Carcass yield and fillet chemical composition of wild and farmed African sharptooth catfish, Clarias gariepinus
Hoffman, L.C.; Casey, N.H.; Prinsloo, J.F. (1993). Carcass yield and fillet chemical composition of wild and farmed African sharptooth catfish, Clarias gariepinus, in: Barnabé, G. et al. Production, environment and quality: Proceedings of the International Conference Bordeaux Aquaculture '92, Bordeaux, France, March 25-27, 1992. EAS Special Publication, 18: pp. 421-432
In: Barnabé, G.; Kestemont, P. (Ed.) (1993). Production, environment and quality: Proceedings of the International Conference Bordeaux Aquaculture '92, Bordeaux, France, March 25-27, 1992. Special Publication European Aquaculture Society, 18. European Aquaculture Society: Gent. 587 pp., meer
In: Special Publication European Aquaculture Society. European Aquaculture Society: Bredene. ISSN 0774-0689, meer
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| Auteurs | | Top |
- Hoffman, L.C.
- Casey, N.H.
- Prinsloo, J.F.
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| Abstract |
The percentage yield and fillet chemical composition of wild and farmed male and female African sharptooth catfish Clarias gariepinus are presented. Farmed males yielded 46.7% fillets compared to 44.2% for wild males, 44.% for wild females and 38.9% for farmed females. Female gonadal mass strongly influences dressout percentage. The fillets of both wild and farmed males and females did not differ statistically in moisture (77.7%), protein (18.2%), fat (2.3%) or ash (0.5%) content. The fatty acid profiles within type were not influenced by sex. The wild catfish had significantly (p<0.05) higher concentrations of C16:1, C17:0, C17:1 and lower concentrations of C18:1 and C18:2 compared to farmed catfish. Clarias gariepinus had 39.5% saturated, 42.6% monounsaturated and 17.3% polyunsaturated fatty acids. Differences in amino acid and mineral compositions of the male and female farmed catfish tested non-significant (p<0.05). However. there were amino acid differences between wild male and female (aspartic acid, glutamic acid, phenylalanine and methionine) and between farmed and wild catfish (tyrosine, valine, leucine and hydroxyproline). Lysine is well represented in the fillets (10% of total amino acids present). Of the essential amino acids tested. Clarias gariepinus fillets contain the following (expressed as % of total amino acids): arganine, 6.1; histidine, 1.9; isoleucine, 3.7; leucine, 6.7; lysine, 10.2; methionine, 2.7; phenylalanine, 3.6; tyrosine, 3.1; treonine, 4.1 and valine, 4.0. Levels of the minerals phosphorus, potassium, manganese and iron differed significantly between type and between sexes within type. No differences were noted for calcium, magnesium, copper or zinc. The mineral content of Clarias gariepinus fillets (mg element/100g wet weight fillet) is: Ca 3.7; P 21.5; Mg 4.8; K 39.1; Fe 1.9; Cu 0.1 and Zn 0.7. Wild fish were heavily infested with nematodes, Contracaecum spp. whilst the farmed fish had no visible infections. |
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