DETECTING SEAFOOD OFF-FLAVORS - LIMITATIONS OF SENSORY EVALUATION

Off-flavors in seafood can occur as a result of many factors. The farm -raised catfish industry considers environmental off-flavors associate d with blooms of blue-green algae and other microbes to be its most si gnificant problem (Tucker and Martin, 1991). Algal blooms can produce geosmin and 2-methylisoborneol (MIB), which impart a muddy, musty flav or in seafood (Johnsen, 1991). Other environmental taints occur in sea food from exposure to wood processing effluents, odorants of detergent s, spilled petroleum products (ASTM, 1996a), and chemical tanker washi ngs and spills (Peels et al., 1988), Postharvest conditions can contri bute to the development of fishy and sour flavors if products are expo sed to temperatures above 4 degrees C after collection; this is due pr imarily to the breakdown of amino acids by bacterial enzymes (Gorga an d Ronsivalli, 1982; Hebard et al., 1982). Freezer storage of seafood c an contribute to development of cardboardy and painty flavors which ar e typically associated with lipid oxidation products (Johnsen and Kell y, 1990; Johnsen et al., 1987).