title: Effect of the antioxidants composition in diet on the sensory and physical properties of frozen farmed Coho salmon (Oncorhynchus kisutch).
abstract: BACKGROUND
  Great attention has been paid to the antioxidants present in farmed fish feeds, with the replacement of synthetic antioxidants by natural ones being a main objective. In the present study, Coho salmon (Oncorhynchus kisutch) was fed a conventional diet that was enriched with different kinds of antioxidants: synthetic antioxidants (butylated-hydroxy toluene and ethoxyquin; diet I), a tocopherols-rich mixture (diet II) and a tocopherols-rosemary extract mixture (diet III). A comparative study of the sensory and physical changes observed in the corresponding frozen products was undertaken.
  
  
  RESULTS
  After 18 months at -18 °C, fish previously fed on diet I showed higher putrid and rancid odours and rancid taste scores, while lower mean typical odour and taste values were attained. Dripping and expressible moisture values obtained for diet II-fish were lower when compared with their counterparts belonging to the diet I; additionally, microstructure analysis revealed that Z-lines integration was better preserved in fish corresponding to diets II and III.
  
  
  CONCLUSIONS
  Diet II has been recognised as being the most profitable to be employed to maintain the sensory and physical properties of the frozen product when long-term storage is considered. Further research is to be continued to optimise the natural antioxidants profile.
authors.affiliation: Department of Food Science and Chemical Technology, Faculty of Chemical and Pharmaceutical Science, Universidad de Chile, Santiago, Chile.
authors.forename: Alicia
authors.initials: A
authors.lastname: Rodríguez
authors.forename: Mónica
authors.initials: M
authors.lastname: Latorre
authors.forename: Mónica
authors.initials: M
authors.lastname: Gajardo
authors.forename: Andrea
authors.initials: A
authors.lastname: Bunger
authors.forename: Alejandro
authors.initials: A
authors.lastname: Munizaga
authors.forename: Luis
authors.initials: L
authors.lastname: López
authors.forename: Santiago P
authors.initials: SP
authors.lastname: Aubourg
mesh_terms: D000821:Animal Feed; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D004032:Diet; D005260:Female; D005395:Fish Oils / Q000378:metabolism; D005519:Food Preservation / Q000379:methods*; D005615:Freezing; D006801:Humans; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D009132:Muscles / Q000187:drug effects; D009812:Odorants; D017684:Oncorhynchus kisutch; D010936:Plant Extracts / Q000494:pharmacology; D027542:Rosmarinus; D017747:Seafood / Q000032:analysis*; D013649:Taste; D024505:Tocopherols / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D005395:Fish Oils; D010936:Plant Extracts; D024505:Tocopherols
keywords: Oncorhynchus kisutch; diet antioxidants; frozen storage; physical properties; quality; sensory acceptance