Structural studies and bioactivity of sodium alginate edible films fabricated through ferulic acid crosslinking mechanism

Sodium alginate (SA) is a well-known naturally occurring seaweed biopolymer and the attracted interest of SA is proficient to develop a characteristic edible film which extended the shelf-life of fruits, vegetables, poultry, and seafood. The objective of the current study focuses on the fabrication and characterization of sodium alginate edible films crosslinked with ferulic acid (FA) at 25, 35, 45 mg/gm of SA and classified as FA150, FA210, FA270. These FA allied SA films are found to be transparent, homogeneous, stable, and more rigid due to the crosslinking of ferulic acid. Further, the experimental films were evaluated to understand the effect of ferulic acid on their characteristic changes i.e., thickness, opacity, water-solubility, solid mass, and moisture content. Likewise, the Tensile strength (TS) and elongation at break percent (E%) are also tested to estimate the film's barrier and physical strength. The intermolecular interactions, microstructure, and surface morphology profiles of developed films were studied using standard Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and Atomic force microscopy (AFM) experimental parameters. Moreover, the FA linked SA edible films were shown potential antioxidant activity profiles with increased concentration of crosslinking agent (ferulic acid) through reducing both 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and ferric ions. Whereas, the developed FA linked SA composite films did not show a potential zone of inhibition against the most common food spoiling bacteria i.e., Klebsiella pneumonia and Salmonella enterica. Thus, the current study endorsed that the FA allied sodium alginate edible films are beneficial for the manufacturing and food processing applications with a key antioxidant function.