Palm, peanut and soy bean oils were exposed to high temperature with and wi
thout food products, and the amounts of polar substances, a measure of heat
abuse, were determined using the time consuming standard procedure (prepar
ative column chromatography) and much faster alternative methods. High perf
ormance liquid chromatography allows complete separation and quantification
of the non-polar and the polar fractions. Low-resolution nuclear magnetic
resonance and near infra-red spectroscopy can also be applied. A commercial
food oil sensor based on dielectric measurements is also useful to investi
gate heat abuse of frying fats and oils. The type of frying food influenced
the rate of sensory deterioration in the oils.