Modeling Heat & Mass Transfer during Deep-Fat Frying

Pantoa is a traditional dairy product of India, which is characterized by light to dark brown crust and creamish-white spongy core. It has optimum sweetness and caramelized flavour with a hard and firm body and slightly chewy texture. It is prepared by blending chhana (heat-acid coagulated milk), khoa(heat-desiccated milk), refined wheat flour and baking powder, followed by deep-fat frying(DFF) of the dough in heat clarified butter or vegetable oil and soaking in sugar syrup. Heat and mass transfer studies on pantoa during DFF was carried out with the objectives that included evaluation of kinetics of quality changes, optimization of frying conditions and modeling of heat and mass transfer. The heat transfer coefficient increased from 100.57 to 211.46 W/m2K while, the moisture transfer coefficient increased from 7.80×10-6 to 9.05×10-6 ms-1 with increase in frying temperature from 125 to 145°C. The thermal diffusion was found to be more prominent at lower temperature of frying, which was superseded by the effect of moisture diffusion at higher frying temperatures. The data derived from the present investigation opens up new avenues in equipment design and energy conservation.