Bioactive Packaging Films Based on Chitosan and Supercritical CO ₂ Extraction From Pseuderanthemum palatiferum Leaves for Fresh‐Cut Apples Preservation

This research aimed to combine chitosan (CS) with Pseuderanthemum palatiferum extract (PPE) obtained by supercritical carbon dioxide extraction to fabricate active CS–PPE films. The CS–PPE films containing different concentrations were evaluated for physicochemical, biological activities, and fruit preservation properties. Films were analyzed via scanning electron microscopy and Fourier transform infrared spectroscopy, confirming the intermolecular interactions between chitosan and the bioactive compounds in the extract. The incorporation of extract reduced the swelling degree and light transmittance, whereas it significantly increased tensile strength and elongation at break ( p < 0.05). The CS films containing 10% PPE (CS–PPE10) exhibited antioxidant activity, scavenging 62.57% ± 1.01% of DPPH radicals, which was approximately 25 times higher than that of CS film. In addition, CS–PPE10 exhibited the largest inhibition zone against Escherichia coli (19.5 ± 0.6 mm) and Staphylococcus aureus (20.3 ± 0.6 mm). The CS–PPE films showed good preservation for fresh‐cut apples ( Malus domestica ) over 6 days of refrigerated storage at 4°C. CS–PP10 films reduced the loss of weight, titratable acidity, total soluble solids, polyphenol compounds, and ascorbic acid content compared with uncoated groups. All results demonstrate that CS–PPE films is potential for preservation of the nutraceutical quality of fruit.