For each fat/oil sample, a karahi (a thick, circular, and deep
cooking pot, similar in shape to a wok, used for open-air deep frying)
containing 500 mL of the fat/oil sample was taken. The fat/oil
temperature was recorded and heating was initiated till the temperature
of the fat/oil reached 180 C. The temperature of fat/oil
was maintained at 180 C for 30 min; thereafter, 30 mL oil were
removed in clean and pre-dried, pre-coded glass bottles and stored
in a cool box. The subsequent heating cycle was performed on the
same fat/oil sample by continuing heating and maintaining the
sample for half an hour at 220 C, and then it was allowed to cool
for 60 min. Subsequently, the same sample was reheated, and theentire process was repeated.