## 3 Results and Discussion
### Migration and Risk Assessment  
The migration of potential volatile compounds from active TPS/PBAT biodegradable packaging containing food preservatives into food simulants was investigated using headspace solid-phase microextraction in combination with a gas chromatography coupled to a mass spectrometric detection (HS-SPME-GC-MS). The food simulants used were simulant D2, simulant C, and simulant B, selected to predict the behavior of this packaging in contact with various types of food [19; 36; 38]. The analysis identified two volatile migrants after exposure to 95% ethanol: glycerin (10.33_92.05), 1,6 Dioxacyclododecane-7,12-dione (18.47_200.10), (Table 4). No migrants were detected in the 10% ethanol and 3% acetic acid simulants. The quantification of volatile compounds was performed using calibration curves generated from standard compounds. Quantification of 1,6-dioxacyclododecane-7,12-dione was performed using calibration curves derived from 1,4,7-trioxacyclotridecanecan-8,13-dione as the standard. The limits of detection (LOD) and quantification (LOQ) are presented in Table 4. These values were determined using the signal-to-noise ratio (S/N) method, where the LOD corresponds to an S/N ratio of 3, and the LOQ corresponds to an S/N ratio of 10. The risk assessment was primarily based on the specific migration limits (SMLs) established by European Commission Regulation (EU) No 10/2011. For compounds not listed in the regulation's positive list, the Threshold of Toxicological Concern (TTC) approach was applied. The TTC method is used to evaluate the safety of substances migrating from food contact materials when specific toxicological data are unavailable, as recommended by EFSA. Each compound was classified into one of the Cramer classes (I, II, or III) based on its chemical structure, with each class being assigned an exposure threshold [39]. The estimated exposures were compared to the TTC threshold and its derived SMLs. If the migration level remained below the derived SML, the compound was considered safe; otherwise, further toxicological evaluation would be required. In this study, the migrant 1,6 Dioxacyclododecane-7,12-dione was classified as Risk I (limit of Cramer Class I of 1.8 mg/person/day and TTC values for Class I), which generally indicates low toxicity. The TTC approach offers a conservative estimate of the acceptable daily intake by considering structural features and assigning a maximum intake level (TTC value) that is unlikely to pose health risks [25; 26; 34]. The migration level of 1,6-dioxacyclododecane-7,12-dione from active TPS/PBAT films was 9.14 \(\pm\) 1.16 mg/kg, which did not exceed the TTC value under the assumed consumption scenario. Additionally, glycerin--listed in the positive list of Regulation (EU) No 10/2011--has a specific migration limit of 60 mg/kg. The observed migration levels of glycerin in all samples remained below this regulatory threshold. Specific migration of non-volatile compounds from the active TPS/PBAT film was determined by UHPLC-Q-TOF-MS, as shown in Table 5. The analysis identified 33 non-volatile migrants, primarily consisting of linear and cyclic PBAT oligomers. A cyclic ester oligomer composed of diethylene glycol and adipic acid was used as a standard for oligomer quantification. Its purity and molecular structure were confirmed by nuclear magnetic resonance (NMR) analysis, conducted at the University of Zaragoza. As these oligomers are not listed in Commission Regulation (EU) No 10/2011 (2011), the Threshold of Toxicological Concern (TTC) approach was applied, as previously described. The results showed a maximum migration level of 0.98 \(\pm\) 0.02 ug/g, which remained below the established safety threshold. Nevertheless, the toxicity of oligomers has become an issue of increasing concern. All of these compounds are classified as NIAS and their actual toxicological profiles remain largely unknown.