A Chitosan-Lasso Peptides Nanoparticle for Enhanced Antibacterial Activity and Fresh-Keeping Efficacy in Eggs and Chilled Chicken

Chemical disinfectants and bacteriophages for controlling Salmonella in foods often have limitations such as residual odor, narrow antimicrobial spectra, and poor stability under food processing conditions. Lasso peptides, with their structural stability, heat resistance, and safe antimicrobial activity, are promising candidates for food preservation. In this study, Chitosan-Citric acid-MccJ25-MccY (CCJY) nanoparticles were prepared via citric acid crosslinking to encapsulate MccJ25 and MccY. The nanoparticles showed high encapsulation efficiency (>96.67%) and maintained their antimicrobial activity in the presence of food matrices. CCJY exhibited strong anti- Salmonella activity on the surface of eggs and chilled chicken, achieving 99.9% bacterial reduction. Importantly, CCJY retained its efficacy after heat treatment and under acidic/alkaline conditions typical of food processing. In egg preservation, CCJY treatment maintained eggshell integrity (0.82% weight loss, Haugh unit 61.12 after 20 days). In chilled chicken, CCJY reduced total bacterial counts by 2.37 log 10 CFU/g and decreased drip loss by 12.5% ( p < 0.001), extending shelf life by 3–4 days. These results demonstrate that CCJY is an efficient and safe antimicrobial formulation suitable for application in egg and meat preservation.