Tailoring structural and functional properties of novel fucoidan–polyvinyl alcohol casting films

This study evaluated the impact of different fucoidan:polyvinyl alcohol (FC:PVA) polymer ratios (0:100, 10:90, 30:70, 50:50, 70:30, 90:10, and 100:0) on the structural and physicochemical characteristics of biopolymer casting films. The gradual addition of PVA to the FC matrix steadily improved the surface uniformity of the films.FTIR analysis demonstrated the development of new intermolecular interactions, predominantly hydrogen bonding, between the hydroxyl groups of PVA and the functional moieties of FC. Based on DSC and XRD analyses, the addition of FC to PVA films reduced both their thermal stability and crystallinity. However, DPPH analysis revealed a significant enhancement in the antioxidant activity of the films, which increasined from 3.4 ± 1.12% in the 0:100 formulation to 57.87± 3.72% in the 100:0 sample. increasinh the proportion of FC in the films resulted in increased opacity and larger ΔE values, accompanied by reduced lightness. Among the prepared formulations, the film with an FC:PVA ratio of 30:70 was identified as the most suitable composition. This formulation exhibited a thickness of 83.60 ± 2.90 µm, a tensile strength of 7.62 ± 0.36 MPa, an elongation at break of 69.88 ± 1.76%, and a water vapor permeability of 1.26 ± 0.03 × 10 -11 g·m⁻¹·h⁻¹·Pa..Overall, the findings suggest that the FC:PVA formulation has potential as an effective material for biodegradable active food packaging.