Chitosan as a Natural Antimicrobial and Nanocarrier: Strategies for Food Preservation and Surface Protection

Chitosan, a naturally derived polysaccharide obtained from chitin deacetylation, has emerged as a versatile antimicrobial agent and nanocarrier with broad potential in food preservation and surface protection. Its intrinsic antimicrobial activity, biocompatibility, biodegradability, and Generally Recognized as Safe (GRAS) status make it highly suitable for sustainable food applications. The cationic nature of chitosan facilitates strong electrostatic interactions with negatively charged bacterial cell membranes, leading to cell disruption, leakage of intracellular components, and inhibition of biofilm formation. Recent advancements in nanotechnology have enhanced these properties by incorporating chitosan with metal and metal oxide nanoparticles (e.g., ZnO, Ag, TiO₂) or natural antimicrobials (e.g., essential oils, plant phenolics) to create hybrid nanocomposite coatings with synergistic effects. Such systems have demonstrated effectiveness against key foodborne pathogens like Listeria monocytogenes, Salmonella Typhimurium, and Escherichia coli on fresh produce, meats, and food contact surfaces. Moreover, chitosan-based films and coatings act as carriers for controlled release of antimicrobial agents, improving food shelf life while minimizing sensory and nutritional impacts. This review highlights current progress in chitosan’s functional mechanisms, its integration with GRAS nanoparticles, and recent developments in food packaging and surface hygiene, emphasizing future opportunities for smart, eco-friendly antimicrobial systems in the food industry.

Keywords: Chitosan, Antimicrobial, Biofilm, Coating, Food Contact, Food Preservation, Nanocarrier.