Scientists have discovered the physical process in the mouth when chocolate is consumed. As chocolate transforms from a solid into a silky emulsion, many individuals find it seductive. The multidisciplinary research team at the University of Leeds has high expectations that their work could pave the way for a new generation of luxury chocolates that are lower in sugar and calories but maintain the same flavour and consistency.
When chocolate is in the mouth, the experience of chocolate is caused by the manner in which it is lubricated, either by components in the chocolate itself, saliva, or a mix of the two.
As a piece of chocolate makes contact with the tongue almost immediately, fat plays a crucial role. After that, solid cocoa particles are liberated, and they become significant in terms of the tactile feeling; hence, the fat deeper inside the chocolate plays a relatively minor function and may be reduced without affecting the texture or flavour of the chocolate.
The science of lubrication offers mechanical insights into how food feels in the mouth. You can use this information to create foods with improved flavour, texture, or health advantages. Whether chocolate contains 5% or 50% fat, it will still produce droplets in the mouth, which provides the chocolate flavour. However, in each step of lubrication, the location of the fat in the chocolate’s composition is significant, and this topic has received scant attention.
The fat layer must be on the outermost layer of the chocolate; this is of the utmost importance, followed by the effective coating of cocoa particles by fat; these elements contribute to the pleasant texture of chocolate.
Tribology is the study of how different surfaces and fluids interact with one another, the amount of friction that occurs between them, and the role of lubrication, which in this context refers to saliva or liquid chocolate. When chocolate is taken, each of these processes moves from the mouth to the stomach.
On an artificial 3D tongue-like surface created at the University of Leeds, tests were done using a luxury brand of dark chocolate. The investigation was conducted using analytical tools from the tribology engineering discipline, including in situ imaging.
When chocolate touches the tongue, it releases a fatty coating that covers the tongue and other oral surfaces. This fatty coating is responsible for the chocolate’s silky texture throughout its consumption.
Dr Siavash Soltanahmadi, who is the lead researcher for this study and works at the School of Food Science and Nutrition at the University of Leeds, says that with an understanding of the physical mechanisms that occur when people consume chocolate, authors believe that a new generation of chocolate can be created that offers the same texture and sensation as high-fat chocolate but is a healthier option.
The researchers suggest that producers may minimise dark chocolate’s overall fat level through intelligent design. Dark chocolate can be manufactured in a gradient-layered architecture with fat coating the surface of chocolates and particles to provide the desired self-indulgent sensation without adding excessive fat to the chocolate’s body.
According to data from the business intelligence firm MINTEL, chocolate sales in the United Kingdom are expected to increase over the next five years. Between 2022 and 2027, sales are projected to increase by 13% to reach £6.6 billion.
The physical approaches employed in the study might be used in the investigation of other foods that experience a phase transition, in which a material transforms from solid to liquid, such as ice cream, margarine, and cheese.