Discarded species in the west Mediterranean sea as sources of omega‐3 PUFA

Abstract

Five discarded fish species in the Alboran Sea, namely axillary seabream (Pagellus acarne), small‐spotted catshark (Scyliorhinus canicula), sardine (Sardina pilchardus), horse mackerel (Trachurus mediterraneus), and bogue (Boops boops) were evaluated as novel sources for the production of omega‐3 polyunsaturated fatty acids (PUFAs). The lipid content of the five species varied significantly within the different seasons, being maximum in spring for axillary seabream, small‐spotted catshark, and bogue (5.1, 2.7, 2.5%, respectively) and in summer for sardine and horse mackerel (13.6 and 6.2%, respectively). Sardine and horse mackerel presented also the maximum amount of eicosapentaenoic acid (EPA) + docosohexaenoic acid (DHA), 3000 and 1300 mg/100 g fish, respectively. Their oils exhibited a composition of EPA + DHA higher than 23% and they were mainly composed by triacylglycerols. Axillary seabream, small‐spotted catshark, and bogue presented a lower amount of EPA + DHA, 960, 650, and 157 mg/100 g fish, respectively, but their oils also exhibited a composition of EPA + DHA higher than 20%. Particularly important was the composition of DHA, 23%, of the oil extracted from small‐spotted catshark. Therefore, the five discarded species studied were found to be valuable raw material for the production of fish oil presenting a high content in EPA and DHA.Practical applications: This work is in line with ongoing EU regulations avoiding fish discards. This has boosted research on the potential of these raw materials for the production of high added‐value products such as omega‐3 PUFAs, which are experiencing a growing commercial demand. This study provides a complete characterization of five discarded species in the Alboran Sea, with special focus on the availability of their omega‐3 content throughout the year. Despite their different lipid content, all the species were good sources for the production of omega‐3. The oils extracted from these species presented a maximum composition of EPA + DHA higher than 20%. Interestingly, small‐spotted catshark's oil was relatively rich in DHA (up to 23%), which makes this oil an excellent functional ingredient for brain and children's health applications. The results obtained provide valuable information for food scientists interested in the production of omega‐3 PUFAs from traditional and alternative fish species.