75 resultados para Oils and fats.
Resumo:
Promotion of adherence to healthy-eating norms has become an important element of nutrition policy in the United States and other developed countries. We assess the potential consumption impacts of adherence to a set of recommended dietary norms in the United States using a mathematical programming approach. We find that adherence to recommended dietary norms would involve significant changes in diets, with large reductions in the consumption of fats and oils along with large increases in the consumption of fruits, vegetables, and cereals. Compliance with norms recommended by the World Health Organization for energy derived from sugar would involve sharp reductions in sugar intakes. We also analyze how dietary adjustments required vary across demographic groups. Most socio-demographic characteristics appear to have relatively little influence on the pattern of adjustment required to comply with norms, Income levels have little effect on required dietary adjustments. Education is the only characteristic to have a significant influence on the magnitude of adjustments required. The least educated rather than the poorest have to bear the highest burden of adjustment. Out- analysis suggests that fiscal measures like nutrient-based taxes may not be as regressive as commonly believed. Dissemination of healthy-eating norms to the less educated will be a key challenge for nutrition policy.
Resumo:
The member countries of the World Health Organization (WHO) have recently endorsed its global strategy on diet, physical activity and health. The strategy emphasises the need to limit the consumption of saturated fats and trans-fatty acids, salt and sugars, and to increase consumption of fruits and vegetables in order to combat the growing burden of non-communicable diseases. This paper attempts a broad quantitative assessment of the consumption impacts of these norms in OECD countries using a mathematical programming approach. We find that adherence to the WHO norms would involve a significant decrease in the consumption of vegetable oils (30%), dairy products (28%), sugar (24%), animal fats (30%) and meat (pig meat, 13.5%, mutton and goat 14.5%) and a significant increase in the human consumption of cereals (31%), fruits (25%) and vegetables (21%). (c) 2005 Elsevier Ltd. All rights reserved.
Resumo:
The mechanism of action and properties of a solid-phase ligand library made of hexapeptides (combinatorial peptide ligand libraries or CPLL), for capturing the "hidden proteome", i.e. the low- and very low-abundance proteins constituting the vast majority of species in any proteome, as applied to plant tissues, are reviewed here. Plant tissues are notoriously recalcitrant to protein extraction and to proteome analysis. Firstly, rigid plant cell walls need to be mechanically disrupted to release the cell content and, in addition to their poor protein yield, plant tissues are rich in proteases and oxidative enzymes, contain phenolic compounds, starches, oils, pigments and secondary metabolites that massively contaminate protein extracts. In addition, complex matrices of polysaccharides, including large amount of anionic pectins, are present. All these species compete with the binding of proteins to the CPLL beads, impeding proper capture and identification / detection of low-abundance species. When properly pre-treated, plant tissue extracts are amenable to capture by the CPLL beads revealing thus many new species among them low-abundance proteins. Examples are given on the treatment of leaf proteins, of corn seed extracts and of exudate proteins (latex from Hevea brasiliensis). In all cases, the detection of unique gene products via CPLL capture is at least twice that of control, untreated sample.
Resumo:
The significance of Plasmodiophora brassicae Woronin and clubroot disease which it incites in members of the family Brassicaceae is reviewed as the focus for this special edition of the Journal of Plant Growth Regulation. This is a monographic treatment of recent research into the pathogen and disease; previous similar treatments are now well over half a century old. Vernacular nomenclature of the disease indicates that it had a well-established importance in agriculture and horticulture from at least the Middle Ages onward in Europe and probably earlier. Subsequently, the pathogen probably spread worldwide as a result of transfer on and in fodder taken by colonists as livestock feed. It is a moot point, however, whether there was much earlier spread by P. brassicae into China and subsequently Japan as Brassica rapa (Chinese cabbage and many variants) colonized those lands in archaeological time. Symptoms, worldwide distribution, and economic impact are briefly described here to provide a basis for understanding subsequent papers. Clubroot disease devastates both infected field and protected vegetable and agricultural Brassica crops. Particular importance is placed on recent reports of crop losses in tropical countries, albeit where the crops are grown in cooler altitudes, and in the Canadian prairie land canola crops. The latter is of enormous importance because this crop is the single most important and essential source of vegetable oils used in human foodstuffs and in industrial lubricants where mineral oils are inappropriate.
Resumo:
The mechanism of action and properties of a solid-phase ligand library made of hexapeptides (combinatorial peptide ligand libraries or CPLL, for capturing the "hidden proteome", i.e. the low- and very low-abundance proteins Constituting the vast majority of species in any proteome. as applied to plant tissues, are reviewed here. Plant tissues are notoriously recalcitrant to protein extraction and to proteome analysis, Firstly, rigid plant cell walls need to be mechanically disrupted to release the cell content and, in addition to their poor protein yield, plant tissues are rich in proteases and oxidative enzymes, contain phenolic Compounds, starches, oils, pigments and secondary metabolites that massively contaminate protein extracts. In addition, complex matrices of polysaccharides, including large amount of anionic pectins, are present. All these species compete with the binding of proteins to the CPLL beads, impeding proper capture and identification I detection of low-abundance species. When properly pre-treated, plant tissue extracts are amenable to capture by the CPLL beads revealing thus many new species among them low-abundance proteins. Examples are given on the treatment of leaf proteins, of corn seed extracts and of exudate proteins (latex from Hevea brasiliensis). In all cases, the detection of unique gene products via CPLL Capture is at least twice that of control, untreated sample. (c) 2008 Elsevier B.V. All rights reserved.
Resumo:
Commercial dodecylbenzene cable fluid was aged at temperatures of 105 and 135 degrees C in dry oxygen-free nitrogen. In addition, selected samples were aged at 135 degrees C under sealed conditions where air was excluded from the headspace above the oil. A variety of analytical techniques, such as ultra-violet visible and infra-red spectroscopy, acid number and water content measurements, were then used to characterize the aged oils. In addition, their electrical properties were assessed by dielectric spectroscopy. Compared with ageing in air, the ageing rate was reduced significantly and, as expected, no major oxidation peaks were detected in the infrared spectrometer. Significantly, very little absorbance at 680 nm ("red absorbers") was detected in samples aged with copper and, consequentially, no large increases in dielectric loss were recorded within the ageing times considered here. This study compliments previous investigations on cable fluid and 1-phenyldodecane aged in air and show that the same ageing indicators are valid in oils aged under conditions which more closely resemble those found in high voltage plant.
Resumo:
A commercial dodecylbenzene (DDB) cable oil was aged at temperatures between 90 and 135 degrees C in air and was analyzed using various analytical techniques including optical and infra-red spectroscopy and dielectric analysis. On ageing, the oil darkened, significant oxidation features were found by infra-red spectroscopy and the acid number, water content and dielectric loss all increased. Ageing in the presence of paper or aluminum did not affect the ageing process, whereas ageing was significantly modified by the presence of copper. An absorption at 680 nm ("red absorbers") was detected by ultra-violet/visible spectroscopy followed by the production of an opaque precipitate. A reaction between copper and the acid generated on ageing is thought to produce copper carboxylates, and X-ray fluorescence confirmed that copper was indeed present in both the aged oil and the precipitate. Significantly, once red absorbers were detected, the dielectric loss increased to catastrophically high values and, therefore, the appearance of these compounds may serve as a useful diagnostic indicator. The development of acidity on ageing appears to be key in initiating the destructive copper conversion reaction and hence the control of oil acidity may be key to prolonging the life of DDB cable oils.
Resumo:
An improved method for the detection of pressed hazelnut oil in admixtures with virgin olive oil by analysis of polar components is described. The method. which is based on the SPE-based isolation of the polar fraction followed by RP-HPLC analysis with UV detection. is able to detect virgin olive oil adulterated with pressed hazelnut oil at levels as low as 5% with accuracy (90.0 +/- 4.2% recovery of internal standard), good reproducibility (4.7% RSD) and linearity (R-2: 0.9982 over the 5-40% adulteration range). An international ring-test of the developed method highlighted its capability as 80% of the samples were, on average, correctly identified despite the fact that no training samples were provided to the participating laboratories. However, the large variability in marker components among the pressed hazelnut oils examined prevents the use of the method for quantification of the level of adulteration. (C) 2003 Elsevier Ltd. All rights reserved.
Resumo:
Atherosclerosis, leading to cardiovascular disease, is a chronic condition involving a strong inflammatory component. There is evidence that the n-3 polyunsaturated fatty acids (PUFA) present in oily fish and fish oils protect against cardiovascular disease. While these fatty acids have well-recognised effects on plasma triacylglycerol concentrations, it is likely that they exert beneficial effects through other mechanisms in addition. A large body of evidence suggests that the n-3 PUFA have anti-inflammatory properties, some of which may be manifested in the arterial wall, either directly or indirectly, to modulate the progression of atherosclerosis. This review critically evaluates the evidence for the anti-inflammatory effects of the n-3 PUFA in cells and on pathways which have a direct influence on atherogenesis in the arterial wall.
Resumo:
Examination by high temperature GC (HTGC) of the methyl esters of the so-called 'ARN' naphthenic acids from crude oils of North Sea UK, Norwegian Sea and West African oilfields revealed the distributions of resolved 4-8 ring C-80 tetra acids and trace amounts of other acids. Whilst all three oils contained apparently the same the proportions of each differed, possibly reflecting the growth tempe acids, ratures of the archaebacteria from which the acids are assumed to have originated. The structures of the 4, 5, 7 and 8 ring acids are tentatively assigned by comparison with the known 6 ring acid and related natural products and an HPLC method for the isolation of the individual acids is described. ESI-MS of individual acids isolated by preparative HPLC established the elution order of the 4-8 ring acids on the HPLC and HTGC systems and revealed the presence of previously unreported acids tentatively identified as C-81 and C-82 7 and 8 ring analogues.
Resumo:
Colorectal cancer (CRC) is a leading cause of cancer incidence worldwide. Lifestyle factors, especially dietary intake, affect the risk of CRC development. Suitable risk biomarkers are required in order to assess the effect that specific dietary components have on CRC risk. The relationship between dietary intake and indicators of fecal water activity has been assessed using cell and animal models as well as human studies. This review summarizes the literature on fecal water and dietary components with a view to establishing further the potential role of fecal water as a source of CRC risk biomarkers. The literature indicates that fecal water activity markers are affected by specific dietary components linked with CRC risk: red meat, saturated fats, bile acids, and fatty acids are associated with an increase in fecal water toxicity, while the converse appears to be true for calcium, probiotics, and prebiotics. However, it must be acknowledged that the study of fecal water is still in its infancy and a number of issues need to be addressed before its usefulness can be truly gauged.
Resumo:
The analysis of organic residues from pottery sherds using Gas-Chromatography with mass-spectroscopy (GC-MS) has revealed information about the variety of foods eaten and domestic routine at Silchester between the second and fourth–sixth centuries A.D. Two results are discussed in detail: those of a second-century Gauloise-type amphora and a fourth-century SE Dorset black-burnished ware (BB1) cooking pot, which reveal the use of pine pitch on the inner surface of the amphora and the use of animal fats (ruminant adipose fats) and leafy vegetables in cooking at the Roman town of Silchester, Hants.
Resumo:
Background: Although there is considerable interest in the postprandial events involved in the absorption of dietary fats and the subsequent metabolism of diet-derived triacylglycerol-rich lipoproteins, little is known about the effects of meal fatty acids on the composition of these particles. Objective: We examined the effect of meal fatty acids on the lipid and apolipoprotein contents of triacylglycerol-rich lipoproteins. Design: Ten normolipidemic men received in random order a mixed meal containing 50 L, of a mixture of palm oil and cocoa butter [rich in saturated fatty acids (SFAs)], safflower oil [n-6 polyunsaturated fatty acids (PUFAs)]. or olive oil [monounsaturated fatty acids (MUFAs)] on 3 occasions. Fasting and postprandial apolipoproteins B-48. B-100, E. C-II, and C-III and lipids (triacylglycerol and cholesterol) were measured in plasma fractions with Svedberg flotation rates (S-f) >400 S-f 60-400, and S-f 20 - 60. Results: Calculation of the composition of the triacylglycerol-rich lipoproteins (expressed per mole of apolipoprotein B) showed notable differences in the lipid and apolipoprotein contents of the SFA-enriched particles in the S-f > 400 and S-f 60-400 fractions. After the SFA meal, triacylglycerol-rich lipoproteins in these fractions showed significantly greater amounts of triacylglycerol and of apolipoproteins C-II (Sf 60-400 fraction only), C-III, and E than were found after the MUFA meal (P < 0.02) and more cholesterol, apolipoprotein C-III (Sf > 400 fraction only), and apolipoprotein E than after the PUFA meal (P < 0.02). Conclusions: Differences in the composition of S-f > 400 and S-f 60-400 triacylglycerol-rich lipoproteins formed after saturated compared with unsaturated fatty acid-rich meals may explain differences in the metabolic handling of dietary fats.
Resumo:
High doses of n-3 PUFA found in fish oils can reduce the circulating concentration of triacylglycerol (TG), which may contribute to the positive impact of these fatty acids on the risk of CVD. The present study aimed to establish the differential impact of EPA and docosahexaenoic (DHA) on plasma lipids and apo in adults. Forty-two normolipidaemic adult subjects completed a double-blind placebo controlled parallel study, receiving an EPA-rich oil (4.8 g EPA/d), DHA-rich oil (4.9 g DHA/d) or olive oil as control, for a period of 4 weeks. No effects of treatment on total cholesterol, LDL-cholesterol or HDL-cholesterol were evident. There was a significant 22% reduction in TG level relative to the control value following the DHA treatment (P=0.032), with the 15% decrease in the EPA group failing to reach significance (P=0-258). There were no significant inter-group differences in response to treatment for plasma apoA1, -C3 or -E levels, although a significant 15% within-group increase in apoE was evident in the EPA (P=0.006) and DHA (P=0.003) groups. In addition, a within-group decrease in the apoAI:HDL-cholesterol ratio was observed in the DHA group, suggesting a positive impact of DHA on HDL particle size. The DHA intervention resulted in a significant increase in the proportion of EPA P=0.000 and DHA P=0.000 in plasma phospholipids, whilst significant increases in EPA P=0.000 and docosapentacnoic acid P=0.002, but not DHA P=0.193, were evident following EPA supplementation (P<0.05). Our present results indicate that DHA may be more efficacious than EPA in improving the plasma lipid profile.
Resumo:
The effect of fruit ripeness on the antioxidant content of 'Hojiblanca' virgin olive oils was studied. Seasonal changes were monitored at bi-weekly intervals for three consecutive crop years. Phenolic content, tocopherol composition, bitterness index, carotenoid and chlorophyllic pigments and oxidative stability were analysed. In general, the antioxidants and the related parameters decreased as olive fruit ripened. The phenolics and bitterness, closely related parameters, did not present significant differences among years. Although in general, the tocopherols decreased during olive ripening gamma-tocopherol increased. Differences between crop years were found only for total tocopherols and alpha-tocopherol, which showed higher content in low rainfall year oils. The pigment content decreased during ripening, chlorophyll changing faster. For low rainfall years, the level of pigments was higher, reaching significant differences between yields. Significant differences among years were found for oil oxidative stability; higher values were obtained for drought years. A highly significant prediction model for oxidative stability has been obtained. (C) 2004 Elsevier Ltd. All rights reserved.