News
Mar 1, 2026 - Foods
Salmonella in Raw Material Logistics: An Underestimated Risk in Silo Transport
In the raw material logistics of the food industry, the transport of bulk goods plays a central role. Cocoa, milk powder, grain, or other powdered ingredients are moved daily in large quantities via silo vehicles, tank vehicles, or IBC containers.
However, it is precisely in this sensitive section of the supply chain that risks often underestimated arise: microbial contamination and the introduction of foreign bodies. After each use, transport containers must be thoroughly cleaned and inspected. In practice, however, deficiencies such as dust deposits, product residues, biofilms, abrasion, or even foreign bodies in hard-to-reach areas are repeatedly found.
Residues from previous transports can thus remain unnoticed in the system and contaminate new batches.
Salmonella enters the supply chain early
When a positive salmonella finding is detected, many companies initially think of hygiene deficiencies in the production process. Transport is frequently not considered as the cause.
However, salmonella can already be introduced at the agricultural level, for example, when fields are fertilized with manure. The pathogens can adhere to raw materials and contaminate containers during transport. If these are then used for sensitive products like cocoa or milk powder, there is a risk of cross-contamination.
In such cases, the actual contamination does not occur in production but already in the logistics process.
Problematic dust fraction and filter mechanism
A particularly critical factor is the uneven distribution of salmonella in the raw material. The bacteria tend to accumulate in the dust fraction rather than being evenly distributed throughout the product.
When samples are taken from well-mixed material, contamination may therefore go undetected. Additionally, contaminated dust settles in filters of silo vehicles or systems. During cleaning by vibration or compressed air, this contaminated dust can re-enter the tank and subsequently be carried into production.
This phenomenon explains why raw materials are assessed as "salmonella negative" during incoming inspections, while a detection occurs later in the production process.
Salmonella is one of the most significant foodborne pathogens and is strictly monitored throughout Europe, among other things, by the European Food Safety Authority (EFSA).
Greatest danger lies before production
As the described mechanism illustrates, the greatest danger often arises not in the actual manufacturing process but already during the transport of raw materials. A critical combination results from:
Salmonella in the dust fraction
insufficiently inspected or cleaned transport containers
lack of seamless traceability
For companies, this means: Raw material logistics must be understood as an integral part of the hygiene concept.
Analytics and prevention
BAV Institute regularly conducts investigations for salmonella. Modern microbiological analytics allow for fast and reliable results and help companies to identify risks early and implement appropriate preventive measures.
Source
German Food Association:
Nutrition currently, January/February 2026 issue.