Fabrication of Plantaricin FB-2 loaded chitosan/agar coatings: Enhancing antimicrobial activity and prolonging fresh pork shelf life

Abstract

Fresh pork is highly prone to spoilage from oxidation and microbial growth. Utilizing edible coatings made from polysaccharides and bacteriocins is an effective strategy to preserve the quality of fresh pork. In this study, a coating film with antimicrobial properties was developed by grafting chitosan (CS) and agar (AG) together and then incorporating the bacteriocin Plantaricin FB-2. The interaction among these three components was verified using Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) analysis. Scanning electron microscopy (SEM) showed that increasing the content of Plantaricin FB-2 in the coating film would change the surface texture of the coating film, making it less smooth. Meanwhile, it would also enhance the hardness and water-holding capacity of the coating film. Additionally, all the coating solutions demonstrated excellent biocompatibility. The inhibition zones for CS/AG/64 and CS/AG/128 against Staphylococcus aureus measured 12.26 mm and 14.56 mm, respectively. The CS/AG matrix also exhibited a slow-release effect on Plantaricin FB-2. The CS/AG/128 coating film effectively preserved the appearance and quality of fresh pork for at least 14 days, as demonstrated by five indicators: color value (L*), juice loss, pH, total volatile basic nitrogen (TVB-N), and total colony count. This antimicrobial-coated film shows significant potential as a packaging material for fresh pork preservation and controlled release. In conclusion, this approach not only extends the shelf life of fresh pork but also offers a promising solution for sustainable food preservation, potentially transforming the landscape of fresh pork packaging.