Assessment of Physico-Chemical Characteristic Deterioration of Lipids by FTIR Spectra for Successively Used Soy Bean and Sunflower Oils in Frying Spice Food Stuffs

Abstract

The quality of edible oils is an emerging factor to decide the quality of fried foods. Elevated temperature favours lipid oxidation. The edible oil is repeatedly used for deep frying at 190 0 C to 200 0 C, the physico-chemical characteristics of the edible oil get deteriorated. A critical evaluation of the degree of lipid oxidation and deterioration in the quality of oil is informative to use fried foods as hygienic or not. The present work mainly focused on the determination of the variation of peroxide value (PV) and p- anisidine value (p-AV) in correlation with FTIR spectra of frying oils used for frying chicken kebab and potato chips at 200 0 C ± 3 0 C which contributes to the rancidity of frying oils. High peroxide value (soybean;20.96 meq / kg, sun flower; 21.05 meq / kg) and p- anisidine value(soybean; 0.15, sun flower; 0.16) with -OH stretching frequency 3470 cm -1 of hydro peroxide contributes to the lipid oxidation product (Hydro peroxide). When the same oil was used fourth or fifth frying, the fried chicken and potato chips become dark in colour and absorbed more oil which leads digestive offsets. In the same time, fried potato chips sustain more oil within it and get rancid soon. The physico- chemical characteristics and FTIR spectra of frying oils decide the quality of oil to use for frying or liable to discard.