Investigation into migrational and sensorial changes of packaging plasticscaused by ionising irradiation

Modern food and packaging technologuses ionising irradiation to control ins ects and micro-biological contamination of packaged food. Also pre-sterilis ation of packaging materials with ionising irradiation in combination with aseptic packaging is applied. In view of consumers care, irradiation of pac kaging materials must not have any negative effects on the food quality, Th e aim of this study was to investigate migrational and sensorial changes of plastics packaging materials caused by gamma -irradiation with different i rradiation doses. Various packaging plastics (two LDPE types, two PP types, PET, PA, PVC and two bag-in-box systems) were treated with irradiation doses between 7 kGy a nd 56 kGy in a commercial irradiation plant. Subsequently, migration into d ifferent food simulants and alternations in the sensory properties were inv estigated als well as the amount of volatile substances by headspace gas ch romatography. As a result, the overall migration into food simulants an the extraction with iso-octane and ethanol, respectively, did not show signifi cant changes effected by irradiation treatment up to doses of 56 kGy, In al l cases, overall migration was below or far below of the migration limit of 10 mg.dm(-2) given by EU regulations. Volatiles formed during the irradiat ion process, however, affected the sensory properties of the investigated p ackaging films, A typical off-odour occurred after irradiation with increas ing irradiation dose and the concentrations of volatile substances correlat ed with the increasing off-odour.