Migration of contaminants by gas phase transfer from carton board and corrugated board box secondary packaging into foods

Abstract

The gas phase transfer of substances from carton board (CB) and corrugated box board (CBB) through intervening layers to foods was studied. Substances covering a boiling point range of 252-425 degrees C and a range of polarities were incorporated into CB and CBB secondary packaging. Benzophenone was present in some CB materials. Where it was not already present in CB or CBB secondary packaging, it was deliberately incorporated for transfer studies. Transfer of substances was measured in nine foodstuff types stored in the secondary packaging at ambient and sub-ambient temperature. The foods were packaged in primary packaging materials that would be used in retail. Two food types were packed and stored in both single- and multipack formats. Foods were sampled at 0, 10, 30, 90 and 200 days and analysed by gas chromatography-mass spectrometry after high-performance size exclusion chromatography clean-up. Percentage transfer was between 0 and 100%. The overall trends were increased transfer of substances with increased storage time; a more rapid transfer of the more volatile substances compared with the less volatile ones and higher levels of transfer of the more volatile substances. No transfer of diheptyl phthalate (DHP) (bp 425 degrees C) as an incorporated substance was detected to any foods over the test period. The presence of an additional layer of packaging (multipack versus single pack) was shown to reduce transfer up to fourfold over 200 days and to increase the lag period for transfer. In terms of slowing transfer, metallized PP/PP laminate proved a more effective barrier than PP which was more effective than paper. It is postulated that there is a cut-off threshold for transfer at ambient and sub-ambient temperatures. Substances that are less volatile than the cut-off are anticipated not to transfer from secondary packaging to foods stored for up to 200 days, where the substances are present in the packaging at or below the levels tested in this study (up to 1 mg dm-2). In this study the volatility cut-off threshold lay between that of 2,2-dimethoxyphenylacetophenone (2,2-DMPAP) (an incorporated substance with bp 352 degrees C) and DHP. Ideally, the cut-off threshold should be expressed in terms of vapour pressure in the packaging material. In practical terms, it may be more appropriate to express as partition coefficient as this is simpler to determine experimentally.

Modelling migration from paper into a food simulant

“…The more volatile substances partitioned more readily in the air at any temperature, presenting a lower partition coefficient (Triantafyllou et al, 2002(Triantafyllou et al, , 2005. However, data seem to indicate that there is not a linear relationship between the boiling point of a substance and its partitioning behaviour (Haack & Franz, 2000;Jickells et al, 2005). The retention behaviour of the substance in the paper matrix depends also on its interaction with fibres surface and, as mentioned before, the cellulose fibres have an overall negative charge due to carboxyl groups from the carbohydrates and the hydroxyl groups of the lignins.…”

“…When there is a head-space in the package over the product, the foods tested show similar migration patterns and final migrant concentrations, regardless of the foods characteristics. In indirect contact, the presence of an additional layer of packaging between the outer secondary packaging and the inner primary packaging was shown to reduce transfer of migrant into food and hence to increase the lag time observed for the transfer of migrant from packaging to food (Jickells, Poulin, Mountfort, & Fernàndez-Ocaña, 2005).…”

Determination of 2,6-diisopropylnaphthalene (DIPN) andn-dibutylphthalate (DBP) in food and paper packaging materials from US marketplaces

“…The concentration levels of DIPN in paperboard range from 2.30 to 62.5 mg kg À1 and it can migrate into food via direct contact or gas phase transport. When the concentration of DIPN in tested paper reached 20 mg kg À1 , its migration to food was detected (Mariani et al 1999;Summerfield and Cooper 2001;Jickells et al 2005), which suggests a potential for contamination of food above the 20 mg kg À1 level. In a number of incidents, phthalates are another type of contaminant often found in food packages.…”

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“…The signalling of 2,6-DIPN was performed on scientific literature because it was detected in foods and food packages [9,10]. As a well-established conservation practice, recycled paper and board products have been used as food-packaging materials in the USA and Europe.…”