Quantification and Distribution of Omega-3 Fatty Acids in South Pacific Fish and Shellfish Species

Abstract

Fatty acid composition and distribution in edible species of fish and shellfish captured in the South Pacific were studied, with a focus on n-3 long-chain polyunsaturated fatty acids (n-3 LCPUFA). Fatty acids were quantified using gas-chromatography coupled with flame ionization detection (GC-FID), and the distribution of different fatty acids within lipid classes (neutral and polar lipids) was achieved after oil extraction using the Folch method and separation of lipid classes via solid-phase extraction for further GC-FID analysis. Red cusk-eel was the fish species with the lowest content of both EPA and DHA (40.8 and 74.4 mg/100 g, respectively) whereas mackerel contained the highest amount (414.7 and 956.0 mg/100 g for EPA and DHA, respectively). Sea squirt was the shellfish species with the highest content of EPA and DHA (375.0 and 165.7 mg/100 g, respectively) whereas the lowest amount of EPA + DHA was found in Chilean abalone (63.6 mg/100 g). PUFA were mostly found in neutral or polar lipids depending on the studied species. Indexes used to discuss the nutritional quality of lipids (PUFA/SFA, n-6/n-3 ratio and the hypocholesterolemic/hypercholesterolemic fatty acid index) were calculated and reported in the manuscript. This information provides a novel nutritional insight which may be useful to help nutritionists and other health professionals give more accurate counseling for the population to reach the recommended daily intakes of EPA and DHA.

Nutritional Indices for Assessing Fatty Acids: A Mini-Review

“…The HH was first used in research on ruminants [ 46 , 77 , 91 ], which was subsequently extended to dairy products [ 54 , 55 , 78 , 86 , 87 ], marine products [ 34 , 36 , 37 , 38 , 39 , 72 , 90 ] , and other fields [ 47 , 48 , 52 , 62 ]. Paiva et al selected four Azorean macroalgae and used the HH as one of the indices to evaluate their nutritional and health promoting aspects, and found that the HH value ranges from 1.26 to 2.09 [ 90 ].…”

“…For shellfish, the HH value ranges from 1.73 to 4.75, except for Loxechinus albus . It is possible that the main food source of Loxechinus albus is algae, leading to a high proportion of SFA, so its HH is only 0.21, lower than in other species [ 34 ]. For fish, the value ranges from 1.54 to 4.83, with the exception of Opisthonema oglinum, which has an HH value of 0.87 [ 36 ].…”

“…Due to the low EPA and DHA contents in terrestrial plants and animals, this index is mostly used to evaluate the nutritional value of seafood and seafood products, particularly fish, which makes it an important nutritional index for seafood. Rincón-Cervera et al studied the fatty acid composition of fish and shellfish captured in the South Pacific, and the results showed that EPA + DHA ranged between 115.15 and 1370.67 mg/100 g in all studied fish species and between 63.61 and 522.68 mg/100 g in all studied shellfish species [ 34 ]. Detailed information about the literature related to EPA + DHA is shown in Table 8 .…”

Heavy Metals Contamination in Shellfish: Benefit-Risk Evaluation in Central Italy

“…Aiming to quantitatively estimate the health benefits of seafood consumption, the EPA and DHA content in mollusks and echinoderms considered, was obtained from literature [ 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 ] ( Figure 2 ). The daily dietary intake of such nutrients in the target population was assessed with the same methodology adopted for contaminants.…”

“…The data was obtained from Prato et al [ 32 ] for oyster, scallop, mussels, brown venus, razor clam, clam and other bivalves, and from Rincón-Cervera et al [ 44 ] for sea urchins and marine gastropods.…”