Edible Film Preparation Using Chitosan/Gelatin/Phlorotannin-Embedded Limosilactobacillus fermentum FUA033 for Strawberry Preservation

In this study, we prepared edible films using chitosan/gelatin/phlorotannins (CGPs) embedded with probiotics and evaluated their preservation effects on strawberries. Edible films encapsulating Limosilactobacillus fermentum FUA033 (CGPFUA033) were prepared using the casting method. The intermolecular interactions, crystal structure, thermal stability, and morphology of the films, both prior to and following the incorporation of L. fermentum FUA033, were characterized using FT-IR, XRD, TG, and SEM analyses. The preservation efficacy of the edible films, with and without encapsulated L. fermentum FUA033, was assessed by monitoring the physical, chemical, and microbial properties, as well as the visual quality, of strawberries during a eight-day storage period. The results showed that encapsulation of L. fermentum FUA033 enhanced intermolecular interactions and thermal stability within the film matrix but did not significantly affect the crystalline structure of the edible film. At 0, 2, 4, 6, and 8 days, the CGPFUA033 treatment had preservation effects: the weight loss was 30.70 ± 1.53%, the total soluble solid content was 8.83 ± 0.28%, the decay index was 45.33 ± 1.53%, the malondialdehyde content was 7.44 ± 0.13 μmol/g, firmness was 21.49 ± 0.83 N, and the ascorbic acid content was 43.51 ± 0.79 mg/100 g. The shelf life of strawberries was extended by six days in the CGPFUA033 treatment group. Therefore, the chitosan/gelatin/phlorotannin edible film embedded with L. fermentum FUA033 has high preservation effects on strawberries, highlighting that L. fermentum FUA033 can be used as a probiotic for enhancing food preservation.