Effect of preparation method and edible oil type on the formation of PAHs in popcorns

In this study, the effects of different popcorn-making techniques on the occurrence of PAH4, PAH16, the sum of light PAHs, the sum of heavy PAHs, and also individual PAHs were determined in popcorns. For this purpose, popcorns were prepared using different oils including refined pomace oil (ROP), refined corn oil (RCO), refined sunflower oil (RSO), refined olive oil (ROO), and virgin olive oil (VOO), with and without salt by traditional heating in a pot and microwave heating for 1, 2, and 3 min. Results revealed that popcorn preparation techniques had a significant effect on PAH concentration. Although prolonged microwave heating caused an overall decrease in PAH16 levels due to volatilization and thermal degradation of low molecular weight PAHs, the formation of thermally stable high molecular weight PAHs, particularly PAH4 compounds, increased under extended heating conditions. Besides, high amounts of PAH4 and PAH16 were observed in the samples prepared with heating in a pot. While the heavy PAHs increased with an increment in the temperature level of microwave application, the light PAHs showed a decrease. Similarly, the heavy PAHs' content increased with the increase of application time in the microwave, while a decrease was observed for the light PAHs. Popcorn samples prepared by ROP contained a higher amount of PAH4 (2.04 µg/kg) and PAH16 (64.19 µg/kg) compared to other oils used. Besides, the samples prepared with ROP contained higher content of AN and FL as light PAHs, and also FA and PY contents were observed at higher levels as heavy PAHs. Regarding the preparation method, AN and FL had higher values as light PAHs, which were found in the samples prepared with the traditional method and also microwave-heated for 3 min. Besides, FA and PY as heavy PAHs occurred at higher levels in the samples prepared with the traditional method.