Famous for Egg Waste

It started with cracking eggs.

Each year, close to 30 percent of the eggs we consume are broken and processed or powdered into foods such as cakes mixes, mayonnaise, noodles, and fast foods. That translates into over 50 million cases of eggs (at 30 dozen eggs to the case) used annually by the food industry. Which creates a big problem.

cracked egg
James Collins

"With that many eggs, you get one heck of a pile of shells," says Joe MacNeil, professor emeritus of food science, "and it costs a pile of money to cart those shells off and dispose of them."

Eggshell waste is a serious matter in the "egg-breaking" industry. Companies are paying up to $100,000 a year to dispose of eggshells in landfills—and the fills are reaching capacity. On top of that, many landfill owners do not want eggshells because the protein-rich membrane which adheres to the shell attracts rats and other vermin.

What makes the eggshell dilemma even more vexing is that the shells are a valuable commodity. Selling for about $100 a ton, they are rich in calcium and can fortify foods from animal feed to orange juice; finely ground, the shells can be used as a substitute for pulp in paper. Even more valuable, however, is the thin membrane that makes them such a nuisance to dispose of: It's made up primarily of collagen. The biomedical uses for raw collagen are manifold: It's used in the production of skin grafts, tissue replacement products, plastic surgery, angioplasty sleeves and cornea repair. But no one could figure out how to separate the membrane from the shell, and stuck together, they were worse than worthless.

MacNeil was determined to try. His early efforts won the support of industry people such as Joel Cutler, of Cutler Eggs in Philadelphia. In 1997 his quest took on new urgency after he attended a meeting at Penn State of representatives from the Egg Processors Association, the Food Manufacturers Consortium, the Egg-breaking Machinery Manufacturers, and the Environmental Protection Agency, who identified eggshell waste as number 15 on the EPA list of food industry pollution problems. MacNeil secured a grant from the Pennsylvania Department of Agriculture and started work.

He tried everything he could think of: submerging eggshells in acid, boiling them, soaking them in various chemicals, tumbling them in a stone-filled chamber, even scraping them with sandpaper.

"It was a big gooey mess, and I was ready to throw in the towel," recalls MacNeil. "No matter what I did, I always found traces of the membrane still attached to the shell."

As a last resort, he adapted some parts from a type of meat grinder. It worked. Thanks to a delicate multibladed knife, the membrane was scraped clean from the shell.

MacNeil knew he'd found a solution to the eggshell problem, but he didn't realize how much it would pay off. "Purified collagen sells upwards of $1,000 per gram," he says. "I didn't know know that when I started, but I sure know it now."

MacNeil took his invention to the University's Intellectual Property Office. As the office staff does with each of the more than 200 inventions that are disclosed to them each year, they worked with MacNeil to find ways of commercializing and marketing his eggshell separation process. A meeting of interested food-industry parties convened, and Joel Cutler of Cutler Eggs emerged with an exclusive license on the process.

"I'd worked with Joe for many years," says Cutler, "and I knew his separation technique would be a workable one. We were ready to devote the time and money to building what we needed to commercialize the process."

And if profits and glory aren't enough, fame is also coming MacNeil's way now that he's solved the eggshell problem. He's sat for interviews for CBS and the Canadian Broadcast Company, and articles have appeared in Business Week and The New Scientist. Best, he received a note from an eight-year-old in California who, having read about his process in the newspaper, enclosed a sample of a dried egg membrane from a chicken egg on her own farm.

"Look at this," MacNeil exclaims, motioning toward the piece of beige stationary on his desk. "I got a fan letter!"

Joseph MacNeil, Ph.D., is professor emeritus of food science in the College of Agricultural Sciences, 119 Borland Lab, University Park, PA, l6802; 814-863-1824; macneil@lazerlink.com. His work was supported by the Pennsylvania Department of Agriculture. Tom Monahan is director of the University's Intellectual Property Office; 814-865-6277; tjm10@psu.edu; www.research.psu.edu/ipo/. Carol Sonenklar is a freelance writer in State College, PA.

Last Updated September 01, 1999