Study on mass transfer ways of UV printing ink ingredients into foodstuffs

Teelke Jung (1) , Thomas Joachim Simat (2) , Werner Altkofer (1)

1 CVUA Stuttgart
2 Chair of Food Science and Food Contact Materials

The ITX case (isopropylthioxanthone) showed conclusively that ingredients of UV inks may migrate into packaged foodstuffs. For multi-layered materials like beverage cartons the only way that mass transfer can occur is by the so called set-off effect. In contrast, in the case of rigid plastics like yoghurt cups, two other methods of mass transfer, permeation and gas phase, have to be considered. In cooperation with producers of ink, plastic cups and yoghurt, a project was conducted in order to elucidate the mass transfer of ink ingredients. In addition, the influence of storage time and age of UV lamps on the migration level was examined. The suitability of 50% ethanol as a simulant for yoghurt was tested, as well. ITX was chosen as a model migrant, as it is easily detectable. Furthermore, the migration of two other substances, the photoinitiator 2-methyl-4'-(methylthio)-2-morpholinopropiophe-none (MTMP) and the amine synergist ethyl-4-(dimethylamino)benzoate (EDAB), which may be used in combination with ITX, was studied. Prior to being filled with yoghurt or 50% ethanol the printed cups were stored under different contact conditions, with and without contact between the inner layer and printed surfaces, in order to distinguish between the possible mass transfer ways. All analyses were performed by means of HPLC-DAD/FLD. It was shown that contamination with ITX and EDAB occurs via set-off and that the degree of migration increases with lamp age and storage time of the unfilled cups. Migration of MTMP was not detectable. The results show, that besides the careful selection of the appropriate raw materials for printing ink, a close monitoring of the process also plays a major role in migration control. In addition, the results proved that 50% ethanol is a suitable simulant for yoghurt.

Mots clés: Life Sciences

Teelke Jung, Thomas Joachim Simat, Werner Altkofer. Study on mass transfer ways of UV printing ink ingredients into foodstuffs. Food Additives and Contaminants, 2010, 27 (07), pp.1040-1049. ⟨10.1080/19440041003596543⟩. ⟨hal-00598953⟩