VATIS UPDATE Article

Researchers from KU Leuven, Belgium, have now developed a quicker way to check whether the cocoa butter is crystallising correctly during the hardening process. The technique can be used ‘online’ to check the chocolate while it’s still on the production line, potentially saving the industry both time and money. “Cocoa butter crystallises as the liquid chocolate hardens. Five types of crystals can be formed during this process, but only one of these has the qualities we want,” explained Imogen Foubert from the KU Leuven.

“We’ve discovered that we can detect differences in the crystallisation of cocoa butter with ultrasonic waves,” added Professor Koen Van Den Abeele from KU Leuven. The new technique involves sending transversal ultrasonic waves through the cocoa butter. The researchers then measure the reflection of these waves for information about the structure of the butter. The technique is similar to the ultrasound echography used to monitor the health and growth of foetuses in the womb.

“When the cocoa butter is liquid, the ultrasonic wave is reflected in its entirety. As soon as the butter crystallises, part of the sound wave penetrates the cocoa butter, so the amount of reflection we measure changes. This enables us to see how the different crystals stick together, which is important for the ultimate properties of the chocolate,” said Professor Van Den Abeele. The researchers have designed a lab prototype, which now needs to be turned into a prototype for use in real chocolate production lines.