On a cool aluminum lab bench at Temple University sit plastic tubs of hard, dark chocolate. A visitor reaches into the tub labeled "Sample B," breaks off a chunk of the smooth chocolate, and slowly chews it. Her eyes open wide.
"It's really good," she says. She smiles broadly.
You might think chocolate that's been pushed through an electric field in a physics lab would be icky. But, a reporter found, it is rich in flavor and smooth. And, surprisingly, it's lower in fat.
Welcome to the newest twist to an ancient treat.
Temple physicist Rongjia Tao and his team have developed a method to reduce the amount of fat in chocolate using an electric field to decrease its viscosity - or thickness - during production.
Their method - described this week in the Proceedings of the National Academy of Sciences - could enable companies to work with lower-fat chocolate. The first products may show up within a year, Tao said.
"The reaction [I've gotten], it's going be a very, very big deal," said Tao, a jovial sort who calls himself a senior citizen and declines to give his age. "Not only in the U.S., but also in Canada and Europe. Many people love chocolate."
Nicki Jene Engeseth, professor of food chemistry at the University of Illinois at Urbana-Champaign, said she worried that the new product might lack oomph in "mouth feel" and the "snap" in chocolate, because those traits are directly related to the fats in cocoa butter.
But "with all the benefits of dark chocolate, if it can be done, it's exciting," she said.
So how did Tao, a physicist who works with laser beams, superconductors, and crude oil, start working with chocolate?
"Yeah, I like chocolate," said Tao, whose office is on the fourth floor of Temple's Science Education and Research Center. "I use chocolate to make waffles. I put it in with the flour - dark chocolate. And my kids love chocolate."
The project wasn't initially Tao's idea.
In 2012, he got a call from London. "They said, 'We've read about your work on reducing the viscosity of crude oil. Are you interested in working with chocolate, to reduce the viscosity of chocolate?"
Tao said the company was a consulting firm for Mars Inc., which ended up partially funding his current work. Its executives wanted a solution to reduce the viscosity of liquid chocolate for production, because chocolate is quite sticky.
"Afterward, I realized there's a more important problem - to reduce the fat," Tao said. "I realized it's a really big problem."
Dark chocolate is made by combining cocoa powder with cocoa butter and sugar. Milk is added to make milk chocolate.
To form it, chocolate is heated to flow through tubes into molds or is poured over other types of candy.
It's the fat in cocoa butter, and sometimes oil, in most manufactured chocolate that makes it smooth and able to flow through pipes easily. Without the fat, chocolate aggregates. So it needs encouragement.
Tao deals with this by forcing the low-fat chocolate through the electric field, which makes the chocolate flow in strings to make the needed shapes.
Low-fat chocolate may sound like a fantastical snacking option, especially dark chocolate. The darker stuff contains antioxidants - it may lower cholesterol, and improve heart health and even brain function. If chocolate were available with less fat, that might be a win-win.
But eating low-fat chocolate - isn't fat where the flavor is?
"Fat does not provide the flavor," said Tao "Chocolate's main flavor is in the cocoa solid."