For many people, eating a piece of chocolate is a pleasurable experience, why should this be so with chocolate compared with other foods? Researchers have been exploring why chocolate feels so good when it is eaten. The answer relates to the process of lubrication.
University of Leeds scientists have deconstructed the physical process occurring within the mouth when a piece of chocolate is eaten. The process of consuming chocolate involves its transition from a solid to a smooth emulsion.
Tests were conducted using a luxury brand of dark chocolate on an artificial 3D tongue-like surface.
The study established that during the moments it is in the mouth, the chocolate sensation arises from the way the chocolate is lubricated. This is a factor either from ingredients in the chocolate itself or from saliva or a combination of the two.
It was also found that fat plays a key function almost immediately when a piece of chocolate is in contact with the tongue. Following this, solid cocoa particles are released. These particles are important in terms of the tactile sensation.
This also means that fat deeper inside the chocolate plays a limited role compared with the particle release. This means that the fat content could potentially be reduced without having an impact on the feel or sensation of chocolate.
Here, the research has an additional focus. By analysing each the steps involved, the researchers are also seeking to unlock the secrets for the development of a new generation of luxury chocolates that will have the same feel and texture but will be healthier to consume.
This is picked up by lead researcher Anwesha Sarkar, Professor of Colloids and Surfaces in the School of Food Science and Nutrition at Leeds, who says: “Lubrication science gives mechanistic insights into how food actually feels in the mouth. You can use that knowledge to design food with better taste, texture or health benefits.”
Building on this, Sarkar puts forward the notion: “If a chocolate has 5 percent fat or 50 percent 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.”
This leads to the future development, which Sarkar summarises as: “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.”
The research appears in the journal ACS Applied Materials & Interfaces, titled “Insights into the Multiscale Lubrication Mechanism of Edible Phase Change Materials.”
