Enriching the egg yolk in n − 3 fatty acids by feeding hens with diets containing horse fat produced in Uruguay

The present study was conducted to evaluate the ability of horse fat produced in Uruguay, compared with other lipid sources supplemented in the diet of laying hens, to modify the lipid composition and the n − 6/n − 3 fatty acid ratio of the produced eggs. For this purpose, 60 laying hens (Gallus domesticus) were fed for 30 days with five experimental diets (12 hens/diet) containing 3% sunflower oil (SO), rice oil (RO), beef tallow (BT), pressed-fat (PF), obtained by pressing fat from bovine viscera, and horse fat (HF) obtained from horse bone medulla. Throughout the trial, feeding rate, shell index, weight and total lipid contents of eggs, were not affected by the different diets. Feeding on the SO and RO diets significantly increased the amount of linoleic acid of the egg, although it was lower in the RO than in the SO eggs. Diet BT did not affect the saturated fatty acid content of the yolks. The diets with animal fats containing 18:3n − 3 (diets PF and HF), resulted in a significant increase in the n − 3 fatty acid contents of the eggs, through an increase of linolenic (18:3n − 3) and docosahexaenoic acid (DHA, 22:6n − 3) contents. Eggs from hens fed the HF diet showed increased linolenic acid (46 mg/yolk) and DHA (71 mg/yolk, 1.7% of total fatty acids) contents. These levels were obtained after two weeks of feeding. Moreover, the fatty acid profiles of eggs from treatment HF were not significantly affected by thermal treatment of the yolks. In conclusion, the fat from horse bone medulla, as produced in Uruguay, can be considered as a suitable lipid source for diets of laying hens, to modify the nutritional composition of the eggs in n − 3 PUFA content, especially DHA, and consequently, the n − 6/n − 3 fatty acid ratio.     

Impact of feed supplementation with different omega-3 rich microalgae species on enrichment of eggs of laying hens

Four different omega-3 rich autotrophic microalgae, Phaeodactylum tricornutum, Nannochloropsis oculata, Isochrysis galbana and Chlorella fusca, were supplemented to the diet of laying hens in order to increase the level of omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA) in egg yolk. The microalgae were supplemented in two doses: 125 mg and 250 mg extra n-3 PUFA per 100 g feed. Supplementing these microalgae resulted in increased but different n-3 LC-PUFA levels in egg yolk, mainly docosahexaenoic acid enrichment. Only supplementation of Chlorella gave rise to mainly α-linolenic acid enrichment. The highest efficiency of n-3 LC-PUFA enrichment was obtained by supplementation of Phaeodactylum and Isochrysis. Furthermore, yolk colour shifted from yellow to a more intense red colour with supplementation of Phaeodactylum, Nannochloropsis and Isochrysis, due to transfer of carotenoids from microalgae to eggs.     

Effect of dietary supplementation of gallic acid and linoleic acid mixture or their synthetic salt on egg quality

The effect of a dietary supplementation of gallic acid and linoleic acid mixture (MGL) and their synthetic salt, sodium 2,3-dihydroxy-5-(((9E,12E)-octadeca-9,12-dienyloxy)carbonyl)phenolate (NGL), on egg quality was investigated. A total of 120 laying hens were allotted into five groups over 4 weeks of the experimental period. Birds were fed the following diets: (1) control [commercial diet (CD)], (2) 0.05% MGL (w/w, GA:LA = 1:1, equal molar ratio), (3) 0.1% MGL, (4) 0.05% NGL, (5) 0.1% NGL. The performance of the hen, the anti-oxidative potential of egg albumen and yolk, and the fatty acid composition and cholesterol content of egg yolk were measured. The TBARS value of egg yolk from hens fed 0.1% MGL and 0.05% NGL was lower than that fed control diet after storage for 14 days. The ABTS⁺ reducing activity of egg albumen was significantly improved by MGL and NGL, but only NGL had an effect on yolk (p < 0.05). The dietary supplementation of 0.05% or 0.1% MGL, and 0.05% NGL raised the PUFAs composition in egg yolk. The cholesterol content of egg yolk from hens fed control diet was higher than those fed 0.1% MGL, 0.05% or 0.1% NGL (p < 0.05). In conclusion, a diet consisting of MGL and NGL can improve the antioxidative potential of egg and the fatty acid quality of egg yolk while lowering the cholesterol level.     

Fatty acid composition of egg yolk phospholipid fractions following feed supplementation of Lohmann Brown hens with humic-fat preparations

The effect of feed supplementation with humic-fat preparations on the fatty acid composition of egg yolk phospholipid fractions was studied. The Lohmann Brown was the experimental hen strain and two feeding mixtures were applied – the standard feed and the mixture supplemented with humic-fat preparations. The fatty acid profile of yolk lipids was significantly affected (P = .05) by the supplementation of feed and total increase of n-3 polyunsaturated fatty acids (PUFA) was established. A different distribution of n-3 PUFA in egg yolk lipid fractions was observed: α-linolenic acid (18:3) was found in the triacylglycerol fraction, whereas docosahexaenoic acid (22:6) was detected in the phospholipid fractions. Supplementation of the hen’s diet with humic-fat preparations resulted in the production of n-3 enriched eggs with decreased n-6/n-3 ratio in all phospholipid fractions in comparison to the eggs from the control group.     

Fatty acid composition of eggs produced by the Slovenian autochthonous Styrian hen

The fatty acid composition of eggs produced by the autochthonous Styrian hen reared in two rearing systems was determined. Eggs were collected four times during the year. The fatty acid composition was determined by the in situ transesterification method and gas chromatography–flame ionisation detection (GC–FID). Eggs of the Styrian hen from free range contained significantly more α-linolenic, eicosapentaenoic (EPA), docosapentaenoic (DPA) and docosahexaenoic acid (DHA), as well as more total n−3 fatty acids. On the other hand, eggs from caged hens contained significantly more linoleic, arachidonic, as well as total polyunsaturated fatty acids (PUFA) and n−6 PUFA. The n−6/n−3 ratio was better from the nutritional point of view in eggs from free range. The fatty acid content is expressed in wt.%, as well as mg/100 g of yolk and mg/100 g of fresh egg, to better understand how much each of fatty acid is consumed with an edible portion.     

Nutrient contents of kale (Brassica oleraceae L. var. acephala DC.)

Fructose, glucose and sucrose, as the major soluble sugars and citric and malic acids, as the major organic acids, were identified and determined in kale (Brassica oleraceae L. var. acephala DC., black cabbage) leaves. Fructose was the predominant sugar (2011 mg 100 g⁻¹ dry wt) identified, followed by glucose (1056 mg 100 g⁻¹ dry wt) and sucrose (894 mg 100 g⁻¹ dry wt). The contents of citric and malic acids were at 2213 and 151 mg 100 g⁻¹ dry wt in the leaves. The 16:0, 18:2n − 6 and 18:3n − 3 fatty acids were the most abundant fatty acids in the leaves. Considering the level of these fatty acids, 18:3n − 3 was found to be the highest (85.3 μg g⁻¹ dry wt), contributing 54.0% of the total fatty acid content. Linoleic acid (18:2n − 6), being the second most abundant fatty acid was present at 18.6 μg g⁻¹ dry wt, contributing 11.8% of the total fatty acid content. In the seed oil of kale, 22:1n − 9 was the most abundant fatty acid (4198 μg g⁻¹ dry wt, 45.7%), with 18:2n − 6 (1199 μg g⁻¹ dry wt, 12.3%) and 18:1n − 9 (1408 μg g⁻¹ dry wt, 14.8%) being the second next most abundant fatty acids. The most abundant amino acid was glutamic acid (Glu) which was present at 33.2 mg g⁻¹ dry wt. Aspartic acid, which was the second most abundant amino acid, was present at 27.6 mg g⁻¹ dry wt and accounted for 10.2% of the total amino acid content of kale leaf. The amino acid content was assessed by comparing the percentages of the essential amino acids in kale leaf versus those of a World Health Organization (WHO) standard protein. The protein of kale leaf compares well with that of the WHO standard. Only one amino acid, lysine, had a score that fell below 100%; the lysine score of kale leaf was 95%. This study attempts to contribute to knowledge of the nutritional properties of the plant. These results may be useful for the evaluation of dietary information.     

Volatile compounds and fatty acid profiles in commercial milk-based infant formulae by static headspace gas chromatography: Evolution after opening the packet

The evolution of the volatile compounds propanal, pentanal and hexanal, and fatty acid profiles were examined in 20 infant formula (IF) milk powders during storage at 25 °C for 70 days after their packaging was opened. Few changes were observed in the fatty acid content during storage, but significant losses were found in C18:2 n − 6 and C18:3 n − 3 for some formulae. All three volatiles increased during storage in all formulae, confirming oxidative stability decreases once packets were opened. Significant correlation (p < 0.05) was detected between hexanal content and oxidation of n − 6 PUFA, specifically C18:2 n − 6 losses, and between propanal content and oxidation of n − 3 PUFA, specifically from C18:3 n − 3 losses.     

Nutritional and sensory aspects of light lamb meat enriched in n−3 fatty acids during refrigerated storage

Fatty acid content and sensory characteristics of meat from light lambs fed three diets supplemented with different sources of n−3 fatty acids (fish oil, extruded linseed and extruded linseed plus microalgae) and a control diet during refrigerated storage have been studied. The meat from lambs fed linseed diets had the highest levels of C18:3 n−3, while animals fed fish oil had the highest long-chain n−3 polyunsaturated fatty acids (PUFA). Thus, 100 g of meat from lamb fed the fish oil diet provided 183 mg of long-chain n−3 PUFA, representing 40% of the daily recommended intake. The levels of n−3, n−6 and long-chain n−3 PUFA decreased during a 7-day storage period. The meat from lambs fed the fish oil diet had high scores of fish odour and flavour and rancid odour and flavour and the lowest overall liking. Rancid odour and flavour increased after storage, mainly in supplemented groups.     

Fatty acid profile of muscles,liver and mesenteric fat in wild and reared perch (Perca fluviatilis L.)

This study addressed determinations of the fatty acid profile of muscle, liver and mesenteric fat in European perch originating from natural aquifers and from intensive rearing in a closed circuit on an artificial feed mixture. The qualitative composition of fatty acids was identical in both groups of perch, except for 16:4 acid identified exclusively in the reared perch. The study demonstrated equal concentrations of saturated (SFA) and unsaturated (UFA) fatty acids in muscles, liver and mesenteric fat of both groups of perch. The wild fish, however, were characterised by lower concentrations of monoenoic (MUFA) and higher concentrations of polyenoic (PUFA) fatty acids. Analyses also demonstrated similar contents of n − 3 PUFA in muscles and their diversified concentrations in liver and mesenteric fat (higher in the wild fish), as well as a higher content of n − 6 PUFA in all samples. The lower content of MUFA in the wild perch was mainly due to lower concentrations of cis18:1 n − 9 and 20:1 n − 9, whereas the higher content of n − 3 PUFA was due to a higher concentration of DHA, and the higher content of n − 6 PUFA was due to a higher concentration of arachidonic acid (AA). The biggest differences between wild and reared perch were detected for AA. The wild and reared perch were also found to differ in the n − 3/n − 6 ratio (higher in the reared fish) and to have similar values for atherogenic index (AI) (except for liver and mesenteric fat) and thrombogenicity index (TI).     

Cooking effect on fatty acid profile of pork breakfast sausages enriched in conjugated linoleic acid by dietary supplementation or direct addition

The effectiveness of increasing CLA in pork products through animal dietary supplementation or direct addition in the product formulation has been studied, and the effect of grilling on dry matter and fat contents and fatty acid composition has been analysed. Sausages made with meat and back fat from pigs with CLA dietary supplementation had the highest saturated fatty acid content. Sausages from dietary supplementation and direct addition had CLA levels between 6% and 7% of total fatty acids. Moisture and fat contents decreased and increased respectively after cooking for the three sausage types (control, dietary supplementation, direct addition). Grilling had little effect on fatty acid levels, especially for sausages with direct addition in the product formulation. In general, saturated fatty acids increased and poly-unsaturated fatty acids decreased due to the increase of C16:0 and to the decrease of C18:2 n − 6c and C18:3 n − 3 fatty acids. Added CLA, both from animal dietary supplementation or direct addition, remained at similar levels in cooked sausages to those found in raw sausages.     

Δ desaturase protein expression and fatty acid composition of longissimus dorsi muscle in lambs fed green herbage or concentrate with or without added tannins

The aims of this study were to investigate the effect of feeding system and of supplementation of tannins (8.93% DM) on the relationship between intramuscular fat content, fatty acid composition and Δ⁹desaturase (Δ⁹d) protein expression in longissimus dorsi muscle of lamb. Twenty-eight Comisana lambs (age 45 days) were fed either vetch (Vicia sativa) or concentrate. The herbage diet was (i) lower in saturated fatty acids (especially in C16:0), C18:1 n−9 and in C18:2 n−6; (ii) higher in C16:1 and C18:3 n−3 when compared to concentrate. Within each feeding system the lambs were divided into two sub-groups, one of which received the diet without tannins supplementation, and the other was fed the diets supplemented with the tannins from Quebracho (Schinopsis lorentzii). The animals were slaughtered at age 105 days. The concentrate feeding system increased (p < 0.01) the total intramuscular fat content and the amount of SFA, MUFA and n−6 PUFA and decreased the level of n−3 PUFA (p = 0.05) when compared to the vetch-fed animals but did not affect Δ⁹ desaturase protein expression. There was no correlation between Δ⁹d protein expression and total intramuscular fatty acids, CLA and MUFA level. It was suggested that in ruminants, in contrast to monogastric animals, Δ⁹d expression does not play the key role in intramuscular fatty acids formation. Tannins supplementation resulted in higher (p < 0.05) muscle levels of transC18:1 and C18:2 n−6. It has also increased Δ⁹d expression in the case of herbage-based diet but not in the case of concentrate-based diet. The mechanism of tannins action on the enzyme expression needs to be elucidated.     

Fatty acid composition of certified organic,conventional and omega-3 eggs

The objective of this study was to compare the fatty acid composition of commercially available conventional, certified organic, and omega-3 eggs. Egg components were assessed, and the fatty acid composition of yolk lipids was determined by gas chromatography. Organic egg yolk contained a higher percentage of palmitic and stearic acids than did conventional yolk (P < 0.05) with no differences observed in the monounsaturated or polyunsaturated fatty acid compositions. Compared with organic and conventional eggs, omega-3 egg yolk contained lower percentages of myristic and palmitic acids, and higher omega-3 fatty acids. In a sub-analysis of conventional egg types, the percent of stearic acid in “cage” egg yolk was significantly lower (P < 0.05) than those of “barn-laid” and “free-range” eggs. “Cage” eggs had a significantly lower percentage (P < 0.05) of arachidonic acid than had “barn-laid” eggs. Consumption of omega-3 eggs has the potential to confer health benefits through the increase in intake of omega-3 fatty acids. With regard to organic or conventional methods of production, the small differences in saturated fatty acids observed in the present study are unlikely to have any significant metabolic effect on the consumer.     

Free aromatic amino acids in egg yolk show antioxidant properties

Laying hens are known to be able to “bio-convert” health-promoting components from the diet into eggs. Wheat and corn are important sources of antioxidant phenolics in the human diet. Given the fact that wheat and corn are major feed ingredients of laying hens in Canada, the objectives of this study were to characterise the presence of novel phenolic compounds in egg yolk and to determine the effect of cooking methods on their content and activity. The total phenolic content of yolk extracts was 3.83 and 3.49 μmol gallic acid equivalents/g dry yolk for wheat-based and corn-based yolks, respectively. Antioxidant properties of yolk extracts were measured by the ORAC, DPPH and ABTS assays. ORAC values were 151.1 ± 26.1 and 155.9 ± 9.5 μmol TE/g for wheat-based and corn-based yolks, respectively. All cooking methods significantly reduced (p < 0.05) the antioxidant values. Ferulic acid was detected in trace amounts and no other phenolic compounds were found. However, tryptophan and tyrosine were found to be two main contributors to the antioxidant property of egg yolk. The contents of total free amino acids were 10081.0 and 10009.5 μg/g in wheat-based and corn-based yolks, respectively; cooking methods were found to reduce significantly the amount of free amino acids.     

Analysis of lipid classes and the fatty acid composition of the salted fish roe food products,Ikura, Tarako,Tobiko and Kazunoko

This study was designed to clarify the content of lipid classes and the fatty acid composition of total lipids (TL), sterol esters (SE), triacylglycerols (TG), phospholipids (PL), phosphatidylcholine (PC), and phosphatidylethanolamine (PE) of the Japanese fish roe products, Ikura, Tarako, Tobiko and Kazunoko. The TL, total cholesterol, TG, and PL content of Ikura were higher than those of Tarako, Tobiko and Kazunoko. Kazunoko had the lowest cholesterol content among these roe products. PC was the main component in the PL class of each fish roe product. The main fatty acids of all roe products were 16:0, 18:1n−9, 20:5n−3, and 22:6n−3. Docosahexaenoic acid (22:6n−3) was rich in the TL, SE, TG, PL, PC and PE fractions of all roe products. In particulars the 22:6n−3 percentage of PC and PE fractions in Tobiko were higher than those of Ikura, Tarako and Kazunoko. These results indicate that the lipid from fish roe products may be a useful food source for maintaining human health.     

Compositions and yield of lipids extracted from hepatopancreas of Pacific white shrimp (Litopenaeus vannamei) as affected by prior autolysis

Compositions and yield of lipids extracted from hepatopancreas of Pacific white shrimp (Litopenaeus vannamei) subjected to autolysis at 60 °C for different times (0, 30, 60, 90 120 and 150 min) were investigated. Extraction yield increased from 7.4% to 8.8% as autolysis time increased from 0 to 150 min. Coincidental increase in total carotenoid content was obtained with increasing autolysis time (p < 0.05). The increases in thiobarbituric acid-reactive substances (TBARS) and p-anisidine value (AV) of lipids were noticeable when autolysis time increased (p < 0.05). However, no changes in free fatty acid (FFA) content were observed within the first 60 min of autolysis (p > 0.05), but subsequently increased up to 150 min. (p < 0.05). No differences in fatty acid profiles of lipids extracted from hepatopancreas without and with 60 min prior autolysis were observed. Lipids extracted contained docosahexaenoic acid (DHA; C22:6(n − 3)) as the most abundant fatty acid, followed by eicosapentaenoic acid (EPA; C20:5(n − 3)). Therefore, prior autolysis at 60 °C for 60 min increased the extraction yield without negative effect on lipid quality.     

Fish oil in feeds for entire male and female pigs: Changes in muscle fatty acid composition and stability of sensory quality

A total of 72 crossbred [(Norwegian Landrace × Yorkshire) × Duroc] male and female growing-finishing pigs were restrictedly fed diets containing fish oil to study the fatty acid composition of Musculus longissimusdorsi and sensory quality of belly and neck. Six diets were used: two low-fat diets with or without 0.5% fish oil added, and four medium-fat diets with palm kernel oil to fish oil in ratios given as % inclusion: 4.1:0.0, 3.9:0.3, 3.6:0.5 and 3.4:0.7. Feeding fish oil gave a dose-dependent response between fatty acids in the diets and in the M.longissimusdorsi and increased the level of very long chain n−3 fatty acids, especially the C22:5n−3 (DPA). A more efficient n−3 fatty acids deposition was obtained when given as a medium-fat diet rather than the low-fat diet. Female pigs had a significant higher percentage of monounsaturated fatty acids and C18:1 than males suggesting a gender related difference in the delta-9-desaturase activity. No significant differences were found in sensory attributes for short-term stored neck and belly. For pigs fed the highest level of fish oil (0.7%) long-term stored (12 months at −80 °C, 6 months at −20 °C) belly showed a slight increase in fish oil flavour. After warmed-over treatment, fish oil odour and flavour as well as rancid flavour were increased in this group. The results suggest levels of dietary fish oil up to 0.5% produce a healthier meat fatty acid composition, without negative effects on sensory attributes, even in long-termed stored belly.     

Lipids from cephalothorax and hepatopancreas of Pacific white shrimp (Litopenaeus vannamei): Compositions and deterioration as affected by iced storage

Lipids from cephalothorax and hepatopancreas of Pacific white shrimp (Litopenaeus vannamei) stored in ice for up to 6 days were extracted and characterised. The extraction yields of lipids from hepatopancreas (10.65–12.64%) were higher than those from cephalothorax (2.59–2.88%). However, no changes in the extraction yield were observed during the storage (p > 0.05). The carotenoid contents of lipids from cephalothorax and hepatopancreas slightly increased within the first 2 and 4 days of iced storage (p < 0.05), respectively, but decreased thereafter (p < 0.05). With increasing storage time, a progressive formation of hydroperoxide was found as evidenced by the increase in the absorbance band at 3600–3200 cm⁻¹ in Fourier transform infrared (FTIR) spectra, and increased peroxide values (PVs) (p < 0.05). The increases in thiobarbituric acid reactive substances (TBARS), p-anisidine value (AnV) and free fatty acid (FFA) content of lipids were noticeable when iced storage time increased (p < 0.05). Those changes indicated that lipid oxidation and hydrolysis occurred in both samples. Phospholipids (PL) were the major components in lipids from cephalothorax (82.51% of total lipids). Nevertheless, lipids from hepatopancreas contained triglyceride (TG) and PL as the dominant components (45.35% and 38.03% of total lipids, respectively). A decrease in the TG content with a concomitant increase in free fatty acid was observed at the end of storage (day 6) (p < 0.05). Decreases in unsaturated fatty acids, especially eicosapentaenoic acid (EPA; C20:5(n-3)) and docosahexaenoic acid (DHA; C22:6(n-3)) were noticeable at day 6 of storage (p < 0.05). Thus, the extended storage time resulted in the enhanced deterioration of extracted lipids.     

Intramuscular fatty acid composition of “Galician Mountain” foals breed: Effect of sex,slaughtered age and livestock production system

The effects of sex, slaughtered age (9 vs. 12 months) and livestock production system (freedom extensive system vs. semi extensive system) of “Galician Mountain” foals breed on the fatty acid composition were studied. The sex and slaughtered age of the animals had no statistical significance in the intramuscular fatty acids. Furthermore, the livestock production system showed differences in the fatty acid profiles from the Longissimus dorsi. The feeding system showed significant differences in PUFA content (P < 0.001) higher in freedom extensive production system that semi extensive system, whereas MUFA content was significantly (P < 0.001) higher in semi extensive system. This major PUFA content in freedom extensive production showed a significant (r = 0.70, P < 0.01) correlation with C18:3n− 3 content and can be attributed to their eaten only pasture until slaughtered. The higher MUFA contents (P < 0.001) observed for semi extensive production system foals were very significant (r = 0.98, p < 0.01) correlated with C18:1cis−9 content and less significant (r = 0.81, P < 0.01) correlated with C16:1cis−9 content. In addition, the data reinforced the evidence that foals from extensive production system on wood pasture have a higher nutritional quality (mainly due to the higher levels of n−3 PUFA) when compared to concentrate-fed foals, as a result of the beneficial effects of grass on meat fatty acid profiles.     

Fatty acid distribution in triacylglycerols and phospholipids of broad beans (Vicia faba)

Fatty acid distribution of triacylglycerols (TAG) and phospholipids (PL) obtained from the four cultivars of broad beans (Vicia faba) was investigated. Total lipids extracted from the beans were separated by thin-layer chromatography into eight fractions. The major lipid components were TAG (47.7–50.1%) and PL (47.5–50.5%), while hydrocarbons, steryl esters, free fatty acids, diacylglycerols (1,3-DAG and 1,2-DAG) and monoacylglycerols were present in minor proportions (1.8–2.4%). The major PL components were phosphatidylcholine (56.4–58.4%), phosphatidylethanolamine (20.3–21.7%) and phosphatidylinositol (16.6–18.6%). Phosphatidylinositol was unique in that it had the highest saturated fatty acid content among the three PL. No significant differences (P > 0.05) in fatty acid distribution existed when the different cultivars were compared. The fatty acid distributions in the TAG were evident among the four cultivars: unsaturated fatty acids were predominantly concentrated in the sn−2 position, and saturated fatty acids primarily occupied the sn−1 or sn−3 position in the oils. These results could be useful to both consumers and producers for manufacture of traditional foods in Japan and elsewhere.     

Selective enrichment of n−3 polyunsaturated fatty acids with C18–C20 acyl chain length from sardine oil using Pseudomonas fluorescens MTCC 2421 lipase

An extracellular lipase purified from Pseudomonas fluorescens MTCC 2421 was used to enrich sardine oil triglycerides with eicosapentaenoic acid (20:5 n−3) and linolenic acid (18:3 n−3) to 35.28% and 8.25%, respectively, after 6 h of hydrolysis. The corresponding n−6 fatty acids (18:2 n−6 and 20:4 n−6) exhibit a reduction (54.93% and 50%, respectively). Structure–bioactivity relationship analyses revealed that the lower hydrophobic (log P values) constants of 18:3 n−3 and 20:5 n−3 (5.65 and 5.85, respectively) result in their higher hydrolytic resistance towards lipase, leading to their enrichment in the triglyceride fraction after lipase-catalysed hydrolysis. Lipase-catalysed hydrolysis of sardine oil for 6 h followed by urea fractionation at 4 °C with methanol provided free fatty acids containing 42.50% 20:5 n−3 and 10.31% 18:3 n−3, respectively. Argentation neutral alumina column chromatography, using n-hexane/ethylacetate (2:1, v/v) resulted in 20:5 n−3 of high purity (83.62%), while 18:3 n−3 was found to be eluted with n-hexane/dichloromethane (4:1, v/v) as eluting solvent with a final purity of 75.31%.