The potential for enhancing oleic acid (cis-18:1) and linoleic acid (18:2) content and lowering medium chain fatty acid (MCFA) content of bovine milk was investigated by abomasal infusion or dietary supplementation of oils. In experiment 1, olive oil, sesame oil, sunflower oil, or fish oil was abomasally infused (155 to 219 g/d) into Jersey cows during the last 6 d of each of four 14-d periods. In experiment 2, canola oil, olive oil, high-oleic sunflower oil, or distilled water (control) was abomasally infused (342 to 371 g/d) into three Holsteins and three Jerseys during the last 5 d of each of four 10-d periods. The intestinal digestibility and concentration of cis-18:1 and 18:2 in milk were proportional to flow of these fatty acids to the duodenum. Also, greater concentration of cis-18:1 in milk was associated with lowered yield of MCFA. During olive oil or sesame oil infusion in experiment 1, for each 100 g of cis-18:1 infused into the abomasum, milk cis-18:1 yield was increased by an average of 47 g, and MCFA yield was reduced by 42 g. The yield of 18:2 in milk was increased by approximately 46 g for each 100 g of infused 18:2 during olive oil or sesame oil infusion. Milk produced during sesame oil infusion, however, had an off-flavor when evaluated by a taste panel. In experiment 2, each 100 g of cis-18:1 infused daily increased milk cis-18:1 yield in Holsteins and Jerseys by 41 and 39 g/d, respectively, whereas recovery of infused 18:2 was 34 g/d for Jerseys and 42 g/d for Holsteins. In experiment 3, 22 Jersey cows were fed a basal diet, or the basal diet supplemented with 3.5% high-oleic canola oil, 3.5% soybean oil, or 1.75% high-oleic canola oil plus 1.75% soybean oil for 5 wk. Dietary canola oil supplementation increased conjugated linoleic acid (CLA) percentage in milk to a moderate level without raising trans-18:1 percentage, whereas feeding either supplement containing soybean oil raised both CLA and trans-18:1 percentages. Concentrations of trans-18:1 and CLA in milk apparently reflected the extent of unsaturated fatty acid biohydrogenation in the rumen. Dietary supplementation with canola oil increased yield of cis-18:1 in milk by 21 g for each 100 g of supplemental cis-18:1 intake. Yield of 18:2 in milk was raised by 3 g for each 100 g of supplemental 18:2 intake by cows fed soybean oil. Using abomasal infusion as an indicator of the maximum potential for apparent recovery of cis-18:1 in milk (39 to 49%), cis-18:1 recovery in response to supplemental cis-18:1 in the diet was approximately half of the potential response due to partial biohydrogenation in the rumen. The apparent recovery of dietary 18:2 in milk was reduced to only one-tenth of the potential yield (31 to 47%) indicated by abomasal infusion of seed oils. Results indicated that the fatty acid profile of bovine milk was altered in a manner that would be beneficial to human health when cows were fed supplemental oleic acid, but further research should focus on safe and economical methods to protect dietary unsaturated fatty acids from biohydrogenation. / Ph. D.

The investigation focussed on the effects of oleic acid esters on the microencapsulation characteristics of the poly( ortho esters) polymer and their role as potential latentiated acid catalysts for the hydrolysis of the polymer backbone thereby influencing release of 5-fluorouracil. Four oleic acid esters, viz., ethyl oleate, propyl oleate, butyl oleate and lauryl oleate were studied. The microspheres were prepared by the emulsion solvent evaporation technique using sorbitan sesquioleate (6.44%w/w) as the surfactant. The microspheres were prepared with a theoretical drug loading of between 13 and 14% by weight and ester loading of 2.46% by weight with respect to the non-volatile components of the system. All the oleic acid esters (2.46% by weight) were found to retard the release of 5-fluorouracil from the microspheres. The maximum control over drug release was offered by ethyl oleate. Ethyl oleate was also found to give the highest percent entrapment of the drug in the microspheres. The release of 5-FU from the microspheres was inversely related to the concentration of ethyl oleate over the concentration range of 0.72% to 2.46% by weight. Gel permeation chromatography, scanning electron microscopy and the in vitro release data suggested that release of 5-FU from the microspheres occurred by a combination of diffusion and polymer erosion. The polymer erosion was further complicated by the by products of ester hydrolysis. Steady state drug release after the lag phase was zero-order. This suggested that polymer degradation in the steady state region erosion process initiated by oleic acid produced as a result of hydrolysis of the oleic acid ester during the release process.

Vegetable oil is an important commodity; however, the majority of commercially available vegetable oils have a fairly short shelf life, which limits their usefulness for long term food storage, disaster relief, space travel, food aid programs, and military rations. Vegetable oils with high oleic acid and reduced linolenic acid contents, especially with added antioxidant combinations, were previously found to have significantly longer oil stability index (OSI) values than traditional vegetable oils. This study used accelerated shelf life testing to estimate the ambient shelf life of high oleic sunflower oil (HOSUN) and high oleic canola oil (HOCAN), each containing 1,000 ppm ascorbyl palmitate, 200 ppm tertiary butyl hydroquinone, and 200 ppm mixed tocopherols. Oils were stored in the dark in low density polyethylene (LDPE), or polyethylene terephthalate (PET) bottles at 30, 40, 50, and 60°C. Control samples were stored in the dark in glass bottles at -50°C. Testing included peroxide values, qualitative headspace volatile analysis, descriptive sensory analysis, and consumer sensory acceptance. The estimated shelf life was calculated from the change in overall acceptance score over time using the Q10 method. The stabilized HOCAN in PET bottles was estimated to have a shelf life at ambient temperature of 6.8 years, while oil stored in LDPE bottles had an estimated shelf life of only 2.7 years. The estimated shelf life of HOSUN at room temperature in PET is 2.6 years and in LDPE is 0.88 years.

No description available.

Milk fat composition determines specific rheological, sensory and physicochemical properties of dairy products such as texture, melting point, flavor, color, oxidation rates, and viscosity. Previous studies have shown that milkfats containing higher levels of long chain polyunsaturated fatty acids have lower melting points and decreased solid fat contents which leads to softer-textured products. An increased risk of higher oxidation rates can be a disadvantage of high levels of polyunsaturated fatty acids. Three different milkfat compositions were obtained through dietary manipulation of cows: high oleic content, high linoleic content and control milkfat. Ice cream and butter were processed from the treated and control milks. Butter and ice cream samples then were analyzed to measure differences in fatty acid profiles and firmness. High-oleic and high-linoleic milkfat had lower concentrations of saturated fatty acids, such as C 16:0. Conjugated linoleic acid content was increased in the high-linoleic milkfat. High-oleic milkfat resulted in a softer butter. Ice cream samples were analyzed to measure differences in viscosity, melting point, oxidation rate and sensory perception. Significant differences (P<0.05) were found in the fatty acid profiles of milkfat, ice cream mix viscosity, peroxide values of ice cream after 3 to 5 months of storage, butter color, and butter firmness. Sensory analyses included a scooping test at -18°C to detect differences in texture. A difference test was conducted to determine oxidation flavor differences between the three ice cream treatments at extended storage times. No significant differences were found in the scooping test or the oxidation flavor difference. Manipulation of the cow's diet increased the total amount of unsaturated fatty acids. It also influenced firmness of butter and behavior of peroxide values during extended storage of high-linoleic ice cream. / Master of Science

Titanium dioxide (TiO2) polymer nanocomposites improve barrier properties to gas and moisture and mechanical strength as well as providing active packaging functions. However, low compatibility between hydrophilic TiO2 nanoparticles and hydrophobic polymers such as polylactic acid (PLA) causes problems due to the tendency of TiO2 nanoparticles (TiO2) to agglomerate and form large clusters. A surface modification of TiO2 with long chain fatty acid may improve the compatibility between PLA and TiO2. The goal of this study was to enhance barrier properties of oxygen and water vapor, mechanical strength and add light protecting function to PLA composites by incorporation of oleic acid modified TiO2 nanoparticles (OA_TiO2). The objectives of this study were: 1) synthesize TiO2 and modify surface of TiO2 with oleic acid, 2) investigate dispersion stability of TiO2 and OA_TiO2 in hydrophobic media, 3) incorporate TiO2 and OA_TiO2 into a PLA matrix and to characterize properties of TiO2PLA (T-PLA) and OA_TiO2 PLA nanocomposite films (OT-PLA), and 4) to determine stability of green tea infusion in T-PLA and OT-PLA packaging model systems during refrigerated storage at 4 °C under florescent lightening. TiO2 was synthesized by using a sol-gel method and the surface of TiO2 was modified by oleic acid using a one-step method. T-PLA and OT-PLA were prepared by solvent casting. TiO2 and OA_TiO2 were analyzed by X-ray diffraction, Fourier transform infrared spectroscopy, thermal analysis and dynamic light scattering. The barrier properties to oxygen and water vapor, morphology, mechanical properties, thermal stability and light absorption properties of T-PLA and OT-PLA were characterized. Dispersion of TiO2 was improved in PLA matrix by the surface modification method with oleic acid. OT-PLA had more effective improvements in the barrier properties and flexibility than T-PLA and PLA, but toughness of the films based on Young's modules of OT-PLA was lower than the T-PLA and the PLA. The OT-PLA may have a potential to be used as transparent, functional and sustainable packaging films, but limited use for complete visible and UV-light protection for photosensitized foods. / Ph. D.

No description available.

Thesis (MSc)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Background:Obesity is a growing global burden; current studies have projected the prevalence of obese / overweight individuals to increase to ~1.35 billion by 2030. A number of factors contribute to cardiovascular diseases, of which the focus of this study is what effect an increased level of free fatty acids has on the flux through the hexosamine biosynthetic pathway (HBP). It has been widely proven that an increased flux through the HBP causes an increase in protein O-GlcNAcylation, which leads to increased reactive oxygen species (ROS) production as well as an increase in cell death (apoptosis). Methods: For the purpose of this study a cell model was used. H9c2 cardiomyoblasts were cultured in 5ml Dulbecco‟s Modified Eagles Medium (DMEM) supplemented with 10% foetal bovine serum and 1% penicillin-streptomycin. The cells were then exposed to 0.25mM monounsaturated fatty acid (oleic acid) for 24, 48 and 72 hours respectively. The cultured cells were then evaluated to assess the degree ROS production, overall O-GlcNAcylation and cell death (apoptosis and necrosis), using flow cytometry and immunofluorescence microscopy. Results: We found that oleic acid causes a significant decrease in ROS production at the 48 hour time point when analysed on the flow cytometer, which indicates that oleic acid is metabolized by the cells in a independent manner. Oleic acid also caused a significant decrease in cell death at all the time intervals. With regard to the HBP, oleic acid activates this pathway but causes downstream cardioprotective effects that do not necessarily occur along this pathway. Conclusion: This study explored whether a monounsaturated fatty acid, oleic acid, is able to act as a novel cardioprotective agent. The in vitro data supports this concept and we showed that it is able to blunt oxidative stress and cell death. It was also found that although oleic acid activated the HBP, it did not mediate its protective effects via this pathway only. / AFRIKAANSE OPSOMMING: Agtergrond: Vetsug is 'n groeiende wêreldlas; huidige studies voorspel dat die voorkoms van vetsugtige / oorgewig individue toe sal neem tot ~1.35 biljoen teen 2030. Alhoewel verskeie faktore tot kardiovaskulêre siektes bydra is die fokus van hierdie studie om die effek van verhoogde vryvetsuurvlakke op die fluks deur die heksosamienbiosintestiese weg (HBW) te ondersoek. Dit is reeds bewys dat verhoogde fluks deur die HBW 'n verhoging in proteïen O-GlcNAsilering lei, wat verder tot verhoogde reaktiewe suusrtofspesies (ROS) vorming aanleiding gee en ook seldood (apoptose) verhoog. Metodes:'n Selmodel is vir die doel van hierdie studie gebruik. H9c2 kardiomioblaste is in 5ml Dulbecco's Modified Eagles Medium (DMEM) gekweek en gesupplementeer met 10% fetale beesserum en 1% penisillien-streptomysien. Die selle is blootgestel aan 'n 0.25mM mono onversadigde vetsuur (oleïensuur ) vir 24, 48 en 72 uur onderskeidelik. Die gekweekte selle is gevolglik ondersoek vir die graad van ROS ontwikkeling, algehele O-GlcNAsilering en seldood (apoptosis en nekrose), deur van vloeisitometrie en immunofluoresensie mikroskopie gebruik te maak. Resultate: Ons het bevind dat oleïensuur 'n betekenisvolle verlaging in ROS ontwikkeling teen 48 uur soos bepaal deur die vloeisitometer, veroorsaak. Dit wys daarop dat oleïensuur deur die selle op 'n onafhanklike wyse gemetaboliseer is. Oleïensuur het ook 'n betekenisvolle verlaging in seldood by alle tydsintervalle veroorsaak. Met betrekking tot die HBW het oleïensuur hierdie weg geaktiveer maar afstroom kardiobeskermings effekte versoorsaak wat nie noodwendig langs hierdie weg onstaan nie. Gevolgtrekking:Hierdie studie het die moontlikheid van 'n mono-onversadige vetsuur, oleïensuur, om op te tree as 'n nuwe kardiobeskermingsmiddel ondersoek. Die in vitro data ondersteun hierdie konsep en hier is aangetoon dat dit wel oksidatiewe stres en seldood onderdruk. Daar is verder bevind dat alhoewel oleïensuur die HBW aktiveer dit nie die beskermings effekte alleenlik via hierdie weg medieer nie.

O fluido multifásico complexo (suco de açaí) tem uma forte interação com membranas poliméricas ou cerâmicas de microfiltração e a formação de incrustação depende da composição e das condições de dinâmica de fluidos. Neste estudo experimental foi investigada a influência dos dois principais ácidos graxos presentes no açaí, ácido oleico e ácido palmítico, em misturas com água e no processo de microfiltração tangencial com membranas cerâmicas de alumina com um tamanho de poro nominal de 0,2 \'mü\'m. Mediu-se o fluxo de permeado em função do tempo, nas pressões transmembranas de 300 kPa, 400 kPa e 500 kPa. Para o fluxo da corrente de alimentação foram encontrados valores de Reynolds numa faixa de 9500 a 31000. Cada amostra de misturas de água/ácido oleico, água/ácido palmítico e água/ácidos oleico e palmítico, foi estudada em três séries de ensaios realizados durante 180 minutos e 72 minutos para a mistura água/ácido palmítico, a temperatura em 25 ºC. Analisou-se as incrustações resultantes e as fortes interações fluido/membrana utilizando o modelo de resistência em série e imagens tomadas por microscopia eletrônica de varredura (MEV). Os melhores resultados de permeado encontrados para a mistura de água/ácido oleico foram para Re = 33000, no entanto, resultados satisfatórios foram encontrados para Re = 20000. Agora para a água/ácido palmítico foram encontrados para Re = 20000. Os melhores resultados de permeado para a mistura água/ácidos oleico e palmítico foram para Re = 31000. De acordo com os resultados das resistências, a mistura água/ácido causa um bloqueio dos poros da membrana, resultando em uma maior diminuição do fluxo transmembrana. A limpeza foi eficiente para reduzir a resistência associada com a polarização. / The complex fluid multiphase (açaí juice) has a strong interaction with polymeric or ceramic membranes for microfiltration fouling and its formation depends on the fluid composition and fluid dynamics conditions. In this experimental study was investigated the influence of two major fatty acids present in açaí, oleic acid and palmitic acid in mixtures with water and in the process of crossflow microfiltration with ceramic membranes. In the separation process is used alumina ceramic membrane with a nominal pore size of 0.2 micrometers. The permeate flux was measured in function of time using the 300 kPa, 400 kPa and 500 kPa for the transmembrane pressure. The flow of feed stream and its respective value of Reynolds were in range of: 8900-3300. For each sample of mixtures oleic acid/water and palmitic acid/water and palmitic acid, oleic acid/ water, three series of experiments were conducted for 180 minutes and 72 minutes for mixture palmitic acid/water at temperature in 25 Celcius. For analyze of fouling resulting from strong interactions fluid/membrane was used the model of resistance in series and images taken via scanning electron microscopy (SEM). The best results for mixing oleic acid/water were to Re = 33000, however, satisfactory results were found for Re = 20000. Now for the palmitic acid/water were found to Re = 20000. For mixture palmitic acid, oleic acid/ water were found to Re = 31000. According to the results of the resistances, the mixture oleic acid/water cause a blockage of the pores of the membrane resulting in a greater decrease of the transmembrane flow. The cleaning is efficient for reducing the resistance associated with the polarization.

INTRODUÇÃO. O termo Lesão Pulmonar Aguda (LPA) é usado para descrever a resposta pulmonar à lesão que ocorre diretamente ou indiretamente nos pulmões. A quebra da barreira alvéolo-capilar determina o influxo de líquido rico em proteínas para dentro dos espaços alveolares, sendo necessária a reabsorção desse líquido no processo de resolução da LPA. A infusão intravenosa de Ácido Oleico (AO) em ratos provoca agudamente edema alveolar difuso e focos hemorrágicos intra-alveolares, sendo um bom modelo de indução. Estudos relatam que o Azul de Metileno (AM) atenua tais lesões, com efeito protetor, no tecido pulmonar, e reduz o edema presente na LPA em animais com sepse através da inibição da guanilato ciclase solúvel (GCs), uma enzima ativadora da via NO-GMPc. OBJETIVO. Estudar a repercussão da inibição da GCs pelo AM na permeabilidade capilar pulmonar ministrando-o antes e após a indução da lesão pulmonar por AO. MÉTODO. Ratos Wistar foram divididos em 5 grupos: Sham com infusão de salina em bolus; AM com infusão de AM por 2h; AO com infusão de AO em bolus, AM/AO com infusão de AM por 2h, sendo que, após 5 min do início, recebeu AO simultaneamente em bolus e AO/AM com infusão de AO em bolus e, após 2h, infusão de AM por mais 2h. Após 4h foi realizada a coleta de materiais (sangue, lavado bronco-alveolar e tecido pulmonar) para análise do NO plasmático e tecidual, gasometria arterial, cálculo do peso úmido/peso seco (PU/PS) e histologia do tecido pulmonar de todos os grupos. A estatística utilizada foi a análise de variância (one-way ANOVA) com p<0.05. RESULTADO. Não foi encontrado hipoxemia grave após 4h de lesão. O grupo AO apresenta um aumento no número de proteínas no lavado bronco-alveolar e na relação PU/PS comparado aos grupos controle: Sham e AM, confirmando a presença de lesão e alteração de permeabilidade pulmonar. Os grupos tratados com AM apresentaram melhora na permeabilidade pulmonar, porém, apenas o grupo pré-tratamento (AM/AO) apresentou diferença estatística na redução do extravasamento de proteínas no lavado. Não foram encontradas diferenças significativas no NO plasmático e tecidual. Na microscopia, a congestão capilar foi intensa, acompanhada de múltiplos focos de edema alveolar, exsudato intra-alveolar proteico, áreas de hemorragia e infiltrado inflamatório neutrofílico, tanto no interstício quanto nos septos alveolares.Os grupos tratados com AM apresentaram diminuição das áreas de edema, exsudação e hemorragia, porém, com maior evidência no grupo AM/AO. CONCLUSÃO. O AM diminui a permeabilidade pulmonar quando administrado de maneira precoce amenizando os danos causados pela LPA induzida por AO. / BACKGROUND. The term Acute Lung Injury (ALI) is used to describe the response to lung injury that occurs directly or indirectly in the lungs. The rupture of the alveolar - capillary barrier determines the influx of protein-rich fluid into the alveolar spaces, the reabsorption of this fluid in the process of resolving the ALI is required. Intravenous infusion of oleic acid (OA) in rats acutely causes diffuse alveolar edema and intra-alveolar hemorrhagic foci, being a good role model induction. Studies have reported that Methylene Blue (MB) attenuates such injuries, with a protective effect in lung tissue and reduce edema present in the ALI present in with sepsis by inhibition of soluble guanylate cyclase (sGC), an activator of the enzyme NO- cGMP pathway. OBJECTIVE. To study the effect of inhibition of sGC by MB in pulmonary capillary permeability ministering to the before and after induction of lung injury by OA. METHOD. Wistar rats were divided into 5 groups: Sham infused with saline bolus, MB infused with MB for 2hrs, OA infused with OA bolus, MB/OA infused with MB for 2hrs, and after 5 min from the beginning, simultaneously received OA bolus and OA/MB infused with OA bolus and after 2hrs, MB infusion for 2hrs. After 4hrs the collection of materials was performed (blood, bronchoalveolar lavage and lung tissue) for analysis of plasma and tissue NO, arterial blood gases, calculation of the wet weight/dry weight (WW/DW) and histology of lung tissue from all groups. The statistic used was analysis of variance (one-way ANOVA) with p<0.05. RESULTS. Not found severe hypoxemia after 4hrs of injury. The OA group shows an increase in the number of proteins in bronchoalveolar lavage and in WW/DW ratio compared to the control groups: Sham and MB, confirming the presence of injury and alterations of lung permeability. The groups treated with MB showed improvement in lung permeability, however, only the pretreatment group (MB/OA) showed statistical significance in reducing the leakage of protein in the lavage. No significant differences were found in plasma and tissue NO. In microscopy, capillary congestion was intense, accompanied by multiple foci of alveolar edema, intra-alveolar proteinaceous exudates, areas of hemorrhage and neutrophilic inflammatory infiltrate in both the interstitium and in the alveolar septa. The groups treated with MB showed reduction in areas of edema, exudation and hemorrhage, however, most obviously in MB/OA group. CONCLUSION. The MB decreases lung permeability when administered as early as possible, mitigating the damage caused by OA-induced ALI.