Pigment-depletion in Atlantic salmon (Salmo salar) post-smolt starved at elevated temperature is not influenced by dietary carotenoid type and increasing α-tocopherol level

• Published in: Food chemistry Vol. 299; p. 125140
• Main Authors: Grünenwald, Martin, Adams, Mark B., Carter, Chris G., Nichols, David S., Koppe, Wolfgang, Verlhac-Trichet, Viviane, Schierle, Joseph, Adams, Louise R.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 30-11-2019
• Subjects: Atlantic salmon; Carotenoids; Elevated temperature; Oxidative stress; Pigmentation; α-Tocopherol; Oxidative stress; Elevated temperature; Carotenoids; Glutathione disulphide (PubChem CID: 65359); Α-tocopherol (PubChem CID: 14985); Malondialdehyde (PubChem CID: 10964); Glutathione (PubChem CID: 124886); Canthaxanthin (PubChem CID: 5281227); α-Tocopherol; Atlantic salmon; Pigmentation; Astaxanthin (PubChem CID: 5281224)
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2019.125140

•Fillets were first loaded with astaxanthin and/or canthaxanthin, and α-tocopherol.•Fillets were partially depleted of pigments after challenge (starvation at 19.5 °C).•Pigment-depletion was fillet-area specific and was not affected by carotenoid type.•Increasing fillet α-tocopherol levels from normal to high did not inhibit depletion.•Challenge did not increase oxidative stress indices under the conditions tested.
Pigment-depletion in the fillets of farmed Atlantic salmon (Salmo salar) arises after periods of elevated water temperatures with voluntary starving. This study tested the effects of dietary pre-loading with different pigment carotenoids (astaxanthin and/or canthaxanthin) combined with two α-tocopherol levels (normal and high: 500 and 1000 mg/kg, respectively) on pigment-depletion in vivo in Atlantic salmon after four weeks of challenge. We also tested whether oxidative stress manifested as an underlying depletion mechanism.
Carotenoid levels in whole fillet homogenates were not decreased significantly post-challenge but fillet α-tocopherol concentrations were increased significantly in contrast to decreased oxidative stress indices. However, image analysis revealed localised fillet pigment-depletion following all dietary treatments. These data imply that localised pigment-depletion was not prevented by pre-loading of the fillet with different carotenoid-types/mixtures and increased of α-tocopherol levels from normal to high, respectively. Further, we suggest that oxidative stress might not facilitate pigment-depletion in vivo.