A team from Temple University’s Department of Physics has just published an article on how you can get better chocolate by running a current along liquid chocolate. That’s right: with just a bit of electricity, you can get “healthier and tastier” chocolate.
Why is this important? Well, chocolate’s good. It’s candy, it’s comfort food, and if you’re particularly keen, you’re going to find a LOT of it on sale after Valentine’s Day if you don’t mind all the heart decorations. It’s also good for you in moderation. It contains theobromine (can lower blood pressure), phenylethyamine (linked to the ‘high’ you get from exercising), and caffeine (sweet, wonderful caffeine). The problem is that there’s a lot of fat involved in making chocolate into bars, bunnies, and other shapes.
See, liquid chocolate is a mixture of things; it’s usually cocoa, sugar, milk, oils, and other fats. The fats are usually cocoa butter, but milk fat may be there. Sure you might just get rid of the problem by just getting rid of all the fats, but then you get into the problem of viscosity, a liquid’s resistance to flowing. Water has a very low viscosity, which is why it flows the way it does. Because of all the solid stuff that’s in liquid chocolate, most importantly the cocoa powder, its viscosity is going to be high. So, instead of flowing like water, it’s going to flow like Pepto-Bismol. If you take out too much of the fats, you end up with something that’s much more solid because of all the cocoa powder, so it’s going to have a hard time moving through the pipes. Adding more pressure probably won’t help. All you’ll get out of it is busted pipes and an exploded factory.
The authors wanted to reduce the amount of fat you have to add without removing the solid cocoa and still have chocolate that can flow through the pipes easily for mass production. They suggest that by adding an electric field, the solid cocoa particles will group up and change shape. Instead of spheres, you get what they describe as a ‘prolate spheroid’, which is the shape of a rugby football. Because of it, the pipes are less packed, allowing more solid cocoa to pass through with less fat. That’s their hypothesis; since chocolate is considered to be an electrorheological fluid, it doesn’t conduct electricity (so don’t use it to charge your phone – it’s a waste of chocolate, and tech support will laugh at you), but its viscosity will change when you apply a current through it.
The most important part of any hypothesis is that it’s testable, and that’s exactly what they did. The result? It lowered the viscosity, so it flowed through the pipes faster. This means that you can actually add more cocoa powder to the mix and it will still flow through the pipes just fine. You end up with “healthier and tastier” chocolate because less fat was needed to keep it viscous and you get a stronger cocoa flavor.
This isn’t the first study that looked at how electric fields can affect the behavior of liquid chocolate. A quick Google Scholar search for ‘electrorheology’ – the process of applying an electric field – and ‘chocolate’ shows that studies have been done on this topic since the 1990s. These authors applied some of the basic research done in the past and even threw in one suggestion of their own – using a magnetic field.
It has just occurred to me that the Large Hadron Collider uses extremely powerful magnets to accelerate particles to near the speed of light. It just so happens to be located in the border between France and Switzerland, both known for very fine quality chocolate. So maybe…?
Main article: Tao R; Tang H; Tawhid-Al-Islam K; Du E; Kim J. (2016) Electrorheology leads to healthier and tastier chocolate. Proc. Nat. Acad. Sci. 10.1073/pnas.1605416113
Banner photo: Creative Commons License, Wikimedia Commons (User: Nieuw)