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The Distribution of Fatty Acids in Flesh and Liver of Papua New Guinean Fish
Abstract
1.1. The lipid content and fatty acid composition of flesh and liver of 19 different species of PNG fish were studied.2.2. The total lipids were extracted with chloroform-methanol (2:1, v/v) and lipid content was determined gravimetrically.3.3. The total lipids transesterified with 7% BF3-MeoH and the distribution of fatty acid profiles were determined by capillary gas-liquid chromatography.4.4. The total lipids of flesh and liver contained a high proportion of unsaturated fatty acids.5.5. The amounts of arachidonic and docosahexaenoic acids were significant.6.6. Eicosapentaenoic acid concentration was appreciable.
... One of the distinctive features of plasma NEFA (and tissue fatty acid composition) in temperate marine teleosts is a high ratio of n-3/n-6 fatty acids (4.7 to 14.4) due to elevated levels of DHA and EPA, which are common in cold-water food chains and have important roles in the function of cold-adapted membranes in fishes (Henderson and Tocher, 1987; Hazel and Williams, 1990; Ballantyne et al., 1993). The tissue lipids of tropical marine teleosts, on the other hand, contain less DHA and more AA and its elongation product docosatetraenoic acid (22:4n-6), resulting in lower n-3/n-6 ratios (Sinclair et al., 1983; Gibson et al., 1984; Hansel et al., 1993). In fact, Sinclair et al. (1984) demonstrated that the relative n-6 fatty acid content in fishes increased as sampling occurred closer to the equator. ...
... The n-3/n-6 ratio has therefore been suggested as a distinguishing feature between marine and freshwater teleosts (Henderson and Tocher, 1987). However, there is reason to hypothesize that this general rule does not hold true for comparisons of plasma NEFA or lipid composition between freshwater and marine fishes from tropical waters because, as previously mentioned, tissue lipids of warmwater marine teleosts contain less DHA and more AA and 22:4n- 6, resulting in low n-3/n-6 ratios (Sinclair et al., 1983; Gibson et al., 1984; Hansel et al., 1993). We tested this hypothesis and evaluated the influence of adaptation to differing environmental salinity on plasma NEFA by comparing plasma NEFA composition between two tropical marine elasmobranchs and two tropical freshwater elasmobranchs. ...
... The tropical elasmobranchs, especially the marine C. punctatum and T. lymma, also had relatively high levels of docosatetraenoic acid (22:4n-6), the elongation product of AA, whereas in temperate marine elasmobranchs this fatty acid is either absent or present in low levels (b 1%) in plasma NEFA (present study; Ballantyne et al., 1993). These results are consistent with previous work done on tropical marine teleosts, which showed that their lipids also include less DHA, and more AA and 22:4n-6 than temperate species (Sinclair et al., 1983; Gibson et al., 1984; Hansel et al., 1993). In elasmobranchs, high levels of 22:4n-6 in plasma NEFA, along with a high AA/DHA ratio, could be considered a marker of a tropical species. ...
We investigated the influence of environments with different average temperatures and different salinities on plasma NEFA in elasmobranchs by comparing species from tropical vs. cold temperate marine waters, and tropical freshwater vs. tropical marine waters. The influence of the environment on plasma NEFA is significant, especially with regard to essential fatty acids (EFA) and the n-3/n-6 ratio. n-3/n-6 ratios in tropical marine elasmobranchs were lower by two-fold or more compared with temperate marine elasmobranchs, because of higher levels of arachidonic acid (AA, 20:4n-6) and docosatetraenoic acid (22:4n-6), and less docosahexaenoic acid (DHA, 22:6n-3), in the tropical species. These results are similar to those in earlier studies on lipids in teleosts. n-3/n-6 ratios and levels of EFA were similar between tropical freshwater and tropical marine elasmobranchs. This suggests that the observation in temperate waters that marine fishes have higher levels of n-3 fatty acids and n-3/n-6 ratios than freshwater fishes may not hold true in tropical waters, at least in elasmobranchs. It also suggests that plasma NEFA are little affected by freshwater vs. seawater adaptation in elasmobranchs. Likewise, we found that plasma NEFA composition and levels were not markedly affected by salinity acclimation (2 weeks) in the euryhaline stingray Himantura signifer. However, in contrast to our comparisons of freshwater-adapted vs. marine species, the level of n-3 fatty acids and the n-3/n-6 ratio were observed to significantly decrease, indicating a potential role of n-3 fatty acids in salinity acclimation in H. signifer.
... Hansel et al. (19)] ...
If a great number of rays are fished in the Tropical East Atlantic Ocean for their caudal fins, only a small amount of ray flesh is processed. Among them, three species of rays, Dasyatis marmorata, Rhinobatos cemiculus, and Rhinoptera marginata, from the Mauritanian coast have been investigated for the fatty acid composition of their lipids. Gas chromatography and gas chromatography-mass spectrometry allowed identification of 50 molecules from muscles, livers, and gonads of these fishes. Principal component analysis, starting from >50 samples, reveals significant differences in various fatty acid distributions, related to the species and sex of the sampled fish. Some of them are preferentially present in one sex or in both species, whereas the occurrence of others characterizes the male and female of one or two species. The results show that rays are potential resources of polyunsaturated fatty acids (PUFA) and should be used in the diet of local populations. The lipidic fractions contained a high amount of PUFA (up to 30% of the total), mainly composed of docosa-4,7,10,13,16,19-hexaenoic acid, eicosa-5,8,11,14-tetraenoic acid, and eicosa-5,8,11,14,17-pentaenoic acid.
This bibliography lists publications on human nutrition and food in Papua New Guinea (and to a lesser extent Irian Jaya/West Papua) for the last decade. It is intended as a background resource, bringing together a considerable body of materials many of which may not usually be indexed in electronic databases. It is a working document only, and thus contains some errors, duplications and uneven reference formats. It is biased toward published material and undoubtedly only scratches the surface of the large “grey “ literature of unpublished government, NGO and consultancy documents.
The listing is focussed on items concerned primarily with human nutrition and food, and thus spans a large fuzzily defined area located between the giants of medicine and agriculture. Obviously, in a country in which subsistence food production is of major significance, there is a large area of potential overlap with the huge literature on agriculture and food production, as well as that of ethnography. With a few exceptions, however, references on agriculture and food production have been excluded, unless they also provide information concerning food intake or nutrient composition. Similarly, much of the general ethnographic literature, which often minimally contains information on food, has not been included. There are three reasons for this specific focus: first, and practically, it limits what would otherwise be a much larger and unwieldy bibliography; secondly, it allow more emphasis on material which is sometimes swamped by the three major areas of agriculture, ethnography and medical research; and thirdly, the latter areas are served already by a range of existing bibliographies and databases.
The present research work was designed to study Dicentrarchus labrax biotransformation and detoxification responses to acute exposure to nickel (Ni) and chlorpyrifos (CHP). Sexually immature sea bass were treated by intraperitoneal injection of nickel chloride (500 μg kg⁻¹), chlorpyrifos (10 mg kg⁻¹), and their binary mixture for 1, 3, and 7 days. Ni and CHP accumulation was quantified in liver after the exposure periods. The following biological responses were measured: (1) NADPH cytochrome P450 reductase (NCR) activity, as phase I biotransformation parameter; (2) gluthathione S-transferase (GST) activity as a phase II conjugation enzyme, acetylcholinesterase activity, and metallothionein (MT) content. Ni bioaccumulation in the liver resulted in an increasing uptake up to 15.48 μg g⁻¹ wet weight (Ni-treated animals) and 16.73 μg g⁻¹ wet weight (mixture-treated animals) after 7 days of exposure. CHP accumulation showed a distinct pattern in animals exposed to the mixture of chemicals in comparison with CHP-treated animals. NCR activity exhibited a marked activation in CHP and mixture-treated animals. GST activity was significantly increased starting from 1 day exposure in CHP-treated animals and after 3 days in Ni-treated animals. MT accumulation increased in all conditions, with a marked synergetic effect after 7 days of exposure. These data should be carefully considered in view of the biological effects of mixture pollutants, particularly in fish farming conditions.
This research was designed to study Sparus aurata (sea bream) biotransformation and detoxification responses to acute exposure to cadmium (Cd). Sexually immature gilthead sea bream were treated by intraperitoneal injection of Cd chloride (200 microg kg(-1)) for 6, 12, 24 and 48 h. Cd accumulation was quantified in sea bream liver by graphite furnace atomic absorption spectroscopy after the various exposure periods. The following biological responses were measured: (1) ethoxyresorufin-O-deethylase (EROD) activity as phase I biotransformation parameter, (2) liver glutathione-S-transferase (GST) activity as a phase II conjugation enzyme and metallothionein (MT) content as specific response to Cd contamination. Cd bioaccumulation in the liver resulted in an increasing uptake up to 10.3 microg g(-1) wet weight after 48 h of exposure. EROD showed a significant activation only after 6 h exposure and a return to control levels after 12 h. GST revealed significant activation starting from 12 h exposure. MT accumulation in liver showed the same behavior as GST activation.
Fatty acid composition in the liver of four ringed-seal (Phoca hispida ssp.) populations, from ocean (Spitsbergen), brackish water (the Baltic Sea) and freshwater (Lake Saimaa and Lake Ladoga) were determined by gas liquid chromatography. The fatty acid compositions in liver were compared with those of the blubber of the seals, which largely reflect the fatty acid supply from marine or freshwater fish. When the ratios of 20:4n-6/20:5n-3 (arachidonic acid/eicosapentaenoic acid, AA/EPA, from 0.06 to 0.55) and n-6 PUFA/n-3 PUFA (n-6/n-3, from 0.09 to 0.35) increased from the marine to freshwater blubber, the corresponding increase in these ratios in the total lipids of the liver was 10-fold or more (AA/EPA: from 1.2 to 13.5 and n-6/n-3: from 0.9 to 3.2). Thus, when available in the diet, AA is preferentially incorporated into the lipids of pinniped liver.
Feeding marine wildlife as a tourism experience has become a popular means by which to attract both people and wildlife, although management efforts are still in their infancy. "Stingray City Sandbar" in the Cayman Islands, where visitors can hand feed free-ranging Southern Stingrays (Dasyatis americana), is a world-famous attraction currently undergoing visitor and wildlife management. One plan is to decrease the amount of nonnatural food provided by tourists with the intention of decreasing stingray habituation to the artificial food source and promoting stingray health. However, the effectiveness of this action is uncertain given that neither the extent of squid composition in the stingray diet nor the degree of nutrient similarity between the fed and natural diets is unknown. We used fatty acid (FA) profile analysis to address these questions by assessing the serum nonesterified FA composition of fed and unfed stingrays around the island and compared them with FA profiles of (1) the provisioned food source (squid) and (2) other warm- and cold-water elasmobranchs (sharks and rays). Our results indicated that fed stingrays were distinct. The FA profiles of the fed stingray population were expressly different from those of the unfed populations and showed a remarkable similarity to the FA composition of squid, suggesting that squid is the main food source. The tropical fed stingrays also exhibited essential FA ratios, specific to both species and habitat, comparable with those of elasmobranchs and squid from cold-water environs, implying that the provisioned food does not provide a similar nutritional lipid composition to that eaten in the wild. Our results suggest that FA profiles are a valuable indicator for the management and monitoring of fed Southern Stingrays because they can be used to assess differences in diet composition and provide an index of nutritional similarity. Our findings are currently being used by Caymanian stakeholders in designing practical management actions for their wildlife attraction.
1.1. The total lipids were extracted from the flesh of 25 species of temperate Australian fish and cephalopods and the fatty acid composition was determined by capillary gas chromatography.2.2. All species were rich in palmitic acid (range 16–25% of total fatty acids) and docosahexaenoic acid (range 15–53%). There were variable amounts of arachidonic acid (range 1–15%) and eicosapentaenoic acid (range 3–23%).3.3. The omnivorous species of bony fish contained more arachidonic acid (mean 10%) than the carnivorous bony fish (mean 5%). The cartilaginous species were relatively low in eicosapentaenoic acid (mean 5%) whereas the cephalopods contained high levels of this fatty acid (mean 18%).
The application of wall-coated open-tubular (capillary) gasliquid chromatographic columns to some current analytical problems in fat research is described. The liquid phase SILAR-5CP in commercially available stainless steel columns has been found to be particularly suitable for rapid screening of fats and oils for total docosenoic acid without interference from other components. Differentiation of two important 22:1 isomers (erucic acid from vegetable oils and cetoleic acid from marine oils) is possible and the erucic acid content of an oil or fat can be estimated in approximately 20 minutes. The effects of partial hydrogenation of fats on the gas-liquid chromatography of these fatty acid structural details are reviewed. The use of other liquid phases such as butanediolsuccinate polyester, and the advantages of SILAR-7CP for study of geometrical isomers in wall-coated open-tubular columns are discussed briefly, and also the potential of support-coated open-tubular columns for similar analyses of longer-chain fatty acids.
The fatty acid methyl esters obtained by the esterification of total lipids extracted from 24 species of fin fish and 4 species
of invertebrates caught in the rivers and coastal waters of southern Australia were analyzed by gas chromatography. The lipids
of most species contained significant levels of arachidonic acid (0.7–15.8%) as well as the more common marine polyunsaturate,
eicosapentaenoic acid (0.7–15.9%). The major ω6 fatty acid present in most species was 20∶4; however, other fatty acids of
this series, including 18∶2, 22∶4 and 22∶5, were present. The level of total ω6 fatty acids ranged from 3.9 to 22.3% of the
total lipid. In general, the level of total ω3 polyunsaturates was higher than the total ω6 fatty acids with levels of ω3
fatty acids ranging from 9.6 to 48.2%. Only 2 fish (barramundi and gurnard perch) had ω6/ω3 ratios greater than 1.0. Most
of the Australian species examined contained low levels of fat (0.5–7.8% of fresh weight). Two species examined, callop (freshwater)
and blue groper (marine) contained sufficient quantities of both fat (7.7 and 7.8%) and arachidonic acid (4.8 and 9.3%) to
warrant consideration for commercial exploitation.
The fatty acid composition of 10 species of fish caught off the northwest coast of Australia (latitude 17°S) was examined.
All species contained high levels of ω6 fatty acids (9.6–23.1% of total fatty acids) with arachidonic acid being the major
ω6 fatty acid (5.9–14.8% of fatty acids). Docosatetraenoic and docosapentaenoic acids of the ω6 series accounted for 3–8%
of the total fatty acids. The ratio of ω6 to ω3 fatty acids in these fish varied from 0.38 to 0.93, compared with an average
ratio of 0.16 for fish from the northern hemisphere (latitude >30°N). The present data and figures from the literature indicate
that the marine food chain in the southern hemisphere contains significant quantities of ω6 fatty acids.
Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are naturally occurring omega (ω)-3 long-chain polyunsaturated fatty acids (PUFAs), which are found in highest quantities in oily fish such as sardines and mackerel. Epidemiological studies of the association between fish intake, ω-3 PUFA intake or blood ω-3 PUFA levels and colorectal cancer (CRC) risk have not consistently suggested beneficial effects of ω-3 PUFAs on CRC (and other gastrointestinal cancer) risk. However, dietary administration of one or both of the main ω-3 PUFAs in rodent models of colorectal carcinogenesis has been demonstrated to reduce colorectal tumour size and multiplicity, compatible with CRC chemopreventative activity. EPA has now been demonstrated to reduce rectal polyp number and size in patients with familial adenomatous polyposis. A randomized polyp prevention trial of EPA is underway in order to test chemopreventative efficacy against 'sporadic' colorectal neoplasia.
This study was designed to measure the effect of dietary n-3 fatty acids (FA) on platelets and blood lipids. Healthy men (n = 9), ages 31 to 65, were fed diets in which salmon was the source of n-3 fatty acids. They were confined in a nutrition suite at this Center for 100 days. Food intake and exercise levels were rigidly controlled. Initially they were placed on a stabilization diet for 20 days, then six men were fed the salmon diet for 40 days. The others remained on the stabilization diet. The two groups switched diets for the last 40 days of the study. Both diets were isocaloric [16% protein, 54% carbohydrate, and 30% fat by energy-% (En%)]. The salmon diet contained 7.5% of calories from n-6 FA and 2% from n-3 FA, primarily eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in a 40:60 ratio, while the stabilization diet contained 7.5% of calories from n-6 FA and less than 0.3% n-3 FA, mainly 18:3n-3. The bleeding time was unaffected by the diets in this study. The prothrombin time was shortened (11.6 sec. vs. 12.6 sec., p less than 0.01) for the subjects consuming the salmon diet as compared to that measured after 20 days of the stabilization diet. Mean platelet volume increased significantly during the period in which the volunteers consumed the salmon diet compared to the baseline diet (p less than 0.01), while the mean platelet levels decreased. Platelet aggregation (PA) was measured in platelet rich plasma before, during, and after the salmon diet using collagen, ADP, arachidonic acid (AA), and thrombin agonists. The PA threshold for ADP was significantly increased for the subjects on the salmon diet (p less than 0.05). No change in the PA threshold was detected for collagen or thrombin. The PA threshold for AA was unchanged also, but the platelets in subjects consuming the salmon diet had a prolonged time to maximum aggregation (p less than 0.01) with this reagent compared to platelets from men on the stabilization diet. Plasma, red cell, and platelet total FA composition was determined by capillary GLC. While the men consumed the salmon diets, there were marked increases (3 to 10-fold) in the EPA and DHA levels in all blood components with concomitant decreases in linoleic acid and AA levels.(ABSTRACT TRUNCATED AT 400 WORDS)
Epidemiological, clinical and experimental studies suggest that dietary fatty acids belonging to two different families, the n-6 and n-3 fatty acids, might be important nutritional factors contributing to the natural history of atherothrombotic and inflammatory disorders. The relationship of these dietary fatty acids to plasma and cell membrane phospholipid composition, the eicosanoid system and related lipid mediators, and the mechanisms involved in cell stimulus-response coupling (such as phospholipase C and phospholipase A2 activation and Ca2+ release) might reveal and modify processes underlying those disorders. It may thus open the development of new approaches to prevention and therapy.
Public interest in the health benefits of seafood lipids, or of fish oils, is a most unusual phenomenon because for once the recommendations of health authorities to "eat more fish" are in accord with newer and popular attitudes. Media exploitation of the more sensational health aspects is also generally in favor of more consumption of seafood. The public is however still confused by the multitude of species of fish and shellfish available, and in a quandary over whether fatty fish are risky in terms of calories or cholesterol, or of more benefit than lean fish in terms of omega-3 fatty acids. Most direct questions on how much omega-3 fatty acids are useful in the diet of an average individual may never be answerable until long term studies with humans are carried out. It does appear that marine fish can be broken down into four convenient categories: lean (including shellfish), low fat, medium fat and high fat; and in this review it is suggested that these could contribute, per 100 grams, respectively about 250, 750, 1000 and 2000 mg of total C20 + C22 omega-3 fatty acids. This intake can compare favorably with the alternative of commonly available fish oil capsules. Moreover this survey shows that at present the composite of total omega-3 fatty acids in fish and shellfish may contain roughly equal proportions of the functionally effective eicosapentaenoic acid, and of docosahexaenoic acid with its as yet unknown long-term biochemical effects, or be biased in favor of more of the latter. To assist the public, nutritionists, dietitians, and researchers this review discusses the distribution of fat in edible fish muscle, the classes of lipids encountered, and the major fatty acids of health interest. Included are limited numbers of analyses from parts of the world other than North America.
1. The fatty acid profiles of all of the acyl-lipid classes of 1- and 10-day-old European oyster Ostrea edulis (L.) larvae were studied in detail by capillary gas-liquid chromatography. 2. No significant changes in the fatty acids were detected between the different larval stages. 3. Total lipid fatty acids showed a higher degree of unsaturation than previously reported. This may be a consequence of the extraction of lipids from the living tissues without sample storage. 4. One-third of the triacylglycerol fatty acids were polyunsaturated. In agreement with the importance of triacylglycerols in lipids of bivalve larvae, it is suggested that this lipid fraction may act as a temporary reservoir of physiologically-important polyunsaturated fatty acids. 5. Free fatty acids and fatty acids from the minor lipid classes are discussed in terms of their possible origin and physiological significances.
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