Development and characterization of zein-based active packaging films containing catechin loaded β-cyclodextrin metal-organic frameworks

In this study, nano-sized β-cyclodextrin (β-CD)-metal-organic frameworks (MOFs) loaded with catechin (CAT) were successfully synthesized, zein films incorporated with different amounts of CAT-β-CD-MOFs (0–8 wt% on zein basis) were developed, and the structure, physicochemical, antioxidant and antimicrobial properties of the films were determined. FT-IR revealed that the CAT-β-CD-MOFs could interact with zein through intermolecular hydrogen bonds. XRD results confirmed the appearance of crystalline peaks due to the presence of CAT-β-CD-MOFs inside the films. SEM showed that the addition of CAT-β-CD-MOFs made microstructure of zein film more smooth and compact. The addition of CAT loaded β-CD-MOFs into zein film significantly decreased the water vapor permeability and swelling degree (p < 0.05). CAT-β-CD-MOFs addition significantly increased tensile strength and elongation at break from 2.53 to 19.24 MPa and 1.65–5.65% (p < 0.05). Moreover, CAT-β-CD-MOFs significantly improved the antioxidant activity of the composite film and the inhibitory activity against tested microorganisms (Escherichia coli and Staphylococcus aureus). CAT has sustained release properties in the composite film. Therefore, it is suggested that zein/CAT-β-CD-MOFs films could offer great potential as active packaging to maintain the food quality.