Is it possible to design the perfect piece of chocolate? Even if it is possible, what does ‘good’ look like? Researchers from Universiteit van Amsterdam have taken tentative steps in this direction, focusing on the mechanics of sensation.
The way food tastes is important, but there are other factors that contribute to the experience, such as the smell. There is also the texture which contributes to ‘mouthfeel’ together with other sensory experiences, such as the sound that food makes when a person bites into it. These factors go some way to determining whether we enjoy the eating experience.
The researchers have been exploring the question of whether it is possible to design edible materials that optimize this enjoyment? The way to examine this is a combination of physics and food technology.
The challenge set was to demonstrate how a mouthfeel of an edible substance can be designed, in a similar way to how the properties of many other materials can be, to become a metamaterial. This means something carefully constructed in the laboratory – in this case, the constituent ingredients of chocolate.
Testing out new processes requires a challenge and chocolate provides this. The food is not an easy material to work with. Simply heating it up and cooling it down can turn soft chocolate into much more brittle tempered chocolate (or the other way around).
To get this right took some practice, and the solution was with carefully heating the chocolate up, adding some cold chocolate, cooling it down again. After this, it was put into a 3D printer.
This enabled the technologist to print essentially any shape of chocolate material they wanted, while guaranteeing that the base material always had the same properties.
The first shape of edible material that the scientists experimented with was an S-shaped chocolate with many twists. The goal was to test how this material would break and how that breaking would be experienced in the mouth.
This was tested mechanically and by giving samples to ten volunteers. It was found that the more cracks that are created when a person’s mouth bites into the chocolate, the better the taste sensation was. After several iterations, the test panel could clearly distinguish between less and more cracks when eating the chocolates. Overall, spiral-shaped chocolate metamaterials worked best.
This enabled further optimisation and by using the 3D printer the number of cracks could be ‘programmed’ into the material. The research has led to a mathematical model that has the potential to be applied to other foodstuffs, with the goal of making the food more enjoyable.
The research appears in the journal Soft Materials titled “Edible mechanical metamaterials with designed fracture for mouthfeel control.”
