Characterization of bacterial cellulose/PVA composite films incorporated with sesame meal protein hydrolysate: Physicochemical, antimicrobial, and antioxidant properties

In this study, the effect of integrating the sesame meal protein hydrolysate (SPH) obtained through Bacillus coagulans fermentation was evaluated in a composite film made from bacterial cellulose (BC) and polyvinyl alcohol (PVA). The amino acid profile of the SPH was evaluated by high-performance liquid chromatography (HPLC). The study investigated physicochemical properties, including moisture, solubility, water vapor permeability (WVP), contact angle, and color. Additionally, mechanical properties, including tensile strength (TS) and elongation to breaking point (EB), as well as antimicrobial and antioxidant activity (DPPH radical scavenging and ferric reducing power), were evaluated. Other characteristics of the film were analyzed using FE-SEM, FTIR and XRD techniques. According to the results, SPH had all the essential amino acids. The findings showed that the incorporation of SPH at concentrations of 10, 15, and 20 % into the composite film decreased the solubility and WVP while the tensile strength was increased significantly (p < 0.05). Furthermore, the formation of hydrogen bonds was identified by FTIR analysis. FE-SEM imaging showed that the SPH was homogeneously dispersed in the film matrix. The crystallinity of the composite film and the interaction between the polymer and SPH were confirmed by XRD. Film containing SPH showed antimicrobial activity against pathogenic strains. Also, by incorporating the SPH up to 20 %, DPPH radical inhibition and ferric reducing power were increased to 68.2 % and 0.68 (absorbance at 700 nm), respectively. The results showed that incorporating SPH into BC/PVA composite films can be utilized as active packaging, effectively prolonging the shelf life of food.