Determination of non-volatile components of a biodegradable food packaging material based on polyester and polylactic acid (PLA) and its migration to food simulants.

Bioplastic materials are increasingly used due to its benefits for the environment preservation. Among them, food packaging materials based on polylactic acid (PLA) are among the most employed. In this work, a sample treatment methodology based on dissolution/precipitation has been optimized, selecting finally dichloromethane/ethanol as solvent/antisolvent system. The extracts obtained were analysed by UPLC-MS(QTOF), that allowed the identification of the main PLA non-volatile components. The recovery results were between 100.9 to 114.0%. The methodology was applied to the analysis of pellets and films of a PLA-polyester blend sample. A total of 37 different compounds were detected, where the four compounds with the highest intensity in pellet samples were cyclic oligomers coming from the polyester part of the blend and composed by adipic acid (AA), phthalic acid (PA) and butanediol (BD). Migration experiments to 3 food simulants were also performed: ethanol 95% (v/v), ethanol 10% (v/v) and acetic acid 3% (w/v). The results showed that in addition to those compounds previously detected in the film, new compounds coming from the reaction of PLA components with food simulants were present in migration solutions.