Modelling of Taste-Taint in Fish ... 51It is acknowledged that manipulation of changing variables i.e., fingerling
livestock, and nutrients in RAS, can affect taste-taint chemical concentration
in growth-water and, in turn, in the fish-flesh. Therefore, a user friendly and
potentially economic model needs to be developed for simulating possible
outcomes in fish with RAS water temperature and harvest time.
There is some urgency to synthesize and test a model that can be applied
to simulate taste-taint chemical uptake, accumulation and elimination over
time. Because a threshold concentration of taste-taint as GSM (0.74 μg kg-^1 )
and MIB (0.7 μg kg-^1 ) (Jones et al., 2013; Robertson et al., 2005) in fish-flesh
for consumer rejection has been established, processes that can be
mathematically modelled are therefore open to optimisation. This is attractive
as an inexpensive and efficient way of RAS farming, and reduces the need for
manually solving potential problems of the biological RAS system. All uptake
and elimination kinetics associated with taste-taint chemicals accumulation in
fish-flesh however need to be taken into account, especially as to how they are
impacted by the physical environment of the RAS i.e., water temperature, and
dissolved oxygen concentration.
Importantly, any proposed model needs to be simple and easy to use. Once
established and validated, it could be used for day-to-day farming operations
as a management tool and potential optimisation(s).
BENEFITS OF THE MODEL TO THE SUPPLY CHAIN
Analyses of GSM and MIB chemical taste-taint in fish-flesh is expensive
and time consuming, and few research institutes have the necessary facilities
(G. Vandenberg, Faculté des sciences de l’agriculture et de l’alimentation,
Université Laval, pers. comm.). It is therefore impractical for daily monitoring
by farmers and fish processors.
Due to these practical limitations, less expensive sensory assessment have
been widely adopted in determining whether fish are tainted beyond a
threshold concentration for market consumption (Grimm et al., 2004; Percival
et al., 2008). However, this is based on human perception and requires experts
to perform the task accurately. It is therefore subjective.
Farmers however are generally unable to afford either the analytical or
sensory method due to associated costs. It is also questionable whether sensory
experts are representative of the general population (Howgate, 2004).
Moreover, it is suggested successive testing of MIB influences the taste