Publikationsdatenbank

Influencing factors and reduction measures affecting the microbial load of hunted roe deer carcasses and meat with special emphasis on rinsing (2023)

Art

Hochschulschrift

Autor

Korkmaz, Birsen (WE 8)

Quelle

Berlin: Mensch und Buch Verlag, 2023 — XII, 118, F Seiten

Sprache

Englisch

Verweise

URL (Volltext): https://refubium.fu-berlin.de/handle/fub188/41487

Kontakt

Institut für Lebensmittelsicherheit und -hygiene

Königsweg 69
14163 Berlin
+49 30 838 62551 / 52790
lebensmittelhygiene@vetmed.fu-berlin.de / fleischhygiene@vetmed.fu-berlin.de

Abstract / Zusammenfassung

Low IML of hunted roe deer carcasses is an important parameter that contributes to the meat quality and food safety of the final product. Therefore, appropriate measures must be taken in the hygienic handling of carcasses in the field to keep the IML as low as possible. These measures, such as rinsing roe deer body cavities, may not only have short-term effects on the IML of carcasses but may also have longer-term effects on the subsequent ML of the obtained meat, e.g., after meat maturation. The time it takes for the meat from roe deer carcasses to reach consumer´s table varies depending on the distribution channel. As this amount of time increases, the ML of the carcasses or meat may also rise, especially when cold-tolerant bacterial species such as Pseudomonas spp. are present. Therefore, appropriate food hygiene, which begins with obtaining primary products during the early steps of the hunting chain, is a prerequisite for producing safe food with the lowest possible IML. Notably, it is a challenge to determine the cause-effect relationship between individual hygiene measures and their effects on the IML and subsequent ML because a large variety of IFs can occur simultaneously during the harvesting process. The aim of this thesis was to investigate the impact of handling practices and hunting-related factors on the microbial condition of hunted roe deer carcasses. First, the effect of rinsing roe deer body cavities on IML and subsequent ML was investigated, as this is a common but controversial cleaning practice in game meat hygiene. Proponents nevertheless recommend rinsing game body cavities, arguing that rinsing could reduce the IML of carcasses, especially in visibly soiled carcasses (Studies I and II). Additionally, the impact of environmental and hunting conditions, animal-related characteristics, and other handling practices during the early hunting chain on the IML of roe deer carcasses were investigated (Study III). As expected and presented in the first study, the bacterial counts in the muscle samples obtained from rinsed and unrinsed carcasses were mostly below the limit of detection both on hunting day and after meat maturation. This is an indicator of good microbial quality in game meat. However, higher IMLs with a wide range of variation were found on the meat surfaces of individual carcasses that were sampled directly after handover on hunting day, which could affect the microbial quality of the final product (Chapter 3.2). Highly varying MLs were also found after a putative or known preventive measure was taken, i.e., rinsing roe deer body cavities on hunting day or after a three-day refrigeration (meat maturation). In contrast to the other investigated bacterial groups, only the Pseudomonas spp. level on belly flap samples in Study I showed a significant increase in relation to time and increased after meat maturation in both rinsed and unrinsed carcasses. Since these increases were found in both rinsed and unrinsed carcasses, no differences could be detected between the MLs of the rinsed and unrinsed carcasses. Ultimately, no reduction in IML and thus no improvement in the microbial quality of the carcasses from rinsing the roe deer body cavities could be determined. Due to hunting and handling conditions, visible soiling was present in some roe deer body cavities, and it was found in the first study that the presence of visible soiling with GIC in body cavities significantly affected the IML. Therefore, in addition to Study I, Study II analyzed the effect of rinsing on the IML of body cavity surfaces that had previously been intentionally soiled with a GIC mixture. Furthermore, in Studies I and II, the subsequent ML of body cavity surfaces were determined after three days of cold storage to investigate the possible effects of time during meat maturation on the IML. Again, no differences in the MLs of rinsed and unrinsed carcasses were observed, whether on hunting day or after cold storage (meat maturation). Due to great importance of the IML on the quality and shelf life of the final product, a cause and effect analysis was performed in Study III (Chapter 3.4). This approach entailed using data from roe deer carcasses with completed sample certificates from Studies I and II to determine the effects of environmental and animal-related factors, as well as the effects of hunting and handling practices, on IML. For example, it was determined that the visual cleanliness of carcasses might not always be associated with low bacterial loads. However, the use of gloves during evisceration reduced the levels of Lactobacillus spp., Enterobacteriaceae, and E. coli compared to evisceration without the use of gloves. In summary, the investigations of the three studies resulted in a valuable contribution of knowledge on the crucial aspects that may influence the IML and thus the microbial quality of hunted roe deer carcasses.