Protein content and amino acid composition of young atlantic halibut (Hippoglossus hippoglossus l.) captured in the autumn in north norway

Abstract

Samples of four lissue-lypes from immature Atlantic halibut (Hippoglossus hippoglossus L.). captured in the autumn, were analysed for total protein content and for free and protein-bound amino acids. The analyses revealed a relatively high total protein content in the muscle tissues, whereas the liver and fin base “notch” had a lower total protein content. The main amino acid residue of the protein was glutamate, with lysine, aspartate, leucine, and arginine also present in considerable amounts. The fraction of free amino acids and ninhydrin-positivc substances was dominated by laurine. The results from the chemical analyses were treated statistically in order to determine possible sexual and/or tissue discrimination. This treatment revealed extensive heterogeneity between tissues, while indications of heterogeneity between sexes were doubtful. The data presented in this paper suggest a possible test diet for young Atlantic halibut and will serve as a good basis for comparison with captive halibut reared on man-made diets. © 1993 Conseil International pour l’Exploration de la Mer.