SCREENING OF VARIOUS FRESH AND USED EDIBLE OILS FOR PEROXIDE VALUES USING IODOMETRIC AND ELECTROANALYTICAL METHODS – A COMPARISON

The determination of the peroxide value is the traditional and most used parameter for measuring the primary products of oxidative degradation. Peroxide group that is O-O group is unstable and release oxygen when heated .oxygen reacts with fat molecules to form peroxides in oils. In addition, the analysis of the peroxide content of oil samples is a very analytical task because high peroxide levels in oils have been a threat to human health. The peroxide value is a suitable parameter for measuring the deterioration of quality of edible oils over prolonged heating. A rapid method for the quantitative determination of peroxide value (PV) of fresh and used edible oils by iodometry and colorimetry is described. An attempt was made to show higher peroxide values in used edible oils compared to fresh edible oils by using iodometric titrations,a series of edible oils were taken and analyzed for PV, based on the co-oxidation of Fe(II) to Fe(III) by hydro peroxides from sample (fat) and the formation of the reddish Fe(III)-thiocyanate complex which is read at 500 nm on a colorimeter. Hence the present work suggests the usage of fresh edible oils to prevent rancidity of oils and other side effects.