Wax Paper Turns "Green"

Agricultural Research Service scientists have developed an inexpensive way to use a corn protein called zein to make a biodegradable coating as a replacement for wax on paper.

Wax paper and other wax-coated packaging is made with waxes from refined petroleum-based products. The food industry is a major user of wax packaging material. Currently, this paper and cardboard isn’t recycled, because the wax coating cannot be cleanly separated from these materials.

While looking for ways to reduce the cost of producing ethanol from corn, researchers with the Engineering Science Research Unit at the ARS Eastern Regional Research (ERRC) Center, Wyndmoor, Pa., isolated a zein-lipid mixture from ground corn. This mixture can easily be applied to paper, and has good grease resistance and water barrier properties.

Zein is a protein found in the corn kernel. Unlike other corn proteins that dissolve in water, zein repels water, making it an ideal coating for packaging materials. Corn contains about 7-10 percent protein, and about 50 percent of those proteins are zein. The estimated cost of extracting zein-lipid mixtures from ground corn by the process developed at ERRC is about $1-2 per pound.

This technology can be used on any packaging material that requires water proofing, such as boxes for perishable fruits, vegetables and fish.

ARS’ technology offers an alternative, environmentally friendly coating for food packaging materials. It also provides an opportunity to strengthen the agricultural production of corn.

ARS is the U.S. Department of Agriculture’s chief research agency.

Scientific contact: Nicholas Parris, Engineering Science Research Unit, ARS Eastern Regional Research Center, Wyndmoor, Pa., phone (215) 233-6453, fax (215) 233-6795, nparris@arserrc.gov.