Determination of the levels of polycyclic aromatic hydrocarbons in toasted bread using gas chromatography mass spectrometry.

Concentration of 16 polycyclic aromatic hydrocarbons (PAHs) in eighteen baked bread samples using gas oven toasting were evaluated in this study. Samples were classified into the following categories: (1) bread baked from white wheat flour, (2) bread baked from brown wheat flour, and (3) sandwich bread baked from white wheat flour. Analysis was performed by GC-MS after Soxhlet extraction of the sample and clean up of the extract. The levels of B[a]P was not detected in ten of eighteen samples. In the rest of the samples, B[a]P are varied from 2.83 to 16.54 μg/kg. B[a]A, CHR, B[b]FA, B[k] FA, IP, DB[a,h]A, and B[ghi]P concentrations were found to be less than 10.0 μg/kg. However, B[a]P are not detected in original white and brown wheat flour. The total PAHs were varied in the range 1.06-44.24 μg/kg and 3.08-278.66 μg/kg for H-PAH and L-PAH, respectively. Reproducibility and repeatability of the proposed method was calculated and presented in terms of recovery and relative standard deviations (RSD, %). Recoveries were varied from 72.46% to 99.06% with RSD ± 0.28-15.01% and from 82.39% to 95.01% with RSD ±1.91-13.01% for repeatability and reproducibility, respectively. Different commercialized samples of toasted bread were collected and analyzed.