Chitosan and gelatin based antimicrobial coating for ensuring microbial safety of chicken and pork meat

Abstract

This study evaluates the antimicrobial efficacy of chitosan (CH) and gelatin (GL) based edible coatings incorporated with Aloe vera gel (AVG), and carvacrol nanoemulsion (CNE) for enhancing microbial safety of chicken and pork meat in refrigerated storage. The coatings were tested against four major foodborne pathogens (Escherichia coli O157:H7, Salmonella typhi, Staphylococcus aureus, and Listeria monocytogenes) under both unpacked (aerobic) and vacuum-packed (anaerobic) conditions. The optimized nanoemulsion (CNE-C2.5) exhibited desirable physicochemical characteristics, including droplet size (∼50.8 nm), low polydispersity index (0.21), and stable zeta potential (−21.4 mV), signifying its uniform dispersion and enhanced bioavailability. In vitro assays confirmed the bactericidal nature of the coating, with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) ranging from 0.06 to 1.0 mg/mL for all pathogens collectively. Application of CH/GL/AVG/CNE-2 on inoculated meat samples suppressed pathogenic growth achieving 6–7 log CFU/cm² reductions during 20-day storage period at 4 °C. The coating maintained consistent antimicrobial performance under both packaging conditions, suggesting its mechanism of action to be oxygen-independent. Overall, the CH/GL/AVG/CNE-2 coating had broad-spectrum efficacy, and prolonged antimicrobial activities. The developed coating is a promising clean-label, natural intervention for enhancing meat safety reducing risks from pathogenic contamination, thereby offering a sustainable alternative to synthetic chemicals in meat industry.