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.

Optimisation of oil extraction from sardine (Sardina pilchardus) by hydraulic pressing

“…However, García‐Moreno et al . () reported that sardine oil obtained by the same extraction process also presented cholesterol (7.5%w) and phospholipids (0.8%w). Although these compounds could be also contained in the extracted oils obtained in this work, they were not identified probably due to the different polarity of the mobile phase employed to develop the silica plates.…”

“…These results are in agreement with our previous work that reported similar protein and ash content for sardine in all the seasons, 17%w and 3%w, respectively. However, the lipid content considerably varied within seasons, reaching minimum values in March (0.6%w) and maximum in June (13.6%w) (García‐Moreno et al ., ). Thus, from these measurements, it was revealed that July, when sardine presented a lipid amount up to 17.7%w, is even a better month to obtain a higher yield of oil from this species.…”

“…Within this group, the major fatty acids were oleic (~12%w), palmitoleic (~7%w) and gadoleic (~4%w). These results are in accordance with previous studies on the fatty acids profile of sardine ( Sardina pilchardus ) (Bandarra et al ., ; García‐Moreno et al ., ).…”

“…These methyl esters were then analysed according to the method described by García‐Moreno et al . (). Matreya (Pleasant Gap, PA, USA) n‐3 PUFAs standard was used for the qualitative fatty acid determination.…”

Production and identification of angiotensin I-converting enzyme (ACE) inhibitory peptides from Mediterranean fish discards

“…Additionally, commercial species such as sardine (Sardina pilchardus), horse mackerel (Trachurus mediterraneus) and axillary seabream (Pagellus acarne) are also discarded in this fishery due to quota restrictions, minimal landing-size requirements or high-grading practices. These species present valuable protein contents, which are practically constant during the year ranging from 17 to 23% depending on the species (García-Moreno, Pérez-Gálvez, Morales-Medina, Guadix, & Guadix, 2013). Therefore, added-value products such as bioactive peptides produced by enzymatic proteolysis can be obtained from the protein fraction of these discarded fish species.…”