EVALUATION OF THE MIGRATION POTENTIAL OF COLORANTS AND ADDITIVES IN PAPERBOARD FOOD PACKAGING MATERIALS

The increasing implementation of wastepaper collection and recovery has led to an increase in the use of recycled paper and board as food packaging materials. These materials, which are made entirely or partially from recycled fibres, are widely used for food packaging in Europe. However, the potential presence of contaminants in recycled pulp raises concerns about their suitability for food contact applications due to the potential for migration issues. In this study, three different paperboard food packaging materials from the Croatian market were tested for their chemical stability and migration of potentially harmful substances. The materials included a Kraftliner sample (made of predominantly virgin fibre pulp), a Brown Testliner sample (top ply made of virgin fibres, bottom ply made of recycled fibre pulp) and a printed French Fries Box (combination of deinked and mechanically recycled pulp). The French Fries Box also contained pigment coating and a partial internal print. The research focused on testing the migration of colorants (EN 646) and fluorescent whitening agents (FWAs) (EN 648) using food simulants such as olive oil, 3% (m/v) aqueous acetic acid, deionized water, isooctane and saliva simulant. In these test methods the test specimen is placed between two glass fibre papers previously saturated with the test liquids and, after the contact time at room temperature, the bleeding of the colorants or FWAs onto the glass fibre paper is evaluated. In addition, the potential transfer of antimicrobial components, indicating the potential toxicity of the material, was also evaluated by testing the growth inhibition of the bacterium Bacillus subtilis (EN 1104). The results of all analyzes performed were compared with the purity requirements for materials set out in the German national regulation and CEPI’s Food Contact Guidelines for the Compliance of Paper and Board Materials and Articles. The results of migration of colorants were observed only in the Testliner sample in cases where food simulants such as water, acetic acid and saliva solution were used. Unacceptable bleeding of FWAs was confirmed in the French Fries Box sample where the highest level of bleeding was observed in the case when food simulant was water, and to a slightly lesser extent FWAs migrated into glass fibre papers saturated with acetic acid and saliva food simulant. The results of the microbiological tests were positive, as no inhibition zones for bacterial growth were detected in any of the tested paperboards, meaning that none of the samples released antimicrobial substances.