Chocolate is produced in a complex process from the fermented seeds - the cocoa beans - of the fruits of the cacao tree. In addition to milk chocolate and white chocolate, chocolates with a high cocoa content are increasingly being launched on the market. To make chocolate from cocoa beans, the cocoa mass is processed with other ingredients, such as sugar, milk powder, etc., in a lengthy and energy-intensive process. Chocolate may contain undesirable substances such as cadmium or mineral oils.
After harvesting, the seeds are released from the cocoa fruit and prepared for fermentation. The cocoa beans are then dried and usually shipped for further processing. After transportation, the cocoa beans must be cleaned in a multi-stage process. Subsequently, the cleaned and roasted beans are broken into small pieces. After removal of the shell pieces, the so-called cocoa nibs are ground and rolled, producing the viscous cocoa mass. This is further processed into either cocoa powder or chocolate.
To produce cocoa powder, the cocoa mass is pressed. During this process, the cocoa butter is removed and the so-called cocoa press cake remains. This is further processed into cocoa powder by grinding.
To produce chocolate from the cocoa mass, the cocoa mass is mixed with other ingredients such as sugar, milk powder, vanilla flavoring, lecithin, etc. in the so-called melangeur, depending on the type of chocolate, and then reduced to tiny cocoa particles in a rolling mill. After fine grinding, the mass is no longer liquid, but dry and crumbly. Conching (heating and stirring for hours) reduces the water content, removes undesirable flavors, and enhances desirable flavors. Conching also liquefies the powder, creating a smooth, glossy, liquid chocolate mass. After conching, the chocolate mass is tempered. This gives it a more beautiful gloss and a firmer/harder break. The tempered chocolate is then poured into the respective molds and slowly hardens. At the end of the entire process, the chocolate is packaged. The packaging protects the chocolate from the environment and is used for marketing purposes.
There are a variety of types and qualities, shapes and flavors. In addition to milk chocolate and white chocolate (containing only cocoa butter as a cocoa ingredient), dark chocolates with a high cocoa content are also marketed. A chocolate with a higher fat content for baking and glazing is called couverture and traded.
Large quantities of chocolate are eaten on special seasonal occasions such as Easter, St. Nicholas or Advent. For the energy balance, this means that larger amounts of sugar and fat are often consumed than we consume.
TheAustrian food pyramid recommends consuming a maximum of one portion of sweets per day.
The World Health Organization (WHO) recommends that no more than 10 percent of the daily energy intake should come fromfree sugar. Free sugar refers to sugar that does not occur naturally in foods such as fruit, but is added to foods to sweeten them, as is the case with chocolate.
A child has a daily energy requirement of 1,800 kcal. This means that a maximum of 180 kcal should come from free sugar. Converted into chocolate, this means that this amount is already reached with less than 1 bar of chocolate (around 90 grams). Adults with an energy requirement of 2,000 kcal consume the maximum amount of sugar with one bar of chocolate. However, since free sugar is added to many foods and chocolate also contains very large amounts of fat (20-30%), both children and adults should consume significantly less chocolate per day, even on special seasonal occasions such as Easter.
With the online tool "Food under the magnifying glass" you can easily access the sugar, fat and energy content of many foods online and compare them with each other.
Cadmium in chocolate
Cocoa beans may naturally contain cadmium. The heavy metal, which occurs in the soil and in the environment, is absorbed by the cocoa plant and thus enters the cocoa bean. Cadmium is found primarily in that part of the cocoa bean that is further processed into cocoa press cake and subsequently into chocolate. Cocoa plants from Central and South America grow mainly on volcanic rock soils with high cadmium content. Therefore, cocoa beans from these regions often contain more cadmium than those from Africa and Asia.
Cadmium accumulates mainly in the kidneys, which can be damaged by long-term oral intake. Damage to bone tissue is also possible.
Mineral oils in chocolate
Mineral oils can get into food and thus into chocolate in various ways: for example, through lubricating oils from harvesting and production plants, through the transport of raw materials (cocoa beans) in bags whose fibers have been treated with oils, or through printing inks from recycled cardboard and recycled paper.
Mineral oils are hydrocarbon compounds that occur in saturated form (MOSH - mineral oil saturated hydrocarbons) and aromatic form (MOAH - mineral oil aromatic hydrocarbons). Some mineral oil compounds, especially some aromatic hydrocarbons (MOAH), can damage DNA, the genetic cell material, as well as cause cancer. Mineral oil residues should therefore not enter food in the first place and should be avoided in food production.
For cadmium, there are legally defined maximum levels for certain cocoa and chocolate products since January 1, 2019, which are set in the Annex Section 3 of Regulation (EC) No. 1881/2006. This is intended to reduce the intake of cadmium from these products for consumers.
In order to verify compliance with the legally defined maximum levels, we tested a total of 42 cocoa and cocoa products on the Austrian market in 2019, specifically milk chocolate, chocolate (without added other foodstuffs, no filled chocolates), cocoa powder and drinking chocolate, and a further 53 chocolates and milk chocolates from small manufacturers in 2021 for their cadmium content. The heavy metal was detected in all the products tested, but none of the samples exceeded the maximum content applicable to the product group in question.
We tested chocolate and chocolate products for their cadmium content from 2010 - 2018. The result: milk chocolates (up to 41% cocoa content) contain an average of 0.03 mg/kg cadmium; dark chocolates with a higher cocoa content (from 41% cocoa content) contain higher cadmium levels, on average 0.15 mg/kg cadmium.
Cadmium contents (mean values)
Cocoa powder and cocoa masses
Dark chocolate (>41% cocoa content)
Drinking cocoa mixtures, drinking chocolate
Other cocoa products (e.g. glaze, couverture, coated fruits)
Milk chocolate (<41 % cocoa content)
Filled chocolate, pralines
Table: Cadmium levels in chocolate, chocolate products and cocoa products in Austria from 2010 - 2017
During investigations, mineral oil residues are also repeatedly detected in chocolate. In 2017, the EU published a recommendation ((EU) 2017/84) on the monitoring of mineral oil hydrocarbons in food and materials and articles intended to come into contact with food. Subsequently, minimization measures and legal requirements are to be developed to reduce or avoid the content of mineral oils in food. Years ago, the problem with mineral oil contamination in foodstuffs packaged with recycled paper and cardboard (e.g. Advent calendars) became known. Here, the mineral oils from the printing inks of the recycled material passed into the food. As a pioneer in Europe, Austria therefore issued a recommendation on the safe use of recycled cardboard in food packaging back in 2012. The transfer of the mineral oil is to be prevented, for example, by incorporating a so-called "barrier" (barrier layer) into the packaging material.
The most common defects in the organoleptic examination of chocolates are whitish to light gray surface discolorations. This superficial coating is either leaked, crystallized cocoa butter (fat bloom) or sugar crystallized on the surface (sugar bloom). Incorrect storage, such as storage that is too warm or storage temperatures that fluctuate too much, can promote the formation of fat bloom. If chocolate moves from a very cold to a very warm storage environment, sugar bloom may form. Ripeness does not generally impair the taste of the product, nor is it of concern from a health point of view, but it does generally impair the appearance (texture) of the product in question (depreciation).
Chocolate food at a glance: Cadmium, sugar, fat
Child (30 kg) with an energy requirement of 1,800 kcal/day:
- Cadmium maximum per day (10.7 micrograms) is reached at 350 grams of milk chocolate or 90 grams of dark chocolate
- Maximum amount of sugar per day (43 grams) is reached at 86 grams of chocolate containing 50 g/100 g sugar (milk or dark chocolate)
- Fat Maximum amount per day (58 grams) is reached at 193 grams of chocolate containing 30 g/100 g fat or at 290 grams of chocolate containing 20 g/100 g fat (milk or dark chocolate)
Adult (70 kg) with an energy requirement of 2,000 kcal/day:
- Cadmium maximum amount per day (25 micrograms) is reached at 833 grams of milk chocolate or 167 grams of dark chocolate
- Maximum amount of sugar per day (48 grams) is reached at 96 grams of chocolate containing 50g/100g sugar (milk or dark chocolate)
- Fat Maximum amount per day (65 grams) is reached at 217 grams of chocolate containing 30 g/100 g fat or at 325 grams of chocolate containing 20 g/100 g fat.
As cadmium is harmful to health, the European Food Safety Authority ( EFSA ) has set a weekly tolerable intake level of 2.5 μg/kg body weight (bw) - which means that no health effects are to be expected at this level of cadmium. Converted into chocolate, this means that a 30 kg child could theoretically eat 3 bars of milk chocolate or 1 bar of dark chocolate every day until the daily tolerable intake of cadmium (10.7 micrograms) was exhausted. For a 70 kg adult, the allowable amount of cadmium (25 micrograms) would be reached with about 8 bars of milk chocolate or 1-2 bars of dark chocolate.
With regard to mineral oil, no tolerable daily intake level can be established, as the data are insufficient to derive an intake level at which there is no health risk.
Last updated: 14.04.2022