Processing effects on the polyaromatic hydrocarbon content of grapeseed oil

Grapeseed oil can occasionally have dangerous levels for human health of polycyclic aromatic hydrocarbons (PAH) due to the drying process, which involves direct contact with combustion gases. Oil samples extracted from grapeseeds before and after drying were analyzed for their PAH content with a new, fast, bi-dimensional liquid chromatography method. Samples collected before drying had relatively high PAH amounts; Benzo(a)pyrene (BaP) content ranged from 0.9 to 2.4 ppb with an average of 1.4 ppb. The high contamination level found in the raw material is probably due to the practice of compacting pomace with bulldozers to reduce its volume before storage. The drying process did not significantly influence the light PAH content, but caused a large increase of the heavy fraction. BaP with an average content of 20.2 ppb, had the largest increase.