What is salmonella and how can an outbreak be prevented?

The chocolate manufacturing process

The pralines, chocolate bars and other chocolate products found on shop shelves are the result of a complete process.

The cocoa bean comes from the cacao tree, Theobroma cacao. After a period of fermentation and drying lasting several days, the cocoa bean is hulled, roasted and ground using a roller mill. This produces cocoa mass. Sugar and cocoa butter are then added. Finally, milk powder, nuts, emulsifiers or other raw materials are added to obtain the various finished products. The chocolate is then conched (the cocoa mass is continuously rubbed against the vessel wall) and tempered (melted and brought to the correct temperature to achieve the desired crystallisation). Once proper crystallisation has been achieved, the chocolate is poured into moulds and, where applicable, decorated. After refrigerated storage and packaging, the chocolate we know ends up on the shop shelves.

How does salmonella end up in chocolate?

In the recent Ferrero incident, salmonella is believed to have developed in a blocked filter of a tank filled with buttermilk, subsequently ending up in the chocolate. The products concerned were recalled, but the problem turned out to be more serious than expected, leading to a full recall in several countries. After thorough cleaning of the lines and several tests, production was able to resume last week. Buttermilk has a pH of 4.5, a level at which salmonella can just about still develop. At the Barry Callebaut plant, lecithin was the cause. Salmonella can also be present in small quantities in cocoa. Indeed, cocoa beans can easily become contaminated where there is a lack of hygiene in the country of origin. To prevent contamination via raw materials, companies are required to request certificates of conformity from their suppliers.

Salmonella also thrives very well in a fatty environment. Chocolate factories are therefore a prime location for it. However, the bacterium is not heat-resistant. Unfortunately, excessively high temperatures have a negative impact on the quality of chocolate products, which prevents reaching the temperature needed to destroy the bacterium.

If salmonella is detected, mandatory notification to the FASFC (Federal Agency for the Safety of the Food Chain) is required.

What are the consequences of salmonella for public health?

Salmonella can be a potentially fatal bacterium, particularly for YOPI (Young, Old, Pregnant, Immunocompromised). This year, more than 150 cases of salmonella have already been reported in the European Union via RASFF (the Rapid Alert System for Food and Feed). These mainly involved children under the age of 10. Salmonella has an incubation period of 1 to 2 days, and symptoms include abdominal pain, fever, acute diarrhoea and vomiting. These symptoms can persist for up to a week and, in the worst case, the patient must be hospitalised.

How can salmonella contamination be prevented?

As has been observed in recent months, salmonella represents a genuine risk, making it necessary to include it in the HACCP study. It is also important to select reliable suppliers and to monitor them by means of supplier assessments, mutual agreement declarations and certificates of conformity confirming the absence of salmonella as well as analysis results. Supplier audits can also be organised as an additional control measure.

Internally, it is furthermore important to put in place an effective cleaning process, a solid HACCP study and a traceability system.

We are happy to help

AMNorman has the expertise required to provide your company with the necessary information. Our AMNorman experts are happy to help chocolate processing companies establish the correct procedures to ensure optimal quality management within the self-checking system.