## 4 PAH Occurrence and Formation in Processed Meat, Edible Oils, and Cereal-Derived Products
### Features Underlying PAH Formation in Cereal and Cereal-Derived Products
Similarly, the PAH content was lower in traditional Iranian Lavash (9.46-152.07 \(\mathrm{\SIUnitSymbolMicro g}\)/kg) and Taftoon (18.19-169.26 \(\mathrm{\SIUnitSymbolMicro g}\)/kg) bread baked for 2.5 min at 315 \(\mathrm{\SIUnitSymbolCelsius}\) in comparison with industrial baquette bread baked for 14 min at 245 \(\mathrm{\SIUnitSymbolCelsius}\) (20.78-228.98 \(\mathrm{\SIUnitSymbolMicro g}\)/kg), which may be attributed to the time-temperature settings of the thermal process [126]. The effect of the baking method on the PAH content in bread displayed reduced contamination in tandoori bread based on a plate (tawa plate) by up to 71.7% when compared to those baked in the oven [127]. In addition, toasting entails variations in PAH accumulation depending on the heating source. No PAHs were detected in electric-oven-baked bread compared to 350 \(\mathrm{\SIUnitSymbolMicro g}\)/kg when using a toaster. Additionally, switching from coal to oak could favor a reduction in PAH levels in toasted bread [156]. In youtiao (wheat-based fried stick), PAH levels between 9.9 and 90 \(\mathrm{\SIUnitSymbolMicro g}\)/kg were found [204]. Moreover, the temperature effect emphasized lower PAH levels in youtiao fried at 160 \(\mathrm{\SIUnitSymbolCelsius}\), as opposed to 170-200 \(\mathrm{\SIUnitSymbolCelsius}\), which generated an increase of up to 30% [5]. In addition, the effect of time was assessed through continuous frying. PAH concentrations in youtiao fried in soybean oil were measured to be 22.25 \(\mathrm{\SIUnitSymbolMicro g}\)/kg PAHs at 2 h, followed by a subsequent decrease in the 4 h-8 h interval (2.01-3.63 \(\mathrm{\SIUnitSymbolMicro g}\)/kg), which was attributed to degradation processes. However, replacing soybean oil with shortening oil resulted in significantly lower PAH levels, irrespective of time [5]. Although addressed in the previous sections covering PAH formation in meat products and vegetable oils, the effect of cooking oil on PAH formation also extends to cereal products. In conjunction with antioxidant extracts, marked changes were observed in youtiao fried in soybean and palm oil [130]. The presence of rosemary extract, tea polyphenol, and bamboo antioxidants in soybean oil showed 23.47%, 11.38%, and 28.85% inhibition of total PAHs in comparison to the 30.30% induced by tert-butyl hydroquinone (TBHQ) in fytouta. The same antioxidant compounds included in palm oil also exerted changes in PAH reduction (27.56%, 9.45%, and 39.26%) in fried youtiao, distinct from those enabled by TBHQ (38.94%) [130]. Other forms of cereal-based products, such as biscuits, including shortcake, digestives, cookies, shorthead, wafers, and crackers, showed variable PAH concentrations (35.7-645.3 \(\mathrm{\SIUnitSymbolMicro g}\)/kg, 75.9-490.7 \(\mathrm{\SIUnitSymbolMicro g}\)/kg, 91.5-537 \(\mathrm{\SIUnitSymbolMicro g}\)/kg, 18.4-522.2 \(\mathrm{\SIUnitSymbolMicro g}\)/kg, 123.5-393.8 \(\mathrm{\SIUnitSymbolMicro g}\)/kg, and 167.2-880 \(\mathrm{\SIUnitSymbolMicro g}\)/kg), stemming from differences in the employed baking methods, along with the choice of fuel type, oven conditions, and raw materials [205]. With fairly high popularity, pasta, including noodles, spaghetti, and macaroni, among others, contains variable PAH concentrations, ranging from 9 to 800 \(\mathrm{\SIUnitSymbolMicro g}\)/kg in Nigerian brands and 2 to 7 \(\mathrm{\SIUnitSymbolMicro g}\)/kg in imported brands [133]. Similarly, [PERSON] et al. (2018) found total PAHs ranging from 0.564 to 7.889 \(\mathrm{\SIUnitSymbolMicro g}\)/kg in noodles from a Nigerian market [134]. Moreover, fried noodles displayed approximately 3-fold higher PAHs than unfried noodles in a Vietnam market [132]. Aside from the operational conditions employed during processing, cereal and cereal-derived products (e.g., flour and bread) undergo PAH contamination through the deposition of atmospheric particles, as well as through polluted water and soil [125].