Letteratura scientifica selezionata sul tema "Oxidation des lipides"
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Articoli di riviste sul tema "Oxidation des lipides":
1
Tenyang, Noël, Roger Ponka e Hilaire Macaire Womeni. "Effect of local hot smoking on proximate composition, lipid oxidation, fatty acid profile and minerals content of Chrysichthys nigrodigitatus from Lake Maga in Cameroon". International Journal of Biological and Chemical Sciences 14, n. 4 (17 agosto 2020): 1124–27. http://dx.doi.org/10.4314/ijbcs.v14i4.5.
Abstract (sommario):
Fish with higher nutrient qualities can be used to solve malnutrition problems in Africa. So the aim of this study was to evaluate the effect of local smoking on proximate composition and lipid oxidation of Chrysichthys nigrodigitatus collected in Cameroon. The proximate composition was assessed using standard methods while lipid quality assessment was based on the determination of biochemical indexes. A change on fatty acid composition was evaluated by gas chromatography while minerals composition was evaluated by spectrophotometer. On nutritional point of view, raw fish have high protein, lipid and ash contents (51.87, 37.48 and 8.55 g/100 g dry weight respectively). Unsaturated fatty acid may be up to 57% of the total fatty acids. Raw C. nigrodigitatus contain reasonable amount of minerals. Smoking process increased ash and lipid content while proteins and moisture contents are reduced in these fish. The iodine value of C. nigrodigitatus was reduced while acid, peroxide and TOTOX values increased during smoking. The marked decrease of polyunsaturated fatty acids was noted during processing. Mineral contents were affected by smoking process. Calcium, magnesium, potassium, sodium, manganese and iron contents increased significantly. In conclusion, hot smoking enhances nutrients content of C. nigrodigitatus while significant reduction in lipid quality was recorded.Keywords: Chrysichthys nigrodigitatus, smoking process, nutritional value, lipid oxidation, mineral contents.
Frence Title; Effet du fumage traditionnel sur la composition chimique, l’état d’oxydation des lipides, la composition en acide gras et la teneur en minéraux de Chrysichthys nigrodigitatus du Lac Maga au Cameroun
Le Poisson est l’une des sources d’éléments nutritifs de qualité pouvant contribuer à prévenir la malnutrition en Afrique. Ce travail s’est donné pour objectif d’évaluer l’effet du fumage traditionnel sur la composition chimique et l’état d’oxydation des lipides de Chrysichthys nigrodigitatus provenant du Lac Maga au Cameroun. Les méthodes standards ont été utilisées pour la détermination de la composition chimique, la mesure de l’état d’oxydation des lipides par des indices chimiques, la composition en acides gras par chromatographie en phase gazeuse et les minéraux par spectrophotométrie. Du point de vue nutritionnel, ce poisson frais contient respectivement 51,87 ; 37,48 and 8,55 g/100 g de matière sèches de protéines, lipides et cendres. Il contient également 57% d’acides gras insaturés et une quantité raisonnable de minéraux. Le traitement de fumage provoque une augmentation de la teneur en cendres et en lipides. Par contre la teneur en eau et en protéines diminuent. L’indice d’iode baisse tandis que les indices d’acide, de peroxyde et de TBARs augmentent. Une diminution du taux d’acides gras polyinsaturés est observée. Les minéraux sont également affectés au cours du fumage. Le traitement de fumage améliore la teneur en nutriments de C. nigrodigitatus, par contre réduit la qualité lipidique de celui-ci.
Mots clés : Chrysichthys nigrodigitatus, fumage, valeur nutritionnelle, oxydation des lipides, teneur en minéraux.
2
Barkova, D. A., N. A. Pudovkin e V. V. Salautin. "FEATURES OF FREE-RADICAL OXIDATION OF LIPIDES IN CHRONIC CYRROSIS OF THE LIVER". Scientific Notes Kazan Bauman State Academy of Veterinary Medicine 234, n. 2 (5 giugno 2018): 40–44. http://dx.doi.org/10.31588/2413-4201-1883-234-2-40-44.
3
Bayburina, G. A., E. A. Nurgaleeva, E. F. Agletdinov e A. F. Samigullina. "Effect of hypoxia tolerance on the relation between indicators of free radical oxidation of lipides and proteins in murine kidneys during the post-resuscitation period". Kazan medical journal 98, n. 6 (15 dicembre 2017): 949–54. http://dx.doi.org/10.17750/kmj2017-949.
Abstract (sommario):
Aim. Study of the relationship between the parameters of free radical oxidation of proteins and lipids in the murine kidneys in the post-resuscitation period after stopping the systemic circulation, depending on their resistance to hypoxia. Methods. The systemic circulation was stopped by intra-thoracic clamping of the neurovascular bundle for 5 minutes, performed under general ether anesthesia in male noninbred white rats, divided after testing into two groups based on resistance to hypoxia. The observation period lasted for 35 days. In the homogenates of kidney tissues, the content of products reactive to tiobarbituric acid, carbonylated proteins, the formation of metal-catalyzed carbonylated proteins and bitirozin were determined. Results. The characteristic manifestation of oxidative stress in the recovery period after stopping blood circulation and resuscitation was found to be reciprocity of the relationship between the levels of lipoperoxidation and oxidative modification of proteins. Highly resistant to hypoxia animals were characterized by high resistance of proteins of kidney tissue to free radical oxidation against the background of high levels of lipid peroxidation. On the contrary, in animals non-resistant to hypoxia, against the background of relatively low values of lipoperoxidation, high levels of oxidative modification of proteins, both initial and induced, were recorded. Conclusion. In post-resuscitation period in highly resistant to hypoxia animals, marked activation of lipoperoxidation occurs accompanied by a transient increase in the carbonylation of proteins in the early observation period; for low-resistant to hypoxia animals high intensity of carbonyl stress against the background of the relative «preservation» of lipid structures of the cell is characteristic, which persists throughout the post-resuscitation period, which can make a significant contribution to kidney damage, increasing the risk of renal failure.
4
Tonda, Rachel, Arlene Lamptey e Brenda Reid. "PSV-15 Variability in the Oxidative Status of Fats and Oils Used in Livestock Diets in North America". Journal of Animal Science 99, Supplement_1 (1 maggio 2021): 197–98. http://dx.doi.org/10.1093/jas/skab054.322.
Abstract (sommario):
Abstract Lipids are essential energy sources in nearly every animal’s diet. However, lipids used in feed formulations today are highly variable in both composition and susceptibility to oxidation – a major source of decreased lipid quality. Feeding oxidized lipids negatively influences animal health and performance, yet data on the oxidative status of commercially used lipids is limited. Herein, the oxidative stability results of lipid samples submitted to Kemin Customer Laboratory Services (CLS) for analysis since 2018 is summarized. Of the 392 samples evaluated, corn oil (n=122), choice white grease (CWG; n=101) and soybean oil (n=66) were the most common. Current oxidation status was assessed by measuring active oxidation markers, including peroxide values (PV; target < 5 meq/kg) and secondary oxidative molecules (hexanal and 2,4-decadienal; target < 50 ppm total). Resistance to future oxidation was evaluated by Oxidative Stability Index (OSI) at 100° C. Lipid PVs ranged from 0 meq/kg to 47.8 meq/kg, with an average PV of 3.4 meq/kg. Total secondary oxidatives averaged 28 ppm, ranging from below the limit of quantitation (5 ppm) to 313 ppm. Based on current oxidative markers, 39% of samples showed no signs of oxidation, 40% had early signs of oxidation, 16% were undergoing active oxidation and 5% were severely oxidized. Lipid OSI times ranged from 0.2 to 144 hours, averaging 17.4 hours. Fifty percent of samples had OSI times of < 10 hours. Further, 46% of animal fats had an OSI < 5 hours, indicating enhanced susceptibility of these fats to future oxidation. In conclusion, >60% of samples showed signs of oxidation, and significant variability in the oxidative status of commercial lipids was observed. To optimize nutritional efficiency and minimize adverse effects of oxidation on overall health of livestock, managing lipid quality – including understanding oxidation risks – should be a major consideration for producers.
5
Kohole Foffe, Hermann Arantes, Ronice Zokou, Gires Boungo Teboukeu, Serge Cyrille Houketchang Ndomou, Fabrice Tonfack Djikeng e Hilaire Macaire Womeni. "Effect of concentration of Allium cepa and Pimpinella anisum powders on the oxidative stability of oils extracted from peanuts cakes". North African Journal of Food and Nutrition Research 7, n. 16 (14 agosto 2023): 24–36. http://dx.doi.org/10.51745//najfnr.7.16.24-36.
Abstract (sommario):
Background: Lipids are responsible for both the undesirable and desirable flavors of food; oxidation of lipids mainly results in the development of off-flavor and lipoxygenase-derived lipid-based volatiles that are responsible for flavor generation. These lipids can be found in animal, vegetable and marine foods sources. Among these vegetable lipids sources, peanuts are one of the main oleaginous used to prepare foods. Aims: This study aimed at assessing the effect of 0.5g, 1g, 2g and 4g of Allium cepa and Pimpinella anisum powders on the oxidative stability of lipids extracted from peanuts cakes. Material and Methods: The total phenolic content, flavonoid contents and the antioxidant properties of these spices were evaluated. In addition, lipids quality was assessed by chemical characterization of oils extracted from peanuts cakes. Results: Results revealed that P. anisum had the highest total phenolic (TPC = 61.66 mg GAE/g), flavonoid (FC = 34.95 mg CE/g) contents and DPPH free radical scavenging activities with values that ranged from 17.66 % to 89.18 %. The analysis of the oxidative state of oils extracted from peanuts cakes prepared with 0.5g, 1g, 2g and 4g of Allium cepa and Pimpinella anisum powders revealed that all oils samples with the exception of those extracted from cakes cooked with 2g and 4g of P. anisum powder had peroxide, P-anisidine, total oxidation, thiobarbituric acid and free fatty acid values in line with those recommended by the Codex Alimentarius. The principal component analysis (PCA) revealed that the free fatty acids, peroxide, P-anisidine, thiobarbituric acid values were more efficient to induce lipids oxidation in peanuts cakes. Conclusions: Preparing peanuts cakes with Allium cepa and Pimpinella anisum powders are more effective to limit lipids oxidation compared to peanuts cakes cooked without spices. Keywords: Allium cepa, Pimpinella anisum, lipids quality, peanuts cakes, antioxidant, oxidative stability.
6
Kohole Foffe, Hermann Arantes, Ronice Zokou, Gires Boungo Teboukeu, Serge Cyrille Houketchang Ndomou, Fabrice Tonfack Djikeng e Hilaire Macaire Womeni. "Effect of concentration of Allium cepa and Pimpinella anisum powders on the oxidative stability of oils extracted from peanuts cakes". North African Journal of Food and Nutrition Research 7, n. 16 (14 agosto 2023): 26–34. http://dx.doi.org/10.51745/najfnr.7.16.24-36.
Abstract (sommario):
Background: Lipids are responsible for both the undesirable and desirable flavors of food; oxidation of lipids mainly results in the development of off-flavor and lipoxygenase-derived lipid-based volatiles that are responsible for flavor generation. These lipids can be found in animal, vegetable and marine foods sources. Among these vegetable lipids sources, peanuts are one of the main oleaginous used to prepare foods. Aims: This study aimed at assessing the effect of 0.5g, 1g, 2g and 4g of Allium cepa and Pimpinella anisum powders on the oxidative stability of lipids extracted from peanuts cakes. Material and Methods: The total phenolic content, flavonoid contents and the antioxidant properties of these spices were evaluated. In addition, lipids quality was assessed by chemical characterization of oils extracted from peanuts cakes. Results: Results revealed that P. anisum had the highest total phenolic (TPC = 61.66 mg GAE/g), flavonoid (FC = 34.95 mg CE/g) contents and DPPH free radical scavenging activities with values that ranged from 17.66 % to 89.18 %. The analysis of the oxidative state of oils extracted from peanuts cakes prepared with 0.5g, 1g, 2g and 4g of Allium cepa and Pimpinella anisum powders revealed that all oils samples with the exception of those extracted from cakes cooked with 2g and 4g of P. anisum powder had peroxide, P-anisidine, total oxidation, thiobarbituric acid and free fatty acid values in line with those recommended by the Codex Alimentarius. The principal component analysis (PCA) revealed that the free fatty acids, peroxide, P-anisidine, thiobarbituric acid values were more efficient to induce lipids oxidation in peanuts cakes. Conclusions: Preparing peanuts cakes with Allium cepa and Pimpinella anisum powders are more effective to limit lipids oxidation compared to peanuts cakes cooked without spices. Keywords: Allium cepa, Pimpinella anisum, lipids quality, peanuts cakes, antioxidant, oxidative stability.
7
Haman, François, François Péronnet, Glen P. Kenny, Éric Doucet, Denis Massicotte, Carole Lavoie e Jean-Michel Weber. "Effects of carbohydrate availability on sustained shivering I. Oxidation of plasma glucose, muscle glycogen, and proteins". Journal of Applied Physiology 96, n. 1 (gennaio 2004): 32–40. http://dx.doi.org/10.1152/japplphysiol.00427.2003.
Abstract (sommario):
Carbohydrates (CHO) can play an important thermogenic role during shivering, but the effect of their availability on the use of other oxidative fuels is unclear. Using indirect calorimetry and tracer methods ([U-13C]glucose ingestion), we have determined the specific contributions of plasma glucose, muscle glycogen, proteins, and lipids to total heat production (Ḣprod) in men exposed to cold for 2-h (liquid-conditioned suit perfused with 10°C water). Measurements were made after low-CHO diet and exercise (Lo) and high-CHO diet without exercise (Hi). The size of CHO reserves had no effect on Ḣprod but a major impact on fuel selection before and during shivering. In the cold, a complete shift from lipid oxidation for Lo (53, 28, and 19% Ḣprod for lipids, CHO, and proteins, respectively) to CHO-based metabolism for Hi (23, 65, and 12% Ḣprod for lipids, CHO, and proteins, respectively) was observed. Plasma glucose oxidation remains a minor fuel under all conditions (<13% Ḣprod), falling to 7% Ḣprod for Lo. Therefore, adjusting plasma glucose oxidation to compensate for changes in muscle glycogen oxidation is not a strategy used for maintaining heat production. Instead, proteins and lipids share responsibility for this compensation. We conclude that humans can show remarkable flexibility in oxidative fuel selection to ensure that heat production is not compromised during sustained cold exposure.
8
Milovanovic, Ljiljana, Ivanka Popovic, Dejan Skala e Snezana Saicic. "Thermogravimetric analysis of the total lipids extracted from the fatty tissue of fallow deer (Cervus Dama dama L)". Journal of the Serbian Chemical Society 71, n. 12 (2006): 1281–88. http://dx.doi.org/10.2298/jsc0612281m.
Abstract (sommario):
Thermogravimetry, TG, of lipids is an appropriate analytical method, commonly used to correlate the kinetic parameters of the thermal degradation of lipids and their composition. Thus, samples of total lipids extracted from the raw fatty tissue of fallow deer were subjected to non-oxidative and oxidative TG analysis. The samples were previously stored for nine months at +4 ?C and -18?C. The material stability was investigated in order to establish the most favorable conditions for the production and storage of different foods. The total lipids were extracted according to the Folch method. The identification and quantitative analysis of the methyl esters of the fatty acids of the total lipids were performed by capillary gas chromatography. Based on the non-oxidative and oxidative TG results, the activation energies of the thermal degradation and oxidation of the total lipids extracted from different samples of fatty tissue were determined. The Doyle-Gorbachev method was used for the calculations. .
9
Nacak, B., H. S. Kavuşan e M. Serdaroğlu. "Effect of α-tocopherol, rosemary extract and their combination on lipid and protein oxidation in beef sausages". IOP Conference Series: Earth and Environmental Science 854, n. 1 (1 ottobre 2021): 012062. http://dx.doi.org/10.1088/1755-1315/854/1/012062.
Abstract (sommario):
Abstract This study focuses on the oxidative changes in lipids and proteins of beef sausages with incorporated a-tocopherol, rosemary extract or their combination during 3 months’ storage at 4°C. For this purpose, sausages were formulated with no antioxidant (Control, C), 200 ppm a-tocopherol (T), 200 ppm rosemary extract (R), and 100 ppm a-tocopherol + 100 ppm rosemary extract (TR). To observe oxidative changes in lipids; peroxide value, thiobarbituric acid reactive substances (TBARS), and total oxidation value (TOTOX), in proteins; sulfhydryl and carbonyl contents were measured. Use of antioxidants and storage time significantly affected oxidative stability of sausages (P<0.05). Antioxidants, individually or in combination, retarded lipid peroxidation and improve the oxidative stability of sausage during storage. The antioxidant combination showed synergistic effect on protein oxidation, as the lowest carbonyl contents were found in TR samples. As a result, a combination of antioxidants with different effect mechanisms could be the better option to prevent oxidative changes in meat products.
10
Tribble, Diane L., Berbie M. Chu, Gerri A. Levine, Ronald M. Krauss e Elaine L. Gong. "Selective Resistance of LDL Core Lipids to Iron-Mediated Oxidation". Arteriosclerosis, Thrombosis, and Vascular Biology 16, n. 12 (dicembre 1996): 1580–87. http://dx.doi.org/10.1161/01.atv.16.12.1580.
Abstract (sommario):
Although the nature and consequences of oxidative changes in the chemical constituents of low density lipoproteins (LDLs) have been extensively examined, the physical dynamics of LDL oxidation and the influence of physical organization on the biological effects of oxidized LDLs have remained relatively unexplored. To address these issues, in the present studies we monitored surface- and core-specific peroxidative stress relative to temporal changes in conjugated dienes (CDs), particle charge (an index of oxidative protein modification), and LDL-macrophage interactions. Peroxidative stress in LDL surface and core compartments was evaluated with the site-specific, oxidation-labile fluorescent probes parinaric acid (PnA) and PnA cholesteryl ester (PnCE), respectively. When oxidation was initiated by Cu 2+ , oxidative loss of the core probe (PnCE) closely followed that of the surface probe (PnA), as indicated by the time to 50% probe depletion (t 1/2 ; 15.5±7.8 and 30.4±12 minutes for PnA and PnCE, respectively). Both probes were more resistant in LDL exposed to Fe 3+ (t 1/2 , 53.2±8.1 and 346.7±155.4 minutes), although core probe resistance was much greater with this oxidant (PnCE t 1/2 /PnA t 1/2, 5.8 vs 2.0 for Cu 2+ ). Despite differences in the rate and extent of oxidative changes in Cu 2+ - versus Fe 3+ -exposed LDLs, PnCE loss occurred in close correspondence with CD formation and appeared to precede changes in particle charge under both conditions. Exposure of LDLs to hemin, a lipophilic Fe 3+ -containing porphyrin that becomes incorporated into the LDL particle, resulted in rapid loss of PnCE and simultaneous changes in particle charge, even at concentrations that yielded increases in CDs and thiobarbituric acid–reactive substances similar to those obtained with free Fe 3+ . These results suggest that oxidation of the LDL hydrophobic core occurs in conjunction with accelerated formation of CDs and may be essential for LDL protein modification. In accordance with the known effects of oxidative protein modifications on LDL receptor recognition, exposure of LDLs to Cu 2+ and hemin but not Fe 3+ produced particles that were readily processed by macrophages. Thus, the physical site of oxidative injury appears to be a critical determinant of the chemical and biological properties of LDLs, particularly when oxidized by Fe 3+ .
Tesi sul tema "Oxidation des lipides":
1
Garcia, Darras Carolina. "Conception et développement d'un microcalorimètre pour l'étude de l'oxydation d'une huile végétale". Thesis, Bordeaux 1, 2012. http://www.theses.fr/2012BOR14517/document.
Abstract (sommario):
L’oxydation des lipides est un phénomène complexe qui génère de nombreux produits qu’il est nécessaire de caractériser de manière précise afin de prévenir leur apparition. Parmi les méthodes pour analyser les produits d’oxydation, l’analyse thermique différentielle, basée sur la mesure différentielle du flux de chaleur dissipé au cours des réactions d’oxydation, est intéressante car elle n’utilise pas de solvant organique. De plus, elle peut être corrélée à l’apparition de produits primaires ou secondaires d’oxydation. Dans ce contexte, nous avons conçu et développé un microcalorimètre basé sur le principe de l’analyse thermique différentielle mais plus adaptable dans la mesure où il permet l’analyse de plusieurs échantillons simultanément dans des coupelles d’analyse de dimensions variables (variation du rapport surface/volume en relation avec les phénomène de diffusion de l’oxygène). Pour le développement du microcalorimètre, les thermopiles sont utilisées dans la configuration adiabatique. Le système de mesure des flux est stable et possède une sensibilité élevée. La validation de la méthode est réalisée par effet Joule et par comparaison des points de fusion de paraffines en calorimétrie différentielle classique. La modélisation des réactions d’oxydation est réalisée afin de mettre en évidence l’influence de l’oxygène sur les cinétiques. Pour une huile riche en acides gras polyinsaturés (huile de cameline), l’enthalpie de la réaction d’oxydation (en début de cinétique) obtenue en condition isotherme (100°C) est corrélée avec la mesure des diènes conjugués (produits primaires d’oxydation). Dans l’ensemble, le microcalorimètre développé est suffisamment sensible et fiable pour mesurer les enthalpies de réactions d’oxydation des lipides des huiles alimentairesLipid oxidation results of many reactions generating numerous oxidation products that are worth characterizing in fats and oils. Among the analysis methods available, differential scanning calorimetry, based on the differential measurement of heat flux dissipated during the oxidation reactions, is convenient because it avoids the use of organic solvents. In this context, we have conceived and developed a microcalorimeter that allows the analysis of up to 5 samples simultaneously, in containers of variable sizes (allowing to vary the surface/volume ratio). For the conception of the microcalorimeter, the thermopiles are used in adiabatic configuration. The system is very stable and allowed flux measurement with a high sensitivity. The validation of the method is performed by Joule effect and by comparison of melting points of paraffins with classical differential scanning calorimetry. The modelization of the oxidation reaction is performed to point out the influence of oxygen on the kinetics. For a polyunsaturated oil (cameline oil), the enthalpy values obtained, at the beginning of the oxidation process, under isothermal condition (100°C) are correlated with the diene conjugated hydroperoxide amount. On the whole, the developed device provided an adaptable, sensitive, solvent-free and low cost method for the measurement of lipid oxidation, particularly suitable for the fast screening of a large set of samples
2
Al-Sayed, Mahmoud Kassem. "Extraction, fractionnement et caractérisation des lipides polyinsaturés d'oeufs de la truite arc-en-ciel (Oncorhynchus mykiss)". Thesis, Vandoeuvre-les-Nancy, INPL, 2007. http://www.theses.fr/2007INPL087N/document.
Abstract (sommario):
Parmi les œufs de poisson, qui sont une ressource aquatique nutritionnelle intéressante, ceux de la truite arc-en-ciel (Oncorhynchus mykiss) contiennent une quantité élevée de protéines et une huile riche en acides gras polyinsaturés (AGPI), avec une proportion très importante de phospholipides. Cependant, l’œuf de poisson présente une capacité élevée d’auto-protection contre les contraintes extérieures, qui limite la destructuration de son réseau protéique par attaque enzymatique. Ainsi, le degré d’hydrolyse des œufs de la truite l’Alcalase®, la Neutrase® et la Protamex® varie entre 3 et 7 %, ce qui est très faible (20 % dans la majorité des protéines animales). L’extraction des lipides après protéolyse partielle est incomplète, probablement en raison d’interactions fortes avec les protéines faiblement hydrolysées. Ils contiennent une teneur élevée en phospholipides (53 % des lipides totaux) et les acides gras polyinsaturés entrent pour 42 % des acides gras totaux. Les AGPI, notamment le DHA, sont situés préférentiellement en position sn-2 sur la molécule de glycérol ce qui est particulièrement intéressant du point de vue nutritionnel. La stabilité à l’oxydation de l’huile a été étudiée par diverses méthodes, dont la spectrométrie infrarouge à transformée de Fourier. Cette méthode s’est avérée extrêmement intéressante pour une analyse structurale de la dégradation de l’huile en cours d’oxydation. Il peut être conclu que les lipides tirés des œufs de la truite arc-en-ciel ou de poisson en général, ont un réel avenir en matière de complément alimentaire ou nutraceutique, à condition de lever l’obstacle de l’hydrolyse enzymatique des protéines du chorion et du vitellusFish eggs, especially those of the rainbow trout (Oncorhynchus mykiss) in the present study, are an interesting nutritional aquatic source. They contain proteins of high value, as well as an oil rich in polyunsaturated fatty acids (PUFA) with a large percentage of phospholipids. However, they exhibit a high auto-protection capacity against environmental constraints and thus, the degree of hydrolysis of rainbow trout eggs by Alcalase®, Neutrase® and Protamex® proteases varied solely within 3-7 %. This value was low compared with the 20 % obtained in most animal proteins. The phospholipid content was high (53 % of total lipids) and PUFA accounted for 42 % of total fatty acids. Among PUFA, DHA was found preferably at the sn-2 position of the glycerol backbone, which is of special interest about nutritional properties. The oil release by enzymatic hydrolysis was found limited compared with chemical methods, probably because of the strong interactions engaged with the incomplete destructured protein network. The oxidative stability of the oil was studied through several methods in which the infrared Fourier transform appeared as the best tool for structural analysis along the oxidation process. As a conclusion, lipids from fish eggs, especially from rainbow trout, could be a nutritional breakthrough, as far the enzymatic hydrolysis of the vitellus and of the chorion proteins is achieved
3
Pernin, Aurélia. "Action antioxydante et antimicrobienne de composés phénoliques dans des milieux modèles et des émulsions riches en lipides insaturés". Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLA033/document.
Abstract (sommario):
Les composés phénoliques pourraient être de bons candidats pour assurer la qualité et la sécurité des produits périssables tels que les aliments prêts-à-consommer. Très répandus dans les plantes et les co-produits agro-industriels, ils peuvent limiter l’oxydation de lipides insaturés d’intérêt nutritionnel (omega-3, dont DHA et EPA) et le développement de bactéries pathogènes alimentaires telles que Listeria monocytogenes.L'objectif de cette thèse est d'évaluer la double activité antioxydante et antimicrobienne de ces composés phénoliques dans des milieux alimentaires complexes et de mieux comprendre les mécanismes d'action associés.L’étude en milieux modèles a tout d’abord permis de mettre en évidence des relations structure-activités et de décrypter certains mécanismes d’action mettant en jeu des paramètres tels que le nombre et l’environnement chimique des groupements phénoliques, le logP, les formes dissociées / non dissociées des acides phénoliques. Les performances de trois composés sélectionnés (eugénol, acide férulique et α-tocophérol) ont ensuite été évaluées dans des milieux alimentaires complexes plus réalistes : des émulsions h/e composées d'huile de poisson, d’une phase aqueuse et de protéines de lactosérum ou Tween 80 en tant qu'émulsifiant. L’acide férulique ne présente aucune activité antioxydante mais peut inhiber le développement de L. monocytogenes. En revanche, l’eugénol et l’α-tocophérol sont de bons antioxydants dans les émulsions à base de protéines de lactosérum alors qu’ils n’y sont pas antimicrobiens. Quelques mécanismes d’action sont proposés pour expliquer ces comportementsPhenolic compounds appear to be good candidates for ensuring the quality and safety of several perishable products like ready-to-eat food. Widely found in plants and byproducts from agro-industries, they offer a potential solution to limit the oxidation of omega-3 polyunsaturated fatty acids (e.g. DHA and EPA) and the growth of foodborne pathogens such as Listeria monocytogenes.The aim of this PhD is to evaluate dual antioxidant and antimicrobial activity in complex food media and to better understand the associated mechanisms of action.First experiments carried out with a series of phenolic compounds in simple model media confirmed this dual efficiency.Interesting structure/activity relationships were highlighted and some mechanisms of action were decrypted, involving parameters like number and chemical environment of phenolic groups, logP, dissociated/undissociated forms of phenolic acids. The performances of three selected phenolic compounds, i.e. eugenol, ferulic acid and α-tocopherol (added alone or as a mixture), were evaluated in more realistic complex food media: o/w emulsions composed of fish oil, aqueous phase and whey proteins or Tween 80 as emulsifiers. Ferulic acid shows no antioxidant activity but can inhibit the development of L. monocytogenes. In contrast, eugenol and α-tocopherol are good antioxidants but not antimicrobials in emulsions formulated with whey proteins. Mechanisms of action are proposed to explain these behaviors
4
Socrier, Larissa. "Influence de la localisation d’antioxydants sur la peroxydation des lipides membranaires : étude du mode d’action de dérivés PBN et de composés phénoliques". Thesis, Compiègne, 2017. http://www.theses.fr/2017COMP2382/document.
Abstract (sommario):
Les espèces réactives de l’oxygène (EROs) sont essentielles à la survie des cellules car elles interviennent dans divers processus physiologiques comme la défense immunitaire ou encore la régulation de voies de signalisation cellulaires. Cependant, un excès d’EROs peut créer un déséquilibre de la balance EROs/antioxydants appelé « stress oxydant ». Le stress oxydant étant impliqué dans l’étiologie de plus de 200 pathologies, l’action des antioxydants est cruciale pour limiter les effets délétères des EROs. Les antioxydants utilisés par les cellules peuvent être de nature chimique. Parmi ceux-ci, l’α-phenyl-N-tert-butyl nitrone (PBN) est particulièrement efficace en milieu biologique pour piéger les radicaux. Cependant, comme cette molécule présente le désavantage majeur de mal cibler les membranes, des nitrones amphiphiles dérivées de la PBN ont été synthétisées. Le premier chapitre décrit l’étude des interactions de nitrones dérivées du cholestérol avec les lipides membranaires. Ces travaux ont souligné l’influence du groupement polaire sur la nature des interactions avec les lipides membranaires. Aussi, l’étude des propriétés antioxydantes a permis de mettre en évidence l’importance de la localisation membranaire et l’influence de l’orientation du groupement PBN sur l’activité protectrice des dérivés. Le second chapitre décrit les résultats des expériences menées avec une deuxième série de dérivés amphiphiles, présentant la particularité d’avoir une chaîne perfluorée comme groupement hydrophobe. Bien que la localisation membranaire de ces dérivés soit nécessaire pour obtenir un effet protecteur significatif, la nature de l’antioxydant semble être ici le paramètre le plus important. Enfin, la combinaison d’antioxydants de nature différente sur une même molécule semble être une stratégie prometteuse pour améliorer l’efficacité antioxydante et créer un effet de synergie. En outre, pour se défendre, les cellules utilisent aussi des antioxydants issus de l’alimentation, en particulier des fruits et légumes. Parmi ces derniers, les composés phénoliques sont reconnus pour leurs effets bénéfiques sur la santé. Les flavonoïdes, les acides phénoliques, les stilbènes et les lignanes constituent les 4 classes principales de composés phénoliques. Les lignanes sont particulièrement présents dans les graines de lin (Linum usitatissimum). Le lin est la plante qui contient le plus de secoisolaricirésinol diglucoside. Afin de mieux comprendre leur fonctionnement et leurs interactions avec les lipides membranaires, plusieurs molécules appartenant à cette classe de composés ainsi que des acides hydroxycinnamiques ont été purifiées à partir du lin. Le troisième chapitre décrit les résultats des expériences menées avec les composés phénoliques extraits du lin. De manière générale, les composés testés se sont avérés efficaces pour protéger les lipides membranaires de l’oxydation. L’étude de leurs interactions avec les lipides membranaires a permis de montrer que le mode d’action des lignanes, qui pénètrent les membranes, est plus efficace que celui des acides hydroxycinnamiquesReactive oxygen species (ROS) are essential in living cells as they intervene in several physiological processes like the immune system and signaling pathways. However, an excess of the production of ROS can alter the equilibrium with antioxidants. This imbalance is called oxidative stress. As oxidative stress has been reported to be implicated in more than 200 diseases, the action of antioxidants to limit the deleterious effects of ROS is crucial. The antioxidants used by the cells can be chemical. Among them, α-phenyl-N-tert-butyl nitrone (PBN) is widely used in biological systems to neutralize ROS. Because this molecule possesses a poor ability to target membranes, our collaborators synthesized amphiphilic nitrones bearing a PBN moiety. The first chapter describes the interactions of cholesterol derived PBN derivatives with the membrane. Results underlined the influence of the polar moiety on the nature of their interactions with membrane lipids. In addition, the evaluation of the antioxidant properties revealed the importance of the membrane localization of the nitrone moiety on the protective activity of the derivatives. The second chapter deals with a second set of amphiphilic nitrones that have the particularity of bearing a perfluorinated chain that constitutes the hydrophobic moiety. We noticed the membrane localization is important for the antioxidant efficiency; however the nature of the antioxidant moiety remains the most important parameter in this case. Finally, the strategy of grafting two different antioxidants on the same carrier seems to be promising to enhance the protective effect and create a synergistic antioxidant effect. However, cells also use natural antioxidants to defend themselves. These antioxidants come from food, especially from vegetables and fruits. Among them, phenolic compounds are known for their beneficial effects on health. Flavonoïds, phenolic acids, stilbenes and lignans constitute the 4 main classes of phenolic compounds. Lignans are particularly present in flaxseed (Linum usitatissimum). Flaxseed is the plant that possesses the highest quantity of secoisolariciresinol diglucoside. In order to understand their mechanisms of action and their interactions with membranes, lignans as well as hydroxycinnamic acids were purified from flaxseed. The third chapter describes the results obtained on model membranes. Generally speaking, both classes of compounds are efficient against lipid oxidation. Studying their interactions with membrane lipids allowed us to show that the mechanism of lignans, that penetrate membranes, is more efficient than the mechanism of hydroxycinnamic acids
5
Roman, Olesea. "Mesure et prédiction de la réactivité des lipides au cours du chauffage d'huiles végétales à haute température". Phd thesis, AgroParisTech, 2012. http://pastel.archives-ouvertes.fr/pastel-00806186.
Abstract (sommario):
Si les lipides contribuent à la valeur nutritionnelle et sensorielle de nombreux aliments, ils sont particulièrement sensibles aux réactions d'oxydation. Les principaux mécanismes mis en jeu lors de l'oxydation des acides gras insaturés sont relativement bien connus. En revanche, il est aujourd'hui quasiment impossible de prédire l'avancement des réactions et souvent nécessaire de recommencer une nouvelle étude de stabilité oxydative pour tout nouveau couple produit alimentaire / procédé de transformation. L'objectif de la thèse est donc de construire un modèle mécanistique couplé à un modèle de transfert de l'oxygène dans le but de prédire l'avancement des réactions d'oxydation dans un milieu lipidique continu et dans des conditions expérimentales définies et contrôlées (température, oxygénation, composition en acides gras, composition en antioxydants). Pour cela, un schéma réactionnel visant à détailler l'ensemble des réactions impliquées dans le phénomène d'auto-oxydation des lipides a été proposé puis un modèle stoechio-cinétique a été construit à partir des valeurs des paramètres cinétiques issues de la littérature. La réactivité des acides gras insaturés présents dans trois huiles végétales d'usage courant (colza, tournesol, tournesol oléique), purifiées de leurs antioxydants naturels, a été étudiée entre 80 et 180°C, en suivant différents marqueurs d'oxydation (diènes conjugués, hydroperoxydes, aldéhydes, polymères). Comme attendu, les cinétiques d'oxydation se sont avérées dépendantes de la composition des huiles en acides gras, de la température et des conditions d'oxygénation. L'ajout d'antioxydant(s) a confirmé l'effet protecteur de l'α-tocophérol, qui n'a pas été amélioré par un enrichissement en acide chlorogénique, acide phénolique naturellement présent dans les graines de tournesol. Les résultats obtenus ont été utilisés pour valider le modèle développé, dont les prédictions permettent de reproduire les tendances expérimentales. Deux limitations ont été mises en évidence au cours de cette phase de validation dont la première concerne la description fiable et précise du mécanisme d'oxygénation du milieu, qu'il sera nécessaire de mesurer dans une huile à haute température pour valider le modèle d'oxydation. Par ailleurs, compte tenu du nombre important de réactions prises en compte, il sera indispensable de disposer d'un jeu de données expérimentales plus important, pouvant inclure des intermédiaires radicalaires. Pour cela, les potentialités de la résonance paramagnétique électronique ont été étudiées au cours de ce travail, à la fois pour suivre les radicaux lipidiques et pour accéder à des paramètres cinétiques pour des réactions radicalaires, peu disponibles dans la littérature.
6
Du, Zhen-Yu. "Consequences of fat feeding on growth and body lipids in a herbivorous fish (Grass carp, Ctenopharyngodon idella) : mechanisms related to fatty acid oxidation". Dijon, 2005. http://www.theses.fr/2005DIJOS019.
Abstract (sommario):
L'objectif de cette thèse est d'évaluer si des régimes riches en graisse peuvent être donnés en élevage aux poissons herbivores. La carpe d'herbe prise comme modèle présente des capacités limitées à utiliser les lipides, avec, sur le long terme, de l'anorexie, une croissance diminuée et une accumulation de lipides dans plusieurs organes. Les capacités du foie à oxyder les acides gras, via les mitochondries et peroxysomes, sont faibles et associées à une accumulation d'acides gras polyinsaturés (PUFA) dans les liquides corporels. L'ingestion en excès d'huile de poisson aboutit à une peroxydation marquée des acides gras s'accompagnant d'effets délétères. L'activité peroxysomale réduite freine la dégradation des PUFA qui s'accumulent dans les lipides. Le fénofibrate, ligand de PPARα , augmente faiblement l'oxydation peroxysomale et atténue quelques effets négatifs des régimes à forte proportion de PUFA. L'augmentation de l'activité mitochondriale pendant le jeûne ne permet pas d'utiliser davantage les PUFA. Globalement la carpe apparaît être un poisson peu exigeant énergétiquement avec des capacités réduites à utiliser les régimes riches en graisses.
7
Ayoub, Pierre. "Molecular dynamics study of pyrene excimer formation and oxidation in lipid bilayer models". Thesis, Strasbourg, 2015. http://www.theses.fr/2015STRAE038/document.
Abstract (sommario):
Nous proposons une nouvelle approche pour déterminer le coefficient de diffusion dans des membranes lipidiques se basant sur la formation d'excimères. Alors que les autres modèles statistiques considèrent le système comme un ensemble de points sur un réseau, nous utilisons un modèle à gros grain afin d'étudier des bicouches lipidiques simulées à l'aide du champs de force Martini. Nous déterminons le taux de réaction dépendant du temps à partir des probabilités de survie obtenues a posteriori à l'aide des trajectoires numeriques des bicouches symétriques de DOPC (1,2-Dioleoyl-sn-glycero-3-phosphocholine) et POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine) simulées à 283 K et 293 K respectivement. Les dynamiques de collision sont obtenues en distinguant virtuellement les molécules simulées. Les sondes fluorescentes sont supposées semblables aux lipides, et par conséquent, ne modifient pas la dynamique. Nous obtenons une expression générale pour la probabilité de survie en combinant approximation des paires indépendantes et propriétés d'échelle, mais aucune hypothèse n'est faite pour le taux de formation d'excimère. En superposant les intensités d'émission de fluorescence normalisées, déterminées numériquement, aux courbes de titrations expérimentales, nous obtenons deux ensembles de résultats pour le coefficient de diffusion latéral, selon que l'association entre feuillets est autorisée ou pas. Nous utilisons un rayon de capture de 0.5 nm, la distance à partir de laquelle les deux sondes réagissent pour former un excimère. En comparant la dynamique Martini aux expériences de fluorescence, il est possible d'estimer le facteur d'accélérationWe propose a novel approach to extract the lateral diffusion coefficient in lipid bilayers using excimer formation. In contrast to previous statistical models that modeled the system as points undergoing jumps from site to site on a lattice, we use coarse-grained molecular dynamics to study lipid bilayers simulated using the Martini force field. We derive time dependent reaction rates from survival probabilities obtained a posteriori from numerically generated trajectories of symmetric DOPC (1,2-Dioleoyl-sn-glycero-3-phosphocholine) and POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine) bilayers at 283K and 293K respectively. Collision dynamics are determined by virtually relabeling the simulated molecules. The fluorescent probes are assumed to behave like ordinary membrane lipids and therefore the dynamics remain unaffected. We derive a generalized expression for the survival probability combining independent pairs and size scaling assumptions, but no assumption is made regarding the kinetic rate of the excimer formation process. By fitting the numerically determined normalized fluorescence emission intensities to experimental titration curves, we obtain two sets of results for the lateral diffusion coefficients depending whether interleaflet excimer association is allowed or not. We use a capture radius of 0.5 nm, the distance at which the probes react to form excimers. By relating Martini dynamics to real fluorescence experiments, we estimate the numerical Martini acceleration factor. We also study mixtures of oxidized-non oxidized DOPC and POPC bilayers using a hydroperoxidized model of these lipids for different concentrations of the oxidized component (3.1%, 25% and 50%). Using pair correlation functions, we extract structural information on the systems and determine whether the two components are prone to mixing or not. Finally, we calculate the thermodynamic mixing parameters within the framework of the virial expansion
8
Garcia, Mendoza Maria del Pilar. "Enrichissement d’huiles végétales par des antioxydants de type phenolique en vue d’applications alimentaires". Thesis, Bordeaux, 2020. http://www.theses.fr/2020BORD0196.
Abstract (sommario):
Les huiles végétales comme les huiles de cameline et tournesol sont des sources d’acides gras polyinsaturés bon pour la santé mais également très sensibles à la dégradation oxydative. Ce travail vise à améliorer la stabilité oxydative d’huiles alimentaires (principalement l’huile de cameline) via l’incorporation de composés phénoliques antioxydants soit comme composé pur (quercétine) soit comme un mélange plus complexe extrait à partir d’un coproduit de la noix. La faible solubilité de la quercétine dans l’huile a été contournée avec succès par le développement d’une voie d’enrichissement sans solvant en présence de phospholipides. Ainsi, la formulation à base de quercétine-phospholipides a permis d’augmenter significativement à la fois la solubilité de la quercétine and la stabilité oxydative de l’huile. Cette stabilité oxydative, mesurée par vieillissement accéléré à chaud, s’est révélée variable selon les concentrations en quercétine et phospholipides. L’hypothèse du rôle central des associations colloïdales dans ces observations a été formulée. Des données sur la solubilité de la quercétine dans différents solvants d’intérêt industriel ont également été générées. Pour les extraits phénoliques à base de tourteau de noix, en plus de l’amélioration de la stabilité oxydative, les paramètres influençant l’extraction ont été identifiés et une modélisation des procédés batch et semi-continu proposée. L’effet protecteur contre l’oxydation de l’huile d’un extrait de noix présentant une haute activité antiradicalaire s’est révélé dose-dépendant et a permis un accroissement significatif de la durée de conservation des huiles enrichiesVegetable oils like camelina and sunflower oils are sources of healthy polyunsaturated fatty acids that are however highly susceptible to oxidative degradation. This work aimed at enhancing the oxidative stability of edible oils, mostly camelina oil by incorporating phenolics antioxidants, either as a pure component, quercetin, or as a more complex mixture extracted from a walnut by-product. The low solubility of quercetin in oils was successfully circumvented by developing a solvent-free route of enrichment in presence of phospholipids, so that quercetin-phospholipids formulation allowed to significantly increase both quercetin solubility and the oxidative stability of the oils. The enhanced oxidative stability, monitored under accelerated conditions of heating, was found to vary according to quercetin-phospholipid concentrations and ratios, and it was assumed that colloidal associations played a key role in the enhancement. Data of quercetin solubility in various solvents of industrial interest were also provided. For phenolic extract recovered from a walnut press-cake in addition to oxidative stability enhancement, modelling of batch and semi-continuous extractions was performed and influent parameters were identified. The protective effect against lipid oxidation of a walnut extract exhibiting high antiradical activity was dose-dependent and significantly extended the shelf life of enriched oils
9
Masoud, Rawand. "Modulating the activity of NADPH oxidase by oxidative stress participants ; lipids and nanoparticles A cell-free system study". Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS028/document.
Abstract (sommario):
La NADPH oxydase de phagocyte est un complexe enzymatique impliqué dans la défense immunitaire contre les pathogènes. Elle est constituée du flavocytochrome b558 membranaire (Cyt b558), composé de deux sous-unités (gp91phox et p22phox) et de quatre sous-unités cytosolubles, p47phox, p67phox, p40phox, et Rac. Sa fonction est de produire au niveau de la paroi des pathogènes des ions superoxyde (O2•−) qui sont transformés en d'autres espèces réactives de l'oxygène (ROS) qui attaquent les lipides, les protéines et l’ADN environnants. Après activation du phagocyte, les sous-unités cytosoliques subissent des modifications post-traductionnelles et migrent vers la membrane pour constituer le complexe NADPH oxydase activé. Le rôle délétère des ROS dans les maladies est connu depuis longtemps. Le but de ma thèse a été d’étudier l’influence de molécules exogènes qui induisent une augmentation du stress oxydatif, sur l’activité de la NADPH oxydase.Dans ce travail, nous avons étudié le fonctionnement de la NADPH oxydase dans un système in vitro dans lequel l’enzyme était activée par la présence d'acide arachidonique (AA). J’ai étudié l'influence de deux types de molécules: une classe de lipides et des nanoparticules (NPs). Pour simplifier le système, nous avons remplacé l’ensemble des sous-unités cytosoliques par une protéine unique appelé trimère qui correspond à une fusion des trois protéines cytosoliques p47phox, p67phox et Rac. Nous avons montré que le trimère est fonctionnellement comparable aux sous-unités cytosoliques séparées. La vitesse de production de O2•−, sa dépendances en fonction de la concentration en AA et de la température, et sa sensibilité aux radicaux libres étaient comparables lorsque le trimère ou les sous-unités séparées étaient utilisés.J’ai étudié les conséquences de la présence de cholestérol et de ses formes oxydées sur la production de O2•− par la NADPH oxydase. Nos résultats montrent clairement que le cholestérol et l’oxystérols ne sont pas des activateurs efficaces de la NADPH oxydase. L’addition d’une quantité physiologique de cholestérol déclenche une faible production d’ions superoxyde. L’addition de cholestérol à des concentrations du même ordre de grandeur pendant le processus d'assemblage (en présence de AA), a un rôle inhibiteur sur la production d’O2•−. Le cholestérol ajouté agit sur les composantes, cytosoliques et membranaires, conduisant à un assemblage imparfait. En conclusion, le cholestérol déjà présent dans la membrane des neutrophiles est optimale pour le fonctionnement de la NADPH oxydase.Il était intéressant de vérifier l'influence des nanoparticules de dioxyde de titane (TiO2) et de platine (Pt) sur le comportement de la NADPH oxydase sachant que l'internalisation cellulaire de ces NPs a pour effet d’activer les neutrophiles et les macrophages et contribue à une sur-production de ROS. En l’absence d'activateur mais en présence de NPs de TiO2 ou Pt, aucune production de O2•− n’était détectée indiquant que les NPs de TiO2 et Pt sont incapables d'activer le complexe par eux-mêmes aussi bien dans le système acellulaire que dans les neutrophiles. Cependant, une fois la NADPH oxydase activée (par AA), la vitesse de production des O2•− est augmentée jusqu’à 40% de sa valeur en l’absence de NPs de TiO2, cet effet étant fonction de leur concentration. Par contre, les NPs de Pt n’ont aucun effet sur l’activité de la NADPH oxydase aussi bien in vitro que dans les neutrophiles. En conclusion, l'hyperactivation de la NADPH oxydase et l'augmentation subséquente de la production de ROS induites par les NPs de TiO2 pourraient participer au développement du stress oxydatif tandis que l'absence d'effet Pt-NPs suggère qu'ils ne provoquent pas de sur-inflammationNADPH oxidase from phagocytes is a multi-subunit enzyme complex involved in the innate defense of organisms against pathogens. It is composed of the membrane-bound flavocytochrome b558 (Cyt b558), comprising two subunits (gp91phox, and p22phox) and four cytosolic components, p47phox, p67phox, p40phox, and Rac. Its function is to produce in the vicinity of the pathogen, superoxide ions that are transformed subsequently into other reactive oxygen species (ROS) and will damage lipids, proteins and DNA. Upon phagocyte activation, the cytosolic subunits undergo posttranslational modifications and migrate to the membrane bound Cyt b558 to constitute the activated NADPH oxidase complex. The damaging role of ROS in cardiovascular diseases has been known for some decades. The aim of my thesis was to study the influence on NADPH oxidase activity, of molecules coming from food and industrial products and known to be involved in increase of oxidative stress.In this work, we studied the NADPH oxidase functioning in an in vitro system in which the components of the enzyme are mixed and activated by the introduction of an amphiphile the arachidonic acid (AA). During my PhD, I have studied the influence of two types of oxidative stress participants: lipids and nanoparticles (NPs). For simplicity, we have replaced the cytosolic subunits by a single protein called trimera, which is a fused construction of three cytosolic proteins p47phox, p67phox and Rac. We have shown that trimera is functionally comparable with the separated cytosolic subunits. The rates of production of O2•−, the dependences of the activity in function of AA concentration and temperature, the presence of two states in the activation process and the sensitivity of NADPH oxidase to free radicals were comparable when either trimera or separated subunits were used.I investigated the consequences of the addition of cholesterol on NADPH oxidase, on the production of ROS. Our results clearly show that cholesterol and oxysterols are not efficient activators of NADPH oxidase. Concentrations of cholesterol similar to what found in neutrophiles trigger a low superoxide production. Addition of cholesterol during the assembly process (in presence of AA) at similar or higher concentrations, has an inhibitory effect on the production of O2•−. Added cholesterol acts on both cytosolic and membrane components, leading to imperfect assembly and decreasing the affinity of cytosolic subunits to the membrane ones. In conclusion, we showed that the cholesterol already present in the phagocyte membrane is optimal for the function NADPH oxidase.It was of interest to check the influence of titanium dioxide (TiO2) and platinum (Pt) NPs on NADPH oxidase especially that cellular internalization of NPs was shown to activate neutrophils and contribute to O2•− overproduction via NADPH oxidase. In the absence of activators and presence of TiO2 or Pt NPs, no production of O2•− could be detected in in vitro system as well as in neutrophils indicating that TiO2 and Pt NPs were unable to activate by themselves the complex. However once the NADPH oxidase was activated by AA, TiO2 NPs increased the rate of O2•− production by up to 40%, this effect being dependent on their concentration. Differently, Pt NPs had no effect both on in vitro system as well as on neutrophils. In conclusion, the hyper-activation of NADPH oxidase and the subsequent increase in ROS production by TiO2 NPs could participate to oxidative stress development while the absence of Pt-NPs effect suggest that they do not induce inflammation status via this complex
10
Kaleem, Muhammad. "Effets des produits d'oxydation de l'acide linoléique sur sa biohydrogénation ruminale". Thesis, Toulouse, INPT, 2013. http://www.theses.fr/2013INPT0042/document.
Abstract (sommario):
La biohydrogénation (BH) ruminale des acides gras polyinsaturés (AGPI) est à l’origine de la production d’AG trans pouvant se retrouver dans les productions de ruminants, dont le lait. Parmi ceux-ci, les isomères t11 auraient des effets bénéfiques pour la santé des consommateurs alors que les isomères t10 sont potentiellement défavorables. En élevage, l’apport de graines oléagineuses dans la ration des vaches permet d’augmenter la teneur du lait en ces acides gras. Or ces graines sont souvent distribuées chauffées pour améliorer leur valeur nutritionnelle. Expérimentalement, les effets des graines chauffées sur les teneurs en isomères t11 dans le rumen ou le lait sont variables, mais généralement elles permettent une augmentation des isomères t11 et une protection des AGPI. Au contraire, des huiles très oxydées par chauffage diminuent fortement les isomères t11 et augmentent parfois les isomères t10. Les produits d’oxydation des lipides générés pendant le chauffage des graines ou des huiles pourraient être incriminés. Les objectifs de la présente étude étaient d’explorer les éventuels effets des produits d’oxydation du c9,c12-C18:2 sur sa BH ruminale. In vitro, la protection des AGPI dans des graines de soja chauffées a été liée aux aldéhydes et en particulier à l’hexanal. L’augmentation des isomères t11 a été observée avec un aldéhyde long et insaturé, le t2,t4-décadiénal, suite à une inhibition de la dernière étape de la BH. Cet effet était concomitant à une modification marquée de la communauté bactérienne du rumen induite par cet aldéhyde. Les hydroperoxydes issus du c9,c12-C18:2 sont le 13HPOD et le 9HPOD. L’augmentation des isomères t10 a systématiquement été reliée au 13HPOD dans nos différentes expérimentations. Aucun mécanisme d’action n’a pu être formellement démontré mais l’effet du 13HPOD s’exercerait plutôt sur le microbiote, car il ne module pas l’activité de la Δ9-isomérase. Quant à la diminution des isomères t11 observée avec les huiles chauffées, elle n’a pas pu être expliquée. Elle pourrait également être liée, au moins partiellement, aux 13HPOD et 9HPOD, capables d’inhiber la Δ12-isomérase. Des modifications des fermentations ruminales, sans altération mesurable de l’abondance, de la diversité ou de la structure de la communauté bactérienne, suggèrent aussi un effet des AGPI chauffés sur l’activité des bactériesRuminal biohydrogenation (BH) of polyunsaturated fatty acids (PUFA) produces some trans FA which can be found in ruminant products. Among them, t11 isomers would be beneficial for human health while t10 isomers are potentially deleterious. In farms, addition of oilseeds to the diet of dairy cows increases these fatty acids in milk. Oilseeds are often heated before incorporation to cow’s diets, to enhance their nutritional value. Experiments investigating effects on t11 isomers content in rumen and milk of cows receiving heated oilseeds provided variable results, but they usually increased t11 isomers and protected PUFA from BH. On the contrary, highly oxidized oil decrease t11 isomers and sometimes increase t10 isomers. Lipid oxidation products generated during heating of oilseeds and oils could be incriminated. The objectives of the present study were to investigate the effects of c9,c12-C18:2 oxidation products on its BH. Protection of PUFA in heated soybeans was linked to aldehydes, mainly hexanal. An increase of t11 isomers was observed with a long and unsaturated aldehyde, the t2,t4-decadienal, due to an inhibition of the last BH step. This effect was concomitant with a modification of bacterial community by t2,t4-decadienal. Hydroperoxides formed during c9,c12-C18:2 heating are 13HPOD and 9HPOD. The increase of t10 isomers in all of our experimentations was systematically linked with 13HPOD. No definitive explanation about the mechanism of action could be proposed, but 13HPOD would most probably act on microbiote since it had no effect on Δ9-isomerase. Our experiments did not explain the decrease of t11 isomers observed with heated oils, which could, at least in part, be due to 13HPOD and 9HPOD, which were able to inhibit Δ12-isomerase Some modifications of ruminal fermentation without measurable alteration of bacterial community abundance, diversity or structure also suggest an action of heated PUFA on bacterial activity
Libri sul tema "Oxidation des lipides":
1
J, St Angelo Allen, American Chemical Society. Division of Agricultural and Food Chemistry. e American Chemical Society Meeting, a cura di. Lipid oxidation in food. Washington, DC: American Chemical Society, 1992.
2
Logan, Amy, Uwe Nienaber e Xiangqing Pan. Lipid oxidation: Challenges in food systems. Urbana, Illinois: AOCS Press, 2013.
3
1948-, Vigo-Pelfrey Carmen, a cura di. Membrane lipid oxidation. Boca Raton, Fla: CRC Press, 1990.
4
1940-, Chow Ching Kuang, a cura di. Cellular antioxidant defense mechanisms. Boca Raton, Florida: C.R.C. Press, 1988.
5
St. Angelo, Allen J., a cura di. Lipid Oxidation in Food. Washington, DC: American Chemical Society, 1992. http://dx.doi.org/10.1021/bk-1992-0500.
6
Catala, Angel. Reactive oxygen species, lipid peroxidation, and protein oxidation. New York: Nova Publishers, 2014.
7
-S, Chan H. W., a cura di. Autoxidation of unsaturated lipids. London: Academic Press, 1986.
8
-S, Chan H. W., a cura di. Autoxidation of unsaturated lipids. London: Academic Press, 1987.
9
Bravo-Diaz, Carlos, a cura di. Lipid Oxidation in Food and Biological Systems. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-87222-9.
10
Hwang, Hong-Sik. Advances in NMR Spectroscopy for Lipid Oxidation Assessment. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-54196-9.
Capitoli di libri sul tema "Oxidation des lipides":
1
Willian, Kyle. "Lipids and Lipid Oxidation". In The Science of Meat Quality, 147–75. Oxford, UK: John Wiley & Sons, Inc., 2013. http://dx.doi.org/10.1002/9781118530726.ch8.
2
Mohd Fauzi, Norsyahida, e Corinne M. Spickett. "Lipid Oxidation". In Oxidative Stress in Applied Basic Research and Clinical Practice, 43–79. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-19096-9_4.
3
Spanier, Arthur M., James A. Miller e John M. Bland. "Lipid Oxidation". In ACS Symposium Series, 104–19. Washington, DC: American Chemical Society, 1992. http://dx.doi.org/10.1021/bk-1992-0500.ch007.
4
Croguennec, Thomas. "Lipid Oxidation". In Handbook of Food Science and Technology 1, 99–131. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2016. http://dx.doi.org/10.1002/9781119268659.ch4.
5
Rustad, Turid, e Eva Falch. "Lipid Oxidation". In Handbook of Seafood and Seafood Products Analysis, 136–44. 2a ed. Boca Raton: CRC Press, 2024. http://dx.doi.org/10.1201/9781003289401-8.
6
O'Brien, N. M., e T. P. O'Connor. "LIPIDS | Lipid Oxidation". In Encyclopedia of Dairy Sciences, 1600–1604. Elsevier, 2002. http://dx.doi.org/10.1016/b0-12-227235-8/00269-8.
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Holtman, W. L., J. C. Heistek, I. Kokkelink e A. C. Douma. "Lipid degradation via β3-oxidation in germinating barley". In European Brewery Convention, 69–76. Oxford University PressOxford, 1993. http://dx.doi.org/10.1093/oso/9780199634668.003.0007.
Abstract (sommario):
Abstract Lipids and their degradation and oxidation products can negatively affect beer quality and brewing process technology. Barley malt is a major source of lipids and lipid degrading enzymes in the brewing process.
8
O'Brien, N. M., e T. P. O'Connor. "Milk Lipids: Lipid Oxidation". In Reference Module in Food Science. Elsevier, 2016. http://dx.doi.org/10.1016/b978-0-08-100596-5.00924-0.
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O’Brien, N. M., e T. P. O’Connor. "Milk Lipids | Lipid Oxidation". In Encyclopedia of Dairy Sciences, 716–20. Elsevier, 2011. http://dx.doi.org/10.1016/b978-0-12-374407-4.00342-3.
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O'Brien, N. M., e T. P. O'Connor. "Milk Lipids: Lipid Oxidation". In Reference Module in Food Science. Elsevier, 2021. http://dx.doi.org/10.1016/b978-0-12-818766-1.00333-0.
Atti di convegni sul tema "Oxidation des lipides":
1
Villeneuve, Pierre, Claire Bourlieu-Lacanal, David McClements, Eric Decker e Erwann Durand. "Lipid oxidation in emulsions and bulk oils: A review of the importance of micelles". In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/lzak8107.
Abstract (sommario):
Lipid oxidation is a major cause of quality deterioration in food or cosmetic products. In these matrices, lipids are often present in a bulk or in emulsified forms. In both systems, the rate, extent and pathway of oxidation are highly dependent on the presence of colloidal structures and interfaces because these are the locations where oxidation normally occurs. In bulk oils, reverse micelles (association colloids) are present and are believed to play a crucial role on lipid oxidation. Conversely, in emulsions, surfactant micelles are present that also play a major role in lipid oxidation pathways. This review discusses the current understanding of the influence of micellar structures on lipid oxidation. In particular, is discussed the major impact of the presence of micelles in emulsions, or reverse micelles (association colloids) in bulk oil on the oxidative stability of both systems. Indeed, both micelles in emulsions and associate colloids in bulk oil are discussed as nanoscale structures that can serve as reservoirs of antioxidants and pro-oxidants and are involved in their transport within the concerned system. Their role as nanoreactors where lipid oxidation reactions occur is also commented. Significance of your research to the AOCS membership? The results underline the importance of a better understanding of the role of micelles in the control of lipid oxidation in food or cosmetic products.
2
Moigradean, Diana, Mariana-Atena Poiana, Despina-Maria Bordean, Daniela Stoin e Liana-Maria Alda. "OXIDATIVE STABILITY OF COCONUT OIL AND WALNUT OIL BY PHYSICO-CHEMICAL ANALYSIS AND FTIR SPECTROSCOPY". In 23rd SGEM International Multidisciplinary Scientific GeoConference 2023. STEF92 Technology, 2023. http://dx.doi.org/10.5593/sgem2023v/6.2/s25.38.
Abstract (sommario):
The indicator of the quality of edible oils is its oxidative stability. The oxidative reactions can be influenced by several factors (light, heat, oxygen reaction with unsaturated lipids) and by chemical and enzymatic mechanisms (autoxidation, photooxidation and lipoxygenases). These factors can accelerate lipid oxidation, decrease oxidative stability and cause significant modification on sensory properties, what lead to nutritional depreciation of edible oil and decrease in the shelf life. The aims of this study are to evaluate the oxidative stability of coconut oil and walnut oil during storage (12 month) because this has a significant influence on degree of oil freshness. The lipid oxidation gives rise to the existence of toxic compounds in the food products and contribute to the development of heart disease, cancer and atherosclerosis. The progress of lipid oxidation was assessed by measuring peroxide value (PV), p-anisidine value (AV) and total oxidation value (TOTOX). The low peroxide value signifies a high oxidative stability. The Totox value gives clear overall data analysis of the freshness of the oil; the lower the Totox value, the better the quality of oils. FTIR spectral data were used to determine the bands, which can be considered as the fingerprints of the oxidation. The results suggest that walnut oil quickly go rancid but the coconut oil keeps its good chemical properties during storage.
3
Alberdi-Cedeno, Jon, Kubra Demir e Marc Pignitter. "Influence of monosodium glutamate on the oxidative stability of meat lipids". In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/mvhi9556.
Abstract (sommario):
Monosodium glutamate (MSG) is an additive (E621) widely used as flavor enhancer in food industry in order to increase palatability, especially in meat and meat derived products. Its use has increased worldwide by 4.80% during 2017–2021. Therefore, its effect on sensory and organoleptic quality of meat and meat derived products has been extensively investigated. However, so far, studies investigating the impact of MSG on the progress of lipid oxidation in meat are lacking. Therefore, the effect of the fortification of pork burger patties with 0–1.2 % MSG was addressed, paying particular attention to the oxidative stability of their lipids. Samples were storage at 8 °C up to 4 days following oven cooking at 180 °C for 10 min. In order to have an overall view, the samples were analyzed by 1H Nuclear Magnetic Resonance (1H NMR) and Solid Phase Microextraction followed by Gas Chromatography-Mass Spectrometry (SPME-GC-MS). The results showed, for the first time, that the fortification of pork burger patties with MSG caused the degradation of their main polyunsaturated acyl groups, linoleic acyl groups (-6) (p< 0.05), as well as some minor components, such as terpenes, after cooking. The decline of non-oxidized lipids was accompanied by the formation of different oxidation compounds, such as aldehydes, ketones and alcohols among others. In general, the total amount of secondary lipid oxidation compounds was enhanced in the presence of 1.2% MSG compared to the non-treated patties (p< 0.05). Moreover, it was observed that the storage at 8 °C did not have any effects on the oxidative stability of the pork lipids. Overall, MSG was shown to promote lipid oxidation in pork burgers raising concerns about its impact on food quality.
4
Van Wayenbergh, Eline, Christophe Courtin, Imogen Foubert e Niels Langenaeken. "Wheat bran protects vitamin A from oxidation during storage". In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/cxaa5765.
Abstract (sommario):
Food fortification is an efficient strategy to prevent vitamin A deficiency, a widely occurring health issue. However, vitamin A is rapidly degraded during food processing and storage, mainly due to oxidation. Therefore, there is a strong need for stabilising agents. In this study, we showed that wheat bran can be used as a natural, healthy and affordable stabilising agent slowing down vitamin A oxidation and lipid oxidation, which are closely related. The stabilising vitamin A-bran interaction was shown during an accelerated storage experiment (60°C, 70% relative humidity) using a model system consisting of wheat bran, soy oil and vitamin A. While vitamin A was degraded entirely after ten days of storage in the absence of wheat bran, vitamin A recovery after two weeks in the presence of native wheat bran was 10%. This increased to 70% when the wheat bran was toasted (30 min, 170°C). The more pronounced stabilising effect of toasted wheat bran may be explained by the absence of endogenous lipase activity, preventing free fatty acid production during storage. While free fatty acid production in the sample with native wheat bran resulted in accelerated vitamin A oxidation, it did not result in accelerated lipid oxidation, suggesting that vitamin A acts as an antioxidant protecting lipids from oxidation. Moreover, wheat bran antioxidants are thought to delay the oxidation of both vitamin A and lipids. In conclusion, toasted wheat bran mixed with oil and vitamin A can be used as a cost-effective and healthy aid in food fortification by providing high vitamin A stability. To successfully apply this stabilisation technique, a good understanding of the interplay between lipase activity, lipid oxidation, wheat bran antioxidants and vitamin A oxidation is crucial.
5
Wu, Haizhou, Bita Forghani, Ingrid Undeland e Mehdi Abdollahi. "Lipid oxidation in sorted herring (Clupea harengus) filleting co-products and its relationship to composition". In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/uelt7673.
Abstract (sommario):
In industrial fish filleting, around 30–70 % of the total weight of the fish end up as side streams (often called by- or co-products), such as the head, backbone, caudal fin, skin, and intestines. Currently, these fractions are dedicated to low value uses as fodder meals or mink feed, even if they contain significant amounts of protein, long chain (LC) n-3 polyunsaturated fatty acids (PUFA), and other nutrients such as vitamins and minerals. However, most fish processors mix their side streams, not least when it comes to small pelagic species like herring. This practice limits use of the side streams for food production since the raw material gets very complex, and since blood, enzymes and lipids from e.g., the viscera and head parts easily contaminate the cleaner parts like the backbones and tails, accelerating e.g., their oxidative or enzymatic degradation. In the present study, lipid oxidation in ice-stored sorted and minced herring fractions (head, backbone, viscera+belly flap, tail, fillet) from spring and fall, and its association with endogenous pro-oxidants, antioxidants and lipid substrates were investigated. Peroxide value (PV) and thiobarbituric acid reactive substances (TBARS) had increased significantly in all fractions after 1 day, but for both seasons, the most rapid PV and TBARS development occurred in head, which also had highest hemoglobin (Hb) levels and lipoxygenases (LOX) activity. Viscera+belly flap was overall the most stable part, and also had the highest -tocopherol content. Pearson correlation analyses across all five fractions confirmed a significant impact of Hb, LOX and -tocopherol on the lipid oxidation susceptibility, while content of total iron, copper, lipids or PUFA provided no significant correlation. Overall, the study showed which pro-oxidants that should be inhibited or removed to succeed with value adding of herring filleting side streams along with the fillet itself.
6
Berton-Carabin, Claire. "Lipid oxidation in Pickering emulsions". In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/nfxb4600.
Abstract (sommario):
Pickering emulsions have garnered great interest in food science lately. These systems are characterized by the use of colloidal particles as physical stabilizers, that strongly anchor at the oil-water interface, instead of conventional emulsifiers. Many biobased particles have recently been identified as useful for this application, which holds potential for revolutionizing the field of food emulsion formulation [1,2]. However, although the potential in terms of physical stabilization of oil-in-water (O/W) emulsions has been thoroughly explored in the past years, how such emulsions may resist lipid oxidation, and whether particles could also be used to protect labile polyunsaturated lipids against oxidation is still questionable. This presentation aims at shedding light on this question by combining a review of the different types of food-compatible particles that have been recognized as useful to form Pickering emulsions, discussing examples of mitigation of lipid oxidation in such emulsions [3,4], and finally reflecting on the desired properties and possible targeted design of particles to achieve dual physical and oxidative stabilization of emulsions [5].[1] Berton-Carabin, C., & Schroën, K. (2015). Pickering emulsions for food applications: Background, trends and challenges. Ann. Rev. Food Sci. Technol., 6, 263–297.[2] Dickinson, E. (2020). Advances in food emulsions and foams: Reflections on research in the neo-Pickering era. Curr. Opin. Food Sci., 33, 52–60.[3] Schröder, A., Laguerre, M., Sprakel, J., Schroën, K., & Berton-Carabin, C. (2020). Pickering particles as interfacial reservoirs of antioxidants. J. Colloid Interface Sci., 575, 489–498.[4] Schröder, A., Laguerre, M., Tenon, M., Schroën, K., & Berton-Carabin, C. (2021). Natural particles can armor emulsions against lipid oxidation and coalescence. Food Chem., 347, 129003.[5] Berton-Carabin, C., Schröder, A., Schroën, K., & Laguerre, M. (2021). Lipid oxidation in Pickering emulsions. In Garcia-Moreno, P., Jacobsen, C., Sorensen, A. D., & Yesiltas, B. (Eds), Omega-3 Delivery Systems, Elsevier, Cambridge, MA., pp. 275-293.
7
Reed, Scott M., Min S. Wang e Erica L. Curello. "Electrophoretic Mobility of Lipid Coated Nanoparticles: Understanding the Influence of Size and Charge on a Lipoprotein Particle Mimic". In ASME 2011 International Mechanical Engineering Congress and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/imece2011-64158.
Abstract (sommario):
Elevated levels of low-density lipoprotein (LDL) are associated with increased risk of coronary heart disease (CHD). Although smaller LDL particles are more atherogenic, it is not clear how LDL particle size influences atherogenesis. Smaller particles may be more prone to macrophage uptake and plaque formation. Alternatively, increased rates of lipid oxidation may explain the atherogenic effects of smaller LDL. We have developed a mimic of LDL that allows independent examination of the effect of LDL size and oxidation. We have engineered LDL mimics using liposome-encapsulated gold nanoparticles, in which the size and surface charge are independently controlled during synthesis. Here we examine the effects of lipid composition on zeta potential and electrophoretic mobility of LDL mimics. Using these mimics, we explored the effect of the lipid coating on the nanoparticles including anionic lipids and oxidized lipids. Dynamic light scattering was used to determine the size of the mimics and gel electrophoresis was used to measure the mobility and calculate zeta potential. The charge of the lipid coating influenced the mobility and we anticipate this will influence how the mimics interacts with proteins.
8
Shumaev, Konstantin, Olga Kosmachevskaya, Dmitry Ivanovich Grachev, Alexey Topunov, Andrew Kimovich Martusevich e Enno Kustavich Ruuge. "АNTIOXIDANT AND ANTIRADICAL PROPERTIES DINITROSYL IRON COMPLEXES UNDER CONDITIONS SIMULATING OXIDATIVE STRESS". In NEW TECHNOLOGIES IN MEDICINE, BIOLOGY, PHARMACOLOGY AND ECOLOGY. Institute of information technology, 2021. http://dx.doi.org/10.47501/978-5-6044060-1-4.50.
Abstract (sommario):
We have demonstrated that dinitrosyl iron complexes (DNICs) eliminate free radicals formed during the interaction of hemoproteins with tert-butyl hydroperoxide, as well as during the co-oxidation of lipids and glucose. Thus, DNICs act as antioxidants under conditions simulating different types of oxidative stress.
9
Durand, Erwann, Nastassia Kaugarenia, Nathalie Barouh, Pierre Villeneuve e Romain Kapel. "Antioxidant chelating peptides production from Rapeseed meal proteins proteolysis." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/whcd7145.
Abstract (sommario):
The oxidative chemical degradation produced by reactive species (free radicals, oxygen, etc.) is responsible for the deterioration of most of the formulated products. One of the main properties of an antioxidant lies in its capacity to limit the chemical propagation of oxidation by reducing free radicals. Another strategy to prevent oxidation is binding transition metals, since they are ubiquitous and deeply involved in the initiation and propagation of lipids oxidation. Naturally occurring phospholipids, polyphenols, proteins, or peptides that can bind metal ions could be more valued than synthetic molecules, for human wellbeing, but also to align with consumer preferences. Yet, EDTA salts and sodium citrate remain the most common metal chelators in foods. In this study, we went to investigate a strategy to develop naturally produced antioxidants peptides from edible plant biomass, such as rapeseed. Several enzymatic hydrolyses of total rapeseed protein isolate with various proteases have been performed, and the produced peptides were screened for their antioxidant capacity. Peptides generated with Prolyve® allowed for particularly high Fe2+ chelation capacity (EC50 = 247 ± 27 µg). Accordingly, the enzymatic processing step with Prolyve® was modeled and optimized to minimize reaction costs and maximize peptide recovery. Then, lipid oxidation was studied in the presence or in the absence of chelating peptides, in micellar, bulk, and oil-in-water emulsion systems, and compared with EDTA salts and sodium citrate. Results clearly emphasized a very interesting potential from the peptides sample to prevent lipid oxidation by chelation of transition metals in emulsified models.This result is particularly important to develop the potential of applications of rapeseed meal in various food formulations. In addition, this study emphasized an approach aiming at developing food chelator peptides from plant proteins, having multifunctional properties, and through sustainable processing.
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Lazaridi, Eleni, e Boudewijn Hollebrands. "Selective ionization of oxidized versus non-oxidized lipid species using different solvent additives in direct infusion MS". In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/uvqo5522.
Abstract (sommario):
Lipid oxidation in food products is a crucial problem that causes undesirable changes in the food’s flavor, texture, nutritional value and consequently reduces shelf life. Even though lipid oxidation has been examined extensively and is rather well understood in bulk oils and fats, the processes behind it in more complex systems like emulsified foods are still largely unresolved. Oxidation reactions are believed to progress from the oil/water interface to the core of the oil droplets, making it important to understand the contribution of interfacial lipids (i.e. MAG, DAG and PL) to the lipid oxidation process. To study this, novel analytical tools are needed that allow the characterization of the highly complex mixture of oxidized species encountered in aged emulsified foods.In this study, a direct infusion mass spectrometry (MS) approach was set up to selectively ionize oxidized lipid species versus their non-oxidized precursors (DAG and TAG). Three mobile phase additives were investigated (NH4HCO2, C2H3NaO2 and NaI) at three different concentrations, and three ion source parameters (i.e. sheath gas temperature, nozzle and capillary voltage)were optimized. A fractional factorial design was conducted to examine not only the direct effect of the operating parameters on selective ionization of oxidized lipid species, but also assess their combined effect. A three level process was chosen to examine the effect of the selected parameters: (1) on the whole mass range of oxidized versus non oxidized lipid species, (2) on selected lipid species and their different oxidized forms, and (3) on the fragments of the lipid species investigated in the previous step. Selective ionization of oxidized versus non-oxidized lipid species was favored more by the use of sodium containing solvent additives. These findings will contribute to future studies on the influence of interfacial composition on lipid oxidation in complex emulsified food systems.
Rapporti di organizzazioni sul tema "Oxidation des lipides":
1
Kanner, Joseph, Mark Richards, Ron Kohen e Reed Jess. Improvement of quality and nutritional value of muscle foods. United States Department of Agriculture, dicembre 2008. http://dx.doi.org/10.32747/2008.7591735.bard.
Abstract (sommario):
Food is an essential to our existence but under certain conditions it could become the origin to the accumulative health damages. Technological processes as heating, chopping, mincing, grounding, promote the lipid oxidation process in muscle tissues and meat foodstuffs. Lipid oxidation occurred rapidly in turkey muscle, intermediate in duck, and slowest in chicken during frozen storage. Depletion of tocopherol during frozen storage was more rapid in turkey and duck compared to chicken. These processes developed from lipid peroxides produce many cytotoxic compounds including malondialdehyde (MDA). The muscle tissue is further oxidized in stomach conditions producing additional cytotoxic compounds. Oxidized lipids that are formed during digestion of a meal possess the potential to promote reactions that incur vascular diseases. A grape seed extract (1% of the meat weight) and butylated hydroxytoluene (0.2% of the lipid weight) were each effective at preventing formation of lipid oxidation products for 3 hours during co-incubation with cooked turkey meat in simulated gastric fluid (SGF). Polyphenols in the human diet, as an integral part of the meal prevent the generation and absorption of cytotoxic compounds and the destruction of essential nutrients, eg. antioxidants vitamins during the meal. Polyphenols act as antioxidants in the gastrointestinal tract; they scavenge free radicals and may interact with reactive carbonyls, enzymes and proteins. These all reactions results in decreasing the absorption of reactive carbonyls and possible other cytotoxic compounds into the plasma. Consumptions of diet high in fat and red meat are contributory risk factors partly due to an increase production of cytotoxic oxidized lipid products eg. MDA. However, the simultaneously consumption of polyphenols rich foods reduce these factors. Locating the biological site of action of polyphenols in the in the gastrointestinal tract may explain the paradox between the protective effect of a highly polyphenols rich diet and the low bioavailability of these molecules in human plasma. It may also explain the "French paradox" and the beneficial effect of Mediterranean and Japanese diets, in which food products with high antioxidants content such as polyphenols are consumed during the meal.
2
Wannasin, Donpon, Celina Fonseca e Eric Decker. Lipid oxidation in oil-in-water emulsions. AOCS, agosto 2022. http://dx.doi.org/10.21748/lox22.1.
3
Kanner, Joseph, Edwin Frankel, Stella Harel e Bruce German. Grapes, Wines and By-products as Potential Sources of Antioxidants. United States Department of Agriculture, gennaio 1995. http://dx.doi.org/10.32747/1995.7568767.bard.
Abstract (sommario):
Several grape varieties and red wines were found to contain large concentration of phenolic compounds which work as antioxidant in-vitro and in-vivo. Wastes from wine production contain antioxidants in large amounts, between 2-6% on dry material basis. Red wines but also white wines were found to prevent lipid peroxidation of turkey muscle tissues stored at 5oC. The antioxidant reaction of flavonoids found in red wines against lipid peroxidation were found to depend on the structure of the molecule. Red wine flavonoids containing an orthodihydroxy structure around the B ring were found highly active against LDL and membrane lipid peroxidation. The antioxidant activity of red wine polyphenols were also found to be dependent on the catalyzer used. In the presence of H2O2-activated myoglobin, the inhibition efficiency was malvidin 3-glucoside>catechin>malvidin>resveratol. However, in the presence of an iron redox cycle catalyzer, the order of effectiveness was resveratol>malvidin 3-glucoside = malvidin>catechin. Differences in protein binding were found to affect antioxidant activity in inhibiting LDL oxidation. A model protein such as BSA, was investigated on the antioxidant activity of phenolic compounds, grape extracts, and red wines in a lecithin-liposome model system. Ferulic acid followed by malvidin and rutin were the most efficient in inhibiting both lipid and protein oxidation. Catechin, a flavonal found in red-wines in relatively high concentration was found to inhibit myoglobin catalyzed linoleate membrane lipid peroxidation at a relatively very low concentration. This effect was studied by the determination of the by-products generated from linoleate during oxidation. The study showed that hydroperoxides are catalytically broken down, not to an alcohol but most probably to a non-radical adduct. The ability of wine-phenolics to reduce iron and from complexes with metals were also demonstrated. Low concentration of wine phenolics were found to inhibit lipoxygenase type II activity. An attempt to understand the bioavailability in humans of antocyanins from red wine showed that two antocyanins from red wine were found unchanged in human urine. Other antocyanins seems to undergo molecular modification. In hypercholesterolemic hamsters, aortic lipid deposition was significantly less in animals fed diets supplemented with either catechin or vitamin E. The rate of LDL accumulation in the carotid arteries was also significantly lower in the catechin and vitamin E animal groups. These results suggested a novel mechanism by which wine phenolics are associated with decreased risk of coronary heart diseases. This study proves in part our hypothesis that the "French Paradox" could be explained by the action of the antioxidant effects of phenolic compounds found at high concentration in red wines. The results of this study argue that it is in the interest of public health to increase the consumption of dietary plant falvonoids. Our results and these from others, show that the consumption of red wine or plant derived polyphenolics can change the antioxidant tone of animal and human plasma and its isolated components towards oxidative reactions. However, we need more research to better understand bioavailability and the mechanism of how polyphenolics affect health and disease.
4
Handa, Avtar K., Yuval Eshdat, Avichai Perl, Bruce A. Watkins, Doron Holland e David Levy. Enhancing Quality Attributes of Potato and Tomato by Modifying and Controlling their Oxidative Stress Outcome. United States Department of Agriculture, maggio 2004. http://dx.doi.org/10.32747/2004.7586532.bard.
Abstract (sommario):
General The final goal and overall objective of the current research has been to modify lipid hydroperoxidation in order to create desirable phenotypes in two important crops, potato and tomato, which normally are exposed to abiotic stress associated with such oxidation. The specific original objectives were: (i) the roles of lipoxygenase (LOX) and phospholipids hydroperoxide glutathione peroxidase (PHGPx) in regulating endogenous levels of lipid peroxidation in plant tissues; (ii) the effect of modified lipid peroxidation on fruit ripening, tuber quality, crop productivity and abiotic stress tolerance; (iii) the effect of simultaneous reduction of LOX and increase of PHGPx activities on fruit ripening and tuber quality; and (iv) the role of lipid peroxidation on expression of specific genes. We proposed to accomplish the research goal by genetic engineering of the metabolic activities of LOX and PHGPx using regulatable and tissue specific promoters, and study of the relationships between these two consecutive enzymes in the metabolism and catabolism of phospholipids hydroperoxides. USA Significant progress was made in accomplishing all objectives of proposed research. Due to inability to regenerate tomato plants after transforming with 35S-PHGPx chimeric gene construct, the role of low catalase induced oxidative stress instead of PHGPx was evaluated on agronomical performance of tomato plant and fruit quality attributes. Effects of polyamine, that protects DNA from oxidative stress, were also evaluated. The transgenic plants under expressing lipoxygenase (LOX-sup) were crossed with catalase antisense (CAT-anti) plants or polyamine over producing plants (SAM-over) and the lines homozygous for the two transgenes were selected. Agronomical performance of these line showed that low catalase induced oxidative stress negatively affected growth and development of tomato plants and resulted in a massive change in fruit gene expression. These effects of low catalase activity induced oxidative stress, including the massive shift in gene expression, were greatly overcome by the low lipoxygenase activity. Collectively results show that oxidative stress plays significant role in plant growth including the fruit growth. These results also for the first time indicated that a crosstalk between oxidative stress and lipoxygenase regulated processes determine the outcome during plant growth and development. Israel Regarding PHGPx, most of the study has concentrated on the first and the last specific objectives, since it became evident that plant transformation with this gene is not obvious. Following inability to achieve efficient transformation of potato and tomato using a variety of promoters, model plant systems (tobacco and potato cell cultures, tobacco calli and plantlets, and Arabidopsis) were used to establish the factors and to study the obstacles which prohibited the regeneration of plants carrying the genetic machinery for overproduction of PHGPx. Our results clearly demonstrate that while genetic transformation and over-expression of PHGPx occurs in pre-developmental tissue stage (cell culture, calli clusters) or in completed plant (Arabidopsis), it is likely that over-expression of this enzyme before tissue differentiation is leading to a halt of the regeneration process. To support this assumption, experiments, in which genetic engineering of a point-mutated PHGPx gene enable transformation and over-expression in plants of PhSPY modified in its catalytic site and thus inactive enzymatically, were successfully carried out. These combined results strongly suggest, that if in fact, like in animals and as we established in vitro, the plant PHGPx exhibits PH peroxidase activity, these peroxides are vital for the organisms developmental process.
5
Min, Byubgrok, Kichang Nam e Dong U. Ahn. Catalytic Mechanisms of Metmyoglobin on the Oxidation of Lipids in Liposome Model System. Ames (Iowa): Iowa State University, gennaio 2012. http://dx.doi.org/10.31274/ans_air-180814-1045.
6
Kanner, Joseph, e Herbert Hultin. Mechanisms and Prevention of Lipid Oxidation in Muscle Foods. United States Department of Agriculture, agosto 1986. http://dx.doi.org/10.32747/1986.7593409.bard.
7
Xiao, Shan, Wan Gang Zhang, Eun Joo Lee e Dong U. Ahn. Lipid and Protein Oxidation of Chicken Breast Rolls as Affected by Dietary Oxidation Levels and Packaging. Ames (Iowa): Iowa State University, gennaio 2013. http://dx.doi.org/10.31274/ans_air-180814-631.
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Xiao, Shan, Wan Gang Zhang, Eun Joo Lee e Dong U. Ahn. Effects of Diet, Packaging and Irradiation on Protein Oxidation, Lipid Oxidation of Raw Broiler Thigh Meat. Ames (Iowa): Iowa State University, gennaio 2013. http://dx.doi.org/10.31274/ans_air-180814-728.
9
Bramlage, William, Nehemia Aharoni, Wassef W. Nawar, Joseph Kanner, Shimon Meir e Sonia Philosoph-Hadas. Control of Lipid Oxidation to Retard Senescence of Plant Tissue. United States Department of Agriculture, maggio 1994. http://dx.doi.org/10.32747/1994.7603823.bard.
10
Kanner, Joseph, Dennis Miller, Ido Bartov, John Kinsella e Stella Harel. The Effect of Dietary Iron Level on Lipid Peroxidation of Muscle Food. United States Department of Agriculture, gennaio 1995. http://dx.doi.org/10.32747/1995.7604282.bard.
Abstract (sommario):
Biological oxidations are almost exclusively metal ion-promoted reactions and in ths respect iron, being the most abundant, is the commonly involved. The effect of dietary iron levels on pork, turkey and chick muscle lipid peroxidation and various other related compounds were evaluated. Crossbred feeder pigs were fed to market weight on corn-soy rations containing either 62, 131 or 209 ppm iron. After slaughter, the muscles were dissected, cooked and stored at 4°C. Heavily fortifying swine rations with iron (>200 ppm) increase nn-heme iron (NHI), thiobarbituric acid reactive substances (TBARS), and decrease a-tocopherol in cooked stored pork but did not increase warmed-over aroma (WOA). NHI and TBARS were higher in cooked pork from pigs fed high-iron diets. Liver iron correlated with muscle iron. TBARS were strongly related with WOA. The role of dietary vitamin E and ascorbic acid on Fe-induced in vivo lipid peroxidation in swine was also evaluated. Moderate elevation in iron stores had a marked effect on oxidative stress, especially as indicated by liver TBARS. Supplemental vitamin E, and to a lesser extent vitamin C, protect against this oxidative stress. Unsupplementation of Fe in the regular diet of turkeys did not affect body weight, blood hemoglobin level, or iron pool in the liver or muscle. The reason being that it contained "natural" ~120 mg Fe/kg feed, and this amount is high enough to keep constant the pool of iron in the body, liver or muscle tissues. Only Fe-supplementation with high amounts of Fe (500 ppm) significantly increased turkey blood hemoglobin and total iron in the liver, in 1 out of 3 experiments, but only slightly affects iron pool in the muscles. It seems that the liver accumulates very high concentations of iron and significantly regulates iron concentration in skeletal muscles. For this reason, it was very difficult to decrease muscle stability in turkeys through a diet containing high levels of Fe-supplementation. It was shown that the significant increase in the amount of iron (total and "free") in the muscle by injections with Fe-dextran accelerated its lipid peroxidation rate and decreased its a-tocopherol concentration. The level and metabolism of iron in the muscles affects the intensity of in vivo lipid peroxidation. This process was found to ifluence the turnover and accumulation of a-tocopherol in turkey and chick muscles. Treatments which could significantly decrease the amount and metabolism of iron pool in muscle tissues (or other organs) may affect the rate of lipid peroxidation and the turnover of a-tocopherol. Several defense enzymes were determined and found in the turkey muscle, such as superoxide dismutase, catalase, and glutathione peroxidase. Glutathione peroxidase was more active in muscles with a high trend of lipid peroxidation, lmore so in drumsticks than in breast muscles, or muscles with a low a-tocopherol content. The activity of glutathione peroxidase increased several fold in muscle stored at 4°C. Our work demonstrated that it will be much more practical to increase the stability of muscle tissues in swine, turkeys and chickens during storage and processing by increasing the amount of vitamin E in the diet than by withdrawing iron supplementation.