Effect of Spawning on Furan Fatty Acid Profile of Edible Muscle and Organ Tissues from Sardine (Sardina pilchardus) and Anchovy (Engraulis encrasicolus)

Abstract

The total fatty acid compositions, especially the furan fatty acid (F-acids) profile, from edible muscle (fillet) and organ tissues (brain, eye, ovaries, and testes) of spawning and nonspawning sardine and anchovy were examined. The spawning season had no effect on F-acid profiles of the fillet and all organ tissues, for both fishes. However, differences among the F-acid fraction of the organ tissues were revealed. The F-acid portion was less than 1% of total fatty acid in all samples. Five F-acid congeners were detected in the fillet, eye, and gonads, while the brain contained only four F-acids. Unlike the F-acids, spawning season affected the docosahexaenoic acid (DHA) abundance in fillet and gonads. DHA enrichment occurred in fillets and gonads from spawning sardine and anchovy. The ratio ω3 PUFA/ω6 PUFA decreases between spawning and nonspawning fillets, thus the fillets from spawning fish have higher nutritional value.

Detailed Study of Furan Fatty Acids in Total Lipids and the Cholesteryl Ester Fraction of Fish Liver

“…Since some F-acids were only present in one or the other fraction, the maximum variety of F-acids was 23. The most abundant F-acids were 12,15-epoxy-13,14-dimethyleicosa-12,14-dienoic acid (11D5) followed by 12,15-epoxy-13,14-dimethyloctadeca-12,14-dienoic acid (11D3) and 10,13-epoxy-11-methyloctadeca-10,12-dienoic acid (9M5), which was in accordance with previous studies (Gunstone et al 1976;Glass et al 1977;Scrimgeour 1977;Gunstone et al 1978;Pacetti et al 2010Pacetti et al , 2013a. Cod liver samples showed a greater variety of F-acids (up to 23) compared to the other fish species (up to 13 F-acids in sea bass from aquaculture).…”

“…Other F-acids showed comparatively low contributions to the F-acid content - in the CE fractions of fish liver (most commonly <2 %). Yet, F-acids of fish species are known to vary due to both exogenous and endogenous factors (Pacetti et al 2013a). In view of the limited number of individual fish livers analyzed in this study, the concentration ratios, especially of the low-abundant homologues, need to be further verified in more comprehensive studies.…”

“…While F-acids play a relevant role in the CE fraction (up to 96 % of the fatty acids (Glass et al 1977;Hammann et al 2015), they contribute only in the permil-range to the total lipids of fish which are mainly characterized by the presence of 20:5n-3 and 22:6n-3 along with 16:0 and 18:1n-9 (Pacetti et al 2010(Pacetti et al , 2013a. However, the sensitivity of the GC/MS-SIM method allowed determining even F-acids with very low contribution in the TG fraction of fish livers without a further enrichment step.…”

Sardine (<em>Sardina pilchardus</em>) spawning in the light of fat content analysis

“…The outcomes of the present study also showed that the fat content in gonads, liver and muscle decreased with the increase in the GSI. The decline in fat content was consistent with that reported by previous studies on small pelagic fish species (Pecquerie et al 2009, Nunes et al 2011, Pacetti et al 2013. However, this decline did not continue for long, which was somewhat surprising considering the fact that the sardine has a relatively long spawning season during which it has to produce many batches of eggs (Ganias et al 2004, Somarakis et al 2006.…”

“…In fact, Zorica et al (2017) found that in the warmer period of the year (June-September), here defined as the feeding phase, sardines consumed higher energy prey such as fish eggs, cladocerans and decapod larvae, resulting in the highest stomach fullness index values. The pattern of acquiring energy reserves before the onset of spawning has previously been reported not only for the sardine (Mustać and Sinovčić 2009, Marin et al 2010, Bandarra et al 2018 and other small pelagics (Hunter and Leong 1981, Cubillos et al 2001, Pacetti et al 2013, but also for many other fish (El Kebir et al 2003, Lloret et al 2008, Grande et al 2016.…”