The influence of electron beam irradiation on antioxidants present in food packaging materials (OPP and LDPE) was studied. After irradiating the materials at dose levels of 2 , 5 , 1 0 and 25 kGy, w e have shown a partial disappearance of the antioxidant (Irganox 1010, lrganox 1076 and lrgafos 168) and a release of three compounds resulting from the antioxidants degradation related to the irradiation dose. Two of these degradation compounds have been analysed quantitatively: the 2,4-di-tert.-butyl-phenol and the 2,6-di-tert.-butyl-p-benzoquinone. The third compound is a phosphate resulting from a phosphite stabilizer (Irgafos 168).

The long-term influence of electron beam irradiation on food packaging materials (OPP) was studied. After irradiating the material at dose levels of 2, 5 and 10 kGy, w e have shown a partial or complete disappearance of the antioxidant (Irganox 1010 and lrgafos 168) over time and a release of five new compounds resulting from antioxidant degradation. All of these degradation compounds have been identified and quantitatively analysed in relation to post-irradiation time and absorbed dose. These results allow an explanation of the antioxidants' behaviour during storage of the irradiated polypropylene at room temperature.

The influence of electron beam irradiation on migrational behaviour of additives present in food packaging material was studied. The migration experiments were carried out on irradiated and non-irradiated polypropylene pouches containing aqueous food simulating liquids (FSL) for 10 days at 40 degrees C. The controls were irradiated and non-irradiated pouches without FSL contact. After the contact period, the polypropylene and the FSL were analysed. A comparison between the results obtained by the two analyses showed the migration of three products of antioxidant degradation from the polypropylene into the FSL, and a partial decomposition of these migrants in the FSL.

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