Effect of Excess Air Levels on PAHs Content in Smoke During Charcoal Combustion in Grilling Process

Abstract

Charcoal grilling may lead to carcinogenic PAHs contamination of grilled food from incomplete combustion of charcoal. The objective of this study was to determine the effect of complete combustion of charcoal on PAHs content in smoke during the grilling process. Firstly, proximate and ultimate compositions of the charcoal were determined to identify the amount of air required for combustion according to stoichiometry. Different excess air levels consisting of stoichiometric air, 60, 100 and 150% excess air during combustion of charcoal on 16 PAHs released in smoke were studied. Moreover, CO and CO₂ concentrations were measured. The use of excess air decreased the emission factor of CO and increased the emission factor of CO₂. The 16 PAHs contents in smoke produced from charcoal combusted with stoichiometric air, 60, 100 and 150% excess air were 73.62, 51.78, 27.68 and 19.23 μg/kg dry charcoal, respectively. The use of excess air during charcoal combustion resulted in significantly lower PAHs contents in the smoke. Therefore, the use of excess air during charcoal grilling is one way to reduce the risk of PAHs contamination in grilled food.