908 resultados para CONJUGATED LINOLEIC-ACID
Resumo:
This study investigated the effect of ethanolic sesame cake extract on oxidative stabilization of olein based butter. Fractionation of cream was performed by the dry fractionation technique at 10 °C, ethanolic sesame cake extract (SCE) was incorporated into olein butter at three different concentrations; 50, 100, 150 ppm (T1, T2, T3) and compared with a control. The total phenolic content of SCE was 1.72 (mg gallic acid equivalent g−1 dry weight). The HPLC characterization of ethanolic sesame cake revealed the presence of antioxidant substances viz. sesamol, sesamin and sesamolin in higher extents. The DPPH free radical scavenging activity of SCE was 83 % as compared to 64 and 75 % in BHA and BHT. Fractionation of milk fat at 10 °C significantly (p < 0.05) influenced the fatty acid profile of olein and stearin fractions from the parent milk fat. Concentration of oleic acid and linoleic acid in olein fraction was 29.62 and 33.46 % greater than the parent milk fat. The loss of C18:1 in 90 days stored control and T3 was 24.37 and 3.58 %, respectively, 58 % C18:2 was broken down into oxidation products over 8.55 % loss in T3. The peroxide value of control, T1, T2, BHT and T3 in the Schaal oven test was 8.59, 8.12, 5.34, 4.52 and 2.49 (mequiv O2/kg). The peroxide value and anisidine value of 3 months stored control and T3 were 1.21, 0.42 (mequiv O2/kg) and 27.25, 13.25, respectively. The concentration of conjugated dienes in T3 was substantially less than the control. The induction period of T3 was considerably higher than BHT with no difference in sensory characteristics (p > 0.05). Ethanolic SCE can be used for the long-term preservation of olein butter, with acceptable sensory characteristics.
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In this study LC n-3 PUFA-specific effects on the degree of monocyte differentiation and macrophage foam cell formation were investigated by treating PMA-induced immature and mature macrophage models with LC n-3/n-6 PUFA during and post-differentiation. During immature macrophage differentiation LC n-3 PUFA alone decreased TNFα mRNA levels. EPA, and the n-6 PUFAs, linoleic acid and arachidonic acid, decreased CD36 mRNA levels, and EPA also downregulated CD49d cell-surface expression. Both LC n-3 PUFA reduced LDLr mRNA levels in immature macrophages, while DHA alone reduced levels in mature macrophages. Post-differentiation, n-3 and -6 PUFA reduced basal, but not oxidised LDL dependent cholesterol levels in immature macrophages. LC n-3 PUFA-specific reductions in LDLr and LOX-1 mRNA expression were also observed.
This study found LC n-3 PUFA specific, anti-atherogenic effects were more significant in immature macrophages. LC n-3 PUFA effects may be modulated by the extent of monocyte to macrophage differentiation.
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This paper compares the volatile compound and fatty acid compositions of grilled beef from Aberdeen Angus and Holstein-Friesian steers slaughtered at 14 months, each breed fed from 6 months on either cereal-based concentrates or grass silage. Linoleic acid levels were higher in the muscle of concentrates-fed animals, which in the cooked meat resulted in increased levels of several compounds formed from linoleic acid decomposition. Levels of alpha-linolenic acid, and hence some volatile compounds derived from this fatty acid, were higher in the meat from the silage-fed steers. 1-Octen-3-ol, hexanal, 2-pentylfuran, trimethylamine, cis- and trans-2-octene and 4,5-dimethyl-2-pentyl-3-oxazoline were over 3 times higher in the steaks from the concentrates-fed steers, while grass-derived 1-phytene was present at much higher levels in the beef from the silage-fed steers. Only slight effects of breed were observed. (C) 2004 Elsevier Ltd. All rights reserved.
Resumo:
The effect on lamb muscle of five dietary supplements high in polyunsaturated fatty acids (PUFA) was measured. The supplements were linseed oil, fish oil, protected lipid (high in linoleic acid (C18:2 n-6) and alpha-linolenic acid (C18:3 n-3)), fish oil/marine algae (1:1), and protected lipid/marine algae (1:1). Eicosapentaenoic acid (C20:5 n-3) and docosahexaenoic acid (C22:6 n-3) were found in the highest amounts in the meat from lambs fed diets containing algae. Meat from lambs fed protected lipid had the highest levels of C18:2 n-6 and C18:3 n-3, due to the effectiveness of the protection system. In grilled meat from these animals, volatile compounds derived from n-3 fatty acids were highest in the meat from the lambs fed the fish oil/algae diet, whereas compounds derived from n-6 fatty acids were highest in the meat from the lambs fed the protected lipid diet. (C) 2004 Elsevier Ltd. All rights reserved.
Resumo:
In this study was analyzed the effect of crop year and harvesting time on the fatty acid composition of cv. Picual virgin olive oil. The study was carried out during the fruit ripening period for three crop seasons. The mean fatty acid composition of Picual oils was determined. The oils contained palmitic acid (11.9%), oleic acid (79.3%), and linoleic acid (2.95%). The content of palmitic acid and saturated fatty acids decreased during fruit ripening while oleic and linoleic acids increased. The amount of stearic and linolenic acids decreased. The amount of saturated acids, palmitic and stearic, and the polyunsaturated acids linoleic and linolenic was dependent on the time of harvest, whereas the amount of oleic acid varied with the crop year. The differences observed between crop years for both palmitic and linoleic acid may be explained by the differences in the temperature during oil biosynthesis and by the amount of summer rainfall for oleic acid content. A significant relationship was observed between the MUFA/PUFA ratio and the oxidative stability measured by the Rancimat method.
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The UK Food Standards Agency convened a group of expert scientists to review current research investigating whether n-3 polyunsaturated fatty acids (PUFA) from plant oils (a-linolenic acid; ALA) were as beneficial to cardiovascular health as the n-3 PUFA from the marine oils, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The workshop also aimed to establish priorities for future research. Dietary intake of ALA has been associated with a beneficial effect on CHD; however, the results from studies investigating the effects of ALA supplementation on CHD risk factors have proved equivocal. The studies presented as part of the present workshop suggested little, if any, benefit of ALA, relative to linoleic acid, on risk factors for cardiovascular disease; the effects observed with fish-oil supplementation were not replicated by ALA supplementation. There is a need, therefore, to first prove the efficacy of ALA supplementation on cardiovascular disease, before further investigating effects on cardiovascular risk factors. The workshop considered that a beneficial effect of ALA on the secondary prevention of CHD still needed to be established, and there was no reason to look further at existing CHD risk factors in relation to ALA supplementation. The workshop also highlighted the possibility of feeding livestock ALA-rich oils to provide a means of increasing the dietary intake in human consumers of EPA and DHA.
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This study has investigated the influence of dietary fatty acid composition on mammary tumour incidence in N-ethyl-N-nitrosourea (ENU)-treated rats and has compared the susceptibility to dietary fatty acid modification of the membrane phospholipids phosphatidyliuositol (PI) and phosphatidylethanolamine (PE) from normal and tumour tissue of rat mammary gland. The incidence of mammary tumours was significantly lower in fish oil- (29%), compared with olive oil- (75%; P < 0.04) but not maize oil- (63%; P < 0.1) fed animals. No differences in PI fatty acid composition were found in normal or tumour tissue between rats fed on maize oil, olive oil or fish oil in diets from weaning. When normal and tumour tissue PI fatty acids were compared, significantly higher amounts of stearic acid (18:O) were found in tumour than normal tissue in rats given olive oil (P < 0.05). A similar trend was found in animals fed on maize oil, although differences between normal and tumour tissue did not reach a level of statistical significance (P < 0.1). In mammary PE, maize oil-fed control animals had significantly higher levels of linoleic acid (18:2n-6) than either olive oil- or fish oil-fed animals (P < 0.05, both cases) and levels of arachidonic acid were also higher in maize oil- compared with fish oil-fed animals (P < 0.05). In tumourbearing animals no differences in PE fatty acid composition were found between the three dietary groups. When normal and tumour tissue PE fatty acids were compared, significantly lower amounts of liuoleic acid (18:2n-6; P < 0.01) and significantly greater amounts of arachidonic acid (20:4n-6; P < 0.05) were found in tumour than normal tissue of rats fed on maize oil. The present study shows that the fatty acid composition of PI from both normal and tumour tissue of the mammary gland is resistant to dietary fatty acid modification. The PE fraction is more susceptible to dietary modification and in this fraction there is evidence of increased conversion of linoleic acid to arachidonic acid in tumour compared with normal tissue. Lower tumour incidence rates in rats given fish oils may in part be due to alteration in prostanoid metabolism secondary to displacement of arachidonic acid by eicosapentaenoic acid, but PE rather than PI would appear to be the most likely locus for diet-induced alteration in prostanoid synthesis in this tissue. Effects of dietary fatty acids other than on the balance of n-6 and n-3 fatty acids, and on prostanoid metabolism, should also be considered. The significance of increased stearic acid content of PI in tumours of olive oil-fed animals and the possible influence of dietary fatty acids on the capacity for stearic acid accumulation requires further study.
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The fatty acid compositions of the -choline and -inositol phospholipids of breast tumours of women undergoing surgery for treatment of breast disease (malignant n = 12; benign n = 10) and normal breast tissue of women undergoing breast reduction surgery (n = 6) were determined. The fatty acid compositions of erythrocyte phospholipids were also determined in the same subjects and in an additional number of normal healthy volunteers (n = 16). Levels of oleic acid were lower in both phospholipid fractions of erythrocytes of women with breast disease and in the phosphatidylcholine fraction of breast tumours compared with normal breast tissue. Significantly higher levels of linoleic acid were found in erythrocytes of tumour-bearing subjects and a similar trend was evident in the phosphatidylcholine fraction of tumour compared with normal breast tissues. Conversely, lower levels of two of the products of linoleic acid chain elongation and desaturation, dihomogamma-linolenic and arachidonic acids, were found in the erythrocyte phospholipids of tumour-bearing subjects and in the choline phospholipids of breast tumour tissues. These data suggest that in women with breast disease, there may be inhibition of 6-desaturase, and enhanced activity of 9-desaturase, enzymes which play an important role in determining membrane phospholipid fatty acid composition. This pattern of altered fatty acid composition characteristic of erythrocyte phospholipids of tumour-bearing subjects and phosphatidylcholine of breast tumour tissue was less evident in the case of the breast tumour phosphatidylinositol in which differences other than those described were seen.
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Milk provides many key nutrients but the saturated and trans fatty acids in milk fat are associated with perceived negative effects on human health, especially cardiovascular disease. Recent epidemiological studies and dietary intervention trials challenge this perception, however; available evidence does not support the concept that consumption of saturated fats or dairy products adversely affects the risk of coronary heart disease (although replacing some saturated fats with mono or polyunsaturated fats is likely to provide benefit). Furthermore, the trans fats found in dairy products are consumed in very low amounts and do not appear to have the negative health effects associated with the consumption of industrial sources of trans fat. Milk fat is an excellent source of oleic acid that originates mainly by endogenous synthesis from stearic acid, but increasing the milk fat content of unsaturated fatty acids requires dietary formulations that bypass rumen biohydrogenation. Recent research indicates that long-chain omega-3 fatty acids and conjugated linoleic acids have potential beneficial effects in health maintenance and the prevention of chronic diseases. Enhancing the milk fat content of these fatty acids offers exciting possibilities, but educating consumers about inaccurate and inappropriate generalisations about fat remains the primary challenge. Finally, individuals do not simply consume milk-fat-derived fatty acids on their own, but rather as components in dairy foods which are highly complex and may contain many beneficial ingredients. Overall, dairy products are critical in providing many of the essential nutrients in the human diet. Nevertheless, dairy products vary in their nutrient composition, including fat, and this needs to be considered in the context of dietary recommendations and our need to consume a balanced diet.
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Malvales is an order of flowering plants with a controversial circumscription. The relationships between taxa, particularly Malvaceae, Bombacaceae, Sterculiaceae, and Tiliaceae, are not well delineated. Several studies have reported the fatty acid compositions of Malvaceae plants but not for taxonomic purposes. In the present study, the fatty acid composition of oilseeds from seven species belonging to the Malvaceae family was determined by capillary gas chromatography/mass spectrometry (GC/MS), and the quantitative distribution of fatty acids was analyzed by a cluster analysis With Euclidean Distance and UPGMA. The oil content in the seeds was very low (8.3-11.8%). The profile of fatty acids showed that there were two distinct groups: species rich in palmitic acid (Herissantia tiubae, Sidastrum paniculatum and Sida rhombifolia) and species rich in linoleic acid (other Sida species). The fatty acid profiles found for Sida species are consistent with other reported data. Although our data support a distinction between Sida and Sidastrum, more species should be analyzed to evaluate the real taxonomic value of differences in fatty acid content for distinguishing Malvaceae. (C) 2010 Elsevier Ltd. All rights reserved.
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Inflammation is a crucial step for the wound healing process. The effect of linoleic and oleic acids on the inflammatory response of the skin during the healing process and on the release of pro-inflammatory cytokines by rat neutrophils in vitro was investigated. A wound in the dorsal surface of adult rats was performed and fatty acids were then topically administered. Both oleic and linoleic acids increased the wound healing tissue mass. The total protein and DNA contents of the wounds were increased by the treatment with linoleic acid. The treatments with oleic and linoleic acids did not affect vascular permeability. However, the number of neutrophils in the wounded area and air pouches was increased and the thickness of the necrotic cell layer edge around the wound was decreased. A dose-dependent increase in vascular endothelial growth factor-alpha (VEGF-alpha) and interleukin-1 beta (IL-1 beta) by neutrophils incubated in the presence of oleic and linoleic acid was observed. Oleic acid was able to stimulate also the production of cytokine-induced neutrophil chemoattractant in inflammation 2 alphalbeta (CINC-2 alpha/beta). This pro-inflammatory effect of oleic and linoleic acids may speed up the wound healing process. Copyright (c) 2007 John Wiley & Sons, Ltd.
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The present study examines the effect of four semi-purified diets (casein-gelatin based) where the source of fatty acids was free (esterified) oleic acid and linoleic acid (LA) (LOA diet), linseed and olive oil (predominantly LA and linolenic acid) (LO diet), cod liver oil (rich in highly unsaturated fatty acids) (CLO diet), and soybean lecithin (phospholipids; mostly LA) (LE diet) on the growth of juvenile South American catfish (surubim, Pseudoplatystoma fasciatum, Pimelodidae) (0.98 +/- 0.04 g individual weight). Fish were fed at a restricted-readjusted feeding rate for 8 wk. At the end of the experiment, LE-diet-fed fish grew significantly larger than those of the other three groups (P < 0.05). Considerable cannibalism was observed in all the treatments. It is suggested that the quantitative growth performance may possibly change under other conditions, with less or no cannibalism. Survival did not differ significantly among the fish fed four different diets. Muscle and liver lipid contents did not vary among dietary treatments (P > 0.05), but whole-body lipid concentrations were affected by dietary treatments. Fish fed LE diet contained significantly lower lipid level than those fed three other diets (P < 0.05). Muscle and liver fatty acid profiles reflected dietary fatty acid composition. Arachidonic acid level was significantly higher in muscle and liver of fish fed LOA and LE diets than in those fed LO and CLO diets. The results suggest that the efficiency of elongation and desaturation of 18C fatty acids depends on the dietary lipid source, and South American catfish has considerable capacity to transform linoleate to arachidonate.
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Objective: To determine whether the fatty acid composition of mid-trimester amniotic fluid differs by ethnicity and pregnancy outcome. Methods: Fatty acid composition was analyzed by gas chromatography in 198 women undergoing amniocentesis at 15-19 weeks gestation. Cytokine levels were determined by ELISA in a subgroup of 52 subjects. Results: The major fatty acids detected were palmitic acid (31.8%) and stearic acid (31.5%). The n-6 polyunsaturated fatty acids (PUFA), linoleic acid (LA, 18: 2) and arachidonic acid (AA, 20: 4), were 11.3%, while the n-3 PUFA fatty acids, alpha linolenic acid (ALA, 18: 3) and docosahexaenoic acid (DHA, 22: 6), were 3.8% of the total. Palmitic acid was a higher percentage in Asians (40.5%) and Whites (34.5%) than in Blacks (22.2%) and Hispanics (23.7%) (p <= 0.0012). Oleic acid (18:1 n-9) was a higher percentage in Blacks (12.2%) and Hispanics (12.1%) than in Whites (9.2%) or Asians (7.5%) (<= 0.0002). LA and AA were higher in Blacks (9.0%, 5.4%) and Hispanics (8.6%, 4.1%) than in Whites (6.1%, 3.7%) and Asians (5.5%, 2.9%) (p <= 0.0002). DHA did not differ among the ethnic groups or according to pregnancy outcome. A reduced palmitic acid percentage was identified in the six women with preeclampsia (p = 0.0233). Tumor necrosis factor-alpha levels were inversely proportional to the palmitic acid percentage (p = 0.0275) and positively associated with the percentages of stearic (18:0) (p = 0.0132) and oleic (p = 0.0290) acids. Conclusions: Amniotic fluid fatty acid composition differed among the ethnic groups and may influence inflammatory mediator production and susceptibility to preeclampsia.
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Conjugated Linoleic Acids (CLAs) comprise a family of positional and geometric isomers of linoleic acid. The main form of CLA, cis-9, trans-11-C18:2 show positive effects in cancer prevention and treatment. The major dietary sources of these fatty acids are derived from ruminant animals, in particular dairy products. In these animals, the endogenous synthesis mainly occurs in mammary gland by the action of enzyme Stearoyl CoA Desaturase (SCD). Different levels of expression and activity of SCD in mammary gland can explain partially the variation of CLA levels in fat milk. Considering a great fat concentration in bubaline milk and the benefit of a high and positive correlation between fat milk and CLA production, this study was carried on with the intention of sequencing and characterizing part of the gene that codifies SCD in buffaloes. Genomic DNA was extracted from blood samples of lactating bubaline which begins to the breed Murrah. After the (acho que nao precisa desse the) extractions, PCR (Polymerase Chain Reaction) reactions were made by using primers Z (sic) (sic) D1 and E1 (sic) (sic) F1. The fragments obtained in PCR were cloned into T vectors and transformed in competent cells DH10B line. After this, three samples of each fragment were sequenced from 5' and 3' extremities using a BigDye kit in an automatic sequencer. Sequences were edited in a consensus of each fragment and were submitted to BLAST-n / NCBI for similarity comparisions among other species. The sequence obtained with Z (sic) (sic) D1 primers shows 938 bp enclosing exons 1 and 2 and intron 1. The primers E1 (sic) (sic) F1 show 70 bp corresponding to exon 3 of bubaline SCD gene. Similarities were obtained between 85% and 97% among bubaline sequences and sequences of SCD gene described in human, mouse, rat, swine, bovine, caprine and ovine species. This study has permitted the identification and partial characterization of SCD codifing region in Bubalus bubalis specie.
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Uncoupling proteins (UCPs) are specialized mitochondrial transporter proteins that uncouple respiration from ATP synthesis. In this study, cDNA encoding maize uncoupling protein (ZmPUMP) was expressed in Escherichia coli and recombinant ZmPUMP reconstituted in liposomes. ZmPUMP activity was associated with a linoleic acid (LA)-mediated H+ efflux with Km of 56.36 ± 0.27 μM and Vmax of 66.9 μmol H+ min-1 (mg prot)-1. LA-mediated H+ fluxes were sensitive to ATP inhibition with Ki of 2.61 ± 0.36 mM (at pH 7.2), a value similar to those for dicot UCPs. ZmPUMP was also used to investigate the importance of a histidine pair present in the second matrix loop of mammalian UCP1 and absent in plant UCPs. ZmPUMP with introduced His pair (Lys155His and Ala157His) displayed a 1.55-fold increase in LA-affinity while its activity remained unchanged. Our data indicate conserved properties of plant UCPs and suggest an enhancing but not essential role of the histidine pair in proton transport mechanism. © 2006 Elsevier Inc. All rights reserved.