Spore-forming bacteria belonging to the genera Bacillus and Clostridium will are present in farm and dairy environments and can easily contaminate milk. Pasteurization of milk kills the vegetative bacteria while bacterial spores will survive. The spores can then germinate, resulting in vegetative bacteria that can grow and cause spoilage of milk and milk products.
The presence of spores in milk and dairy products can lead to major financial losses to the dairy industry due to:
1. Suboptimal product quality, which leads to reduced shelf life and increased food waste
2. Need for extensive disinfection procedures
3. Increased resources for quality and food safety control
Even though Norwegian raw milk has a high microbiological quality, the dairy industry experiences quality problems in cheese related to the presence of Clostridia. To prevent the occurrence of quality-deteriorating Clostridia in dairy products, there is a need for more knowledge regarding how different processing steps affects the composition and survival of different Clostridial species. The CLOBIO project aims to cover these knowledge gaps by analyzing the composition and dynamics of Clostridia along the production lines for cheese and milk powder by analyzing the entire nucleotide sequences from all bacteria in the sample and by identifying individual bacterial isolates using MALDI-TOF analyzes and genome sequencing. Every month for two years, we have collected samples along the production chain for semi-hard cheeses, from the milk enters the dairy, during processing and storage. This gives us more knowledge about from where quality-deteriorating bacteria come from and how they are affected by various production steps. We have now isolated a number of potentially quality-deteriorating bacterial species from whey and casein grains and will now investigate how they behave along the production chain for semi-hard cheeses in a small-scale cheese production at the FoodPilotPlantNorway. Efforts are also being made to assess the accuracy and sensitivity of the methods used commercially to detect Clostridia in the production chain. Results from commercially used tests methods are compared with data from microbiological analyses made in the CLOBIO project. The knowledge produced in the project will be used by the dairies to optimize their hygiene work and will be important for developing strategies to reduce losses along dairy value chains. This will ensure food safety and promote food production in a more cost-effective and sustainable way. CLOBIO thus follows Norwegian agricultural policy goals for future-oriented and increased food production.
The presence of Clostridia in dairy products impose problems to the dairy industry related to product spoilage, which leads to food waste and financial losses. Farming practices is today the most important factor in controlling spoilage-associated and potentially pathogenic Clostridia in raw milk. However, despite the high quality of Norwegian milk, problems related to the presence of Clostridia in dairy products remain. For further preventive measures, more knowledge is needed on the composition and behavior of Clostridia present along dairy processing lines. CLOBIO will use state-of-the-art technologies, such as high throughput sequencing and metabolomics, to increase the knowledge on Clostridia present along the dairy processing lines of cheese and milk powder. Dairy samples will be collected along the processing lines, starting from when the raw milk arrives at the dairy plant, during processing and under product storage until the end of shelf life. CLOBIO will assess how different processing steps affect the composition and survival of Clostridia. Samples will be collected, over a period of two years, from three dairy plants to capture seasonal variations and the influence of the geographical location on the composition of Clostridia in the dairy samples. Hypotheses generated in the project will be tested in a pilot scale at the FoodPilotPlant, Norway. Although, pathogenic Clostridia have not been detected in Norwegian dairy products, their potential occurrence in dairy products will also be addressed in this project. The knowledge gained in CLOBIO will be implemented directly in the dairy industry’s hygienic work and in their strategies for reducing losses along the value chain caused by Clostridial contamination. This will ensure food safety and promote food production in a more cost-effective and environmentally sustainable way. Altogether, the proposed project follow the Norwegian agricultural policy goals for future-oriented and increased food production.