Reduced-fat chocolate

Scientists have found a way to use an electric field to reduce fat in liquid chocolate — maintaining a suitable viscosity for the manufacturing process while yielding a healthier end product.

Chocolate has levels of fat that typically range from 40–60%, but lowering the fat content has proved problematic in the past. Lead study author Rongjia Tao, professor of physics at Temple University, explains that when fat is removed from liquid chocolate, its viscosity, or consistency, changes and the chocolate jams the pipeline as it travels through the manufacturing process.

Tao and his team theorised that by applying an electric field, they could accomplish two things: they could reduce the viscosity enough to reduce the fat and also increase the density of the particles to maintain proper flow of chocolate through the manufacturing process.

The key was applying the electric field in the same direction as the flow of the chocolate. Traditionally, electrorheology (ER), the practice of using electric fields on liquids, works perpendicularly to the liquid flow direction. Tao’s team believes this method could be applicable to any liquid for which there’s a need to reduce viscosity.

Electrorheology works by changing the alignment of the particles in a liquid using electric fields. In the current study, ER aggregated the cocoa solid particles into short chains, which allowed the scientists to reduce the viscosity and reduce the fat but maintain the flow.

For precision, Tao and his team invented their own device to test their theory. They were able to reduce the fat on several different brands of chocolate by 20%, better than they anticipated. Their findings are published in the Proceedings of the National Academy of Sciences.

And the most important question — how does it taste?

“The treated chocolate has wonderful taste,” said Tao. “Some people even claim that the ER-treated chocolate has a slightly stronger cocoa flavor, better than the original chocolate.”

Tao’s hope is that the first consumers will be able to decide for themselves in a year.