Source Of Long-chain Research Articles

Are Upwelling Systems an Underestimated Source of Long Chain Omega‐3 in the Ocean? The Case of the Southern Benguela Upwelling System

AbstractThe Benguela upwelling system (BUS) is one of the world's most productive ecosystems, supporting globally relevant fisheries. The BUS marine community is modulated by the availability of nutrients and omega‐3 long chain polyunsaturated fatty acid (hereafter, LC omega‐3). Phytoplankton growth in the BUS can be supported by upwelled nitrate, a new nitrogen (N) source to the surface, or by recycled N such as ammonium. Preferential assimilation of one N source over another may yield differences in LC omega‐3 production between high and low food‐quality species. To evaluate how upwelling and the N source(s) consumed by phytoplankton influence LC omega‐3 production, we sampled a BUS anchor station daily for 10 days. Upwelling on days 5–7 supplied high concentrations of nutrients to the surface, while pre‐ and post‐upwelling, surface waters were stratified and nutrient concentrations were low. LC omega‐3 and phytoplankton concentrations were near‐zero during upwelling, and elevated pre‐ and post‐upwelling. Throughout our sampling, nanoplankton (2.7–10 µm) dominated primary production (30–95%), relying mainly on nitrate to support their growth. Surface LC omega‐3 concentrations reached peaks of 215 and 175 µg L−1 pre‐ and post‐upwelling, up to 10 times higher than previous measurements from the BUS (<5 µg L−1). Pre‐upwelling, non‐diatom trophic markers (18:1n − 9, 18:4n − 3, 18:5n − 3) were dominant, with a switch over just two days to diatom trophic markers post‐upwelling (16:1n − 7, 16:2n − 4, 16:2n − 7, 16:3n − 4, 16:4n − 1). This study reveals the key role of upwelling in promoting phytoplankton LC omega‐3 production, which is tightly coupled to the supply of new nitrate. Additionally, the high observed LC omega‐3 concentrations suggest that global LC omega‐3 production is underestimated.

Risk and benefit assessment of seafood consumption harvested from the Pertuis Charentais region of France

Seafood is well recognized as a major source of Long Chain n-3 Polyunsaturated Fatty Acids (LC n-3 PUFA, especially ecosapentaenoic acid, i.e. EPA and docosaheaxaenoic acid, i.e. DHA) and essential trace elements (As, Cu, Fe, Mn, Se, and Zn). It is also a source of non-essential trace elements (Ag, Cd, Hg, Pb) that can be deleterious for health even at low concentrations. Edible parts of sixteen species (fish, cephalopods, crustaceans and bivalves) of great importance in the Pertuis Charentais region, one of the main shellfish farming and fishing areas along the french coastline, were sampled in winter and analyzed to determine their fatty acid (FA) composition and trace element concentrations. Based on these analyses, a suite of indices was calculated to estimate risk and benefit of seafood consumption: the n-6/n-3 ratio, the atherogenic index, the thrombogenic index, the EPA + DHA daily recommended portion, as well as the maximum safe consumption. The results showed that fish contributed the most to LC n-3 PUFA supply, while bivalves and crustaceans were more beneficial in essential trace elements. Whatever the species, the concentrations of non-essential elements were not limiting for seafood consumption, as important amounts of the analyzed species can be eaten daily or weekly before becoming hazardous to consumers. Yet, concentrations of Hg in dogfish and seabass can become a concern for frequent seafood consumers (>three meals a week), confirming that varying seafood items is a key point for consumers to optimize the benefits of diverse seafood resources. Considering FA composition, whiting and pilchard are the most beneficial fish species for human diet, while surmullet was the least beneficial one. However, using an index integrating the relative risk due to Hg content, the surmullet appears as one of the most beneficial. This study provides a temporal shot of the quality of marine resources consumed in winter period in the studied area and highlights the complexity of a quantitative risk and benefit assessment with respect to the biochemical attributes of selected seafood.

Choline and methionine supplementation in layer hens fed flaxseed: effects on hen production performance, egg fatty acid composition, tocopherol content, and oxidative stability

Choline is an essential nutrient in laying hen diets and is needed for the formation of phosphatidylcholine (PC), that serves as a rich source of long chain (≥20 C) n-3 fatty acids (FA) in eggs. Methionine (Met) is the first limiting amino acid in layer hen diets and serves as a lipotropic agent with antioxidant properties. The objectives of the current study is based on the hypothesis that choline and Met supplementation will enhance egg PC and n-3 FA status, lipid stability, and production indices in layer hens fed flaxseed. Ninety-six, 40-wk-old laying hens (W-36 White Leghorns) were randomly allocated to 4 treatment groups, with 6 replicates containing four hens per cage. Hens were fed corn-soybean meal-based diet containing 0% flaxseed (Control), 15/100 g flaxseed (Flax), Flax+50% more methionine requirement for W-36 White Leghorns (Flax+Met), or Flax+0.15g/100g choline chloride (Cho) (Flax+Cho). All experimental diets were isocaloric and isonitrogenous and fed for a period of 120 d. Egg production and egg mass (g/hen/d) was higher for Flax+Met and Flax+Cho when compared to Flax and Control (P < 0.05). Egg weight was greater (P < 0.05) among hens fed the Control and Flax+Cho diets compared to Flax diet. Feeding flaxseed to hens led to over 6-fold increase in total n-3 FA. Choline supplementation increased egg α-tocopherol content (P < 0.05) while reducing lipid oxidation products measured as thiobarituric acid reactive substances in egg yolk (P < 0.05). Neither Met nor Cho had any impact on docosahexaenoic (22:6 n-3) acid concentration in eggs from hens fed flaxseed. However, addition of Met and Cho to layer diets increased docosapentaenoic acid (22:5 n-3) levels in eggs from hens fed flaxseed (P < 0.05). The PC content was lower in Control and Flax+Met (P < 0.05) when compared to Flax+Cho group. No difference was found in total lipid or phosphatidylethanolamine content of eggs (P > 0.05). The results from the current study suggest that n-3 FA content of egg yolk can be greatly increased by feeding flaxseed but reduced egg production. However, dietary Met and Cho can improve production performance in hens fed flaxseed-containing diets. Addition of Cho to flaxseed increased in egg weight, yolk α-tocopherol levels, PC content and oxidative stability of eggs when compared to hens fed flaxseed. Met and choline could be used in flaxseed (>15%) to increase egg production and egg mas.

Review on docosahexaenoic acid in poultry and swine nutrition: Consequence of enriched animal products on performance and health characteristics.

Omega-3 polyunsaturated fatty acids (n-3 PUFA) are linked to a variety of health benefits against human disorders and disease. However, the typical western diet is generally low in n-3 PUFA and high in n-6 PUFA, suggesting that the recommended intake of these essential fatty acids is seldom achieved. Therefore, dietary enrichment of animal meat and eggs with n-3 PUFA could help increase consumption of these fatty acids. Fish oils and microalgae (MA) are rich sources of long chain n-3 PUFA, specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Feeding these marine products has been shown to increase DHA content of tissues and yolk, however, this may also lead to an increased requirement for anti-oxidants to prevent oxidative deterioration and associated negative sensory attributes. Nonetheless, increased DHA has been linked to promising results in animal growth, fertility, immunity and bone strength in both pigs and poultry. These findings suggest that feeding DHA-rich ingredients to mono-gastric can enrich human diets as well as providing additional benefits to the animal.

Spatial Distributions and Potential Sources of Long Chain (C30, C32 1,15-) Alkyl Diols in Surface Sediments from Eastern China Marginal Seas

Long chain alkyl diols have shown important potential for the reconstruction of sea surface temperature, productivities and upwelling conditions in marine or lacustrine environments. However, little is known about the distribution and sources of the diols in eastern China marginal seas (CMS), which are areas of important organic carbon sink. Here the contents of C30 and C32 1,15-diols were analyzed in 181 surface sediments from eastern CMS. The similar distribution pattern and strong linear correlation between C30 and C32 diols indicated that they had similar biological source, with a dominance of C30 diol. Their contents ranged from 7–2726 ng g−1 for C30 diol and 5–669 ng g−1 for C32 diol, and both showed higher values mainly in the mud area of the Yellow Sea, while the TOC normalized contents showed a more obvious seaward increasing trend. The similar distribution pattern and significant positive correlation between diols and the other marine biomarkers (brassicasterol, dinosterol, C37 alkenones) indicated C30 and C32 diols in eastern CMS were mainly from marine algae. This conclusion was also supported by principal component analysis (PCA). Our results also showed that sediment diol contents were generally related to marine productivity, suggesting that diols could be applied for marine productivity reconstruction in eastern CMS.

Why is it important to use algae in aquaculture?

Algae and especially microalgae are very promising into eventual biotechnological applications. Indeed, microalgae are unique compared to other living organisms thanks to their valuable biochemical compounds for aquaculture, human health food, biofuels and other applications. Recently, studies on the oleaginous microalgae, for instance, those from the genus Chlorella , have emerged their uses for commercial exploitations with applications focused on nutrition and aquaculture uses. Chlorella minutissima has outstanding features in health and nutrition; and it could play an important part in aquaculture improvement methods as it produces significant amount of polyunsaturated fatty acids. Microalgae are considered to be among the promising feedstocks for aquaculture in the future. For this end Chlorella minutissima is an oil-rich green alga, was studied in many reports as a source of long chain n-3 polyunsaturated fatty acids (n-3 LC-PUFA) to replace control diet without microalgae for rotifers, which serve in turn as food for early stages of fish.

Increasing desirable polyunsaturated fatty acid concentrations in fresh beef intramuscular fat.

Abstract Beef is an excellent source of protein, B vitamins and trace minerals and can be an important source of long chain n-3 polyunsaturated (PUFA) and other bioactive fatty acids such as vaccenic acid (VA) and conjugated linoleic acid (CLA). However, beef consumption has been declining mainly due to concerns over its saturated fat content. Despite generalizations about beef fat, fatty acid analyses of retail beef suggests that lean beef falls within dietary recommendations for fat intake (total and saturated), can be a rich source of heart healthy cis -monounsaturated fatty acids and has a low n6-/n3-PUFA ratio. Since the 1970s, numerous attempts have been made to increase the PUFA content of beef, particularly n-3 PUFA and to further increase the content of VA and CLA. This has been mainly done by feeding cattle PUFA rich sources such as fresh forage (pasture), conserved forage, oil seeds, plant or marine oils or their combinations. The main challenge when trying to enrich beef with PUFA has been their extensive biohydrogenation in the rumen resulting in limited deposition compared with monogastrics (e.g. pigs and chickens). To address this, several techniques to protect PUFA against ruminal biohydrogenation or to reduce the extent of biohydrogenation have been investigated including different methods of feed processing, encapsulation of oil inside a microbial resistant protein matrix (e.g. formaldehyde-treated protein), chemical modification of fatty acids (calcium salts or amides) or protection using plant secondary metabolites and enzymes. The present review examines the fatty acid composition of retail beef in relation to human health and evaluates the effectiveness of different feeding strategies and possibilities for future improvement in the content of healthful fatty acids in beef, specifically vaccenic, rumenic and omega-3 fatty acids.

Microalgae and organic minerals enhance lipid retention efficiency and fillet quality in Atlantic salmon (Salmo salar L.)

Pure spray dried DHA rich microalgae biomass (Schizochytrium sp.) was used to replace fish oil as a source of long chain n-3 polyunsaturated fatty acids (n-3 LC-PUFA) in medium (150gkg−1; MF) and low fish (100gkg−1; LF) meal diets for Atlantic salmon post smolt supplemented with either inorganic or organic minerals (OM: Zn, Cu, Mn, Fe and Se). The diets were balanced for total saturated fatty acids (SFA), sum DHA+EPA and n-3/n-6 ratio and had similar protein and energy digestibility and high pellet technical quality. Lipid digestibility was above 90% in all diets, nevertheless 2.3% lower in the diet containing 50gkg−1 microalgae, compared to the control, mainly due to the lower digestibility of SFA in the microalgae rich diets. The experimental fish grew from 0.4kg to 1.1kg with no significant differences in growth rate (TGC 3.7–3.8) or feed conversion ratio (FCR 0.7) among the dietary treatments. The retention efficiency of EPA+DHA in salmon body was significantly improved in the fish fed diets containing increasing levels of microalgae, and thus lower EPA/DHA ratios. Moreover, liver lipid levels were decreased and dress-out percentage increased by increasing microalgae dietary supplementation level. The fillet levels of SFA and DHA+EPA were similar for all treatments. Improved fillet quality in terms of lower gaping scores was observed with increasing dietary inclusion level of Schizochytrium sp. and even more pronounced for salmon fed organic minerals. No significant effects on fish blood plasma chemistry and whole body mineral content were observed. Statement of relevanceAquaculture is in urgent need of adequate volumes of new LCn-3PUFA sources, alternative to fish oil. The current work documents the feasibility of using practically relevant levels of heterotrophic microalgae as LCn-3PUFA source in the diet of Atlantic salmon in terms of extruded feed production feasibility, general fish performance, fish fillet product quality (nutritional and technical), nutrient retention efficiency and blood chemistry.

Fish consumption and resilience to depression in Japanese company workers: a cross-sectional study.

BackgroundDepression is a common disorder that is influenced by psychosocial factors in the workplace. Increasing resilience, the ability to cope with stress in the face of adversity, is considered an important strategy to prevent depression. It has been suggested that consumption of fish, which is a major source of long chain n-3 polyunsaturated fatty acids (LC n-3 PUFA), may prevent depression. However, associations between depression, resilience, and fish consumption have not been documented.The aim of the study is to investigate the association between fish consumption and resilience to depression.MethodsParticipants were 527 Japanese employees at three worksites of a large company. The Center for Epidemiologic Studies Depression (CES-D) Scale was administered to assess depressive symptoms, and the 14-item Resilience Scale (RS-14) was administered to assess resilience. A self-report questionnaire extracted from the Food Frequency Questionnaire was used to measure fish consumption frequency. Regression analyses were conducted to assess a mediation model based on a statistical analysis framework defined by Baron and Kenny. The indirect association of resilience was calculated with the bootstrapping method. Each analysis was adjusted by age, sex, marital status, work position, and educational background.ResultsThe association between fish consumption frequency and total CES-D score was significant (B = −0.94; p = 0.011). The association between fish consumption frequency and total RS-14 score was significant (B = 1.4; p = 0.010), as was association total RS-14 score and the total CES-D score (B = −0.34; p < 0.001). When controlling for total RS-14 score, there was no longer a significant association between fish consumption frequency and total CES-D score. The bootstrapping results revealed that significant indirect association though fish consumption frequency and total CES-D score (bias corrected and accelerated confidence interval = −0.83 to −0.13; 95 % confidence interval) through total RS-14 score.ConclusionsFish consumption might be associated with resilience to depression. Further studies are needed, particularly double blind randomized placebo controlled intervention trials on the potential preventative effect of LC n-3 PUFA on resilience to depression.

DHA/EPA Consumption by Pregnant Women in Louisiana

Dietary Guidelines for Americans 2010 recommends consumption of 8‐12 oz of seafood/week for women who are pregnant or breastfeeding to achieve an average DHA+EPA intake of 200‐250 mg/day. In an on‐going study of overweight pregnant women in Louisiana we assessed, by repeated 24‐hour dietary recalls using the U of Minnesota Nutrient Data System for Research (NDSR), intake of seafood and fatty acids. Women were 20‐34 y of age and entered the study at 17‐20 wks of pregnancy. Depending on when women had been recruited into the study, women to date had completed 1‐7 recalls. On average, women (n=8) consumed 46 mg/day of dietary DHA+EPA and with supplementation, 225 mg (n=7). The range of dietary DHA+EPA intake, without supplementation (prenatals /other commercially available supplements) was 8‐101 mg/day and with supplementation, 72‐408 mg/day. Without supplementation with DHA+EPA, 8/8 of the women were consuming &lt;200 mg/day DHA+EPA. Seven of 8 women reported supplementation and 2 of 7 women who supplemented consumed &lt;200 mg DHA+EPA/day. Fish consumed included shrimp, crab, catfish, and fish sticks. The data point to a need for nutrition education for pregnant women, breastfeeding women, and women of childbearing ages regarding the importance of consuming fish varieties that are good sources of long chain n‐3 polyunsaturated fatty acids.Funded in part by: LSU Undergraduate Research Grant (C Thaxton); USDA AFRI 2012‐67017‐19293 (CJL‐K); and LSU AgCenter.

Farmed Atlantic salmon (Salmo salar L.) is a good source of long chain omega‐3 fatty acids

SummaryThe limited amount of fish oils available has resulted in an increased use of vegetable oils in the feed for farmed fish, such as Atlantic salmon. The aim of this study was to evaluate how this has affected the fatty acid (FA) composition of farmed Atlantic salmon and to compare the FA composition of 20 farmed Atlantic salmon with that of 20 wild Atlantic salmon caught in the sea. Fillet fat of farmed salmon was about 12%, which is twice that found in wild salmon. The FA composition of the farmed salmon confirmed a substantial inclusion of vegetable oils in the feed, but the total amount of long chain n‐3 FA present in the fillets of farmed salmon was higher than in the wild fish. A standard portion of farmed Atlantic salmon fillet (200 g) provides approximately 2 g of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which is four times higher than the minimum daily intakes recommended by the UK's Scientific Advisory Committee on Nutrition and the World Health Organisation.

Atlantic Salmon (Salmo salar): The “Super-Chicken” of the Sea?

In this article, the definition of sustainability is discussed, particularly in relation to the use of marine feed resources. The current review gives an overview of the development of Atlantic salmon (Salmo salar) aquaculture and how it has evolved due to changes in legal and management framework conditions. Atlantic salmon production is characterized with high utilization of nutrients, a high yield of production, and a large demand for rendered by-products. All of these factors compare favorably to production of most terrestrial farm animals. Historically, salmon feed has contained fishmeal and fish oil as the primary protein and fat source. Rising demand for feed ingredients has not increased pressure on forage fish resources. Rather, there has been an increased use of plant protein and fat sources. Increased utilization of plant ingredients may not be as sustainable as often claimed. Provided that marine harvest is carried out within legal frames, harvesting the marine ecosystem is a sustainable operation, and at present, the only significant source of long chain n-3 fatty acids. It is concluded that Atlantic salmon farming can be compared to raising a marine “super chicken” being among the most sustainable meat products in the world food market.

Transgenic conversion of omega-6 into omega-3 fatty acids in a mouse model of Parkinson's disease

We have recently identified a neuroprotective role for omega-3 polyunsaturated fatty acids (n-3 PUFAs) in a toxin-induced mouse model of Parkinson's disease (PD). Combined with epidemiological data, these observations suggest that low n-3 PUFA intake is a modifiable environmental risk factor for PD. In order to strengthen these preclinical findings as prerequisite to clinical trials, we further investigated the neuroprotective role of n-3 PUFAs in Fat-1 mice, a transgenic model expressing an n-3 fatty acid desaturase converting n-6 PUFAs into n-3 PUFAs. Here, we report that the expression of the fat-1 transgene increased cortical n-3:n-6 PUFA ratio (+28%), but to a lesser extent than dietary supplementation (92%). Such a limited endogenous production of n-3 PUFAs in the Fat-1 mouse was insufficient to confer neuroprotection against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine neurotoxicity as assessed by dopamine levels, tyrosine hydroxylase (TH)-positive neurons and fibers, as well as nigral Nurr1 and dopamine transporter (DAT) mRNA expression. Nevertheless, higher cortical docosahexaenoic acid (DHA) concentrations were positively correlated with markers of nigral dopaminergic neurons such as the number of TH-positive cells, in addition to Nurr1 and DAT mRNA levels. These associations are consistent with the protective role of DHA in a mouse model of PD. Taken together, these data suggest that dietary intake of a preformed DHA supplement is more effective in reaching the brain and achieving neuroprotection in an animal model of PD.

Fatty acid intakes and food sources in a population of older Australians.

To document dietary intakes and food sources of fatty acids among older Australians. Population-based survivor cohort. Two postcode areas in the Blue Mountains, West of Sydney, Australia. In 1997-9, 2334 people aged 55 years and over, participated in a 5-year follow-up of the cohort attending the Blue Mountains Eye Study (BMES). Dietary data were collected using a semi-quantitative food frequency questionnaire by 2005 persons (86% of those examined). Types of fats were classified as saturated fatty acids (SFA), monounsaturated (MUFA), polyunsaturated (PUFA) and trans unsaturated fatty acids. Mean total fat intake contributed 31.3% of daily energy intake (12.2% SFA, 11.2% MUFA, 5.0% PUFA). Mean omega 3 (n-3) PUFA intake comprised 0.5% of energy intake (long chain n-3 PUFA provided mean intake of 260mg, consisting of eicosapentaenoic (EPA), docosapentaenoic (DPA) and docosahexaenoic (DHA) fatty acids) and the n-6: n-3 PUFA ratio was 9:1. The main fatty acids contributing to the diet were palmitic acid, oleic acid and linoleic acid. Meat products were the highest contributors to total fat and MUFA intakes; milk products were the highest contributor to SFA intakes; and fat spreads and oils, and breads and cereals were the main food groups contributing to PUFA intakes. Fish was the main source of long chain n-3 fatty acids. This population-based descriptive study documents fatty acid intakes in a population of older Australians. It will serve as a basis for investigations of associations between dietary fatty acid intakes and a number of eye diseases.

The effect of level of dietary fish oil inclusion on intake and methane emissions of beef steers

Irish livestock account for 0.55 million tonnes of methane (CH4) annually from enteric fermentation and manure management (EPA, 2006). However, recent studies have shown the potential to reduce ruminal methanogenesis through strategic dietary supplementation with polyunsaturated fatty acids (PUFA; Jordan et al. 2006). This is likely to be mediated, in part, through the unsaturated double bonds of PUFA acting as sinks for free hydrogen during ruminal biohydrogenation. Fish oil is acknowledged as the richest natural source of long chain n-3 PUFA such as eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids (Ruxton et al., 2004). Despite this, there is little published information on the effect of dietary fish oil supplementation on in vivo ruminal methanogenesis in cattle. The aim of this study was to assess the effect of a novel concentrated n-3 PUFA fish oil, on the intake and CH4 emissions of beef steers.

Spirulina maximaandDiacronema vlkianummicroalgae in vegetable gelled desserts

PurposeThe purpose of this paper is to develop microalgae vegetable‐based gelled desserts (similar to “dairy desserts”) prepared with pea protein isolate,Spirulina maximaandDiacronema vlkianumbiomass, rich in essential fatty acids (omega‐3 polyunsaturated fatty acid's (PUFA)). The effect of microalgae concentration and gelling temperature on the colour, texture and fatty acid profile of the gels was investigated.Design/methodology/approachPea protein isolate (4 per cent), κ‐carrageenan (0.15 per cent) and starch (2.5 per cent) were used to produce a gelled dessert that was further enriched with microalgal biomass (0.1‐1.0 per cent). The gels were prepared using different temperatures, ranging from 75 to 90 ○C. Colour, total pigments (carotenoids), texture and fatty acid profile of the gels were evaluated.FindingsThe addition ofDiacronemaandSpirulinamicroalgal biomass to vegetable gelled deserts, results in a novel alternative food product, with PUFA's (e.g. EPA, DHA and GLA), with favourable texture characteristics, particularly forDiacronema, due to the structural reinforcement, representing a new food market niche.Practical implicationsNowadays there is an increasing consumer demand for more natural food products, presenting health benefits. Microalgae are able to enhance the nutritional content of conventional food and hence to positively affect humans health due to their original chemical composition, namely as a source of long chain omega‐3 PUFA.Originality/valueAs far as the authors are aware the use of these microalgae in gelled desserts, in association with vegetable proteins, is an innovative food application.

Lipid changes and sensory quality of whole- and gutted rainbow trout during storage in ice

.Background. The aquaculture rainbow trout may be a valuable source of long chain n-3 polyunsaturated fatty acid (LC n-3 PUFA). In the retail these fish are mainly present as a whole or gutted. The present study was aimed at comparing changes occurring in lipids of whole and gutted rainbow trout stored in ice. Materials and Methods. The analysis were performed after 0, 3, 7, and 14 days of storage in ice at 2°C and the following assays were carried out: proximate composition; lipid composition high pressure liquid chromatography (HPLC); fatty acid composition gas chromatography /mass spectrometry (GC/MS) by direct tissue saponification; contents of lipids extracted, using the Bligh-Dyer technique; UV-VIS, IR, and fluorescence lipid spectra; peroxide value (PV); anisidine value (AsV); and acid value (AC). Results. Gutting prior to storage made it possible to extend the sensory shelf-life by about 2–3 days and affected the quantitative fatty acid composition and oxidation level during storage in ice. The rainbow trout lipids are resistant to oxidation; oxidation product decomposition rather than lipid oxidation proceeds during storage, the decomposition being more intensive in whole than in gutted fish. It is only when the fish lose their eating quality (2 weeks) that a small increase in the level of oxidation occurs, accompanied by an about 15% loss of n-3 PUFA and a 20% loss of DHA, but only in the whole fish. Conclusion. Gutting rainbow trout prior to storage in ice is appropriate by the extending the shelf-life by about 2–3 days and keeping stable amount of n-3 PUFA during 2 weeks of storage.

Long-chain conversion of [13C]linoleic acid and α-linolenic acid in response to marked changes in their dietary intake in men

We studied the long-chain conversion of [U-13C]alpha-linolenic acid (ALA) and linoleic acid (LA) and responses of erythrocyte phospholipid composition to variation in the dietary ratios of 18:3n-3 (ALA) and 18:2n-6 (LA) for 12 weeks in 38 moderately hyperlipidemic men. Diets were enriched with either flaxseed oil (FXO; 17 g/day ALA, n=21) or sunflower oil (SO; 17 g/day LA, n=17). The FXO diet induced increases in phospholipid ALA (>3-fold), 20:5n-3 [eicosapentaenoic acid (EPA), >2-fold], and 22:5n-3 [docosapentaenoic acid (DPA), 50%] but no change in 22:6n-3 [docosahexanoic acid (DHA)], LA, or 20:4n-6 [arachidonic acid (AA)]. The increases in EPA and DPA but not DHA were similar to those in subjects given the SO diet enriched with 3 g of EPA plus DHA from fish oil (n=19). The SO diet induced a small increase in LA but no change in AA. Long-chain conversion of [U-13C]ALA and [U-13C]LA, calculated from peak plasma 13C concentrations after simple modeling for tracer dilution in subsets from the FXO (n=6) and SO (n=5) diets, was similar but low for the two tracers (i.e., AA, 0.2%; EPA, 0.3%; and DPA, 0.02%) and varied directly with precursor concentrations and inversely with concentrations of fatty acids of the alternative series. [13C]DHA formation was very low (<0.01%) with no dietary influences.

Effect of dietary concentrations of n-3 polyunsaturated fatty acids on the n-3 polyunsaturated fatty acid content of edible poultry tissues: a review and meta analysis

The nutritional benefits of consuming long chain n-3 polyunsaturated fatty acids (PUFA), which are predominantly found in oily fish, are well known but consumption of oily fish is declining. Poultry consumption, on the other hand, is increasing, but poultry meat is generally a poor source of long chain n-3 PUFA. The concentrations of the n-3 PUFA α-linolenic acid (LNA), EPA and DHA in poultry meat may be increased by feeding birds diets that are themselves rich in these acids. The objective of this study was to review the literature to determine what relationship if any there was between n-3 PUFA content in the diet and edible tissues of poultry.

Polyunsaturated fatty acids and inflammation

The n-6 polyunsaturated fatty acid arachidonic acid gives rise to the eicosanoid family of inflammatory mediators (prostaglandins, leukotrienes and related metabolites) and through these regulates the activities of inflammatory cells, the production of cytokines and the various balances within the immune system. Fish oil and oily fish are good sources of long chain n-3 polyunsaturated fatty acids. Consumption of these fatty acids decreases the amount of arachidonic acid in cell membranes and so available for eicosanoid production. Thus, n-3 polyunsaturated fatty acids act as arachidonic acid antagonists. Components of both natural and acquired immunity, including the production of key inflammatory cytokines, can be affected by n-3 polyunsaturated fatty acids. Although some of the effects of n-3 fatty acids may be brought about by modulation of the amount and types of eicosanoids made, it is possible that these fatty acids might elicit some of their effects by eicosanoid-independent mechanisms. Such n-3 fatty acid-induced effects may be of use as a therapy for acute and chronic inflammation, and for disorders that involve an inappropriately-activated immune response.