oil type and of the number of repetitions in a repeated frying process.
Most of the work has been published in a PhD thesis available from the British Library
Work related to the changes in the oil has been published (have a look in publications page).
Work related to the changes in the potato is under preparation for publication.