0000000000278555

AUTHOR

J. Vielma

Effect of peracetic acid on levels of geosmin, 2-methylisoborneol, and their potential producers in a recirculating aquaculture system for rearing rainbow trout (Oncorhynchus mykiss)

In recirculating aquaculture systems (RAS)s, off-flavors and odors, mainly caused by geosmin (GSM) and 2-methylisoborneol (MIB), can accumulate in the flesh of fish from RAS water, reducing the profitability of production. In this study, peracetic acid (PAA) was applied in three application intervals to pump sumps of rainbow trout (Oncorhynchus mykiss) reared in RAS. Using a real-time polymerase chain reaction (qPCR), the potential off-flavor producers were quantified using geoA and MIB synthase genes. Streptomyces was identified as the major GSM producer, and biofilters showed the highest number of potential off-flavor producers. Concentrations of GSM and MIB were analyzed in the circulati…

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Effects of sesame seed meal and bambaranut meal on growth, feed utilization and body composition of juvenile African catfish Clarias gariepinus

Plant proteins are plausible fishmeal substitutes but are deficient in some essential amino acids (EAA) like lysine and methionine. Combination of different plant proteins with complimentary EAA could be a useful alternative. Bambaranut (Voandzeia subterranea) contains high amount of lysine while methionine is in sesame seed (Sesamum indicum). This experiment tested effects of combining sesame seed meal (SSM) and bambaranut meal (BNM) on juvenile African catfish Clarias gariepinus. Inclusion levels (%) of SSM:BNM in four novel diets were feed 1 (F1) 0:35, feed 2 (F2) 11.7:23.3, feed 3 (F3) 23.3:11.7, feed 4 (F4) 35:0. Catfish (initial weight ± SD 11.7 ± 0.56 g) were stocked in four replicat…

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Depuration of geosmin- and 2-methylisoborneol-induced off-flavors in recirculating aquaculture system (RAS) farmed European whitefish Coregonus lavaretus

European whitefish Coregonus lavaretus has increasingly become an important species for aquatic food production, especially in the Nordic countries. Whitefish is produced in traditional cage and pond operations, and in recirculating aquaculture system (RAS) in which, unfortunately, off-flavors and odors, mostly caused by geosmin (GSM) and 2-methylisoborneol (MIB), can accumulate in fish flesh from the circulating water. GSM and MIB have very low human sensory detection limits and, therefore, often disliked by consumers even at low concentrations. In this study, concentrations of GSM and MIB in RAS farmed European whitefish were studied by an analytical method based on headspace solid phase …

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