
Soapstock Waste May Yield New ProductsBy Jan Suszkiw March 22, 1999A biodegradable film made from an oilseed byproduct called soapstock may
offer a new material for encapsulating chemicals, packaging fresh produce and
other uses. Gummy and amber-colored, soapstock results from using hexane and other
industrial substances to extract and refine edible oil from the seed of cotton,
safflower and sunflower crops. For example, cottonseed processors alone
generate 60-120 million pounds of soapstock annually. Most goes into animal
feedstuffs containing seedmeal. But oilseed processors are seeking new, more profitable uses, note chemical
engineers Sam Kuk and Amy Ballew of the Agricultural Research Service in New
Orleans. ARS is the U.S. Department of
Agricultures chief scientific agency. About a year ago, Kuk and Ballew began experimenting with ways to exploit
soapstocks cache of plant esters, glycerides, and
phospholipids--substances that make it biodegradable, malleable and soluble in
both water and oil. Initially, they faced a problem encountered by scientists before them: how
to rid soapstock of water and hexane without eliminating its desirable
properties. The answer, they discovered, lay in a combination of treatments,
including freeze-drying at -40 degrees Celsius, and fine-grinding. A hydrated
paste made from the ground soapstock is also spread onto glass plates or
spheres to form thin, flexible films. The scientists are seeking an industrial partner to help refine the films
and explore their commercial potential. One interest is developing a packaging
material to wrap fresh produce like bell peppers or cucumbers that perish
easily. Another possibility is encapsulating fungicides and other chemicals in
slow-release formulations. Studies show that when placed in water, the
soapstock capsules degrade at a rate that delays the release of fungicide by
about three hours. This may also apply for pharmaceutical compounds. Scientists also are testing a soapstock gel for hair styling and coloring. Scientific contact: M. Sam Kuk, Amy Ballew,
Commodity
Utilization Research Unit, ARS
Southern Regional
Research Center, New Orleans, LA phone: (504) 286-4552, fax: (504)
286-4419, [email protected].
Story contacts Commodity Utilization Research Jan R Suszkiw U.S. Department of Agriculture | |