Child with a chocolate bar

Child with a chocolate bar

Source: Getty Images/Westend61, Guntmar Fritz

“Nine out of ten people like chocolate, the tenth lies.” John Tullius

We all love chocolate, everyone knows that. This is indisputable and true for all time. Chocolate tastes good, smells good and makes us feel good. It can be comforting and stimulating, and when consumed in moderation, chocolate is even good for our health. Only around seven grams of chocolate a day can lower the risk of cardiovascular diseases, strokes in particular. This is a finding from a large-scale study published by the German Institute for Human Nutrition (DIfE) in 2010. If only there weren’t disadvantages associated with chocolate consumption. Not only is there the risk of weight gain due to the high sugar and fat content, but cocoa, the base element of chocolate, also contains - besides many substances with beneficial effects - unhealthy substances. For example, cadmium which is released into plants naturally from the soil can be present in cocoa, as can acrylamide which is produced when the cocoa beans are roasted. How can we tell how much of these harmful substances are present in chocolate?

What substances are in my chocolate?

Chemists Dr. Matthias Koch from the Organic Trace and Food Analysis Division and Dr. Sebastian Recknagel from the Inorganic Reference Materials Division know how this can be tested. They detect small amounts of contaminants in food and other substances. It is also advantageous for food producers and retailers to know the amount of cadmium or acrylamide present in cocoa and whether their products comply with the food regulations. On 1 January 2019, an EU regulation came into force specifying a maximum level of 0.60 miligrammes of cadmium per kilogramme of cocoa powder and maximum levels for various chocolate products. The heavy metal, cadmium, is very slowly excreted from the human body and accumulates mainly in the kidneys. This is why for many categories of food, the EU has previously made provisions for maximum levels of cadmium. Until now, there have been no limits for acrylamide in food. However, in 2018, the EU set out new guidelines and measures to minimise the content for certain foods.

Cadmium is tasteless

Consumers depend on food analyses being conducted correctly. Dr. Koch says, “In most cases, you cannot taste or smell whether or not a particular substance is present in a food product. We are talking here about very small quantities. The human tongue or nose cannot detect these. It is impossible to taste cadmium and acrylamide in chocolate.”

Sometimes the experts cannot easily determine the presence of a particular harmful substance in a sample and whether the value is too high. In the laboratory, they must first ensure that the analytics are suitable for the detection of subtle differences. For this purpose, a legally prescribed value is required, which aims to protect the consumer and make food safe, in addition to the valid calibration standards, analytical methods and appropriate reference materials. The chemists must ensure that the instruments display precisely, that the chemicals are faultless, and the procedure is carried out accurately. In short, their analytics must be suitable for carrying out measurements correctly. Reference materials contain particular substances in precisely defined quantities, and they can serve as a comparison in measurements and, therefore, as quality control. This is what makes them significant for manufacturers and testing laboratories alike. Dr. Koch says, “It is as if I were checking that my folding rule is displaying accurately. To do this, I need a comparison.”

BAM develops new reference materials

Reference materials for cadmium and acrylamide in cocoa powder have previously not been available on the market. That is why BAM is now developing three new reference materials. The certified cadmium levels will be close to the EU maximum levels, as well as above and below them. The new materials will also trace defined acrylamide contents. Chemists at BAM will use products with a natural strain of cadmium and acrylamide as a starting material for their development.

Savour chocolate without hesitation

Consumers will not notice anything. And BAM is making a small contribution to ensuring that they can continue to enjoy their chocolate in the future.