Mineral oil in sunflower seeds: the sources

All sunflower oils previously analyzed were found to be somewhat contaminated with mineral oil. Now sunflower seeds harvested manually or mechanically, sampled from the field to the drying at the collection centers, were analyzed in order to determine the sources. The composition of the mineral oil saturated hydrocarbons in the hand-picked seeds suggested the presence of mainly lubricating oil from the atmosphere. Referring to the oil in the seeds, concentrations ranged from 0.1 mg/kg in a rural area of Switzerland to 2.4 mg/kg near the town of Zurich. Harvesters contaminated the seeds with up to 7 mg diesel oil/kg oil and up to 11 mg/kg lubricating oil. The drying in one of the collection centers added 30-40 mg/kg fuel oil. It is surprising how little attention is paid to food contamination by mineral oil products despite concentrations widely exceeding the acceptable daily intake specified by the WHO/JECFA.