Measure of thermo-oxidation of vegetable oils microwave-heated in model systems

A study was conducted to evaluate the extent of thermo-oxidative degradatio n in different types of oils (sunflower, soybean, peanut, and virgin of oli ve) microwave heated in model systems. The acidity determination, peroxide value, specific UV spectrophotometric constants, and p-anisidine value - us eful for a basic evaluation - were carded out, Polar compounds and the sing le classes of substances constituting them were also determined to better e stimate the extent of oxidative and hydrolytic degradation of the oils unde r study. The obtained results showed a high oxidative degradation degree of the oils that, however, seemed to be correlated to the poly-enoic fatty ac id content and to the presence of pro-oxidant substances. The hydrolytic de gradation, otherwise, resulted moderate.