Influence of different fatty acids and emulsifiers on astaxanthin deposition and astaxanthin metabolism in salmonids (AstaFeE)

• Applicants: Professor Dr. Gerald Rimbach; Professor Dr. Carsten Schulz
• Subject Area: Animal Breeding, Animal Nutrition, Animal Husbandry
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 546734849

The quality of fish products depends largely on the diet of these animals. A decisive factor in feed for salmonids is the astaxanthin content, which gives them their typical fillet coloration. However, this xanthophyll is associated with high costs and relatively low utilization in salmonids. There is still little scientific knowledge about the metabolic processes responsible for utilization. However, it has been shown that various dietary fats have an influence on the absorption of astaxanthin. The applicants' own preliminary work has already demonstrated the latter. Based on these results the present project aims to investigate the influence on biomagnification and fillet pigmentation of rainbow trout through differences in the degree of saturation and the C-atom chain length of various feed-borne fatty acids, as well as through the properties of different emulsifiers in vivo. In addition to these feeding experiments, the molecular mechanisms of astaxanthin transport and metabolism will be investigated in cell culture models and in situ. The findings from the in vitro and in situ experiments supplement the results from the feeding trials with the underlying metabolic processes. This not only provides new and extremely important insights into this topic from a scientific point of view, but also enables practical translation in fish nutrition in order to achieve sustainable savings in high-priced astaxanthin. The planned project duration is 36 months.

• DFG Programme: Research Grants