Preparation and characterization of probiotic Bacillus velezensis 906 metabolites /potassium sorbate/ polyvinyl alcohol antimicrobial blend film

Abstract

Films with excellent mechanical properties and antimicrobial activity have potential applications in food preservation. The antimicrobial film was prepared by blending probiotic Bacillus velezensis 906 metabolites (906), potassium sorbate (PS), and polyvinyl alcohol (PVA). The film was characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermal stability analysis. The mechanical, barrier, and antimicrobial properties of the film were tested. The results of the physicochemical analysis indicated that, compared to the pure PVA film, the film's mechanical properties decreased, while its barrier properties and hydrophobicity increased with the addition of PS and 906, respectively. The results of the antimicrobial tests revealed that the blend film exhibited significant antimicrobial activity against Vibrio parahaemolyticus, Psychrobacter maritimus, Oceanobacillus kimchii, Pseudomonas aeruginosa, and Listeria monocytogenes. SEM demonstrated good fusion between the components of the PVA/PS/906 film, resulting in a dense and crack-free structure. FTIR suggested that PS and 906 enhance molecular interactions within the film matrix. XRD revealed that the film was crystallized, with 906 increasing the crystallinity of the bonds between the film components. Thermal analysis indicated the thermal stability of the films was enhanced. Consequently, the PVA/PS/906 blend film shows significant potential for application in the preservation of aquatic products.