Katrina Cavlek, Roland Kallenborn, Kenneth A. Kristoffersen, Hanne Marie Dvele and Dag Ekeberg
Faculty of Chemistry, Biotechnology and Food Science (KBM), Norwegian University of Life Sciences (NMBU), Ås,
Norway
Email: Katrina.cavlek@nmbu.no
The growing demand for sustainable food and feed sources has increased the interest in alternative marine resources rich in essential fatty acids. Tunicates are low-trophic filter feeders that contribute to nutrient recycling and water purification while providing valuable biomolecules such as lipids, proteins, and cellulose [1]. The tunicate Ciona intestinalis is particularly promising for integration into circular food systems, as it can convert nutrients from eutrophic environments into high-quality biomass suitable for food and feed applications.
Figure: C. intestinalis adults. Photo credit: Morten Munthe
C. intestinalis has been identified as a potential new marine source of n-3 fatty acids, especially when its lipid-rich biomass is cultivated at scale [2]. Fatty acid methyl esters (FAMEs) profiling is a well-established analytical approach for characterizing the lipid fraction in biological materials, providing insights into nutritional quality and biochemical composition. Since lipids are primarily composed of triglycerides, molecules consisting of a glycerol backbone esterified with three fatty acids, FAME profiling provides a reliable means of assessing the diversity and abundance of these essential components in marine organisms such as C. intestinalis [3].
This study examines the fatty acid composition of C. intestinalis collected from four locations in the inner Oslofjord to assess spatial variation and nutritional potential. Across all sites, tunicates exhibited a consistent fatty acid composition dominated by long-chain omega-3 polyunsaturated fatty acids (PUFAs), primarily eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which together represented nearly half of the total fatty acids. The samples showed favourable n-6/n-3 ratios and high proportions of PUFAs, indicating strong nutritional value. Minor site-specific variations were observed, likely reflecting local environmental conditions and food availability, but overall compositional stability remained high.
The results confirm that C. intestinalis from the inner Oslofjord possesses a robust and beneficial fatty acid profile independent of sampling location. These findings support its potential as a climate-friendly, nutrient-rich marine resource for sustainable food and feed production in Norway.
1. Hrůzová, K., Second-generation biofuel production from the marine filter feeder Ciona intestinalis. ACS Sustain Chem Eng 8 (22): 8373–8380. 2020.
2. Zhao, Y., et al., Fatty acid and lipid profiles with emphasis on n‐3 fatty acids and phospholipids from Ciona intestinalis. Lipids, 2015. 50(10): p. 1009-1027.
3. David, F., P. Sandra, and A.K. Vickers, Column selection for the analysis of fatty acid methyl esters. Food Analysis Application. Palo Alto, CA: Agilent Technologies, 2005. 19: p. 19.