Influence of Fat Content on Uptake and Depuration of the Off-flavor 2-Methylisoborneol by Channel Catfish (Ictalurus punctatus)

Abstract

Channel catfish (Ictalurus punctatus) of different tissue fat contents (0.5–11.0%) were held in water containing approximately 0.5 μg/L of the off-flavor compound 2-methylisoborneol (MIB) for various times. A new analytical method was developed to quantify tissue burdens of MIB. Fish showed significant bioconcentration of MIB after 2 h and equilibrium by 24 h. The fatter fish (> 2.5% muscle fat) accumulated nearly three times more MIB than lean fish (< 2%). Purging fish in MIB-free water indicated that leaner fish depurate faster (8 h) than fatter fish (48 h). Fat content had more influence in determining the time for return to acceptable flavor than initial MIB concentration. Managing catfish production to harvest leaner fish could minimize the impact of off-flavor on fish producers.