Chocolate coats tongue to give melt-in-mouth sensation, study finds | Science

According to scientists, the irresistible sensation of chocolate melting in the mouth depends on how it lubricates the tongue.

One study investigated the physical process by which a solid square of chocolate turns into a smooth emulsion. It was found that the chocolate released a fatty layer that coats the tongue, giving a smooth sensation the entire time it is in the mouth.

Dr Siavash Soltanahmadi, lead researcher of the study at the University of Leeds, said the findings could be used to create low-fat chocolate that mimics the feel of a high-fat product.

“We believe a next generation of chocolate can be developed that offers the feel and feel of high-fat chocolate but is a healthier choice,” she said.

Soltanahmadi and colleagues set out to investigate texture sensation using a luxury brand of dark chocolate and an artificial tongue. The device has a 3D printed tongue-like texture, is kept at 37C (98.6F) and is enabled to move like a human tongue.

They found that immediately after the chocolate is placed in the mouth, the tongue is coated with a fatty layer, which depends on the fat content of the chocolate. After that, the solid cocoa particles are released and they become important in terms of the sensation of touch, the researchers found.

“We’re showing that the fat layer should be on the outer layer of the chocolate, that’s the most important, followed by the effective coating of the cocoa nibs with the fat, that helps the chocolate feel so good,” she said.

This implies that the fat deeper within the chocolate plays a limited role in contributing to sensitivity and can be reduced without affecting the way the chocolate feels in the mouth. The researchers suggested that chocolate with a gradient of fat content or a low-fat bar coated in high-fat chocolate could work well as a healthier alternative.

Soltanahmadi said creating healthier chocolate was a challenge for the food industry because low-fat versions weren’t always as tasty.

“Our research opens up the possibility that manufacturers can intelligently design dark chocolate to reduce overall fat content,” she said. “We believe that dark chocolate can be produced in an architecture with gradient layers of fat covering the surface of the chocolate and particles to provide the desired indulgence experience without adding too much fat within the body of the chocolate.”

The researchers suggested that similar techniques could be applied to help design healthier versions of other foods that change from a solid to a liquid in the mouth, such as ice cream or cheese. The findings are published in the journal ACS Applied Materials & Interfaces.