Occurrence of C15-C45 mineral paraffins in olives and olive oils.

Different classes of olive oils and other olive samples (olives, olive paste and olive pomace) collected during their production were analysed for mineral paraffins in the range of C(15)-C(45). None of the 22 extra virgin olive oils contained mineral paraffins above the detection limit of 1 mg kg(-1). Also, lampante virgin olive oil from the olive mill showed no detectable amounts, but olive oil from the market contained 6-30 mg kg(-1). This contamination cannot be attributed to the refining step, which, on the contrary, partially removes the more volatile hydrocarbons, but could result from transport. Olive-pomace oils obtained by second centrifugation contained 16-145 mg kg(-1) mineral paraffins, presumably because of contamination during storage of the pomace. All olive-pomace oils from solvent extraction contained more than 100 mg kg(-1) mineral paraffins, also mainly from storage. Deposition of particulate matter from the air, vehicle exhaust emissions and direct contamination from the bulldozers used to move the pomace were identified as potential sources.