By Andrea Hargraves 
Scientists have discovered why chocolate is irresistible beyond its taste.
The work was carried out by researchers from the School of Food Science and Nutrition in Leeds, UK, who analyzed in depth the physical process that occurs in the mouth when eating a piece of chocolate and the pleasure that results from its touch and texture.
The study, the conclusions of which have been published in the journal ACS Applied Materials and Interface, could, according to officials, contribute to the development of a new generation of chocolate with the same feel and texture but healthier for consumption.
The tests were carried out using a brand of fine dark chocolate on an artificial tongue-like surface designed at the University of Leeds. The study concluded that in addition to the taste, chocolate is also irresistible because of the process in which it turns from a solid into a soft emulsion in the mouth, due to the ingredients themselves and their mixing with saliva.
Fat plays a major role the moment a piece of chocolate comes into contact with the tongue. After that moment, the cocoa solids are released and become important in terms of sense of touch.
Therefore, the deep fats within chocolate play a very limited role and can be reduced without affecting feelings of pleasure in consumption, the work’s authors argue.
The researchers used analytical techniques from an engineering field called tribology, which studies the friction, wear, and lubrication that occur during contact between moving, solid surfaces.
In this case, scientists investigated the interaction between the ingredients of the chocolate itself and saliva, and how, when it comes into contact with the tongue, it releases a fatty film that covers the tongue and other surfaces of the mouth, and it is this film that makes this product soft all the time in the mouth.
For the team of researchers, the physical techniques used in the study can be applied in investigating other foods that undergo a phase change, in which matter changes from a solid state to a liquid state, such as ice cream, butter, or cheese.
The project of which this study is a part has received funding from the European Research Council under the European Union’s Horizon 2020 research and innovation programme.