Effect of microwave, deep frying and oven cooking on destruction of zearalenone in spiked maize oil

Mycotoxins are one of the most common types of chemical hazards related to edible oils. Although the refining process can remove such contaminations, they may still be present in the final oils due to defects during the refining steps. In addition, most oils produced in local manufactories are not refined and as such may be contaminated with mycotoxins. However, the effect of various cooking methods on the stability of mycotoxins in edible oils has rarely been studied. Hence, this study evaluated the impact of microwave, deep frying and oven cooking on the degradation of spiked zearalenone (50, 100 and 200 μg/l) in maize oil. Measurements were done by high performance liquid chromatography-fluorescence detection. The results showed that the majority of treatments, including time-temperature combinations of frying (130-190 °C for 2.5 and 5 min), oven cooking (110-230 °C for 2.5 and 5 min) and exposure time of microwave (2.5, 5 and 10 min) reduced zearalenone levels. Microwave cooking of samples containing 200 μg/l of zearalenone for 10 min showed the highest degradation of the toxin (~ 38%) following first order kinetics. The extent of destruction achieved by frying and oven cooking was also dependent on the initial concentration of zearalenone. These findings can be helpful to evaluate the chemical safety of edible oils or foods prepared by them.