Polycyclic Aromatic Hydrocarbons (PAHs) in Edible Oil: Temperature Effect on Recovery from Base Hydrolysis Product and Health Risk Factor

This study investigates the concentration levels of selected priority PAHs; Phenanthrene (Phe), benzo[a] pyrene (BaP) and benzo[k] fluoranthene (BkF) in three brands of refined edible seed oils (30 samples). The samples were hydrolyzed in methanolic potassium hydroxide, and the PAH extracted in n-hexane according to standard methods. The PAH extracts were cleaned using solid phase extraction (SPE), and then separated and quantified using a GC-FID (Schimadzu-2010 plus). Results showed that the concentrations of PAHs detected in the different edible seed oils varied. The mean concentration of the PAHs in edible oil derived from a blend of sunflower and soya bean seeds (S-blend) were the least and ranged; BaP, 1.95±0.15μg/kg and BkF, 2.12±0.30μg/kg. The mean concentration of BaP and BkF in edible oil SA1ranged, 2.13±0.45μg/kg and 1.90±0.42μg/kg, respectively, and 1.71±0.35μg/kg and 4.46±0.41μg/kg, respectively in extract obtained from SA2. Edible oil sample SA2 had the highest concentration of BkF 4.46 μg/kg, while SA1 had the highest concentration of BaP 2.13 μg/kg. The recovery of the evaluated PAH fractions obtained from low temperature hydrolysis product were the highest compared to those obtained at higher temperatures. The effect of temperature on the recovery of PAHs from alkaline hydrolysis products, and the potential consequences of dietary exposure were also discussed.