Behavior of Polycyclic Aromatic Hydrocarbons Generated by Thermal Cooking

Abstract

The generation of polycyclic aromatic hydrocarbons (PAHs) by thermal cooking was evaluated depending on the main components of foods, i.e., carbohydrate, protein and fat contents. Seven foods were tested for grilling and the cooking exhaust was collected. Then the PAHs in the exhaust gas were analyzed. The concentrations of particulate PAHs in the cooking exhaust of low-fat foods such as scampi, sasami chicken and corn were lower, whereas much higher concentrations of PAHs were observed in the cooking exhaust of rich-fat foods such as rainbow trout and pork. Phenanthrene, fluoranthene and pyrene were the dominant components of PAHs, accounting for 53 to 62% to the total PAHs, regardless of food types. The concentration of PAHs in the cooking exhaust was positively correlated to the amount of fat in the food, however not with the amount of carbohydrates and protein. From the results above, it was indicated that the concentration of PAHs in the cooking exhaust was estimated by the amount of fat in the food, regardless of food type. Furthermore, the behavior of PAHs generated by pork grilling was evaluated, showing that only 0.02% of the PAHs generated were estimated to be residual in the food. Almost all of the PAHs generated were transferred to the gas phase and 53% of those were emitted to the outdoors while 47% were removed by the ventilating fan filter.