Applying an electric field to liquid chocolate in the flow direction can reduce the fat level in chocolate by 10% to 20%, according to Mars-funded research conducted by Temple University.
 
The study was published in Proceedings of the National Academy of Science (PNAS).

Rongjia Tao, lead researcher and professor of physics at Temple University in Philadelphia, Pennsylvania, told ConfectioneryNews current chocolate products contain too much fat, leading to obesity, and claimed no solution has been found to deal with the issue for decades.

Two chocolate manufacturers, Proctor & Gamble and Nabisco, introduced some low-calorie fat to substitute for cocoa butter in their products, the study says. However, the fats used are not allowed in most countries, such as Canada and Western Europe.

Methodology: reducing chocolate’s viscosity using electrorheology
The study says when the concentration of cocoa solid is high, removing a small amount of fat will jam the chocolate flow.

“But chocolate is always liquid when it’s made,” Tao said.

Tao’s team used electrorheology, a method they found that can improve transportation of crude oil, during chocolate in the making.

“We aggregate the suspended particles into prolate spheroids [by applying an electric field],” Tao said. “This micro structure change reduces the viscosity in the flow direction, and enables us to reduce the fat level by 10% to 20%.”

Easy and inexpensive to use
Chocolate manufacturers only need to add a viscosity reduction device downstream next to the pump, according to Tao.

"Roughly, the manufacturer first select the proper amount of cocoa solid and cocoa butter, melt the butter, mix them with all the ingredients together. Then, the pump pushes the mixture (liquid chocolate) into the viscosity reduction device, which utilizes the electric field to reduce the viscosity of liquid chocolate to the desired level. Afterwards, the treated liquid chocolate flows into the production line to carry out the same production procedures."

Researchers typically let the liquid chocolate flow to pass the electric field for five seconds.

Tao said that the technology should not be expensive on an industrial level. In addition, as cocoa solid is cheaper than cocoa butter, the new low-fat chocolate also has lower material cost. 

‘Wonderful taste’

The electrorheology-treated chocolate has wonderful taste, researchers said.

“Some people even claim that the chocolate has a slightly stronger cocoa solid flavor, better than the original chocolate,” says the study.

“We are thus expecting a new class of healthier and tastier chocolate products soon.”

Research funded by Mars
Temple University is the patent holder of the methodology that alters the viscosity of liquid chocolate through the application of an electric field.

Even though researchers received funding from Mars Chocolate to conduct the research, Tao said the university has to choose which chocolate manufacturer it will grant the patent to.

“There are chocolate companies from all over the world, mostly small brands, have shown their interest,” he said. “Our school will pick one in the next a few weeks.”