Physicists at Temple University in Philadelphia have come up with a novel approach to manufacturing chocolate that could allow for a lower fat content. Current techniques rely on a relatively high fat percentage — as much as 40 percent — to keep chocolate in liquid form during production, but the new method detailed in a study published today suggests that can be circumvented with the clever application of an electric field.

Electrorheology, as this field of research is called, is concerned with the deformation and flow of matter when affected by electricity. What the Temple researchers found was that an electric field applied in the flow direction of a liquid stream of chocolate helped to reduce its viscosity along that direction. Because this field polarizes the cocoa particles, they were able to essentially reorient and aggregate the particles inside the chocolate, turning them into short chains that flow more easily. The liquid's viscosity was made anisotropic, which is to say that it was reduced only in the flow direction, the one that matters.

A less viscous chocolate mixture means a lower minimum required fat content, and the Temple team claim their approach can reduce that figure from 40 percent down to 32 percent. Their argument is that chocolate containing less fat would be healthier to consume, owing primarily to the associated reduction in calories. High-fat chocolate leads to obesity, they contend, although they do also concede that the majority of fat in chocolate is cocoa butter, which actually has quite a few health benefits in and of itself.

The study is published today in the Proceedings of the National Academy of Sciences journal and is already bolstered by two granted patents from the US Patent and Trademark Office. It received funding from Mars Chocolate, a company that would understandably be interested in promoting research into developing new chocolate manufacturing methods. The study authors say they are "expecting a new class of healthier and tastier chocolate soon," though those are the claims that their report doesn't corroborate with any hard data.

There's no guarantee that Mars or any other company that might be interested in adopting the technique would use it to replace the fat with something healthier. The potential for marketing a lower-fat chocolate is obviously huge, however, which is what makes this exciting for the big producers. For us humble geeks, it's just really cool to see the problem of viscosity ameliorated with the help of some clever electrical engineering.