Mass transfer ways of ultraviolet printing ink ingredients into foodstuffs.
The case of isopropylthioxanthone (ITX) showed conclusively that the ingredients of ultraviolet printing inks may migrate into packaged foodstuffs. For multilayered 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 the age of ultraviolet lamps on the migration level was examined. The suitability of 50% ethanol as a simulant for yoghurt was also tested. ITX was chosen as a model migrant, as it is easily detectable. Furthermore, the migration of two other substances, the photo-initiator 2-methyl-4'-(methylthio)-2-morpholinopropiophenone (MTMP) and the amine synergist ethyl-4-(dimethylamino)benzoate (EDAB), which may be used in combination with ITX, was studied. Before 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 the printed surfaces, in order to distinguish between the possible mass transfer ways. All analyses were performed by means of high performance liquid chromatography with diode array and fluorescence detection (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.
Jung
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T
CVUA Stuttgart, D-70736 Fellbach, Germany. teelke.jung@cvuas.bwl.de
Simat
T J
TJ
Altkofer
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D010129:4-Aminobenzoic Acid / Q000032:analysis / Q000737:chemistry; D000327:Adsorption; D002851:Chromatography, High Pressure Liquid; D005506:Food Contamination / Q000517:prevention & control*; D005511:Food Handling / Q000379:methods; D005515:Food Labeling / Q000379:methods*; D018857:Food Packaging; D005740:Gases / Q000737:chemistry; D007281:Ink; D008029:Lighting / Q000379:methods; D057230:Limit of Detection; D008956:Models, Chemical; D009025:Morpholines / Q000032:analysis / Q000737:chemistry; D009994:Osmolar Concentration; D010969:Plastics / Q000737:chemistry; D011427:Propiophenones / Q000032:analysis / Q000737:chemistry; D015203:Reproducibility of Results; D013050:Spectrometry, Fluorescence; D013997:Time Factors; D014466:Ultraviolet Rays / Q000009:adverse effects; D044004:Xanthones / Q000032:analysis / Q000737:chemistry; D015014:Yogurt / Q000032:analysis; D062366:para-Aminobenzoates
D005740:Gases; D009025:Morpholines; D010969:Plastics; D011427:Propiophenones; D044004:Xanthones; C523330:ethyl 4-N,N-dimethylaminobenzoate; D062366:para-Aminobenzoates; C514852:isopropyl thioxanthone; C552725:2-methyl-4'-(methylthio)-2-morpholinopropiophenone; D010129:4-Aminobenzoic Acid