Comparisons of Uptake and Depuration of 2-Methylisoborneol in Male, Female, Juvenile, and 3MC-induced Channel Catfish Ictalurus punctatus

The occurrence of off-flavors in farm-raised channel catfish is a major burden to the catfish culture industry, causing millions of dollars worth of market-ready fish to be rejected each year. Off-flavors are believed to be the result of exposure and subsequent accumulation of certain volatile microbial metabolites such as 2-methylisoborneol. In this study, the uptake and elimination of ¹⁴C]-2-methylisoborneol equivalents were examined in juvenile and mature channel catfish. The described method is presented as a simple and inexpensive procedure for comparing treatment effects on off-flavor elimination rates. In addition, the effects of the cytochrome P4501A inducing agent 3-methylcholanthrene on 2-methylisoborneol depuration was studied in juvenile fish. Uptake was determined during a 24–h static exposure to waterborne 2-methylisoborneol (7.6 ± 3.7 μg/L). Uptake equilibrium had been established in all groups by 12 h, with total uptake higher in juvenile fish. Depuration rates were not different between untreated groups (t_½ a = 12.r122.4 h; t_½β= 91.3–143.7 h); however, the depuration half-lives for 3-methylcholanthrene treated juveniles were significantly longer than those of controls.