The answer to one of the most costly problems in the catfish industry is under research by a pair of scientists here at Mississippi State University. Anita Kelly, a fisheries biologist, and Tor Schultz, a wood chemist in forest products, are investigating ways to prevent the problem known as “off-flavor.”
This problem causes catfish to “develop an undesirable musty or muddy taste,” Kelly said.
The problem directly associated with this off-flavor plague exists within a blue-green alga in ponds where catfish are farmed. Because compounds similar to those produced by pine trees were determined to be the root of the problem, Schultz was a logical partner for the research effort.
“The blue-green alga produces two chemicals that accumulate in catfish tissue and the result is musty or muddy flavor,” Schultz said.
While catfish farmers can eliminate off-flavor by transferring affected fish to ponds with clean water, this process requires significant time and labor.
Kelly and Shultz’s findings suggest that some common products may offer immediate help in controlling the problem that costs catfish producers nearly $60 million annually. This lost revenue is associated with high cost of current control methods and the fact that producers are forced to keep fish with “off-flavor” from the market until their condition and flavor quality improve.
The current research of Kelly and Schultz involves the use of hydrophobic compounds that have the ability to absorb various chemicals but are insoluble in water. The compounds include paraffin wax, common plastics, rubber and corn oil. According to Schultz, the process of using these compounds has been found to be both cost effective and environmentally friendly.
“We found that 85 percent of the chemicals that cause off-flavor can be absorbed in 24 hours by adding a small amount of an organic substance to pond water,” Shultz said.
The goal of the project is to find a final product that can be easily handled and removed, such as wax. This would mean that farmers could remove the treatment formula once the off-flavor compound has been eliminated.
Funding for the project comes from the university’s Forest and Wildlife Research Center and the Mississippi Agriculture and Forestry Experiment Station.