Microbiological Quality of Water Immersion-Chilled and Air-Chilled Broilers

Abstract

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.

Prevalence Analysis and Molecular Characterization of Salmonella at Different Processing Steps in Broiler Slaughter Plants in South Korea

“…Chilling is a step for inhibiting pathogens during broiler processing (Sánchez and others ; Zhang and others ). Eviscerated carcasses are normally chilled by a water immersion or air chilling system.…”

Enhancement of bactericidal effects of sodium hypochlorite in chiller water with food additive grade calcium hydroxide

“…Poultry meats will be contaminated with bacteria through attachment of feces during the processing course, and the contaminated meats will release these bacteria into the environment, and non-contaminated meats will thereby be contaminated [19, 25]. Once bacteria attached to the meats, it was difficult to kill the bacteria on meats [14, 30]. It is desirable to kill bacteria immediately before attachment to the other meats.…”

“…Tsai et al [27] and Northcutt et al [22] reported that chiller tanks at the processing plants contained around 0.35 or 0.16% suspended solids, respectively. Although chicken is chemically sanitized during processing and subsequently cleaned before packaging, some microorganisms cannot be removed completely, especially bacteria strongly attached to chicken skin [5, 14, 23, 30]. This is because these microorganisms, including Salmonella and Campylobacter, are able to become entrapped in deep skin layers, crevices, or feather follicles, thus becoming protected from chemical agents [5, 15, 29].…”

“…[21] also reported that while chlorine control was important for reducing Escherichia coli levels during chilling, it played a less significant role in the management of cross-contamination issues. Once the bacteria attach to the surface of chicken meats, it is very difficult to remove or kill these bacteria [1, 14, 30]. It is desirable to kill bacteria before they attach to poultry meats to reduce cross-contamination.…”

The evaluation of combined chemical and physical treatments on the reduction of resident microorganisms and Salmonella Typhimurium attached to chicken skin

“…can occur at various stages of poultry processing such as scalding, defeathering, evisceration, and chilling (Lillard, 1989;Hafez et al, 1997;Ono and Yamamoto, 1999;Buhr et al, 2005;McKee, 2012). Although chicken is chemically sanitized during processing and subsequently cleaned before packaging, some microorganisms cannot be removed completely, especially for bacteria strongly attached to chicken skin (Ko et al, 2005;Zhang et al, 2011). This is because these microorganisms including Salmonella and Campylobacter are able to become entrapped in deep skin layers, crevices, or feather follicles, thus becoming protected from chemical agents (Krysinski et al, 1992;Mosteller and Bishop, 1993;Yang et al, 2001;Chantarapanont et al, 2004).…”