Effects of dietary vegetable oil supplementation on fillet quality traits, chemical and fatty acid composition of African catfish (&amp;lt;i&amp;gt;Clarias gariepinus&amp;lt;/i&amp;gt;)

A Szabó,T Molnár,P Horn,C Hancz,L Locsmándi,G Bázár,R Romvári,E Molnár,L Szathmári

doi:10.5194/aab-52-321-2009

Effects of dietary vegetable oil supplementation on fillet quality traits, chemical and fatty acid composition of African catfish (&lt;i&gt;Clarias gariepinus&lt;/i&gt;)

A Szabó, T Molnár + Show 7 more

Open Access

https://doi.org/10.5194/aab-52-321-2009

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Abstract

Abstract. The effects of dietary fish oil (FO), soybean oil (SO) and linseed oil (LO) (12 % crude fat content each) in African catfish (Clarias gariepinus) diets were tested on the fillet flesh quality, chemical and fatty acid (FA) composition, after 3 and 6 weeks of feeding. The bodyweight gain of fish and the fillet dry matter, crude protein and crude fat content was not different among the divergent treatments. High (>20 %) total n3 FA supplementation significantly increased the moisture loss of fillet (FO, LO). Applying the simple FA dilution model (JOBLING 2004a, 2004b), the incorporation dynamics of the most largely dosed FAs were accurately predictable after 3 weeks (R² between observed and estimated data for total n3 FAs: FO 0.95, LO 0.73 and for α-linolenic acid, LO 0.97). In the fillet FA composition the metabolism of n3 acids was more pronounced. The large provision of α-linolenic acid (LO) had a pronounced effect on the longchain, polyunsaturated n3 FA proportions (eicosapentaenoic and docosapentaenoic acids), while no effect was experienced on docosahexaenoic acid. This study suggests that daily bodyweight gain is not, while fillet flesh quality and FA composition is slightly compromised when fish oil is substituted for vegetable oils.

Highlights

Unsaturated, essential n3 fatty acids have beneficial health effects and are more and more frequently ingested via fish or fish products (BURR 1981)
Fatty acid incorporation experiments are highly successful for the accurate prediction of the fillet fatty acid composition (JOBLING 2004a, 2004b), as well in the pre-defined modification of the fillet FA profile, e.g. for the production of cardioprotective human diets (TORSTENSEN et al 2004)
An altered cellular lipid profile may lead to severe modifications of the fillet quality attributes, as it has been demonstrated for the thawing loss process of catfish fillets (BAKER 1997)

Summary

Introduction

Essential n3 fatty acids have beneficial health effects and are more and more frequently ingested via fish or fish products (BURR 1981). Fatty acid incorporation experiments are highly successful for the accurate prediction of the fillet fatty acid composition (JOBLING 2004a, 2004b), as well in the pre-defined modification of the fillet FA profile, e.g. for the production of cardioprotective human diets (TORSTENSEN et al 2004). Besides a very robust knowledge on the fatty acid metabolism of sea- and freshwater species (GREENE and SELIVONCHICK 1987, HENDERSON and TOCHER 1987), the contribution of dietary fatty acids to the fillet quality attributes is less known. A basic mode of action of dietary highly unsaturated FAs may be connected to the fact that they are effectively incorporated into the cellular membranes (HENDERSON and TOCHER 1987). The link between dietary fatty acids and fillet water-holding capacity may be the cellular membrane rigidity, as influenced by the diet (DOBRETSOV et al 1977)

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