Research
| Title： | The ratio between digestible protein and digestible energy affects accumulation and depuration of geosmin and 2-methylisoborneol (2-MIB) in Japanese seabass (Lateolabrax japonicus) raised in a recirculated aquaculture system |
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| First author： | Lu, Qiang; Zou, Yuan; Zhang, Yuexing; Huang, Liying; Liu, Haokun; Dong, Zhiyong; Yin, Xiaolong; Storebakken, Trond |
| Journal： | AQUACULTURE RESEARCH |
| Years： | 2022 |
| DOI： | 10.1111/are.15554 |
| Abstract： | Actinobacteria and cyanobacteria accounted for less than 1% of total of bacteria in water in a recirculated aquaculture system (RAS) during a 15-week feeding trial with 0.11-g Japanese seabass. Resulting concentration of geosmin and 2-methylisoborneol (2-MIB) in RAS water was 169 and 45 ng L-1, sufficient to produce strong off-flavour. The seabass were fed diets with 42%, 45% and 49% protein, and each protein level was supplemented with 15% or 18% lipid. Accumulation of off-flavours was independent of diet in fatty ventral tissue. Dietary protein significantly reduced off-flavours in lean, dorsal tissue. This was mainly rationalized by linear reduction in 2-MIB in response to increasing DP/DE and a strong, 2nd degree polynomial response in geosmin. The ratio between geosmin and 2-MIB was slightly higher at the beginning of a 10-day period with clean water and fasting, than what was observed throughout depuration. 2-MIB remained between 0.2 and 1 mu g kg(-1) in dorsal tissue throughout depuration. Geosmin in ventral tissue ranged from 10 to more than 30 mu g kg(-1)at the termination of the feeding period and was reduced to a range from 6 to 20 mu g kg(-1) by depuration. |
