WATER COULD BE SAFE, INEXPENSIVE SOLVENT
FAYETTEVILLE, Arkansas, December 18, 2001 (ENS) - Replacing solvents in food and pharmaceutical processing with plain water could reduce costs and eliminate some environmental problems, say University of Arkansas researchers Ed Clausen and Julie Carrier.
Clausen, professor of chemical engineering, and Carrier, associate professor of biological engineering, presented their findings at the American Institute of Chemical Engineers Conference on Food Engineering.
"It has always amazed me that a chemical as toxic as hexane is used as a solvent in processing soybeans, for example," said Clausen. "I think it has largely been a matter of using something you know works rather than trying to find a less toxic alternative."
Clausen and Carrier developed their water based extraction process while studying milk thistle. Carrier, who specializes in neutraceuticals, or foods with medicinal properties, needed a safe method for extracting the active ingredients, flavonolignans, from the plant.
"Neutraceuticals are plant based extracts that are effective in treating diseases," explained Carrier. "Milk thistle, for example, contains six compounds that may have therapeutic value in treating several diseases, including prostate cancer and liver disease."
Clausen and Carrier compared their hot water extraction process with a standard chemical extraction process. They found that similar concentrations of the compounds were obtained by using both processes.
"Under certain temperature and pressure conditions, water begins to act like an organic solvent," explained Clausen. "Although this is a known phenomenon, it has not been applied to food and pharmaceutical processing before."
Current industrial processing techniques use a solvent, such as hexane, to extract the desired compounds from the plant. The solvents must then be removed before the compound can be used.
Water extraction is a cost effective alternative because it eliminates the solvent recovery stage, the researchers said. Water is also less expensive than most industrial solvents.
"Water extraction allows us to reduce the number of steps in the process," Carrier said. "And because it is environmentally benign, it doesn't present many of the problems encountered with use and disposal of many industrial solvents.":
