For chocolate fans, taste is an important part of loving this treat, but researchers have now shed light on why the irresistible fudge feels so good.
Scientists have decoded the physical process that takes place in the mouth, as when a piece of chocolate is eaten, it transforms from a solid to a smooth emulsion.
They suggest that the location of the fat in the chocolate helps make the texture so appealing.
By analyzing each of the steps, researchers at the University of Leeds hope their findings will lead to the development of luxury chocolate with the same feel and texture that is healthier to eat.
When chocolate comes into contact with the tongue, it leaves an oily film that covers the tongue and other surfaces in the mouth.
This makes it feel smooth the entire time it is in the mouth.
According to research, the feeling of chocolate in the mouth is caused by the way the chocolate is lubricated, either by the chocolate itself, saliva, or a combination of the two.
Once the chocolate comes into contact with the tongue, the oil has a key role to play.
Then the solid cocoa particles are released and become important in terms of tactile sensation.
Therefore, the researchers suggest that the fat deeper in the chocolate plays a somewhat limited role and can be reduced without affecting the feel or feel of the chocolate.
Anwesha Sarkar, professor of colloids and surfaces at the School of Food Science and Nutrition in Leeds, said: “The science of lubrication provides mechanical insights into how food actually feels in the mouth.
“You can use this knowledge to design foods with better taste, texture, or health benefits.
“If a chocolate bar contains 5% or 50% fat, it still creates droplets in the mouth, and that gives you a chocolatey feel.
“However, it is the location of fat in the structure of chocolate that is important at all stages of lubrication and is rarely explored.
“We show that the fat layer has to be on the outer layer of the chocolate, that’s the most important, followed by the effective coating of the cocoa particles with fat, which helps the chocolate feel so good.”
The study, published in the journal ACS Applied Materials and Interfaces, did not look at how chocolate tastes, but instead focused on feel and texture.
The tests were conducted using a luxury brand of dark chocolate on an artificial 3D tongue-like surface designed at the University of Leeds.
Dr Siavash Soltanahmadi, from Leeds School of Food Science and Nutrition and lead investigator of the study, said: “With an understanding of the physical mechanisms that occur when people eat chocolate, we believe that a new generation of chocolate can be developed that offers the feel and feel of high-fat chocolate, but is a healthier choice.
“Our research opens up the possibility that manufacturers can cleverly design dark chocolate to reduce its overall fat content.
“We believe dark chocolate can be produced in a gradient layered architecture that coats the surface of the chocolates and particles with oil to deliver the sought-after self-indulgence experience without adding too much fat to the body of the chocolate.”
The researchers believe that the physical techniques used in the study could be applied to the study of other foodstuffs that undergo phase change, such as ice cream, margarine or cheese.