Alteration of the sensory perception of the muddy/earthy odorant 2-methylisoborneol in channel catfish Ictalurus punctatus fillet tissues by addition of seasonings

Commercial production of catfish requires frequent feeding, which contributes to effusive microbial blooms in ponds. Microbial production of the muddy metabolite 2-methylisoborneol (MIB) can reduce fish flavor quality. Although commercial seasonings may be added to fillets, little information is available concerning the sensory interaction of seasonings and MIB. The replicate sensory evaluation of catfish fillet samples containing either 1.0 or 10.0 ppb chemically-synthesized MIB conducted under controlled conditions indicated a more frequent acceptance of fish as on-flavored in samples treated with a “ lemon-pepper” commercial seasoning preparation than either untreated samples or those treated with a “ cajun-spice” seasoning blend. In addition, experimentation conducted with fish containing MIB from biological sources within the production pond, indicated a similar reduction in MIB flavor of lemon-pepper-treated samples. Although a 4-terpenol co-eluted with MIB from lemon-pepper treated samples subjected to gas chromatography mass spectroscopy, the compound(s) in the lemon-pepper preparation that interfere with the perception of MIB was (were) not identified.