The estimated requirements for marine n-3 long chain (LC) poly unsaturated fatty acids (PUFAs) for human and aquaculture is higher than the amount that can be produced from industrial fisheries, if the fisheries should be sustainable. Hence, new raw materials or better utilization of existing ones must be implemented. Currently, starfish is an underutilized raw material. Analysis of the composition of starfish oil reveals that starfish can be a new source of marine n-3 PUFA oil. Starfish oil contains EPA and DHA both in the form of triglycerides and phospholipids. Moreover, the oil contains pigments such as astaxanthin (Sørensen et al., 2022). Because of the highly unsaturated nature of the starfish oil it is susceptible to lipid oxidation. Therefore, its oxidative stability and application of antioxidants to extend the shelf life should be evaluated. The aim of this study was therefore to evaluate the composition and oxidative stability carried out in accelerated test (Oxypres; 80°C, 5 bar) of starfish oil and compare results with those obtained with common cod liver and krill oils. Moreover, the ability of different commercial antioxidant blends to maintain oil stability during storage (3 weeks, 20ºC) was evaluated. The oxidative stability was evaluated by measuring the development of primary and secondary oxidation products- and consumption of tocopherols during storage. The starfish oil was extracted using supercritical CO2 extraction with ethanol as co-solvent. The results showed that the oxidative stability was lower for an unrefined starfish oil compared to high quality krill and cod liver oils, starfish oil < krill oil < fish oil. The oxidative stability for the starfish oil was improved with the addition of some antioxidant blends (Synerox 4-147(rosemary extract, tocopherol, ascorbyl palmitate) and Grindox 539 (ascorbyl palmitate, tocopherol, lecithin)) as measured by a longer induction period (IP) in the Oxypress. The development of PV was only reduced by two of the antioxidants (Grindox 539 and Duralox MAN 5 NS (ascorbic acid, tocopherol, rosemary extract, citric acid) in the end of the storage period. Furthermore, the ability of the antioxidant to reduce the development of volatiles were different for different volatile compound. However, the increase in of the concentration of 2,4-heptadienal, a volatile compound produced from oxidation of omega-3 fatty acids, was reduced most with addition of green tea followed by Grindox 539 and Duralox MAN NS 5, which could potentially be efficient antioxidants for stabilizing starfish oil.
OXI-019: Starfish Oil – Characterization and Oxidative Stability
