The AVS project "Dyeing of Salmon with Natural Pigments" has been completed and has final report of the project now been released. The project investigated the effect of different pigments and their concentration in Atlantic salmon feed on flesh color. The main results of the project were that there was an insignificant difference in body color between the dyeing methods tested. All the pigments gave an acceptable flesh color to the fillets.
The project was carried out in collaboration with Matís, Hólar University, the LAXÁ Feed Factory and Nofima in Norway. The dye Panaferd AX, derived from the bacterium Paracoccus carotinifaciens, was mixed in different concentrations in experimental feed and the effect evaluated. The reference was the chemical pigment Lucantin® Pink, which is currently most commonly used in feed for farmed salmon. Initially, the dye Aquasta® was also to be tested, but it disappeared from the market and was therefore only used in the first part (of three) of the experiment. In the second part of the experiment, therefore, only a comparison of flesh-coloring with Panaferd AX and Lucantin Pink, given in varying amounts with different sizes of fish.
The project carried out feed experiments where salmon were farmed in aquaculture tanks for a total of 438 days.
At the beginning of the study, it was investigated how much pigment was lost during the production of the experimental feed. The study showed that when using Panaferd AX, only 76.9% of astaxanthin was added, compared to 100 + % when Lucantin Pink was used. Therefore, 30% more of astaxanthin in the form of Panaferd i needs to be added to the feed to ensure that the fish has the same amount of pigment as was obtained using Lucantin Pink.
Growth, feed intake, feed utilization and survival were normal in all groups in the experiment. The results showed little difference in body color between treatments, but there was little correlation between the chemical concentration of pigments and the visible color.
The result of the experiment was that all the dyeing methods tested and both the dyes studied gave a similar and acceptable flesh color in salmon fillets. Panaferd AX is an organic alternative for dyeing farmed salmon, if care is taken to mix enough in the feed to cover the loss of astaxanthin in the feed production process.
Further information can be obtained from Jón Árnason at Matís and Ólafur Ingi Sigurgeirsson at Hólaskóli.