11 Sep 2019
chocolate inspection

Chocolate Inspection: X-ray Detection of Product Variations & Defects in Confectionery Products

Most chocolate production lines nowadays are equipped with metal detectors. However, this type of inspection can primarily detect metal, and is  not capable of detecting foreign material such as glass, stones, rubber or plastic. Increasingly more confectionery producers have discovered the capabilities and tremendous value that an X-ray inspection system can bring to their production line.


Besides detecting different types of physical contamination, X-ray systems can fulfill key roles in your product control, that can have a critical impact on the final product. X-ray inspection system can solve the problem of “the white layer” that form on top of chocolate, and prolong the product lifespan of chocolate, as well as reducing product waste.

Fig. 0 Preview of the software used by our low-energy X-ray systems to view and analyze foreign bodies contamination and product defects and variations in chocolate products.


Above a certain temperature, the fat in chocolate turns liquid and starts migrating through the product variations out of tolerance (e.g. pores, holes, thickness) inside the chocolate, reaching the surface and forming the white layer, called the fat bloom. Even though the fat bloom does not have negative consequences on consumer health, the aesthetic appearance creates the impression of an old, dated product which should no longer be consumed.


The fact that the product changes composition and appearance between production and shelves is problematic, especially since the alteration is directly influenced by storage temperature, and not necessarily storage duration. This essentially means that if not stored at optimal temperature, a chocolate bar can change appearance even on the way from the production plant to the supermarket, before even reaching the shelves.

chocolate inspection

Fig. 1 Infographic describing the causes of fat bloom in chocolate products and how this phenomena can be avoided using low-energy X-ray inspection.

So what can chocolate producers do to avoid this unfortunate situation? The solution lies in reducing the number of pores in the chocolate. Reduced porosity will directly impact lipids ability to migrate towards the surface. Less pores – less fat covering the chocolate, but how?


With the power of low-energy, high-definition and high-contrast, the system verifies the structure and homogeneity of chocolate, density, density distribution. These are critical capabilities in determining the porosity and  identify irregularities in the product. All this assessment happens in a few seconds, while the system also check for physical contamination with foreign bodies.

Fig. 2 X-ray image displaying the physical contamination of a chocolate bar with a foreign body.

It is also possible to analyze different types of variations in chocolate. For example, producers of chocolate with different fillings can check the distribution of hazelnuts for instance, variation in coating thickness, shape, and of course, possible damages to the shape of the chocolate.


Tailored image analysis routines and advanced PLC control,  combined with a 0.1 mm resolution, makes the systems easily integrated into complex manufacturing lines, enabling complex classification and sorting, with multiple I/O possibilities at line speeds up to 30 m/min.

Fig. 3 X-ray image illustrating the visibility of various chocolate filling ( in this case hazelnuts), and proving our X-ray system’s capability of assessing the distribution and uniformity of fillings in chocolate products.

Interested in finding out more about chocolate inspection?


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