Microbial contamination in a chicken slaughterhouse: insights from sampling throughout production

Description

Aim: The high volume of chicken processed in slaughterhouses creates a challenging environment where contamination of the carcasses may be difficult to avoid, even with proper hygienic measures. To obtain knowledge of the processing environment, sampling was carried out at a slaughterhouse immediately after the daily hygienic procedures (n=5) and after the production of the first and the last batches (n=10). The sample points analysed were chicken cages, scalding water, cutting blades, and three conveyor belts, which are the sequential steps the chickens go through at the factory. Method: SodiBox sampling cloths were used to swab ~1000 cm2 of each sampling point, peptone water was added, and the cloths were homogenised for 60 seconds. The scalding water was directly analysed. After appropriate dilutions, total viable counts (TVC) were enumerated on plate count agar. Statistical analysis comprised one-way ANOVA and Tukey HSD tests. Results: Overall, between the first and the last production batch, the microbial load of the chicken cages and of the scalding water decreased. However, considering the high variability of the results from the first batches (compared to the last ones), no significant differences (p>0.6) could be observed. Further investigation on the reason for this large variability is needed. Regarding the cutting blades, no differences (p=1) were observed between the TVC of samples collected after the hygienic procedures and after the production of the first batch. Similarly, for each of the three belts, the microbial load also remained stable from the first to the last production batch (with TVC of 2-3 log CFU/cm2). Between conveyor belt #1 and #3, TVC were also comparable (p>0.1). These results suggest that cutting blades and conveyor belts do not become increasingly contaminated throughout production. Conclusion: This work revealed the large variability in microbial load at specific sampling points at a slaughterhouse. Moreover, it provided insight on the bacterial levels of blades and belts, that must be reduced, even though this may not be straightforward considering the high volume of carcasses processed and the lack of time to pause the production and sanitise these points.

Period	Nov 2025
Event title	39th EFFoST International Conference 2025
Event type	Conference
Location	Porto, PortugalShow on map