Double-layer packaging film based on potato peel starch/bacterial nanocellulose incorporating red plum anthocyanins and citral emulsion for seafood preservation

Petroleum-derived packaging polymers are widely used in food packaging due to their excellent barrier properties, mechanical strength, and low cost. However, environmental and health concerns have motivated researchers to seek eco-friendly alternatives. This research presents the development of a double-layered film composed of potato starch and bacterial nanocellulose (BNC), incorporating red plum peel extract (RPPE) and a citral emulsion for extending the shelf life of cold-stored shrimp. The average size of the emulsion particles found to be 276.8 ± 8.16 nm, with a polydispersity index of 0.273 ± 0.02, aligning with the microscopy results. Moreover, the water contact angle increased from 53.03 ± 8.1° for the control film to 80.51 ± 1.3° for the double-layer film, indicating that the incorporation of BNC and citral emulsion increased hydrophobicity, thereby impacting the stability of the film. X-ray diffraction analysis revealed a reduction in the intensity of the starch crystalline peaks at angles of 17° and 23°, accompanied by an increase in amorphous characteristics, whereas the characteristic peaks of bacterial nanocellulose at 16.5° and 22.5° remained unchanged. In addition, the double-layer film exhibited an inhibition zone of ∼ 15 mm against S. Typhimurium , confirming the antimicrobial potential of the produced double layer film. Overall, these findings of this research suggest that the double-layered film, developed as a smart and active packaging, has the potential to monitor the freshness of seafood products while simultaneously prolonging their shelf life.