## 3 Results and Discussion
### Hazardous Compounds in WOF  
The formation of potential carcinogens needs to be examined in fried foods because the frying process involves exposure to high temperatures. PAHs and acrylamide are known as typical carcinogenic compounds in fried foods. This study investigated how the changes in PAHs and acrylamide contents in WOF samples varied with the different frying temperatures and types of frying oil.  
PAHs are a class of organic compounds that are produced through the incomplete combustion or pyrolysis of organic matter [5]. Monounsaturated hydrocarbons in oils and fats undergo aromatization and dehydrocyclization, favoring the formation of PAHs and, therefore, also the contamination of foodstuffs processed using these oils [6; 30]. Table 1 lists the amounts of eight PAHs in WOF samples for different frying temperatures and for different types of vegetable oils. All PAHs were detected in WOF produced using soybean oil, while no PAHs were found in WOF samples prepared using corn and canola oils. Moreover, some PAHs, such as B[b]F, I[c,d]P, D[a,h]A, and B[g,h,i]P, were found in this study in WOF samples produced using palm oil. In general, unsaturated fatty acids are considered to produce more PAHs due to their structure, making it easier to form free radicals and/or small molecules compared with saturated fatty acids [31]. However, in this study, PAHs were not detected in WOF samples produced using corn and canola oils, which have higher proportions of unsaturated fatty acids than soybean and palm oils. In general, all PAHs studied were found to be not detected or at trace (or very low) levels regardless of oil types and heating temperatures. The type of vegetable oil was sensitive to the formation of some PAHs, although it was not significantly affected by heating temperatures in this study.  
samples at 140 \({}^{\circ}\)C. However, it was formed only in soybean oil at 165 \({}^{\circ}\)C, whereas it was found in all samples at 190 \({}^{\circ}\)C. Based on these results, it might be considered that the formation of acrylamide was considerably influenced by both heating temperatures and oil types.  
To ensure the safety of PAHs in edible oils, the European Union (EU) has established a limit of 10 \(\mathrm{\SIUnitSymbolMicro g}\)/kg for the total amount of PAH4 (B[a]A, CHR, B[b]F, and B[a]P) and 2 \(\mathrm{\SIUnitSymbolMicro g}\)/kg for B[a]P in vegetable oils. The KMFDS has similarly established a limit of 2 \(\mathrm{\SIUnitSymbolMicro g}\)/kg for B[a]P in all edible oils. The amounts of PAHs in all of the samples analyzed in this study were within the EU and KMFDS limits. Acrylamide formation in foodstuffs varies greatly depending on the temperature and duration of processing. International organizations such as the World Health Organization (WHO) and the Codex Alimentarius Commission (CODEX) have not established international standards for acrylamide in edible oils. In 2021 the KMFDS set recommended standards for acrylamide in infant food (\(\leq\)0.3 mg/kg), cereals (\(\leq\)0.3 mg/kg), snacks (\(\leq\)1 mg/kg), French fries (\(\leq\)1 mg/kg), coffee beans (\(\leq\)0.8 mg/kg), processed grains (\(\leq\)1 mg/kg), and instant foodstuffs (\(\leq\)1 mg/kg), but these do not address edible oils. Under the conditions used in the present study, acrylamide was detected at 36.46 \(\mathrm{\SIUnitSymbolMicro g}\)/kg in the WOF samples. The present results can therefore be used to develop legal regulations on hazardous compounds for frying oils used with Allium species, as well as forming the basis for research into the industrial processing of Welsh onion fried.