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Researchers Unlock The Mystery Of The Jellybean

April 10, 2000
University Park, Pa. — The association of jellybeans with the Easter season is as commonplace as chocolates on Valentine’s Day and evergreens at Christmas. But most who love munching on the jelly-filled delicacies in the sugar shell know little about the creation and physics of this confectionery marvel.

Gregory Ziegler, associate professor of food science at Penn State University, set out to unlock the mystery of the jellybean last year. Specifically, he sought the answer to the question that has baffled jellybean manufacturers since the candy was first introduced in 1861: why does it take seven long days to produce a single bean?

"We were trying to find out why it takes so long to create a finished, polished jellybean," said Ziegler. "Basically, you’ve got a sugar shell on the outside of a jelly center, and we knew that it takes a few days of aging time for that shell to harden sufficiently to be able to polish it. Our objective was to determine why that process took so long."

In Pennsylvania — a state that accounts for one-fifth of the nation’s $23 billion confectionery industry each year — solving that mystery and developing a more expedient process for creating the perfect jellybean is of significant interest.

According to Ziegler, it was initially presumed that aging was a period of drying — that the sugar shell surrounding the soft starch center simply had to dry before it was hard enough to polish. Polishing involves applying a saturated sugar solution on the rough surface of tumbling beans, which eventually crystallizes solidly enough to be waxed to a smooth gloss typical of jellybeans.

Researchers have tried unsuccessfully for decades to speed up this aging process through artificial drying techniques. Ziegler, however, proposed that the aging process actually required the natural movement of moisture from the shell to the jelly core, which enhances its softness. To remove moisture through a dryer would inhibit this process and result in a different texture to the shell and the hardening of the jelly.

To investigate this theory, Ziegler enlisted the help of Dr. Bruce Balcom, director of the University of New Brunswick’s Magnetic Resonance Imaging (MRI) Research Centre. They were assisted by Penn State graduate student Michelle Troutman, who completed her masters degree work in food science at Penn State last November with a thesis based on this project. Troutman’s participation, including work at New Brunswick, was funded through a fellowship from the Pennsylvania Manufacturing Confectioners’ Association.

The collaborative effort involved using Balcom’s MRI equipment to take real-time, cross-sectional pictures of a newly produced jellybean throughout its aging period. The test revealed what Ziegler suspected: moisture gradually moves in waves from the shell to the center of the bean.

"It’s almost like curing cement," said Ziegler. "It’s not so much the dryness as we initially thought — it’s the curing time. The curing time has two opposite but essential functions: it hardens the shell but softens the center. There is no way to artificially stimulate that process."

These findings leave confectioners with the reality that technology cannot provide a catalyst for the complex evolution of the jellybean. And for the foreseeable future, Ziegler expects the colorful sweets found in abundance at this time of year will continue to be produced in the same deliberate manner as they were when invented more than 140 years ago.

"Somtimes good things just take time," he said.


Contact: Tysen Kendig, Department of Public Information, (814) 865-7517 or .