A new study has found that the melt-in-the-mouth sensation of chocolate is due to the way it lubricates the tongue, The Guardian reported.

A research team at the University of Leeds, UK, found that chocolate releases a fatty film that coats the tongue, giving a smooth sensation while it is in the mouth.

Lead researcher Dr Siavash Soltanahmadi said that the findings could be used to design low-fat chocolate that mimicked the sensation of a high-fat product.

“We believe that a next generation of chocolate can be developed that offers the feel and sensation of high-fat chocolate yet is a healthier choice,” Soltanahmadi was quoted as saying in the 13 January report.

The research team investigated texture sensation using a luxury brand of dark chocolate and an artificial tongue. A device with a 3D-printed tongue-like texture was kept at 37C (98.6F) and powered to move like a human tongue.

The researchers found that soon after the chocolate was placed in the mouth, the tongue became coated in a fatty layer. After that, solid cocoa particles were released and became important in terms of the tactile sensation.

“The fat layer needs to be on the outer layer of the chocolate, this matters the most, followed by effective coating of the cocoa particles by fat, these help to make chocolate feel so good,” Soltanahmadi added.

The results of the research implied that the fat deeper inside the chocolate played a limited role in contributing to sensation and could be reduced without having an impact on how the chocolate feels in the mouth, the report said.

Chocolate bars with a fat content gradient or a low-fat bar coated in high-fat chocolate, could work well as a healthier alternative, the researchers said.

Soltanahmadi said creating healthier chocolate was a challenge for the food industry as low-fat versions were not always as appetising.

“Our research opens the possibility that manufacturers can intelligently design dark chocolate to reduce the overall fat content,” she said. “We believe dark chocolate can be produced in a gradient-layered architecture with fat covering the surface of chocolates and particles to offer the sought after self-indulging experience without adding too much fat inside the body of the chocolate.”

Similar techniques could be applied to help design healthier versions of other foods that transform from a solid to a liquid in the mouth, such as ice-cream or cheese, according to the researchers.

The results of the research study were published in the ACS Applied Materials & Interfaces journal.