MIGRATION OF MINERAL HYDROCARBONS INTO FOODS .3. CHEESE COATINGS AND TEMPORARY CASINGS FOR SKINLESS SAUSAGES

Levels of mineral hydrocarbons which have migrated from wax coatings i nto cheese have been determined for 20 retail samples using a gas chro matographic procedure. Contamination was limited to the outermost 2 mm of cheese in direct contact with the wax where levels of hydrocarbons were found to range from 10 to 150 mg/kg. On a whole cheese weight ba sis these amounted to < 1 to 27 mg/kg (< 0.2 to 3 mg/dm2 contact area) . Components attributed to hydrocarbons in cheese samples remote from the waxed surface (background levels) were typically 3-5 mg/kg. Backgr ound levels were subtracted from the results for surface samples to ob tain migration values. There was evidence that the surface contaminati on of cheese with mineral hydrocarbons occurred by a combination of di ffusion into the cheese and adhesion of wax components onto its surfac e. Mineral hydrocarbons are used in the manufacture of the temporary c asings used to mould skinless sausages. Of 33 retail products examined , including skinless sausages, hot-dog sausages and frankfurters, 25 ( 75%) contained levels of mineral hydrocarbons from 10 to 105 mg/kg. Th ese hydrocarbons were shown to be present principally at the surface o f the food and so could be attributed to migration. Nine other minced meat products were examined for comparison, including minced beef, pat e, sausage meat and sausages with skins. Levels of mineral oil in thes e products were insignificant by comparison, typically below the limit of detection of ca 4 mg/kg, indicating insignificant adventitious con tamination from routes other than migration.