Researchers check chocolate quality using ultrasound waves
The quality of chocolates mainly depends on the crystals that form during the hardening of the chocolate.
The new method developed by the researchers at the University of Leuven is expected to result in huge costs and time savings for the chocolate industry.
KU Leuven department of microbial and molecular professor said: "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. The number, size, shape, and the way in which the crystals stick together play an important role as well."
KU Leuven department of physics and astronomy professor Koen Van Den Abeele said: "We've discovered that we can detect differences in the crystallisation of cocoa butter with ultrasonic waves."
The new technique involves sending transversal ultrasonic waves through the cocoa butter and then measuring the reflection of these waves to know the structure of the butter.
Abeele added: "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."
Abeele said that the technique is similar to the ultrasound echography used to check the health and growth of foetuses in the womb. ■