Tainting of farmed fish by geosmin and 2-methyl-iso-borneol: A reveiw of sensory aspects and of uptake/depuration

The review is a critical appraisal of the literature on sensory properties of geosmin and 2-methyl-iso-borneol (MIB) as chemicals that induce taints in freshwater fish, discusses the perception of these chemicals in fish as taint, particularly quantitative aspects, and discusses the kinetics of the uptake and depuration of the chemicals into/from fish. Reasonable values of detection thresholds of geosmin and MIB in water are 0.015 and 0.035 mug l-1, respectively. Their detection thresholds in fish are affected by the lipid content of the fish. The kinetics of uptake and depuration of geosmin and MIB can be modelled very well by the one compartment kinetic model extensively used in studies of uptake of polluting chemicals. Geosmin and MIB contents in fish reduce exponentially with time in the depuration phase, but intensity of taint is predicted to decline linearly with depuration time. The implications for quality assurance and depuration practices in aquaculture of the sensory properties of geosmin and MIB and of factors that affect the kinetics of uptake and depuration are discussed. [PUBLICATION ABSTRACT]