Production of n − 3 polyunsaturated fatty acid concentrate from sardine oil by lipase-catalyzed hydrolysis

The production of n − 3 polyunsaturated fatty acids (n − 3 PUFAs) concentrate from oil extracted from Pacific sardines (Sardinops sagax) was studied using lipase-catalyzed hydrolysis. Commercially available microbial lipases, from Candida Rugosa (CR), Candida cylindracea (CC), Mucor javanicus (MJ), and Aspergillus niger (AN) were used for enzymatic hydrolyses with extracted sardine oil, run at 37 °C with constant stirring for 1.5, 3, 6, and 9 h. Fatty acid composition analysis by gas chromatography showed that the refined unhydrolyzed oil contained 26.86% of eicosapentaenoic acid (EPA) and 13.62% of docosahexaenoic acid (DHA) (wt/wt%). CR lipase was the most effective in concentrating n − 3 PUFA. Hydrolysis with 250 U CR lipase increased EPA concentration to a relatively constant level of 33.74% after 1.5 h. DHA levels were also significantly increased from 13.62% to 29.94% with 500 U after 9 h. Compared to CR and CC lipases, MJ and AN lipases resulted in low n − 3 PUFA concentration. Triacylglycerol levels decreased significantly as reaction time progressed.     

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).     

Lipid oxidation of stored eggs enriched with very long chain n−3 fatty acids,as affected by dietary olive leaves (Olea europea L.) or α-tocopheryl acetate supplementation

The antioxidant potential of dietary olive leaves or α-tocopheryl acetate supplementation on lipid oxidation of refrigerated stored hen eggs enriched with very long-chain n−3 fatty acids, was investigated. Ninety-six brown Lohmann laying hens, were equally assigned into three groups. Hens within the control group were given a typical diet containing 3% fish oil, whereas other groups were given the same diet further supplemented with 10 g ground olive leaves/kg feed or 200 mg α-tocopheryl acetate/kg feed. Results showed that α-tocopheryl acetate or olive leaves supplementation had no significant effect on the fatty acid composition and malondialdehyde (MDA) levels of fresh eggs but reduced their lipid hydroperoxide levels compared to controls. Storage for 60 d decreased the proportions of polyunsaturated fatty acids (PUFAs) but increased those of monounsaturated fatty acids (MUFAs) in eggs from the control group, while had no effect on the fatty acid composition of the eggs from the other two groups, which showed decreased levels of lipid hydroperoxides and MDA. Therefore, the very long chain n−3 PUFAs in eggs were protected from undergoing deterioration partly by olive leaves supplementation and totally by α-tocopheryl acetate supplementation. In addition, incorporating tocopherols into eggs might also provide a source of tocopherols for the human diet.     

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.     

Different oilseed supplements alter fatty acid composition of different adipose tissues of adult ewes

Twenty-five mature Small Tail Han ewes were used to investigate the effects of supplemental oilseeds in the diet (sunflower seed, safflower seed, rapeseed, and linseed) on fatty acid composition in different tissues (longissimus lumborum muscle, tail fat, subcutaneous back fat and kidney fat). Averaged over tissue, safflower and sunflower seed was most effective (P < 0.05) in enhancing the concentration of conjugated linoleic acid compared to rapeseed, linseed, and control (1.35% and 1.15% vs. 0.80%, 0.80%, and 0.75%, respectively). Linseed supplemented ewes had lesser n−6/n−3 value (2.48, P < 0.05) compared to sunflower and safflower supplemented ewes (6.12 and 3.90, respectively). Fatty acid composition for most major fatty acids differed among tissues (P < 0.05) but tissue differences varied depending on oilseed supplement (P < 0.05). Proportions of conjugated linoleic acid were greatest in tail fat (1.54% vs. 0.82%, 0.79% and 0.70% for kidney, back, and muscle fat, P < 0.05) as were total unsaturated fatty acids (49.1% vs. 42.4%, 36.7% and 33.4% for muscle, back, and kidney fat, P < 0.05) and tail fat was the most responsive tissue to improvement in fatty acid profile through supplementation. Beneficial fatty acid content of tissues can be increased by oilseed supplementation, but the magnitude of increase varies according to tissue.     

Evaluation of lipid oxidation in spaghetti pasta enriched with long chain n−3 polyunsaturated fatty acids under different storage conditions

This study investigated lipid oxidation in spaghetti enriched in long chain n−3 polyunsaturated fatty acids (LC n−3 PUFA) by the addition to semolina of an integrator containing eicosapentaenoic acid and docosahexaenoic acid. Two oxidative parameters were evaluated: peroxide value (PV), to assess primary oxidation and oxidised fatty acids to quantify secondary oxidation products. Functional spaghetti had a shelf life comparable to control pasta. LC n−3 PUFA were not significantly implicated in the onset of oxidation in spaghetti stored under daylight and accelerated oxidation in a laboratory heater. Storage decidedly affected shelf life: PV in functional spaghetti increased from 7.1 to 43.4 meq O₂/kg of fat under light exposure over 12 months, and from 7.1 to 16.2 meq O₂/kg under accelerated ageing at 55 °C for 27 days, reproducing about 18 months at room temperature. Oxidised fatty acids increased in fortified spaghetti from 4.8 to 13.8 g/100 g of fat under light exposure over 12 months and from 4.8 to 7.8 g/100 g of fat at 55 °C in 27 days. The high sensitivity of spectrophotometric and chromatographic analytical methods permitted the evaluation of primary and secondary oxidative derivatives in small amounts of fat.     

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.     

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.     

Quality characteristics of Dutch-style fermented sausages manufactured with partial replacement of pork back-fat with pure, pre-emulsified or encapsulated fish oil

Dutch-style fermented sausages were manufactured with 15% and 30% pork back-fat substitution by pure or commercial encapsulated fish oil, either added as such or as pre-emulsified mixture with soy protein isolate. Adding commercial encapsulated fish oil was the most important factor influencing the chemical composition. The fat content was not significantly different between products (p > 0.05). The n−6/n−3 ratio decreased from 8.49 in controls to 0.90-2.47 in modified products. Lipid oxidation parameters (propanal and hexanal) showed much higher values for sausages with pure fish oil than for products with encapsulated oil. For the latter, lipid oxidation was similar to controls. Products with encapsulated or pre-emulsified oil were significantly firmer than products from other treatments in physical and sensory analysis (p < 0.05). Overall, it is technologically feasible to enrich dry fermented sausages with n−3 fatty acids from fish oil and the application of commercial encapsulated fish oil seems to be the best in retaining overall quality.     

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.     

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).     

Fatty acid compositions of selected varieties of Spanish dry ham related to their nutritional implications

Five varieties of Spanish dry cured ham were studied to assess their nutritional value in relation to fatty acids. Ten hams of the Traditional Speciality Guaranteed (TSG) “Jamón Serrano”, and the Protected Designations of Origin (PDO) “Jamón de Teruel”, “Dehesa de Extremadura”, “Jamón de Huelva” and “Guijuelo”, were analysed. Iberian hams (“Dehesa de Extremadura”, “Jamón de Huelva” and “Guijuelo”) were characterised by a lower proportion of saturated fatty acids (SFA) and a significantly higher percentage of monounsaturated fatty acids (MUFA) than white hams (“Jamón Serrano” and “Jamón de Teruel”). The Iberian varieties also showed a high proportion (approximately 50%) of C18:1 n − 9, while “Jamón Serrano” showed the highest percentage of C18:2n−6. The PUFA/SFA (P/S) ratio of the five varieties was ? 0.19, with the highest ratio corresponding to “Jamón Serrano” (0.3). The n−6/n−3 ratio was in the order of 13/1 in “Jamón Serrano” and “Jamón de Huelva”, and ranged from 9.3/1 to 10.3/1 in the other varieties. The most favourable hypocholesterolemic/Hypercholesterolemic (h/H) ratio (?2.5) was found in the Iberian varieties. TSG “Serrano” was shown to supply the lowest percentage of the recommended daily intake of MUFA, the Iberian varieties showed the highest percentage of the daily intake of long-chain PUFA, and PDO “Dehesa de Extremadura” showed the highest percentage of the intake of C18:3n−3. The higher MUFA proportion and h/H ratio observed in the Iberian hams, together with their contribution to the recommended daily intake of fatty acids, would make these products more suitable for healthier diets, although consumption must be recommended in moderation.     

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.     

Effects of feeding flaxseed or sunflower-seed in high-forage diets on beef production,quality and fatty acid composition

Yearling steers were fed 70:30 forage:concentrate diets for 205 d, with either grass hay (GH) or red clover silage (RC) as the forage source, and concentrates containing either sunflower-seed (SS) or flaxseed (FS), each providing 5.4% oil to diets. Feeding diets containing SS versus FS significantly improved growth and carcass attributes (P < 0.05), significantly reduced meat off-flavor intensity (P < 0.05), and significantly increased intramuscular proportions of vaccenic (t11-18:1), rumenic (c9,t11-CLA) and n − 6 fatty acids (FA, P < 0.05). Feeding diets containing FS versus SS produced significantly darker and redder meat with greater proportions of atypical dienes (P < 0.05). A significant forage × oilseed type interaction (P < 0.05) was found for n − 3 FA, α-linolenic acid, and conjugated linolenic acid, with their greatest intramuscular proportions found when feeding the RC-FS diet. Feeding GH versus RC also significantly improved growth and carcass attributes, sensory tenderness (P < 0.05) and significantly influenced intramuscular FA composition (P < 0.05), but overall, forage effects on FA profiles were limited compared to effects of oilseed.     

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.     

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 of neutral and phospholipids of three endangered trout: Salmo trutta caspius Kessler, Salmo trutta labrax Pallas and Salmo trutta macrostigma Dumeril

Total (TL), neutral (NL) and phospholipid (PL) amounts and fatty acid (FA) composition of female Salmo trutta caspius, Salmo trutta labrax and Salmo trutta macrostigma were investigated during one year. Twenty-three FAs were identified in both NLs and PLs. The principal FAs of both fractions were palmitic acid in saturated fatty acid, oleic acid in monounsaturated fatty acid, docosahexaenoic acid (DHA) in n-3 polyunsaturated fatty acids (n-3 PUFAs) and linoleic acid in n-6 PUFAs. The highest values for TLs, NLs and PLs were found in winter. As a general trend, the highest n-3/n-6 ratios and eicosapentaenoic acid (EPA) + DHA amounts were found in the winter and this coincided with the lowest gonado-somatic index.     

Mortadella sausage manufactured with Caiman yacare (Caiman crocodilus yacare) meat,pork backfat,and soybean oil

Mortadellas manufactured using Caiman yacare meat (70%) and pork fat (30%) were reformulated by substituting pork fat with increasing amounts of soybean oil (25%, 50%, and 100%) and evaluated 7, 30, and 60 days post-manufacture. The substitutions resulted in an increase in fat content and in the percentage of polyunsaturated fatty acids (total PUFA; 18:2 n − 6 and 18:3 n − 3), and a reduction in saturated fatty acids (total SFA; 14:0 and 16:0). These alterations reduced (P < 0.01) the indices of atherogenicity and thrombogenicity by 4- to 5-fold in the formulation with 100% soybean oil compared to the original formulation. The levels of TBARS obtained at day 7 were positively correlated (P < 0.01) with 18:2 n − 6 and 18:3 n − 3 (r = 0.83 and 0.84, respectively) and negatively correlated with 17:0 and 17:1 (r = − 0.91 and − 0.89, respectively). All formulations received favourable overall acceptability by the sensory panel.     

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.     

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.