DETERIORATIVE EFFECTS OF REPEATED BOILING ON THE NUTRITIVE VALUE OF EDIBLE OILS
The deteriorative effect of high temperature exposure to the quality of food grade oils is a well-established fact. However the toxic effects of the end products of thermal oxidation on the natural nutritive value that the oil possesses is not clearly known. So the present exercise is an attempt to understand the toxic effects of repeated boiling, a major culinary practice seen in many parts of the world. Fresh oils and oils stored for long periods in inappropriate conditions are being employed as comparators. Frequently used food grade oils, divided into three categories i.e. fresh, long stored and overcooked were analyzed for their normal lipid quality indices; primary, secondary and total oxidation status and total phenolic contents. Deterioration rate of overcooked oils was found to be almost comparable to that of long stored oils. A significant decline of the total phenolic content observed in the overcooked oils has been represented as loss of nutritive value.