GLOBAL AND SPECIFIC MIGRATION OF ANTIOXIDANTS FROM POLYPROPYLENE FILMS INTO FOOD SIMULANTS

Global migration and specific migration of antioxidants (AOs)-Irgafos 168 [tris(2,4-di-tert-butylphenyl) phosphite], Irganox 1076 [octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl-propionate], and Hostanox SE2 (d isteary thiodipropionate) - from polypropylene (PP) films into food si mulants (water, 3% acetic acid, 95% ethanol, olive oil, and heptane) w ere studied. Films (50, 100, and 200 mu m thick) were exposed to simul ants at temperature-time conditions simulating migration under retorti ng and long-term storage. Global migration into aqueous simulants was independent of film thickness and conditions of exposure, so it seems as if the migration process was limited to the dissolution of migrants on the contacting surface. Global migration to fatty food simulants w as dependent on simulant, conditions of exposure, and in some cases fi lm thickness. Specific AO migration was analyzed from dry residues obt ained from global migration analysis. Migration of AOs into aqueous si mulants was below the detection limit (0.01 mg/dm(2)). Migration into fatty food simulants was dependent on the simulant. The extractive pow er of simulants was similar to that observed in global migration studi es. Specific migration into heptane was independent of the polymer mas s, though dependent on the thickness. Migration into ethanol was depen dent on both mass and thickness. A theoretical discussion about the co ntroversial effect of thickness on migration results, based on the kin etics of the process, is presented.