Science

Chocolate’s Feel Good Factor

You’ve probably had enough of chocolate after Christmas – but perhaps not because a new study has explored what makes it so desirable.

Just as silk is smooth against the body giving the feeling of luxurious softness so too is chocolate as it melts within the mouth, making it irresistible to many.

A team of scientists from Leeds University have been investigating chocolate as it melts within the mouth in the hopes of being able to develop a luxury version which is also healthier. The issue is with the crucial role fat in the confection plays in the texture and meltiness. If the fat content could be reduced without any loss of texture then that would be a ‘healthier’ version.

a confocal microscope image of molten dark chocolate. Image credit: Dr Siavash Soltanahmadi.

Anwesha Sarkar, Professor of Colloids and Surfaces in the School of Food Science and Nutrition at Leeds, explained:

“If a chocolate has 5% fat or 50% fat it will still form droplets in the mouth and that gives you the chocolate sensation. However, it is the location of the fat in the make-up of the chocolate which matters in each stage of lubrication, and that has been rarely researched. 

“We are showing that 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.”  

Chocolate comes from South America and became popular in Western cultures from its introduction in the 16th century onwards. From then on its history is enmeshed in the slave trade and exploitation. Today it has been transformed from its origins as a bitter tasting drink to a sweet confectionary.

Revenue from chocolate sales in the UK is forecast to grow over the next five years, according to research from the business intelligence agency MINTEL. Sales are expected to grow 13% between 2022 and 2027 to reach £6.6 billion.

Dr Siavash Soltanahmadi, from the School of Food Science and Nutrition at Leeds and the lead researcher in the study, said:

“With the understanding of the physical mechanisms that happen as people eat chocolate, 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.  

“Our research opens the possibility that manufacturers can intelligently design dark chocolate to reduce the overall fat content.  

“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.” 

The project received funding from the European Research Council under the European Union’s Horizon 2020 research and innovation programme. It was published in ACS Applied Materials & Interfaces: “Insights into the multiscale lubrication mechanism of edible phase change materials”