INCORPORATION OF NANOCLAY AND ORANGE PEELS EXTRACT INTO PLA FOR FOOD APPLICATIONS: MIGRATION ASSESSMENT

摘要

This research investigated the overall and specific migration from two different formulations of PLA: one obtained with addition of nanoclay as a filler (PLA_Clay), and another one obtained with the addition of an antioxidant extract from waste orange peels (OPE) as an active component for food application (PLA_OPE). Overall migration was always below the current European limit of 10 mg/dm2 set for food contact materials (maximum 0.2 mg/dm2 from PLA_Clay into distilled water and 2.7 mg/dm2 from PLA_OPE into 3 % acetic acid). Specific migration of clay elements and particles from PLA_Clay was evaluated by different techniques (atomic absorption spectroscopy, SEM and SEM microanalysis). A very limited release of clay elements was measured, with the highest migration found for calcium. SEM observation showed the release of particles also of size < 1 μm. The migration testing conditions of 10 days at 40 °C showed a swelling of the PLA which was enhanced by nanoclay presence. A maximum 2.5 % of the phenolic compounds of the incorporated OPE were released in the simulant 20 % ethanol, which is compatible with the fact that the OPE had been obtained through aqueous ethanol extraction.