Open AccessEffects of Temperature on the Uptake and Depuration of 2‐Methylisoborneol (MIB) in Channel Catfish Ictalurus punctatus
Author(s) -
Johnsen Peter B.,
Lloyd Steven W.,
Vinyard Bryan T.,
Dionigi Christopher P.
Publication year - 1996
Publication title -
journal of the world aquaculture society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.655
H-Index - 60
eISSN - 1749-7345
pISSN - 0893-8849
DOI - 10.1111/j.1749-7345.1996.tb00589.x
Subject(s) - ictalurus , catfish , biology , metabolite , ictaluridae , fish fillet , fillet (mechanics) , fish <actinopterygii> , zoology , food science , fishery , biochemistry , materials science , composite material
The microbial metabolite 2‐methylisoborneol (MIB) imparts a muddy off‐flavor to channel catfish Ictalurus punctatus . Uptake and depuration of MIB from fish are important considerations in the design and implementation of systems to remove off‐flavors from fish prior to processing. The kinetics of MIB uptake by channel catfish were determined by placing fish in 6.5, 14.0, 25.0, and 34.0 C water containing approximately 1.0 μg/L chemically‐synthesized MIB. Fish were sacrificed following 0, 2, 4, 8, and 24 h exposure to MIB. Fillet tissue samples were subjected to gas chromatographic and fat content analysis. The model for MIB uptake was: MIB in fillet tissue (μg/kg) =−0.61 ± 4.2 [log( h ± 1)] ± 0.0076( T ) ( h ) ± 0.089( T ), where h is the duration of exposure to MIB in hours and T is the water temperature in degrees C. The model accounted for 74% of the total variation observed in the tissue MIB concentrations and indicated that the fillet fat content was not strongly correlated with MIB uptake. To investigate the depuration of off‐flavors, exposure to MIB was halted. Tissue samples were obtained 4, 8, 24, 48, and 72 h from fish held at 6.5, 14.0, 25.0, and 34.0 C. These data yielded the model: MIB in fillet tissue (μg/kg) = 3.6 ± 0.176( T ) – 2.06 [log( h ± 1)] – 0.00296( T ) ( h ) ± 0.197 (% fat), where h is the duration of exposure to MIB in hours, T is the water temperature in degrees C, and % fat is the % fat in the fillet tissue. The model accounted for 67% of the total observed variation in tissue MIB concentrations. Reducing the fat content of fish and optimizing water temperatures may augment MIB removal from fish tissues prior to processing.