## 4 Discussion
Among the tested formulations, FPC + HNE-PLE showed superior mechanical and barrier properties, including higher TS, greater flexibility, and significantly lower water vapor permeability (WVP). These enhancements can be linked to the higher extraction efficiency of PLE (Table 2), which enabled the extraction of more plasticizing biocompounds from neem leaves compared to MAE. In contrast, FPC + HNE-MAE exhibited the lowest TS and highest WVP values, indicating reduced performance. The barrier properties of food packaging, especially WVP, play a crucial role in controlling moisture transfer and extending the shelf life of food products [35; 51; 52]. Lower WVP values are particularly desirable as they minimize water transfer between the food product and its surrounding environment [35; 53; 54; 55]. In this study, FPC + HNE-PLE significantly reduced the WVP of FPC (\(p\geq 0.05\)), while FPC + HNE-MAE did not cause any statistically significant changes (\(p\geq 0.05\)). This improvement with HNE-PLE can be attributed to PLE's ability to extract biomolecules with both hydrophilic and hydrophobic properties, resulting in an enhanced barrier effect. Consequently, FPC + HNE-PLE provided the lowest WVP value and emerged as the most effective material for food packaging applications requiring moisture control. Several studies have explored the mechanical and barrier properties of packages incorporated with phenolic compounds to application as intelligent films. To this end, [PERSON] et al. (2024) [56] demonstrated that roselle-based films had a tensile strength of 13.42 MPa and an elongation at break of 25.53%. In contrast, lithchi shell extract-based films exhibited enhanced mechanical properties, including a higher tensile strength of 18.60 MPa and a significantly greater elongation at break of 116%, along with improved barrier properties such as water vapor transmission rates of 1.62-1.65 \(\times\) 10-12 g-cm/cm\({}^{2}\)-Pa s [57]. [PERSON] et al. (2020) [58] reported that torch ginger-based films had the highest elongation at break (85.14%). Purple sweet potato anthocyanin films provided a tensile strength of 9.28 MPa and an elongation at break of 9.87% [59]. Anthocyanin-based films, [PERSON] and [PERSON] (2018) [60] highlighted cassava starch-based bioplastics reinforced with nanoclay, which showed an increase in tensile strength from 5.2 MPa to 6.3 MPa. When correlating the color results with the water vapor permeability (WVP) data (Table 3), it was observed that the incorporation of HNE-PLE into FPC significantly reduced its permeability (2.0 g\(\cdot\)mm/d\(\cdot\)m\({}^{2}\cdot\)kPa) compared to FPC alone (5.2 g\(\cdot\)mm/d\(\cdot\)m\({}^{2}\cdot\)kPa). The different treatments applied to the papayas are shown in Figure 14. Based on the results of the present study, the observed reduction in WVP likely influenced the respiratory metabolism of the papaya fruits, consequently contributing to the delayed ripening. A lower WVP could restrict both moisture loss and gaseous exchange across the fruit's surface, potentially limiting the availability of oxygen. This limitation in oxygen supply would be expected to result in a decreased respiratory rate. As respiration is a key metabolic process providing energy for various physiological changes during ripening, a slower rate could directly impact the biosynthesis and action of ethylene--a primary plant hormone that triggers and regulates fruit maturation. Therefore, the reduced gas exchange due to lower WVP likely suppressed respiration, leading to diminished ethylene production and a subsequent delay in the ripening process [61]. As suggested by [PERSON] et al. (2019) [62] and [PERSON] et al. (2020) [63], bioactive food packaging gradually releases active molecules into the surrounding environment or absorbs compounds that contribute to food spoilage. This mechanism helps delay the ripening process and minimizes water loss, thereby preserving the quality of the fruits during storage.