Salmonella spp. and Hygiene Indicator Microorganisms in Chicken Carcasses Obtained at Different Processing Stages in Two Slaughterhouses

Abstract

Chicken meat is considered an important vehicle of foodborne pathogens such as Salmonella spp., demanding an effective control of its contamination during industrial processing. This study aimed to investigate the presence of Salmonella spp. and microbiological indicators at different stages of processing in two slaughterhouses (Sh1, high-capacity; Sh2, low-capacity). Surface samples of chicken carcasses were collected in the following sequential stages: (A) immediately before evisceration, (B) after evisceration, (C) after showering, and (D) after chiller. All samples were submitted for detection of Salmonella spp. and enumeration of mesophilic aerobes, total coliforms, thermotolerant coliforms, and Escherichia coli. The obtained means and frequencies were compared by analysis of variance and chi-square tests (p < 0.05), considering different slaughterhouses and stages of processing. No significant differences were observed between the frequencies of Salmonella spp. obtained at different steps in Sh1 and Sh2 (p > 0.05). Sh2 showed higher levels of microbiological contamination when compared with Sh1 for mesophilic aerobes (in stages B and D), total coliforms and thermotolerant coliforms (stage D), and E. coli (all stages) (p < 0.05). The variation in the levels of contamination by microbiological indicators over the processing indicated the significance of different control procedures adopted by slaughterhouses for the microbiological quality of chicken carcasses.

Escherichia coli and E nterobacteriaceae counts on poultry carcasses along the slaughterline: A systematic review and meta-analysis

“…Seven studies described the evisceration process with an overall inconsistent effect size (Barbut, Moza, Nattress, Dilts, & Gill, 2009;Berrang & Dickens, 2000;Gill, Moza, Badoni, & Barbut, 2006;Matias, Pinto, Cossi, & Nero, 2010;Smulders et al, 2011;Vaidya, Paturkar, Waskar, Zende, & Rawool, 2005). Four studies failed in reaching statistical significance (p < 0.05) while, among the others, two showed a significant increase and one a marked decrease in E. coli counts (Fig.…”

Self-Monitoring Microbiological Criteria for the Assessment of Hygienic Procedures During Chicken Slaughtering

“…Recorded counts after evisceration of chicken (C2) varied among slaughterhouses, without a coherent pattern (Table 3), while the microbiological counts in the chicken carcasses after pre-chilling (C3) were higher in Sl2 when compared to Sl1 and Sl3 for all researched microbiological groups (p<0.0.5, Table 3). The higher temperatures in the chilling tanks from Sl2 when compared to Sl1 and Sl3 can explain these results (Table 5), showing that temperature and water renewal were more important as factors of microbiological control than chlorine, which on its own showed no effect, as also observed by Allen et al (2000), Jimenez et al (2003), Matias et al (2010), and Rodrigues et al (2008). Chilling is considered to play a major role in microbiological contamination during chicken slaughtering, and studies assessing the use of alternative procedures and equipment, such as spraying of cold air instead of immersion in cold water, indicate its relevance in reducing the counts in chicken carcasses (Hutchison et al, 2006;Vaidya et al, 2005;Zweifel et al, 2015).…”

“…Finally, Sl3 presented an increase of sample frequencies with counts higher than reference values of mesophilic aerobes and E. coli among C1 and C2 (Figure 1), despite their mean counts being significantly different (Table 3). These results demonstrate the relevance of the intermediary stages of slaughtering as potential sources of microbiological contamination, like the automatic evisceration in large slaughterhouses in which the control can be more difficult (Goksoy et al, 2004;Matias et al, 2010;Rodrigues et al, 2008;Vaidya et al, 2005;Zweifel et al, 2015). In addition, based on this analysis it becomes clear that there is a need to consider additional microbiological criteria to assess the hygienic procedures in chicken slaughterhouses.…”

Inspected and non-inspected chilled chicken carcasses commercialized in Viçosa, MG, Brazil: microbiological parameters and Salmonella spp. occurrence

“…and E. coli, in non-inspected chicken carcasses. However, it must be considered that the usual chicken slaughtering occurs in an industrial scale, which facilitates the microbiological contamination due to the automation and velocity of the process (MATIAS et al, 2010). In counterpart, non-inspected chicken carcasses are usually obtained from small producers that slaughter a little number of birds, minimizing the contamination.…”