Pectin or chitosan coating fortified with eugenol reduces Campylobacter jejunion chicken wingettes and modulates expression of critical survival genes

Campylobacter jejuniinfection in humans is strongly associated with the consumption of contaminated poultry products. With increasing consumer demand for minimally processed and natural product, there is a need for novel intervention strategies for controlling C. jejuni. Antimicrobial coatings are increasingly being used for preventing food contamination due to their efficacy and continuous protection of product. This study investigated the efficacy of pectin and chitosan coating fortified with eugenol to reduce C. jejunion chicken wingettes. Pectin, chitosan, and eugenol are generally recognized as safe status compounds derived from berries, crustaceans, and cloves respectively. Each wingette was inoculated with a mixture of 4 wild-type strains of C. jejuni(approximately 10⁷CFU/sample) and randomly assigned to controls, pectin (3%), chitosan (2%), eugenol (0.5, 1, or 2%), or their combinations. Following 1 min of coating, wingettes were air-dried, vacuum sealed, and sampled on 0, 1, 3, 5, and 7 d of refrigerated storage for C. jejuniand aerobic counts (n = 5 wingettes/treatment/d). In addition, the effect of treatments on wingette color and expression of C. jejunisurvival/virulence genes was evaluated. All 3 doses of eugenol or chitosan significantly reduced C. jejuniand aerobic bacteria from 0 d through 7 d. Incorporation of 2% eugenol in chitosan improved coating efficiency and reduced C. jejunicounts by approximately 3 Log CFU/sample at the end of 7 d of storage (P< 0.05). Similarly, the antimicrobial efficacy of pectin was improved by 2% eugenol and the coating reduced C. jejuniby approximately 2 Log CFU/sample at 7 d of storage. Chitosan coating with 2% eugenol also showed greater reductions of total aerobic counts as compared to individual treatments of eugenol and chitosan. No significant difference in the color of chicken wingettes was observed between treatments. Exposure of C. jejunito eugenol, chitosan, or combination significantly modulated select genes encoding for motility, quorum sensing, and stress response. Results demonstrate the potential of pectin or chitosan coating fortified with eugenol as a postharvest intervention against C. jejunicontamination on poultry products.