Dangerous desserts (and why 375 is the magic number for testing Salmonella in chocolate)

Chocolate should be a treat, and never an ordeal.

But now, perhaps more than ever, manufacturers and the analytical labs that support them need to be alert to the threat of Salmonella in cocoa products.

Like most foods grown in the ground, cacao beans are vulnerable to Salmonella contamination by animal and even human waste products – via routes such as unclean water and improper handling.

Apart from contaminated cacao, other raw ingredients have the potential to introduce Salmonella – some of them introduced only after the heating or dry-roasting process that  also acts against bacteria in the cacao beans.

Moreover, according to a study led by researchers at the University of Naples, the “low water activity and high fat content (of cacao beans) increase the thermal resistance of the pathogen so that… considerable heating is required to eliminate Salmonella.”

Add to this the growing popularity of ‘raw’ chocolate products – made using a heating process where temperatures do not exceed 42°C – and the risks of consumers contracting Salmonella from chocolate are arguably greater than ever.

In this context, company and third-party laboratory analysis to detect unwanted bacteria provides another vital failsafe – but even at this stage, Salmonella presents further complications for chocolate makers.

That’s because contamination with Salmonella is generally very sporadic – often involving only a few grams out of thousands of kilos of raw materials, which makes it very hard for laboratories to detect when testing a 25g portion.

To meet this specific challenge, the chocolate industry has introduced alternative sampling and testing plans, meaning that checks for the presence of Salmonella are now widely performed on 375g tested portions of chocolate products.

Several food diagnostic firms have also developed specific methods and protocols to detect Salmonella in larger quantities - and now LGC AXIO Proficiency Testing is providing the final link in the quality assurance chain by introducing a unique 375g Salmonella in cocoa PT sample.

Participating in a proficiency testing programme such as the AXIO Quality of Chocolate (QCS) scheme is essential in ensuring that the Salmonellatesting methods in your laboratory are both fit for purpose and properly implemented - and for giving you confidence in the measurement of your results.

For 40 years, AXIO has been a trusted partner for laboratories working to keep food safe for everyone.

We move with the world’s changing demands, which is why we’ve launched our ground-breaking new sample (PT-CT-720), supplied as 375g of cocoa powder (plus vial), with Salmonella species as the target analyte.

Drawing on decades of proficiency testing and our truly global reach, AXIO is your perfect partner in proficiency testing.

Head to lgcstandards.com/AXIO to find out more and place your order.

LGC. Science for a safer world.