Influence of a nanoscale coating on plucking fingers and stainless steel on attachment and detachment of Salmonella Enteritidis, Escherichia coli and Campylobacter jejuni.

Gastroenteritis caused by Campylobacter represents the most common reported foodborne bacterial illness worldwide, followed by salmonellosis. Both diseases are often caused by the consumption of contaminated, insufficiently heated poultry meat. This can result from contamination of the meat during the slaughtering processes. Food contact surfaces like stainless steel or plucking fingers contribute significantly to cross-contamination of poultry carcasses. Modification of these surfaces could lead to a reduction of the bacterial burden, as already proven by successful application in various food industry sectors, such as packaging.In this study, nanoscale silica-coated and uncoated stainless-steel surfaces and plucking fingers were compared on a pilot scale regarding attachment and detachment of Campylobacter jejuni, Salmonella Enteritidis and Escherichia coli.The bacteria did not adhere less to the coated plucking fingers or stainless-steel sections than to the uncoated ones. The coating also did not lead to a significant difference in detachment of Campylobacter jejuni, Salmonella Enteritidis and Escherichia coli from the investigated surfaces compared to the uncoated ones.Our study did not reveal any differences between the coated and uncoated surfaces with regard to the investigated bacteria. In order to achieve a better adaptation of the coating to slaughterhouse conditions, future studies should focus on its further development based on the investigation of specific coating parameters.

Impact of nanoscale silicon dioxide coating of stainless-steel surfaces on Listeria monocytogenes.

High resistance to environmental factors as well as the ability to form biofilms allow Listeria monocytogenes to persist for a long time in difficult-to-reach places in food-producing plants. L. monocytogenes enters final products from contaminated surfaces in different areas of plants and poses a health risk to consumer. Modified surfaces are already used in the food industry to prevent cross-contamination. In this study, stainless-steel surfaces were coated with nanoscale silicon dioxide and the effects on attachment, bacterial growth and detachment of L. monocytogenes were evaluated. Attachment was considered for three different ways of application to simulate different scenarios of contamination. Bacterial growth of L. monocytogenes on the surface was recorded over a period of up to 8 h. Detachment was tested after cleaning inoculated stainless-steel surfaces with heated distilled water or detergent. Coating stainless-steel surfaces with nanoscale silica tends to reduce adherence and increased detachment and does not influence the bacterial growth of L. monocytogenes. Further modifications of the coating are necessary for a targeted use in the reduction of L. monocytogenes in food-processing plants.

Pulsed light treatment for the reduction of Salmonella Typhimurium and Yersinia enterocolitica on pork skin and pork loin.

The aim of the presented study was to investigate the impact of pulsed light on the reduction of Salmonella Typhimurium and Yersinia enterocolitica on pork skin and loin. Fluences of 0.52 to 19.11 J/cm2 were applied to the pathogen-inoculated products to perform microbiological studies, as well as analyses of color, temperature, lipid peroxidation and odor. Reductions on pork skin ranged from 1.73 to 3.16 log for Salmonella and from 1.48 to 4.37 log for Yersinia. Microbial reduction was significantly lower on pork loin, varying between a minimum of 0.4 and a maximum of 1.7 log for both pathogens. Treatments ≥7.36 J/cm2 modified the color parameters of pork skin and fluences ≥9.66 J/cm2 rendered pork loin samples less red. All studies with pulsed light resulted in odor changes, except for the experiment on pork skin at 0.52 J/cm2. Despite significant microbiological reduction on pork skin, further studies should be carried out to optimize this promising technology.