Improving Microbial Quality of Ostrich Meat Using Mechanically Deboned Chicken Meat Protein Nanocomposite Coating Incorporated With <i>Ziziphora clinopodioides</i> Essential Oil and Eugenol During Cold Storage

ABSTRACT The objective of this study was to compare the in vitro antibacterial activities of conventional (non‐nanocomposite) and nanocomposite (nanoclay‐based) coatings made from mechanically deboned chicken meat protein (MDCM‐P) enriched with Ziziphora clinopodioides essential oil (ZEO) and/or eugenol (EUG) against foodborne pathogens. Subsequently, best‐performing coatings identified through in vitro tests were evaluated for effects on microbial quality, safety (via inoculation with Staphylococcus aureus and Escherichia coli O157:H7), and sensory characteristics of ostrich meat during 21‐day storage at 4°C. Based on GC–MS results, carvacrol (62.5%) was the major compound of ZEO. Particle size of nanocomposites ranged from 137 to 514.8 nm. The well‐diffusion method showed that Listeria monocytogenes was the most sensitive and E. coli O157:H7 the most resistant bacterium. Ostrich meat coated with MDCM‐P nanocomposite containing ZEO (16 mg/mL) and EUG (16 mg/mL) demonstrated improved microbial quality compared to uncoated meat, showing reductions in total viable bacteria (9.29 to 6.33 log 10 CFU/g), psychrotrophs (10.41 to 6.45 log 10 CFU/g), lactic acid bacteria (8.36 to 6.07 log 10 CFU/g), coliforms (8.41 to 5.46 log 10 CFU/g), and molds and yeasts (8.17 to 5.26 log 10 CFU/g), and enhanced microbial safety by lowering S. aureus (7.44 to 5.27 log 10 CFU/g) and E. coli O157:H7 (8.42 to 5.25 log 10 CFU/g) counts. Furthermore, it exhibited improved sensory attributes, achieving an overall acceptability score of 5.4 compared to 2.15 for control. These findings suggest that MDCM‐P nanocomposite coating containing ZEO and EUG shows potential as an active packaging material to improve microbial quality and safety of refrigerated ostrich meat.