Active Biopolymeric Packaging for Fatty Foods: Chitosan/Electrospun Zein Bilayer Membranes with Natural Additive

This study aimed to develop zein-chitosan bilayer membranes incorporated with lyophilized jaboticaba epicarp extract (LJEE) for applications in food packaging. The LJEE was initially characterized for its total phenolic content (TPC), antioxidant activity (AA), total anthocyanin (TA), and phenolic profile via HPLC analysis. The characterization revealed promising properties, with TPC, AA, and TA values of 89.33 ± 3.46 mgGAE g^-1, 70.85 ± 1.85%, and 416.74 ± 9.43 mg cn-3-glu/100 g, respectively. Notable bioactive compounds identified included gallic acid, caffeic acid, p-coumaric acid, trans-ferulic acid, kaempferol, and cyanidin-3-glucoside (cn-3-glu), present in higher concentrations than other compounds. The bilayer membranes were produced using chitosan film (first layer) and electrospun zein fiber (second layer). LJEE was incorporated into the zein solution, producing an active bilayer membrane (ABM). A control bilayer membrane (CBM), without LJEE, was also formulated. Zein solutions were evaluated according to their surface tension and contact angle with the chitosan film surface, and the addition of LJEE improved adhesion. The incorporation of LJEE into the membranes significantly reduced water solubility and water vapor permeability. The mechanical properties of the bilayer membranes were favorable, particularly in terms of elongation at break. Morphological analysis of the electrospun fibers showed homogeneous fibers with average diameters of 975 and 675 nm for CBM and ABM, respectively. FTIR analysis demonstrated interactions between the components of the extract and the biopolymers, while thermal analysis demonstrated that the addition of the extract did not negatively affect membrane stability, indicating that the bilayer configuration provides greater structural stability than the chitosan film alone. The migration of bioactive compounds from ABM to different food simulants was also investigated, and better results were observed in oil. Additionally, ABM exhibited antimicrobial activity in the oil simulant, effectively inhibiting S. aureus and E. coli. The results suggest that these bilayer membranes with LJEE can be used as a promising material for active food packaging, preferably serving fatty food products.