Development of a food packaging antibacterial hydrogel based on gelatin, chitosan, and 3-phenyllactic acid for the shelf-life extension of chilled chicken

Food safety caused by microbial contamination is an important problem that is difficult to solve for the food industry. In this study, the effective antibacterial hydrogel from electrospinning nanofibers prepared using gelatin, chitosan, and 3-phenyllactic acid (PLA) after water absorption was used to improve the antibacterial performance and prolong the shelf life of chilled chicken meat. The structure, water-absorbing ability, antibacterial ability, and fresh-keeping ability of this hydrogel were characterized. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy showed that the carboxyl group in PLA reacted with the amino group in chitosan, which formed amide bond under acidic conditions. This bond enhanced the water absorption and stability of the hydrogel. Low-field nuclear magnetic resonance showed that the addition of PLA not only changed the structure of hydrogels but also changed the ratio of different states of water in the hydrogels. The swelling ratio of GCP-1 hydrogel was two times larger than that of GCP-0 hydrogel, and scanning electron micrographs showed that the GCP-1 hydrogel after water absorption had a unique spongy shape. Furthermore, the GCP-1 hydrogel effectively inactivated foodborne pathogens Staphylococcus aureus and Escherichia coli and prolonged the preservation of chilled chicken to 4 days. This study provides an innovative way to apply electrospinning nanofibers in food packaging.