QUALITY EVALUATION OF REFRIGERATED CHICKEN WINGS TREATED WITH ORGANIC ACIDS

Influences of photosensitizer curcumin on microbial survival and physicochemical properties of chicken during storage

Curcumin is a natural plant derived antimicrobial, which was shown to inactivate or inhibit the growth of a broad spectrum of microorganisms through photodynamic inactivation. The purpose of the present study is to evaluate the influence of curcumin against commensal spoilage bacteria on chicken, foodborne pathogens, and the chicken skin pH and color. Chicken skin samples were immersed into water, photosensitizer curcumin (PSC), or peracetic acid (PAA). PSC samples were subsequently subjected to illumination by LEDs (430 nm). The PSC treatments did not inhibit the outgrowth of the four groups of spoilage bacteria evaluated. PSC treatment resulted in 2.9 and 1.5 log CFU/cm² reduction of L. monocytogenes and Salmonella, respectively. Over a 10-d period, population of Salmonella remained significantly lower on PSC treated samples compared to other treatments. PSC treatment resulted in no significant changes in pH or color as compared to water treated samples. This research suggests PSC effectively controlled pathogen outgrowth on chicken without negatively influencing quality; and may be suitable for use in commercial chicken processing.

Edible Coatings Fortified With Carvacrol Reduce Campylobacter jejuni on Chicken Wingettes and Modulate Expression of Select Virulence Genes

Campylobacter jejuni, a leading cause of foodborne disease in humans, associate primarily with consumption of contaminated poultry and poultry products. Intervention strategies aimed at reducing C. jejuni contamination on poultry products could significantly reduce C. jejuni infection in humans. This study evaluated the efficacy of gum arabic (GA) and chitosan (CH) fortified with carvacrol (CR) as an antimicrobial coating treatment for reducing C. jejuni on chicken wingettes. Aforementioned compounds are generally recognized as safe status compounds obtained from gum arabic tree, crustaceans and oregano oil respectively. A total of four separate trials were conducted in which wingettes were randomly assigned to baseline, saline control (wingettes washed with saline), GA (10%), CH (2%), CR (0.25, 0.5, or 1%) or their combinations. Each wingette was inoculated with a cocktail of four wild-type strains of C. jejuni (∼7.5 log10 cfu/sample). Following 1 min of coating in aforementioned treatments, wingettes were air dried (1 h) and sampled at 0, 1, 3, 5, and 7 days of refrigerated storage for C. jejuni and total aerobic counts (n = 5 wingettes/treatment/day). In addition, the effect of treatments on wingette color was measured using a Minolta colorimeter. Furthermore, the effect of treatments on the expression of C. jejuni survival/virulence genes was evaluated using real-time quantitative PCR. Results showed that all three doses of CR, CH or GA-based coating fortified with CR reduced C. jejuni from day 0 through 7 by up to 3.0 log10 cfu/sample (P < 0.05). The antimicrobial efficacy of GA was improved by CR and the coatings reduced C. jejuni by ∼1 to 2 log10 cfu/sample at day 7. Moreover, CH + CR coatings reduced total aerobic counts when compared with non-coated samples for a majority of the storage times. No significant difference in the color of chicken wingettes was observed between treatments. Exposure of pathogen to sublethal concentrations of CR, CH or combination significantly modulated select genes encoding for energy taxis (cetB), motility (motA), binding (cadF), and attachment (jlpA). The results suggest that GA or CH-based coating with CR could potentially be used as a natural antimicrobial to control C. jejuni in postharvest poultry products.

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

Campylobacter jejuni infection 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. jejuni on 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 10⁷ CFU/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. jejuni and aerobic counts (n = 5 wingettes/treatment/d). In addition, the effect of treatments on wingette color and expression of C. jejuni survival/virulence genes was evaluated. All 3 doses of eugenol or chitosan significantly reduced C. jejuni and aerobic bacteria from 0 d through 7 d. Incorporation of 2% eugenol in chitosan improved coating efficiency and reduced C. jejuni counts 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. jejuni by 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. jejuni to 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. jejuni contamination on poultry products.

Use of Caprylic Acid in Broiler Chickens: Effect on Campylobacter jejuni

The effect of caprylic acid (CA) on Campylobacter jejuni in chickens was evaluated using two approaches: dietary supplementation or surface treatment of chilled chicken carcasses. To analyze the dietary effect of CA, individually housed broiler chickens (n = 48) were artificially infected with C. jejuni VFU612 (10(6) colony-forming units [CFU]/bird) on the 21st and 35th days of life. Dietary CA (2.5 and 5 g/kg of feed, fed throughout the entire experiment) significantly decreased C. jejuni shedding (p<0.05). However, the effect only lasted for 3-7 days after infection. The numbers of Campylobacter shed by the positive control birds reached its maximum on the 37th day of life, while on that same day, both Treatment I and Treatment II groups shed significantly lower (p<0.05) numbers of Campylobacter (by 0.8 and 1.8 log10 CFU/g, respectively). Also, peak shedding was delayed by 1 day in both treated groups. After euthanasia of each chicken on the 42nd day of life, no differences in Campylobacter counts in the crop, gizzard, ileum, and cecum were found between the positive control and the treated groups (p>0.05). Surface contamination of the chilled chicken halves was performed with C. jejuni VFU612 (clinical isolate) and CCM6214 (collection strain). Surface treatment with CA at 1.25 and 2.5 mg/mL for 1 min significantly reduced C. jejuni VFU612 contamination of chicken skin (p<0.05) by 0.29-0.53 and 1.14-1.58 log10 CFU/g of skin, respectively. Counts of C. jejuni CCM6214 were reduced by 0.68-1.65 log10 CFU/g of skin). In conclusion, dietary CA affected numbers of C. jejuni in the gastrointestinal contents of chickens, whereas surface treatment reduced C. jejuni contamination in processed chicken carcasses.

Evaluation of consumable household products for decontaminating retail skinless, boneless chicken breasts

The effect of 15 consumable products, including juices, wines, and vinegar, used as rinsing agents on microbial loads of retail skinless, boneless chicken breasts was evaluated in two studies. Ten breasts were rinsed for 1 min with each solution. Samples were swabbed before and after rinsing with a cellulose sponge and evaluated for total aerobic (APC), total coliform (TCC), and generic Escherichia coli counts by Petrifilm methods. No differences were found in initial APC or TCC in either study, with initial mean APC ranging from 5.30 to 7.05 log CFU/cm2 and initial mean TCC ranging from 2.21 to 3.36 log CFU/cm2. In study 1, the APC for breasts rinsed with distilled white vinegar (3.22 log CFU/cm2) was lower than for those rinsed with all other solutions except cranberry juice cocktail (3.86 log CFU/cm2). The TCC for breasts rinsed with distilled white vinegar (0.00 log CFU/cm2) and cranberry juice cocktail (0.20 log CFU/cm2) were lower than those for all other solutions except 10% NaCl (0.43 log CFU/cm2) and 10% NaHCO3 (0.48 log CFU/cm2). In study 2, APC values for breasts rinsed with red wine (5.29 log CFU/cm2) and white wine (5.32 log CFU/cm2) were lower than for breasts rinsed with the other three solutions. The TCC after rinsing with chicken broth (4.48 log CFU/cm2) was higher than for all other solutions except Italian dressing. Although distilled white vinegar was the most effective rinsing agent, all solutions produced lower counts after rinsing, indicating that consumers could use rinsing to remove microorganisms from chicken breast surfaces prior to cooking.