Investigation of the Safety of Polyethylene Terephthalate/Aluminium Foil/Polyamide/Retort Cast Polypropylene Composite Film Packaging Pouches for Prepared Dishes

The full chain of prepared dishes involves hot filling into the package and high‐temperature steaming with packaging, which may lead to more migrants from the package into the prepared dishes due to the high temperature. This study focused on the safety of the prepared dishes packaging. First, migration tests were designed to fully simulate the entire contact process between polyethylene terephthalate/aluminium foil/polyamide/retort cast polypropylene (PET/Al/PA/RCPP) composite films packaging pouches and prepared dishes throughout the full chain, based on GB 31604.1‐2023. A comparison was made with room temperature simulation tests to investigate the effects of high temperature on migrants. Gas chromatography‐mass spectrometry (GC‐MS) and ultra‐high‐performance liquid chromatography quadrupole time‐of‐flight mass spectrometry (UPLC‐QTOF‐MS) were used for the non‐target screening of the migrants. A total of 17 non‐volatile compounds were identified in the full‐chain simulation, while only seven were detected in the room temperature simulation. Especially, the oligomers of inner polyamide 6 (PA 6) migrated through the RCPP layer into the simulants. Principal component analysis (PCA) and orthogonal partial least squares‐discriminant analysis (OPLS‐DA) were employed to visualize differences in migrants between the full‐chain and room temperature simulation. Based on the quantitative analysis, risk assessment was conducted. Ethylene glycol adipate cyclic oligomers exceeded the toxicological concern threshold under full‐chain simulation, necessitating more refined risk assessment approaches. These results confirm that high temperature promotes the migration of substances from the packaging, suggesting that prepared dishes should avoid hot filling in the future. If conditions allow, consumers had better not heat them in their packaging to minimize exposure to migrants.