Partnership Could Oust
Off-Flavor in Fish
September 22, 2000
Agricultural Research Service
scientists are teaming up with Abraxis, Inc., of Hatboro, Pa., to help rid fish
of offensive flavors known as off-flavors.
Researchers with ARS
Health Research Laboratory in Auburn, Ala., signed a two-year Cooperative
Research and Development Agreement with the small, minority-owned company.
The thrust of the agreement will be to develop monoclonal
antibodies--proteins that lock onto a very specific molecule--that could
ultimately be used in a test kit to detect geosmin in fish ponds and drinking
water. Geosmin, which is Greek for smells like dirt, is one of
several compounds produced by algal organisms that grow in groundwater
and soil and is a major cause of off-flavor. It has an aroma that people
typically associate with soil.
Another important algal compound that causes off-flavor, methylisoborneol,
will not be studied under this agreement.
Geosmin is produced by blue-green algae blooms--pond scum--in ponds and
other water bodies, including sometimes in catfish ponds. Catfish absorb these
compounds, resulting in bad or dirty-tasting fish. To ensure bad-tasting fish
dont reach consumers, farmers take their catfish to a processing plant,
where a panel of people eat and smell a cooked catfish fillet to check for
off-flavor. If the fish fillet tastes bad, the processing plant will not buy
the producers fish. This results in major losses for producers, costing
about $16 million annually.
Currently, there are no effective, environmentally friendly methods to clean
up algal blooms in ponds. A geosmin monoclonal antibody could pave the way for
more precise water-quality tests and other corrective treatments. It would
enable catfish farmers to detect geosmin in water and clean it up before it
became a problem.
ARS is the U.S. Department of
Agricultures chief scientific research agency.
Scientific contact: Richard A. Shelby, ARS Aquatic Animal Health
Research Laboratory, Auburn, Ala., phone (334) 887-4526, fax (334) 887-2983,
Fernando Rubio, Abraxis, Inc., Hatboro, Pa., phone (215) 957-6477, fax (215)