The Effect of Fatty Acids and Meat Oils Combustion on PAH Formation in Smoke during Grilling Process

Oil droplets from foods can cause the formation of Polycyclic Aromatic Hydrocarbons (PAHs) in smoke and contaminate grilled food. The aim of this research was to examine the effect of the number of carbon atoms, degree of double bonds, and types of fatty acids on the formation of PAHs in smoke during grilling process.

Four fatty acids consisting of palmitic acid, stearic acid, linoleic acid, and oleic acid, and three animal oils consisting of chicken skin oil, beef oil, and striped catfish oil had been studied. The smoke obtained during the combustion of fatty acids and animal oils was collected in a PUF/XAD-2/PUF absorption tube, and the analysis of 16 major PAHs was done using Gas Chromatography-Mass Spectroscopy (GC-MS). The experiments were conducted in three replicates.

Linoleic acid and oleic acid generated relatively higher concentrations of PAHs in the smoke, at 48.53 and 46.81 ppm, while stearic acid and palmitic acid provided PAHs in the smoke at 6.15 and 3.87 ppm. The rank of the highest PAH concentration levels in order of decreasing in smoke included striped catfish oil, chicken skin oil, and beef loin oil, with values of 50.22, 35.07, and 33.62 ppm, respectively. A variety of fatty acids were found in animal oils, but some fatty acids, such as arachidic acid (20:0), mead acid (20:3), behenic acid (22:0), erucic acid (22:1), cervonic acid (DHA) (22:6), lignoceric acid (24:0), and nervonic acid (24:1), were not found in chicken skin oil or beef oil. Fatty acids in the striped catfish oil had longer carbon chains (20:0, 20:3, 22:0, 22:1, 22:6, 24:0, 24:1) compared to other animal oils and a higher degree of double bonds, thus giving a higher PAHs concentration.

It can be concluded that PAH concentration present in the smoke of animal oils depends on the number of carbon atoms, the degree of double bonds in the molecules, and the types of fatty acids.