Antimicrobial activity of cetylpyridinium chloride against Listeria monocytogenes on frankfurters and subsequent effect on quality attributest

Antimicrobial interventions to reduce Salmonella and Campylobacter populations and improve shelf life of quail carcasses

Quail (Coturnix japonica) is processed and marketed as fresh meat, with limited shelf life. The objective of this study was to evaluate the efficacy of antimicrobial interventions during slaughter on reducing Salmonella and Campylobacter contamination and to determine the microbiological shelf life of quail during refrigerated (4°C) storage. Three antimicrobials, peracetic acid (400 ppm; PAA), Citrilow (pH 1.2), and Cecure (cetylpyridinium chloride [CPC], 450 ppm), along with a water and no-treatment control were evaluated. Quail carcasses (n = 75) were inoculated with a cocktail of nalidixic acid–resistant Salmonella Typhimurium and gentamicin-resistant Campylobacter coli. After 30 min of attachment time, quail carcasses were submerged in each antimicrobial solution for 20 s with air agitation. Noninoculated quail carcasses (n = 25) were similarly treated, packaged, and stored under refrigeration (4°C). Aerobic plate counts (APC), psychrotroph counts (PC), Enterobacteriaceae counts (ENT), total coliform counts (TCC), and Escherichia coli counts on quail carcasses were determined on 1, 4, 7, and 10 d. Salmonella and Campylobacter populations were determined by plating on Petrifilm APC supplemented with 200-ppm nalidixic acid and Campy Cefex agar supplemented with 200-ppm gentamycin, respectively. No significant reductions in (P > 0.01 log cfu/mL) in APC, PC, ENT, TCC, and E. coli counts were observed on carcasses submerged in water. However, treatments with PAA, Citrilow, and CPC significantly reduced (P ≤ 0.05) Salmonella and Campylobacter coli contamination. Citrilow showed greater (P ≤ 0.05) reduction in Salmonella and Campylobacter population (1.90 and 3.82 log cfu/mL reduction, respectively) to PAA and CPC. Greater (P ≤ 0.05) reductions in APC, PC, ENT, TCC, and E. coli counts (2.22, 1.26, 1.47, 1.52, and 1.59 log cfu/mL, respectively) were obtained with the application of CPC. Application of antimicrobial interventions resulted in a reduction in Campylobacter and Salmonella, APC, PC, and ENT populations after treatments (day 0) and throughout the storage period (day 10). Use of antimicrobial interventions after slaughter can improve the microbiological safety and shelf life of quail.

Growth Inhibitory Effects of Adhatoda vasica and Its Potential at Reducing Listeria monocytogenes in Chicken Meat

The inhibitory effects of Adhatoda vasica ethanolic leaf extract (AVELE) against Listeria monocytogenes were examined to assess its potential to preserve minimally processed meat products safely. The total phenolic, flavonoid, and alkaloid levels in AVELE were 10.09 ± 4.52 mg of gallic acid equivalents (GAE)/g, 22.43 ± 1.62 mg of quercetin equivalents/g, and 19.43 ± 3.90 mg/g, respectively. AVELE (1, 5, 10, or 20%) had considerable antibacterial effects against L. monocytogenes NCIM 24563 in terms of the inhibitory zones (7.4-13.6 mm), MIC (100 mg/mL or 10% formulated solution), reduced cell viability, potassium ion efflux, and the release of 260-nm absorbing materials and extracellular ATP. AVELE was used as a rinse solution (5, 10, and 20%) for raw chicken breast meat. A 20% rinsing solution applied for 60 min inhibited the L. monocytogenes NCIM 24563 counts significantly on raw chicken breast meat. Moreover, L. monocytogenes NCIM 24563 did not grow in the meat sample when the rinse time was increased to 90 min at the same concentration. L. monocytogenes showed a greater reduction to ~3 CFU/g after rinsing with a 10 and 20% AVELE solution for 30 min than with a 5% AVELE solution. The rinsing processes with AVELE produced the final cooked chicken products with higher sensory attribute scores, such as taste, juiciness, and tenderness, compared to the control group along with a decrease in microbial contamination. Chicken meat rinsed with AVELE (rinsing time of 90 min) showed better sensory attribute scores of juiciness and tenderness, as well as the overall sensory quality compared to the untreated group. This research highlights the effectiveness of AVELE against L. monocytogenes NCIM 24563, suggesting that AVELE can be used as an effective antimicrobial marinade and/or a rinse for meat preservation.

Microbiological quality of water immersion-chilled and air-chilled broilers

Carcass chilling during broiler processing is a critical step in preventing growth of pathogenic and spoilage bacteria. The objective of this study was to compare the microbiological quality of air- and water-chilled broiler carcasses processed at the same commercial facility. For each of four replications, 15 broilers were collected from the same commercial processing line after evisceration, after spraying with cetylpyridinium chloride (a cationic disinfectant), and after air chilling or water immersion chilling (WIC). All carcasses were quantitatively examined for mesophilic aerobic bacteria, Escherichia coli, coliforms, and Campylobacter as well as for the presence of Salmonella and Campylobacter. No significant differences (P > 0.05) were seen between air and water chilling for E. coli or coliforms or for the incidence of Salmonella and Campylobacter. Lower numbers of Campylobacter were recovered from WIC than from air-chilled carcasses (P < 0.05), but the incidence of Campylobacter on WIC carcasses was similar, suggesting that some Campylobacter organisms were injured rather than killed during WIC. In-line spraying with the disinfectant effectively decreased the incidence of Salmonella and Campylobacter on prechilled carcasses; however, cells presumably injured by the sanitizer recovered during chilling. Therefore, on-farm intervention strategies remain critically important in minimizing the spread of microbial contaminants during processing.