If you had pecan pie on your Thanksgiving menu, it could have been made with pecans that had been stored for about 10 to 12 months. And nuts stored that long can rapidly become stale unless kept frozen.
But ARS research horticulturists Elizabeth A. Baldwin and Bruce W. Wood have teamed up to extend the shelf life of pecans. Baldwin has developed an edible coating that keeps pecans stored for 10 months at room temperature from becoming rancid.
At the ARS Citrus and Subtropical Products Laboratory in Winter Haven, Florida, Baldwin used three different coatings made from cellulose that kept the nuts tasting good.
"Cellulose, the most abundant polysaccharide found in nature, is an all-natural product. It is commercially available and relatively inexpensive," she says. "It would be easy for a processor to spray these coatings on the nutmeats."
According to Baldwin, the experimental coatings are made from three types of cellulose: methyl, hydroxy propyl, and carboxy methyl. "Carboxy methyl cellulose (CMC) turned out to be the best preserver of flavor. It also gave the pecans a high gloss, improving their appearance.
"Although the CMC coating imparted a shine, the nuts didn't look or feel oily," says Baldwin. "And their color was not as dark as the control, or untreated, nuts. The color is a potentially important factor because consumers associate dark-colored pecans with rancidity, a condition when oxygen enters the nut and breaks down, or oxidizes, some of its fat."
The coatings, which are generally recognized as safe by the U.S. Food and Drug Administration, would need to be listed on the label as an ingredient.
Wood, who heads the ARS Southeastern Fruit and Tree Nut Research Laboratory in Byron, Georgia, collaborates with Baldwin on the project.
"The pecan industry is interested in further developing the coatings, which could promote year-round consumption," he says.--By Doris Stanley, Agricultural Research Service Information Staff.
Elizabeth A. Baldwin is at the USDA-ARS Citrus and Subtropical Products Research Laboratory, P.O. Box 1909, Winter Haven, FL 33880; phone (941) 293-4133, ext 119, fax (941) 299-8678.
Bruce W. Wood is at the USDA-ARS Southeaste rn Fruit and Tree Nut Research Laboratory, 21 Dunbar Rd., Byron, GA 31008; phone (912) 956-6421, fax (912) 956-2929.
"Storing Pecans Longer, Better" was published in the January 1999 issue of Agricultural Research magazine.