|
|
|
| Registros recuperados: 33 | |
|
| |
|
| |
|
|
| Del Ré,Patrícia Vieira; Jorge,Neuza. |
| Studies have been carried out in order to increase the stability of vegetable oils due to economic and health protection reasons. There is a growing interest in the addition of natural antioxidants; especially herbs and spices. For this reason, this study aimed at evaluating the antioxidant potential of the oleoresins of oregano, basil, and thyme, as well as their behavior when applied to soybean oil under various concentrations. Firstly, the antioxidant activity was determined by the β-carotene/linoleic acid system and by the quantification of total phenolic compounds. Next, different concentrations of oleoresins (500 to 3000 mg.kg-1) were added to the soybean oil, and its antioxidant potential was analyzed using the oxidative stability through a Rancimat... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Spice extracts; Oxidation; Induction period. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-20612011000400021 |
| |
|
| |
|
| |
|
|
| Genot, Claude; Eymard, Sylvie; Viau, Michèle. |
| Increase the consumption of long-chain omega 3 polyunsaturated fatty acids (LC ω3 PUFA) is highly recommended for their health benefits. However, these fatty acids are very prone to oxidation, which can impair sensory, nutritional and functional properties of foods. In this paper the various ways that increase LC ω3 PUFA stability during processing and storage of food products are reviewed. To efficiently protect LC ω3 PUFA during processing and storage of foods, a combined strategy, taking into account both the matrix and the process should be undertaken. First the quality of the raw materials should be rigorously controlled by, for example, increasing contents of in situ antioxidants and decreasing length of storage. Then, during processing and storage... |
| Tipo: Text |
Palavras-chave: Oxidation; Lipids; Omega 3 polyunsaturated fatty acids; Antioxidants process; Formulation; Structure. |
| Ano: 2004 |
URL: https://archimer.ifremer.fr/doc/00480/59157/61786.pdf |
| |
|
|
| Le Gac, Pierre-yves; Choqueuse, Dominique; Paris, Marc; Recher, G.; Zimmer, Celine; Melot, D.. |
| In the offshore industry polymer coatings are widely used to ensure thermal insulation of steel pipes, and to avoid over-cooling of the hot oil inside. Because of very severe service conditions (i.e. high temperature, high pressure and presence of seawater) and an expected life time of 20 years, durability of these coatings is a major issue for this industry. Polypropylene and polyurethane are often used for this application, nevertheless these polymers have some limitations in terms of processing time for polypropylene and maximum service temperature for polyurethane. Polycyclopentadiene (pDCPD) shows good processing characteristics and low thermal conductivity, so this polymer could be a good alternative coating in the offshore industry, but the... |
| Tipo: Text |
Palavras-chave: Polydicyclopentadiene; Seawater; Accelerated ageing; Oxidation; Offshore; Field joint. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00114/22534/20233.pdf |
| |
|
|
| Ali,S; Rajput,N; Li,C; Zhang,W; Zhou,G. |
| ABSTRACT The present study was carried out to investigate the influence of freezing-thawing cycles (0, 2, 4 and 6) on lipid oxidation and myowater contents and distribution. Nine replicates of chicken breast meat samples were used for each cycle. Lipid oxidation was determined by measuring peroxide value, and malondialdehyde (MDA) concentrations, which reflect thiobarbituric acid reactive substance (TBARS). Color was determined with a digital colorimeter. Muscle moisture contents were determined by drip loss and thawing loss, water holding capacity, and nuclear magnetic resonance (NMR). The results showed that, as the number of freeze-thaw cycles increased, meat redness decreased and MDA and peroxide values increased. Drip loss and thawing loss tended to... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Freeze-thaw cycles; Chicken meat; Oxidation; Drip loss; Color. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2016000100035 |
| |
|
|
| Silva-Kazama,Daniele Cristina da; Santos,Geraldo Tadeu dos; Pintro,Paula Toshimi Matumoto; Visentainer,Jesuí Vergílio; Kazama,Ricardo; Petit,Hélène Véronique; Marchi,Francilaine Eloise de. |
| Eight Holstein cows with body weight 570 ± 43 kg and 60 ± 20 lactation days were distributed in a double Latin square design with four 21-day periods to determine the effects of feeding ground or whole flaxseed with or without monensin supplementation (0.02% on a dry matter basis) on fatty acid profile of butter stored for 15 and 45 days. Ground flaxseed supply, in comparison to whole flaxseed, reduced relative percentages of 16:0, cis7-16:1, 17:0, and cis10-17:1 but it increased those of cis9,trans11-18:2, cis3-18:3, and omega 3 fatty acids in butter fat, reducing relative percentage of medium-chain fatty acids and increasing the content of polyunsaturated fatty acids. Supplementation with monensin increased relative percentages of cis9,trans11-18:2 and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Butter; Dairy cow; Fatty acid; Flaxseed; Oxidation. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982010001000028 |
| |
|
| |
|
| |
|
|
| RAMÍREZ-ANAYA,Jessica del Pilar; MANZANO-HERNÁNDEZ,Ariana Jocelyn; TAPIA-CAMPOS,Ernesto; ALARCÓN-DOMÍNGUEZ,Karina; CASTAÑEDA-SAUCEDO,Ma Claudia. |
| Abstract Virgin oil from avocados (Persea americana Mill.) is obtained by mechanical processes after pulp malaxation at temperatures that minimize oxidation and improve separation. The objective of this study was to assess the effect of time (0, 20, 30, 40, 60, 120 and 180 min) and temperature (40 and 50 °C) conditions during pulp malaxation on extraction yield, nutritional value (normalized fatty acid profile) and specific extintion (K232 and K270) of virgin oil extracted under laboratory conditions from avocados cultivated in southern Jalisco, Mexico. When pulp was malaxated for 120 min at 40 and 50 °C, a larger proportion of oil was extracted (82.9 ± 0.3% and 80.2 ± 0.8%, respectively). We observed that the normalized percentage of the fatty acids... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Essential fatty acid; Fatty acids; Linoleic:palmitic ratio; Oil yield; Oxidation. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-20612018000200223 |
| |
|
|
| LAMUELA-RAVENTÓS,ROSA M; GIMENO,EVA; FITÓ,MONTSE; CASTELLOTE,ANA-ISABEL; COVAS,MARIBEL; DE LA TORRE-BORONAT,M. CARMEN; LÓPEZ-SABATER,M. CARMEN. |
| Phenolic compounds have shown to inhibit LDL oxidation in vitro and ex vivo; however, they are hydrosoluble compounds while LDL is a lipoprotein. Analysis of phenolic compounds in LDLs by HPLC is necessary to demonstrate their binding capacity to lipoproteins. We developed and validated a solid phase extraction method (SPE) that allowed us the purification of LDL samples and their analysis by HPLC. This methodology allowed us to demonstrate the in vitro binding capacity of tyrosol, one of the main phenolic compounds in olive oil, to LDL. In the intervention dietary study with volunteers, food rich in phenolic compounds affected LDL composition. Changes in LDL phenolics composition are not observed after the short-term ingestion of food rich in phenolic... |
| Tipo: Journal article |
Palavras-chave: Antioxidant; LDL; Olive oil; Oxidation; Phenol; Tyrosol. |
| Ano: 2004 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602004000200011 |
| |
|
|
| Passier, Hf; Dekkers, Mj. |
| Low-temperature magnetic properties of eastern Mediterranean sediments from a box-core have been investigated. This box-core contains the present-day oxic-suboxic boundary that is situated at the top of the relic of the youngest sapropel (S1). The upper half of sapropel S1 has been oxidized, and Fe oxides have precipitated in the oxidized sapropel. Zero-field-cooling (ZFC) and field-cooling (FC) saturation remanent magnetization (M-r; induced in a field of 2.5 T at 20 K after cooling from 300 K with or without the 2.5 T field) was measured during warming to 300 K. An M (r) imparted at room temperature (RTSIRM) was cycled to 20 K as well. The difference between ZFC and FC curves around the Verwey transition, as estimated by the parameter delta(FC)... |
| Tipo: Text |
Palavras-chave: Geochemistry; Low-temperature magnetism; Magnetite; Marine sediments; Oxidation; Sediment magnetism. |
| Ano: 2002 |
URL: https://archimer.ifremer.fr/doc/00223/33399/31887.pdf |
| |
|
|
| Roekens, E.J.; Van Grieken, R.E.. |
| The rate of iron(II) oxidation in the North Sea water of pH 5.5-10 in the range 10-25°C has been studied. The oxygenation rate depends linearly on the iron(II) and dissolved oxygen concentrations. The second-order dependence on (OH<sup>-</sup>), found by several investigators for synthetic solutions, was confirmed in seawater, but only for pOH>6.9. For pOH<5.9 the rate appeared to be independent of the pOH. In the intermediate range, pOH<5.9-6.9, corresponding to the natural pH of seawater, a first-order dependence on the pOH is obeyed. The important discrepancy in the literature between the second-order rate constant for NaCHO<sub>3</sub> solutions and for seawater can be attributed predominantly to the incorrect... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Iron; Kinetics; Oxidation. |
| Ano: 1983 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3293 |
| |
|
|
| Passier, Hf; De Lange, Gj; Dekkers, Mj. |
| Magnetic properties (IRM, ARM, chi (in), S-ratio at 0.3 T, room temperature (RT) hysteresis and thermomagnetic curves) and geochemical data (Fe, S, Mn, Al, Ti, organic C) were studied in two eastern Mediterranean boxcores (ABC26 and BC19) at a resolution of 3-5 mm. The boxcores contain sapropel S1 (9-6 kyr BP) at a few decimetres below seafloor. The magnetic fraction consists predominantly of single-domain (SD) to pseudo-single-domain (PSD) magnetite in the entire cores. The original input of magnetic grains comes from two sources: aeolian dust (both cores) and volcanic ash from the Minoan eruption of Santorini (core BC19 only). Non-steady-state diagenesis has changed the magnetic mineralogy considerably in these alternating organic-rich /organic-poor... |
| Tipo: Text |
Palavras-chave: Geochemistry; Magnetite; Marine sediments; Mediterranean Sea; Oxidation; Sediment magnetism. |
| Ano: 2001 |
URL: https://archimer.ifremer.fr/doc/00221/33184/31805.pdf |
| |
|
|
| Morita, R; Jones, R. |
| The nitrifying bacteria were found to survive 24 weeks in the absence of ammonium without decreasing their number of cell size. Because H sub(2), CO, and CH sub(4) are present in the marine environment, these substrates were investigated as a possible source of the energy of maintenance for the nitrifying bacteria. super(14)CO and super(14)CH sub(4) were found to be oxidized by the nitrifiers. N-serve was found to inhibit the oxidation of CO. Using the nitrifiers' ability to oxide CO, a method for the determination of the nitrification rate was developed. The ability of nitrifiers to oxidize CO may play a significant role in the cycling of CO sub(2) in the marine environment. Whether CO and CH sub(4) oxidation play a role in the survival of nitrifiers in... |
| Tipo: Text |
Palavras-chave: Methane; Carbon dioxide; Survival; Bacteria; Nitrification; Nitrogen cycle; Oxidation; Carbon cycle; Biogeochemistry; Metabolism. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-975.pdf |
| |
|
| |
|
|
| Natori,Mariene Miyoko; Oliveira,Ricardo Henrique Franco de; Parisi,Giuliana; Bonelli,Antonio; Melo,Mariza Pires de; Viegas,Elisabete Maria Macedo. |
| ABSTRACT The objective of this research was to evaluate the growth performance, oxidative stress, and fatty acid profiles of lambari (Astyanax altiparanae) fed diets containing different lipid sources: soybean oil, linseed oil, and freshwater fish residue oil combined or otherwise with sesame oil (SEO). The fish (mean weight 0.95±0.46 g; mean length 4.21±2.77 cm) were distributed into 24 cages (cage capacity: 0.70 m3; fish density: 276 individuals m−3) in six treatments and four replicates. After 80 days of feeding, they were weighed, and samples were collected for assay of catalase, glutathione reductase (GR), and lactate dehydrogenase (LDH) enzyme activities in muscle and analysis of the fatty acid profiles of polar and neutral fractions of whole... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fish; Lipid; Nutrition; Oxidation. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982019000100150 |
| |
|
|
| Le Gac, Pierre Yves; Roux, Gerard; Verdu, Jacques; Davies, Peter; Fayolle, Bruno. |
| Thermal oxidation in air at atmospheric pressure, in the 80-140°C temperature range and in oxygen at 100°C in the 0.02-3 MPa pressure range, of unvulcanized, unstabilized, unfilled polychloroprene (CR) has been characterized using FTIR and chlorine concentration measurement. The kinetic analysis was focused on double bond consumption. A mechanistic scheme involving unimolecular and bimolecular hydroperoxide decomposition, oxygen addition to alkyl radicals, hydrogen abstraction on allylic methylenes, alkyl and peroxyl additions to double bonds and terminations involving alkyl and peroxy radicals was elaborated. The corresponding rate constants were partly extracted from the literature and partly determined from experimental data using the kinetic model... |
| Tipo: Text |
Palavras-chave: Polychloroprene; Oxidation; Radical chain; Kinetics. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00199/31010/29413.pdf |
| |
| Registros recuperados: 33 | |
|
|
|
