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.     

Concentration of n‐3 polyunsaturated fatty acids in cholesterol‐reduced cod‐liver oil by lipases

This study was conducted to elucidate the effects of different lipases originated from Candida rugosa (CR), porcine pancreas (PP) and Aspergillus niger (AN) on the degree of hydrolysis (DH) in cholesterol‐reduced cod‐liver oil (87.5%) and evaluate the changes in n‐3 polyunsaturated fatty acid concentrations in the oil hydrolysed by the lipases. The lipase‐catalysed hydrolysis of cholesterol‐reduced cod‐liver oil was performed at 37 °C for 8 h. Among all the lipase samples studied, DH in the oil after lipase‐catalysed hydrolysis followed the decreasing order: CR lipase (70.01%) > PP lipase (26.18%) > AN lipase (18.57%). Triacylglycerol levels in the oil hydrolysed by all the lipases studied decreased, while mono‐ and diacylglycerol levels increased during lipase‐catalysed hydrolysis. The eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) concentrations in cholesterol‐reduced cod‐liver oil hydrolysed by the CR lipase were remarkably higher than those by the PP or AN lipase. Thus, it is suggested in this study that the CR lipase appears to be most suitable for producing and n‐3 polyunsaturated fatty acids including EPA and DHA concentrates from cholesterol‐reduced cod‐liver oil.     

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.     

Healthier oils stabilized in konjac matrix as fat replacers in n − 3 PUFA enriched frankfurters

Nutritional, sensory and technological properties of frankfurters as affected by reformulation processes designed to reduce fat content and improve fatty acid profile were investigated. Healthier oils stabilized in oil in water emulsion or in konjac matrix gel were used as fat replacers. Results showed that improved fat content by the replacement of pork backfat with konjac gel and by the addition of healthier oils stabilized by various different systems, both resulted in products with very similar characteristics. From a nutritional standpoint, reformulated frankfurters with konjac gel and/or added a healthier oil combination may claim “reduced fat content” and/or “high omega 3 fatty acid content” according to European Regulation, since they could contain less than 30% of the fat in the reference product and more than 0.6 g of ALA/100 g and more than 80 mg of the sum of EPA plus DHA per 100 g, respectively. Chill storage over 40 days generally had little effect on the technological characteristics of frankfurters.     

Repeated hydrolysis process is effective for enrichment of omega 3 polyunsaturated fatty acids in salmon oil by Candida rugosa lipase

Enrichment of omega 3 polyunsaturated fatty acids (PUFA) in the glyceride fraction of salmon oil was performed by Candida rugosa lipase (CRL)-catalysed hydrolysis. Total omega 3 PUFA content in the product was 38.71% (mol.%), more than double of the initial level. The hydrolysis reaction was scaled up to 1 l in a stirred tank reactor without any decrease in the selectivity of the reaction. Moreover, non-steroselectivity and acyl chain specificity of CRL-catalysed hydrolysis, as well as CRL’s recognition of the whole triacylglycerol molecule, were proved. The product was purified by short path distillation, which was also shown to contribute to the recovery of omega 3 PUFA in residue. After the removal of free fatty acids, the final product was subjected to a second round of hydrolysis to concentrate omega 3 PUFA further to 50.58%. Recoveries of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) decreased slightly after the second round of hydrolysis, while oleic acid (OA) content was not affected.     

Synthesis of monoacylglycerol rich in polyunsaturated fatty acids from tuna oil with immobilized lipase AK

The aim of this study was to produce monoacylglycerols (MAG) rich in polyunsaturated fatty acids (PUFA), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), by glycerolysis of tuna oil with lipase AK from Pseudomonas fluorescence immobilized on Accurel EP-100 (IM-AK). tert-Butyl methyl ether (MTBE) was the most suitable organic solvent after screening a list of different solvents and their mixtures. The optimum conditions for MAG production were: 10% w/v of tuna oil in MTBE; mole ratio of glycerol to tuna oil 3:1, water added 4 wt% in glycerol; the amount of IM-AK 30 wt%, based on tuna oil. The temperature was controlled at 45 °C. Under these conditions, with a 24 h reaction, the yield of MAG was 24.6%, but containing 56.0 wt% PUFA (EPA and DHA). Stability of the IM-AK was also studied. The hydrolytic activity of the enzyme remained at 88% and 80% of initial activity after incubating in MTBE for 24 h at 4 and 45 °C, respectively. The K_m and V_max values of the lipase-catalyzed glycerolysis of tuna oil in MTBE were found to be 19.5 mM and 2.71 mg MAG/min, respectively, for IM-AK.     

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).     

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%.     

Development of dry fermented sausages rich in docosahexaenoic acid with oil from the microalgae Schizochytrium sp.: Influence on nutritional properties,sensorial quality and oxidation stability

Significant enrichment of dry fermented sausages in n−3 polyunsaturated fatty acids (PUFA) was achieved by incorporating algae oil from Schizochytrium sp. into an emulsion that partially substituted pork backfat from the traditional formulation. Two different levels of substitution were initially tested, both including BHA and BHT as antioxidants: (15% and 25%). A triangular test showed that products with 25% substitution were not sensorially acceptable. Sausages with 15% substitution supplied 1.30 g/100 g product of docosahexaenoic acid (DHA), with an interesting n−6/n−3 ratio of 2.62. No signs of oxidation were detected at the end of the ripening process, with low values of TBARs (<0.2 mg/kg), peroxides (<2 meq O₂/kg fat) and volatile aldehydes. Storage of these sausages under vacuum during 30 days totally guaranteed their stability, whereas after 90 days certain degree of oxidation was detected, only by means of aldehydes analysis. Hexanal, nonanal and dienals increased, whereas no increment in TBARs or peroxides were observed. Aerobical storage of these sausages was not viable due to a high oxidation susceptibility of the new formulation, despite the use of antioxidants.     

Concentration of eicosapentaenoic acid and docosahexaenoic acid from fish oil by hydrolysis and urea complexation

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) derived from chemically or enzymatically hydrolyzed from sardine oil were concentrated by urea complexation. The enzymatic hydrolysis was effected in aqueous emulsion using five commercial lipases from Pseudomonas, three immobilized (PS-CI, PS-CII and PS-DI) and two soluble lipases (AK-20 and PS-30). EPA and DHA were determined by gas–liquid chromatography as methyl esters. Results showed that an immobilized lipase preparation (PS-CI) produced the highest degree of hydrolysis for EPA and DHA (81.5 and 72.3% from their initial content in the oil) after 24 h. After complexation of saturated and less unsaturated free fatty acids, the highest concentration of EPA (46.2%) and DHA (40.3%) was obtained using an ethanolic solution with 20% (w/w) urea and 12% (w/w) PS-CI hydrolyzed with a 78% yield. Combination of enzymatic or chemical hydrolysis with urea complexation is a promising method to obtain highly concentrated n-3 PUFA from sardine oil.     

Total lipid content and fatty acid composition of commercially important fish species from the Mediterranean, Mar Grande Sea

The fatty acid (FA) profiles of 11 commercially important fish species from the sea of Southern Italy (Mar Grande Sea) were investigated.The results showed significant differences among the fatty acid profiles of the examined fish (p < 0.05). A relatively high proportion of n − 3 polyunsaturated fatty acids (PUFAs), of which more than 70% were accounted by docoesahexaenoic acid (DHA) and eicoesapentaenoic acid (EPA) in salema, bogue, common two-banded seabream and sand smelt, and lower proportions of oleic acid (C18:1n − 9) and palmitic acid (C16:0) also dominating. The percentages of EPA and DHA were between 5.03-8.61% and 9.85-17.39% of total lipid, respectively.The results showed that the fish examined are a good source of n − 3 PUFAs, resulting in a very favourable n3 - n6 ratio, especially in salema, sand smelt, common two-banded seabream and picarel.     

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.     

Fatty acids and sensory characteristics of Spanish dry-cured loin enriched in acid α-linolenic and α-tocopherol

The effects of using α-linolenic and α-tocopherol acid-enriched pork on the fatty acids and sensory characteristics of Spanish dry-cured loins were investigated. For the study, five batches of Spanish dry-cured loins were manufactured using pork loin enriched in polyunsaturated n − 3 fatty acids and α-tocopherol. Tissues were obtained from pigs fed on diets with the same ingredients, except for the oil source which corresponded to: [sunflower (C), linseed (L) and linseed and olive (1/1, w/w) (LO)] and two different amounts of α-tocopheryl acetate [20 (C, L and LO) or 200 (LOE and LE) mg/kg diet]. Dry-cured loins with polyunsaturated fatty acid n6/n3 ratios below 4 were obtained from linseed and linseed/olive oil-enriched batches. Dry-cured loin manufactured with pork from animals fed on diets enriched only with linseed oil presented the worst sensory characteristics and higher TBAR values than did dry-cured loins from animals fed on diets enriched with linseed and olive oil and linseed oil plus tocopheryl acetate.     

Preparation of eicosapentaenoic acid concentrates from sardine oil by Bacillus circulans lipase

An extracellular lipase derived from Bacillus circulans, isolated from marine macroalga, Turbinaraia conoides, was used to prepare n-3 polyunsaturated fatty acid (PUFA) concentrates from sardine oil triglycerides. The enzyme was purified 132-fold with specific activity of 386 LU/mg. The purified lipase was able to enrich sardine oil with 37.7 ± 1.98% 20:5n-3 and 5.11 ± 0.14% 18:3n-3 in the triglyceride fraction after 3 h of hydrolysis. Lower hydrophobic constants of n-3 fatty acids (18:3n-3_logP = 5.65; 20:5n-3_logP = 5.85, respectively) than n-6 (20:4n-6_logP = 6.16) resulted in higher hydrolytic resistance of the former toward lipase, leading to their enrichment in the triglyceride fraction. Lipase-catalysed hydrolysis of sardine oil for 3 h, followed by urea complexation, provided free fatty acids containing 51.3 ± 4.65% 20:5n-3. The purified methyl ester of 20:5n-3 (68.29 ± 2.15%) from the urea concentrate was attained by chromatography on argentated neutral alumina.     

The effect of replacing dietary fish oil with canola oil on fatty acid composition and expression of desaturase and elongase genes in Jade Tiger hybrid abalone

This study investigates the effect of graded substitution of dietary fish oil (FO) with canola oil (CO) on fatty acid composition and expression of Δ-6 desaturase and elongase 2 genes in the muscle of Jade Tiger hybrid abalone. The control diet contained 1.5% FO supplement (0% CO). Four other diets contained FO/CO in ratios of 3:1 (CO 25%), 1:1 (CO 50%), 1:3 (CO 75%) and 100% CO. The result demonstrated that abalone fed the diets supplemented with 25% and 50% CO showed similarly high levels of total omega-3 polyunsaturated fatty acid (n-3 PUFA), eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) (P < 0.05) as the 0% CO group. The highest levels of total PUFA and total monounsaturated fatty acids were found in the 100% CO group (P < 0.05). The results also showed that Δ-6 desaturase and elongase 2 gene expression was increased in a graded manner by increasing dietary CO (P < 0.05). It was concluded that replacement of FO by CO at the levels of 25-50% can improve the contents of health-benefiting EPA and DHA in abalone.     

Changes in fatty acid composition in muscle of three farmed carp fish species (Labeo rohita,Cirrhinus mrigala,Catla catla) raised under the same conditions

This study was carried out to determine the proximate composition, fatty acid profile and biometric data for farm fish species Labeo rohita, Cirrhinus mrigala, Catla catla raised under identical conditions. The analysed fish species were found as source of high polyunsaturated fatty acids with low fat high protein. Fat content of the fish fillets was in range 2.57–3.11 g/100 g. Whereas fat content for feed was 14.90 g/100 g. The protein level for the three fish ranged from 20.00–23.57 g/100 g and in feed it was estimated in the range of 67.70 g/100 g. The palmitic acid and stearic acid were the main saturated fatty acids (SFA), oleic acid was the predominant MUFA while the docosahexanoic acid and eicopentanoic acid were the major PUFA. The percentage of DHA exceeded that of EPA in all fish species analysed. The n−3/n−6 ratio ranged from 1.69–1.91. PUFA/SFA ratio was much higher in L. rohita (1.40) due to abundance of n−3 PUFA, particularly DHA.     

Nutritional composition of blubber and meat of hooded seal (Cystophora cristata) and harp seal (Phagophilus groenlandicus) from Greenland

Seal blubber and skin are widely used, but the utilisation of blubber and meat for human consumption is limited. The aim of this study was to evaluate the nutritional composition of seal blubber and meat. The fatty acid composition, selected minerals and trace-elements, vitamins, amino acids and proximal composition of blubber and meat from hooded seal (Cystophora cristata) and harp seal (Phagophilus groenlandicus) from the “West Ice” near Greenland were analysed. The results showed that seal blubber is an excellent source of long- and very long-chain (VLC) n − 3 polyunsaturated fatty acids (PUFAs), in addition to long- and VLC monounsaturated fatty acids (MUFAs). Eicosapentaenoic acid (EPA) content contributed to a clear separation between blubber and meat from the two species. The blubber of harp seal showed the highest EPA (9.2%), whereas the muscle of harp seal showed the lowest EPA (3%) content. Seal meat is lean with less than 2% total fat, mainly composed of MUFAs, long- and VLC n − 3 PUFAs. In addition, the meat contains a high amount of proteins with a well-balanced amino acid composition. The trace-element content of seal meat is very high, particularly iron (379 μg/g muscle in hooded seal) and zinc (30 μg/g muscle in harp seal), as also is the vitamin content, especially vitamins A, D₃ and B₁₂. The seals included in this study varied greatly in age and size, which in turn may be the principal reason for the great individual variation observed in nutritional composition. On average, however, consumption of only 40 g seal meat covers the recommended daily intakes of iron and vitamin B₁₂ for young women. In conclusion, as long as the products fulfil the amending legislations regarding contaminants, both seal blubber and meat, from the present species, represent high quality food regarding nutrients and bioactive components beneficial for human health.     

Effect of source of dietary fat on pig performance,carcass characteristics and carcass fat content,distribution and fatty acid composition

Seventy gilts were used to compare the effect of including 10% tallow (T), high-oleic sunflower oil (HOSF), sunflower oil (SFO), linseed oil (LO), a fat blend (FB), or an oil blend (OB) in finishing diets vs. feeding a semi-synthetic diet with no added fat (NF) on pig performance, carcass traits and carcass fatty acid (FA) composition. Carcasses from SFO-fed gilts had greater fat and lower lean compositions than carcasses from T-fed gilts. Gilts fed NF had greater loin fat than FB-fed gilts, and greater flare fat, loin intermuscular fat and fat:lean than T-fed gilts. Bellies from NF-fed gilts had lower lean and higher intermuscular fat and fat:lean than other diets except HOSF. Fat source had minor effects on animal performance, carcass characteristics and carcass fat content and distribution, whereas feeding NF resulted in carcasses and major cuts with higher fat content. Diets rich in polyunsaturated FA (PUFA) did not reduce fat deposition in separable fat depots with respect to monounsaturated FA (MUFA) and saturated FA (SFA). Carcasses from gilts fed NF had a high degree of saturation (40.6% SFA) followed by carcasses of T- and FB-fed gilts. Feeding HOSF, SFO and LO enriched diets elevated the percentages of MUFA (56.7%), n−6 (30.0%) and n−3 (16.6%) PUFA, respectively, whereas carcasses from gilts fed OB had greater percentages of n−3 FA (14.8% n−3, 0.9% EPA, 1.0% DPA, 3.1% DHA) than gilts fed FB (6.72% n−3, 0.1% EPA, 0.4% DPA, 0.1% DHA).     

Physicochemical changes in ω − 3-enhanced farmed rainbow trout (Oncorhynchus mykiss) muscle during refrigerated storage

Physicochemical changes of ω − 3-enhanced farmed rainbow trout (Oncorhynchus mykiss) fillets developed by dietary modification with flaxseed oil and α-tocopheryl acetate (α-TA) were determined during storage at 2 °C. Trout were fed experimental diets for 120 days followed by processing to obtain boneless skinless fillets. The dietary modification increased concentration of total ω − 3 fatty acids in the fillets, which enhanced chances for lipid oxidation during storage. The fillets were vacuum or non-vacuum packed and stored at 2 °C for 10 or 12 days. Dietary α-TA resulted in higher (P < 0.05) concentration of α-tocopherol in fillets during storage; however, it did not retard (P > 0.05) lipid oxidation. Vacuum packaging resulted in much lower (P < 0.05) TBARS and higher (P < 0.05) retention of α-tocopherol during storage than non-vacuum packaging. However, α-tocopherol unlike vacuum packaging better protected ω − 3 FA in the fillets during storage.     

Seasonal variation in the fatty acid composition of three Mediterranean fish – sardine (Sardina pilchardus), anchovy (Engraulis encrasicholus) and picarel (Spicara smaris)

The total fat contents and the fatty acid compositions of three common Mediterranean fish, namely sardine (Sardina pilchardus), anchovy (Engraulis encrasicholus) and picarel (Spicara smaris) were determined at bimonthly intervals for a one-year period. The purpose of this work was to study the seasonal variation of the fatty acids in the three fish that are some of the best sources of n − 3 fatty acids. The fat and fatty acid content of the investigated fish species show a significant seasonal dependency. Two of the fish (anchovy and picarel) have the highest fat content during the late winter – spring period. On the other hand, sardine shows the highest fat concentrations during the spring-early summer period. The fish that showed the highest variation in fatty acid composition was the anchovy. The sardine was found to be the best source of n − 3 fatty acids during the one-year period (35.35 g/100 g fatty acids). Finally the picarel had the highest oleic acid content (on average, 13.89/100 g fatty acids).