Migration of additives from plastics films into edible oils and fat simulants

Abstract

The migration of two different additives from high-density polyethylene (HD-PE), from polyvinyl chloride (PVC) and from polystyrene (PS) into edible oils and fat simulants has been investigated using the radiotracer technique and contact times of 60 days at 20°C and 5 hr at 65°C. The 14C-labelled plastics additives used were Ionox 330 (1,3,5-trimethyl-2,4,6-tris-(3,5-di- tert-butyl-4-hydroxybenzyl[ 14C])benzene), Advastab (now Irgastab) 17 MOK (di- n-octyl[1- 14C]-tin-2-ethyl- n-hexyl dithioglycollate), stearic acid[1- 14C]amide and n-butyl stearate[1- 14C]. The edible oils used were Biskin (a partially hydrogenated groundnut oil), coconut oil, sunflowerseed oil, olive oil and butter. Synthetic triglycerides and organic solvents such as alkanes, di- n-alkyl ethers, methanol and paraffin oil were used as fat simulants. The measurements showed organic solvents to be unsuitable as general fat simulants. The migration values of an additive from a plastics film into different edible oils were so similar that one edible oil could serve as a simulant for all others. However, the presence of other naturally-occurring substances makes the analytical determination of migrated additives in edible oils very difficult, so a synthetic triglyceride mixture with extraction properties similar to those of coconut oil was developed to serve as a standard fat simulant. Analytical studies with this fat simulant, HB 307, proved its advantages over coconut oil. Its suitability as a standard fat simulant was confirmed in migration tests.