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United States Department of Agriculture

Agricultural Research Service

Title: Detection of Catfish off-Flavor Compounds by Trained Dogs

Authors
item Shelby, Richard
item Schrader, Kevin
item Tucker, Archie
item Klesius, Phillip
item Myers, L - AUBURN UNIVERSITY

Submitted to: Aquaculture Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 16, 2004
Publication Date: April 1, 2004
Citation: Shelby, R.A., Schrader, K., Tucker, A., Klesius, P.H., Myers, L.J. 2004. Detection of catfish off-flavor compounds by trained dogs. Aquaculture Research.Vol.52(4)

Interpretive Summary: "Off-flavor" is a particular problem in the catfish industry due to the accumulation of "musty-earthy" tasting compounds in the meat. These compounds are the result of 2-methylisoborneol and geosmin which are produced by blooms of blue-green algae in the pond water. The purpose of this research was to train dogs to detect these compounds in water at levels which would be typical of an off-flavor event in catfish pond culture. The dogs were given 1 out of 5 choices of off-flavor and "on-flavor" water samples and were trained to sit at boxes containing off- flavor sample tubes. At the lowest concentration tested, 10 parts per trillion of the target compound, the mean correct responses for the 3 dogs were 37% , 43% and 67%. Additional testing was conducted using pond water samples containing known amounts of these two compounds which occurred naturally. Correct responses for off-flavor samples varied from 30% to 95%, depending on the sample and the dog. On-flavor samples were correctly identified with 96% accuracy for all dogs and all samples. Dogs may provide practical early detection of off-flavor problems in catfish ponds.

Technical Abstract: A group of six mixed-breed dogs was trained to detect 2-methylisoborneol (MIB) and geosmin (GSM) in laboratory-prepared water. Three of the dogs which were most responsive to training were selected for further testing to measure their ability to detect these compounds at levels which would be typical of the early stages of an 'off-flavor' event in catfish pond culture. The dogs were given 1 out of 5 choices of off-flavor and 'on-flavor' water samples and were trained to sit at boxes containing off flavor sample tubes. At the lowest concentration tested, 10 parts per trillion (ppt) of the target compound, the mean correct responses for the 3 dogs were 37% , 43% and 67%. Additional testing was conducted using pond water samples containing known amounts of these two compounds which occurred naturally. Correct responses for off-flavor samples varied from 30% to 95%, depending on the sample and the dog. On-flavor samples were correctly identified with 96% accuracy for all dogs and all samples. Dogs may provide practical early detection of off-flavor problems in catfish ponds.

Last Modified: 8/1/2014
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