University professors work to improve all steps of chocolate making

In innocuous greenhouses and University laboratories, scientists are creating prototypes for the chocolate of the future.

Genetically engineered cacao plants grow in one laboratory, injected with synthetic DNA found in jellyfish to make them glow in the dark.

In another area, a single thread, called a staminode, is plucked from a cacao plant's flower and cloned into entire batches of plants.

Chocolate is studied at a molecular level at another building, where the size of the chocolate particles is regulated to create the perfect chocolate taste and texture without the fat. Trained graduate students test the final results.

The Cocoa, Chocolate and Confectionery Research Group, composed of seven University professors with help from many others, studies chocolate and candy from every angle -- chemistry, sensory response, biology and engineering.

Pennsylvania is an ideal location for chocolate research because 40 percent of the nation's chocolate is manufactured here, said Greg Ziegler, associate professor of food science.

With chocolate and candy manufacturers such as Mars, Hershey Food Corp. and several wholesalers nearby, the University is a hub for the latest in chocolate research, he said.

Many of those companies help to fund the research.

"They all join together to fund things that are for the common good to the whole industry," said Mark Guiltinan, associate professor of molecular biology.

The group has already passed at least one major milestone -- this summer, it created the first genetically engineered cacao plant.

Ten years from now, cacao plants may be engineered for resistance to disease, better quality or greater yields, Guiltinan said.

But for now, engineered plants have been implanted with a "marker gene," created in a DNA synthesizer, the same gene found in phosphorescent jellyfish.

"If you shine a blue light on the plants, they glow green," he said.

This technology will eventually be combined with existing cloning technology, he said, to speed growth of engineered plants. To create genetically identical "cloned" plants, the millimeters-long staminode is taken out of a cacao plant's flower and placed in a food solution. The piece grows into several cacao plants.

As Guiltinan's group develops the cocoa plant, others work on perfecting the finished product.

Ziegler studies how to make a low-fat chocolate without compromising texture and taste.

Using equipment often found in a materials science lab, he studies the material that makes up chocolate, jelly beans and other candies.

Taste tests of the creations are done several times a week in Borland Lab. Graduate students evaluate each food using criteria such as sweetness, chocolate flavor and ability of food to melt in the mouths, Ziegler said.

When a confection is ready to be tested, graduate students sit in booths and concentrate on the taste, said Ruth Hollender, instructor of food science, who leads the tests. Though the students are not allowed to talk, she said they usually enjoy taking the tests.

"You don't want to make it sound like it's really serious," she said. "But it's not a party mood."