title: Engineered maize as a source of astaxanthin: processing and application as fish feed.
abstract: Astaxanthin from a transgenic maize line was evaluated as feed supplement source conferring effective pigmentation of rainbow trout flesh. An extraction procedure using ethanol together with the addition of vegetal oil was established. This resulted in an oily astaxanthin preparation which was not sufficiently concentrated for direct application to the feed. Therefore, a concentration process involving multiple phase partitioning steps was implemented to remove 90 % of the oil. The resulting astaxanthin raw material contained non-esterified astaxanthin with 12 % 4-keto zeaxanthin and 2 % zeaxanthin as additional carotenoids. Isomeric analysis confirmed the exclusive presence of the 3S, 3'S astaxanthin enantiomer. The geometrical isomers were 89 % all-E, 8 % 13-Z and 3 % 9-Z. The incorporation of the oily astaxanthin preparation into trout feed was performed to deliver 7 mg/kg astaxanthin in the final feed formulation for the first 3.5 weeks and 72 mg/kg for the final 3.5 weeks of the feeding trial. The resulting pigmentation of the trout fillets was determined by hue values with a colour meter and further confirmed by astaxanthin quantification. Pigmentation properties of the maize-produced natural astaxanthin incorporated to 3.5 µg/g dw in the trout fillet resembles that of chemically synthesized astaxanthin. By comparing the relative carotenoid compositions in feed, flesh and feces, a preferential uptake of zeaxanthin and 4-keto zeaxanthin over astaxanthin was observed.
authors: Biosynthesis Group, Institute of Molecular Biosciences, Goethe University Frankfurt, Max von Laue Str. 9, 60438, Frankfurt, Germany.
authors: Jürgen
authors: J
authors: Breitenbach
authors: School of Biological Sciences, Royal Holloway, University of London, Egham, Surrey, UK.
authors: Marilise
authors: M
authors: Nogueira
authors: Department of Plant Production and Forestry Science, University of Lleida-Agrotecnio Center, Lleida, Spain.
authors: Gemma
authors: G
authors: Farré
authors: Department of Plant Production and Forestry Science, University of Lleida-Agrotecnio Center, Lleida, Spain.
authors: Changfu
authors: C
authors: Zhu
authors: Department of Plant Production and Forestry Science, University of Lleida-Agrotecnio Center, Lleida, Spain.
authors: Teresa
authors: T
authors: Capell
authors: Department of Plant Production and Forestry Science, University of Lleida-Agrotecnio Center, Lleida, Spain.|Catalan Institute for Research and Advanced Studies (ICREA), Barcelona, Spain.
authors: Paul
authors: P
authors: Christou
authors: Pilot Pflanzenöltechnologie Magdeburg e.V. (PPM), Berliner Chaussee 66, 39114, Magdeburg, Germany.
authors: Gunther
authors: G
authors: Fleck
authors: Institute of Fisheries Ecology, Johann Heinrich von Thünen-Institute, Wulfsdorfer Weg 204, 22926, Ahrensburg, Germany.
authors: Ulfert
authors: U
authors: Focken
authors: School of Biological Sciences, Royal Holloway, University of London, Egham, Surrey, UK.
authors: Paul D
authors: PD
authors: Fraser
authors: Biosynthesis Group, Institute of Molecular Biosciences, Goethe University Frankfurt, Max von Laue Str. 9, 60438, Frankfurt, Germany. sandmann@bio.uni-frankfurt.de.
authors: Gerhard
authors: G
authors: Sandmann
mesh_terms: D000821:Animal Feed; D000818:Animals; D002338:Carotenoids / Q000378:metabolism*; D017686:Oncorhynchus mykiss / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000737:chemistry / Q000235:genetics; D024341:Xanthophylls / Q000096:biosynthesis / Q000235:genetics; D003313:Zea mays / Q000737:chemistry / Q000235:genetics
chemical_list: D024341:Xanthophylls; D002338:Carotenoids; C005948:astaxanthine
keywords: Astaxanthin extraction; Astaxanthin isomers; GM maize; Trout colouration; Trout feeding