AEI 6:105-117 (2014) - DOI: https://doi.org/10.3354/aei00119
Reducing geosmin off-flavor compounds and waste outputs through dietary phosphorus management in rainbow trout aquaculture
Pallab Sarker1,3,*, Alexandre Pilote1, Marc Auffret2, Émilie Proulx1, Richard Villemur2, Marie-Hélène Deschamps1, Grant Vandenberg1
ABSTRACT: The aquaculture industry has long recognized the need to reduce phosphorus (P) waste outputs associated with environmental impact, and reduce off-flavor producing compounds, which can impact the quality of the fish product. This study was undertaken to investigate the effects of dietary high P (HP) and low P (LP) on growth, nutrient digestibility, P retention, and P loading as well as their correlation to the synthesis of geosmin-associated off-flavor in a recirculating aquaculture system of rainbow trout Oncorhynchus mykiss. The above diets were fed to quadruplicate tanks of rainbow trout (average mass ± SD: 127.4 ± 3.1 g) for 84 d. Results showed that the effects of the HP and LP diets on growth and P retention were not significantly different. While the apparent digestibility of P and other nutrients were higher in fish fed the LP diet, P waste outputs and geosmin levels in the fillets of fish were higher in fish fed the HP diet. Magnesium (Mg2+), potassium (K+) and zinc (Zn2+) concentrations in tank water were significantly lower in fish fed the HP diet than the LP diet in most of the sampling events. Furthermore, the tank water geosmin concentration was not strongly proportionally correlated with tank water-soluble P concentration for both the LP and HP diets. There was a strong proportional linear relationship between the geosmin concentration in tank water and in trout fillet for both the LP and HP diets. Results suggest that off-flavor contents in fish fillets and water were related to the dietary P level and metabolic P waste outputs into the system, findings that have implications for the formulation of sustainable diets for rainbow trout.
KEY WORDS: Recirculating aquaculture system · Metabolic phosphorus waste · Off‑flavor · Geosmin · Oncorhynchus mykiss · Growth · Nutrient digestibility · Nutrient retention
Full text in pdf format  | Cite this article as: Sarker P, Pilote A, Auffret M, Proulx É, Villemur R, Deschamps MH, Vandenberg G
(2014) Reducing geosmin off-flavor compounds and waste outputs through dietary phosphorus management in rainbow trout aquaculture. Aquacult Environ Interact 6:105-117. https://doi.org/10.3354/aei00119
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