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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Uticaj ekstrudiranja na promene odabranih fizičko-hemijskih svojstava soje

Kukić Predrag 02 February 2018 (has links)
<p>Cilj istraživanja je da se utvrde promene hemijskog sastava proizvoda na izlazu iz ekstrudera i prese (sojine pogače i ulja), tj. njihovog kvaliteta sa aspekta njihove dalje primene u proizvodnji stočne hrane, primene u prehrambenoj industriji ili daljoj primeni sojinog ulja u proizvodnji biodizela, a sve u funkcionalnoj zavisnosti od promenljivih karakteristika ulazne sirovine i parametara rada ekstrudera. Ekstrudiranje sojinog zrna vr&scaron;ilo se na ekstruderu tip E751, proizvođača &bdquo;SREM PRODUKT&ldquo; DOO iz Laćarka, a presovanje na presi tip PM-5S proizvođača &bdquo;BRONTO&ldquo; iz Ukrajine. Istraživanja koja su sprovedena u ovoj doktorskoj disertaciji rađena su kao doprinos pro&scaron;irenju znanja vezanih za proces proizvodnje sojine pogače i sojinog ulja, a pored toga&nbsp; kako bi dobili praktične smernice za optimalnu kontrolu i modelovanje procesa estruzije i ceđenja soje kao i projektovanja ekstrudera. U cilju dobijanja i analiziranja podataka koji bi mogli da utvrde promene hemijskog sastava proizvoda na izlazu iz ekstrudera i prese (sojine pogače i ulja), tj. njihovog kvaliteta sa aspekta njihove dalje primene u proizvodnji stočne hrane, primene u prehrambenoj industriji ili daljoj primeni sojinog ulja u proizvodnji biodizela, a sve u funkcionalnoj zavisnosti od promenljivih karakteristika ulazne sirovine i parametara rada ekstrudera, sprovedena su eksperimentalna i laboratorijska ispitivanja. Eksperimentalna istraživanja su namenjena praktičnoj primeni kojom bi se proces proizvodnje sojine pogače i sojinog ulja mogao usavr&scaron;iti i optimatizovati. Rezultati koji su dobijeni ovim istraživanjima mogu biti korisni svima koji se bave proizvodnjom sojine pogače i sojinog ulja. Eksperimentalna istraživanja obavljana su na ekstruderu tip E-751 i presi tip PM-5S, ali su rezultati primenjivi i na drugim ekstruderima i presama drugih proizvođača koji koriste soju kao sirovinu i proizvode&nbsp; sojinu pogaču i sojino ulje. Na osnovu izvr&scaron;enih istraživanja, obrađenih i prodis<br />___________________Doktorska disertacija,&nbsp; autor:Kukić Predrag_____________________<br /><br /><br />_______________________________________________________________IV od 34<br />kutovanih rezultata do&scaron;lo se do funkcionalnih zavisnosti između pojedinih parametara ekstruzije i od promenljivih karakteristika ulazne sirovine sa jedne strane i karakteristika ekstrudata i sojinog ulja sa druge strane i na osnovu toga do&scaron;lo se do određenih zaključaka. Na osnovu eksperimentralnih ispitivanja ocenjen je uticaj promene odabranih fizičkohemijskih svojstava soje pri ekstrudiranju zrna soje. U disertaciji se krenulo od analize polazne sirovine tj. soje i njenog sadržaja proteina, ulja, slobodnih masnih kiselina i vlage, a zatim variranjem režima rada ekstrudera tj. doziranja ulaznog materijala praćeno preko opterćenja pogonskog elektromotora ekstrudera izraženog preko jačine struje [A], povr&scaron;ine otvora mlaznice i vlažnosti soje, praćen je sadržaj slobodnih masnih kiselina, fosfora i vlage u sojinom ulju posle presovanja ekstrudata, kao i sadržaj proteina, vlage, ulja, aktivnost ureaze i PDI u sojinoj pogači. Na osnovu sprovedenih istraživanja do&scaron;lo se do funkcionalnih zavisnosti između zadatih režima rada ekstrudera, ulazne sirovine i odabranih fizičko-hemijskih svojstava soje pri ekstrudiranju zrna soje. Tako da se sa porastom povr&scaron;ine otvora mlaznice i doziranja mase povećava se produkcija sojine pogače. Produkcija sojine pogače se povećava i kada se vlažnost ulazne sirovine povećava. Sa povećanjem vlažnosti ulazne sirovine i interakcije doziranja mase i povr&scaron;ine otvora mlaznice sadržaj vlage u sojinoj pogači se povećava. Na osnovu izvedenih istraživanja može se tđ. zaključiti da sa povećanjem povr&scaron;ine otvora mlaznice ekstrudera raste sadržaj ulja u sojinoj pogači za svaku od tri vlažnosti soje kao ulazne sirovine, dok sa povećanjem doziranja ulazne sirovine smanjuje se sadržaj&nbsp; ulja u sojinoj pogači za svaku od tri mlaznice. Povećanjem povr&scaron;ine otvora mlaznice ekstrudera, dolazi do smanjenja sadržaja proteina u sojinoj pogači, dok je obrnuto kod povećanja doziranja ulazne sirovine, tj. sa povećanjem doziranja sirovine u ekstruder povećava se sadržaj proteina u sojinoj pogači. Pozitivan efekat aktivnosti ureaze (∆pH) u<br />___________________Doktorska disertacija,&nbsp; autor:Kukić Predrag_____________________<br /><br /><br />_______________________________________________________________V od 34<br />sojinoj pogači je za veće vrednosti kako povr&scaron;ine otvora mlaznice, tako i interakcije promenljivih W (vlažnosti soje) i D (doziranje mase soje određeno preko opterećenja elektromotora). U sojinoj pogači PDI se povećava sa povećanjem vlažnosti ulazne sirovine, povr&scaron;ine otvora mlaznice ekstrudera i doziranja zrna soje kao ulazne sirovine. Razmatrajući dobijene podatke za sojino ulje dobijeno ceđenjem produkta ekstruzije dobijenog ekstruzijom soje sa predviđenim vlažnostima ulazne sirovine do&scaron;lo se do zaključka da se produkcija ulja smanjuje sa povećanjem povr&scaron;ine otvora mlaznice ekstrudera, a da pri povećanju doziranja ulazne sirovine povećava se produkcija sojinog ulja. Sadržaj vlage u sojinom ulju smanjuje se sa povećanjem povr&scaron;ine mlaznice ekstrudera, kao i sa povećanjem doziranja ulazne sirovine. Na osnovu ocenjenog modela najveće vrednosti sadržaja SMK se postižu pri najmanjim razmatranim vrednostima vlažnosti ulazne sirovine, pri čemu sadržaj SMK se povećava sa povećanjem doziranja mase.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Sadržaj fosfora u ulju se smanjuje sa povećanjem doziranja ulazne sirovine u ekstruder. Veća temperatura eksturzije [oC] postiže se pri manjim vrednostima vlage i povr&scaron;ine otvora mlaznice. Sa povećanjem doziranja mase i pri fiksnim vrednostima vlage i povr&scaron;ine otvora mlaznice očekivana vrednost temperature eksturzije opada. Sa povećanjem doziranja sirovine u ekstruder maksimalna očekivana vrednost potro&scaron;ene energija po kilogramu produkcije (sojina pogača + sojino ulje) se smanjuje. Sa povećanjem doziranja sirovine u ekstruder maksimalna očekivana vrednost potro&scaron;ene energije po kilogramu produkcije sojine pogače se smanjuje. Sa povećanjem doziranja sirovine u ekstruder minimalna očekivana vrednost potro&scaron;ene energije po kilogramu produkcije sojinog ulja se povećava</p> / <p>AB&nbsp;<br /><br />The aim of this research is to determine the changes in chemical composition of the products at the outlet of the extruder and press (soya meal and oil), i.e. their quality in terms of their further use in animal feed production, food industry or the further use of soybean oil in bio-diesel production, with the functional correlation between the variable characteristics of feedstock and operating parameters of the extruder. Extrusion of soybeans was carried out on the extruder, type E-751, manufactured by &quot;SREM PRODUKT&quot; DOO from Lacarak, and pressing of oil on the press, type PM-5S, manufactured by &quot;BRONTO&quot; from Ukraine. Studies that were conducted in this PhD Thesis were done as a contribution to the expansion of knowledge related to the production process of soya cake and soya oil, and to provide practical guidelines for the optimal control and modeling of the extrusion process and squeezing soybeans, as well as for the designing of the extruder. Some experimental and laboratory tests were conducted in order to obtain and to analyze data that could determine changes in chemical composition of the products at the outlet of the extruder and press (soya cake and oil), i.e. their quality in terms of their further use in animal feed production, food industry or the further use of soybean oil in bio-diesel production, all with the functional correlation between variable characteristics of feedstock and operating parameters of the extruder. Experimental researches are intended for practical application, by which the production process of soya cake and soybean oil could be enhanced and optimized. The results obtained in these researches can be useful to everyone involved in the production of soya cake and soya oil. Experimental studies were carried out on the extruder, type E-751 and the press, type PM5S, but the results are also applicable to other extruders and presses from other manufacturers, that use soybean as a raw material and produce soybean cake and soybean oil. The conducted researches, processed and discussed results have led to the functional correlations between different extrusion parameters and variable characteristics of the incoming raw<br />___________________Doktorska disertacija,&nbsp; autor:Kukić Predrag_____________________<br /><br /><br />_______________________________________________________________IX od 34<br />materials on the one hand, and the characteristics of the extrudate and soybean oil on the other hand, and further on to the certain conclusions. Based on the experimental researches, the impact of changes in selected physical and chemical properties of soybeans was evaluated in the extrusion of soybeans. The PhD Thesis started with the analysis of raw material i.e. soybean and its composition: protein, oil, free fatty acids (FFA) and moisture, and then, the content of free fatty acids, phosphorus and moisture in soybean oil after pressing the extrudate were monitored, as well as protein, moisture, oil, urease activity and PDI (Protein Dispersibility Index) in soya cake by varying the operating mode of the extruder, i.e. feeding of raw material, monitored via load of the main drive motor of the extruder expressed through amperage [A], the die openings surface and moisture of soybeans. The conducted researches have led to the functional correlations between the preset operating modes of the extruder, incoming raw material and selected physical and chemical properties of soybeans in the extrusion process. Thus, with increasing the die openings surface and feeding mass, the production of soya cake is being increased as well. Production of soya cake is also increased with the increase of moisture in the incoming raw material. Moisture content in soya cake is being increased with the increase of moisture content in a feedstock and interactions of feeding mass and the die openings surface. Based on the conducted researches, it can be concluded that the oil content in soybean cake is being increased with the increase of the extruder die openings surface for each of the three moisture content in soybean as a feedstock, while the oil content in soybean cake is being decreased with increased dosage of feedstock for each of the three extruder dies. By increasing the surface area of the extruder die openings, there is a decrease of the protein content in soya expeller cake, while vice versa, with an increase in the dosing of input raw material, i.e. with increasing dosage of raw material to the extruder, the protein content in soya expeller cake is increased. The positive effect of urease activity (&Delta;pH) in soya cake is for larger values of the surface of extruder die<br />___________________Doktorska disertacija,&nbsp; autor:Kukić Predrag_____________________<br /><br /><br />_______________________________________________________________X od 34<br />openings as well as for the interaction of variables W (moisture in soybean) and D (soybean mass dosage determined via the load of the main electric motor). PDI in soybean cake increases with the increase in moisture content of raw material, the surface of the extruder die openings and the dosing of soybeans as a feedstock. Considering the data obtained for soybean oil, manufactured by squeezing the extruded soy product with the predicted moisture content in the feedstock, it has been concluded that the oil production decreases with increasing the surface of the extruder die openings, while by increasing the dosage of incoming raw material, the production of soybean oil is increased. Moisture content in soybean oil is reduced with the increase of the surface of the extruder die openings, as well as with an increase in dosage of feedstock. Based on the evaluated model, the largest values of FFA content were achieved with the smallest considered values for the moisture content in the incoming feedstock, wherein the content of FFA increases with increasing the feeding mass. The phosphorus content in the oil decreases with increasing the feeding of raw material into extruder. Higher extrusion temperatures [oC] are achieved at the lower values of moisture and surface of extruder die openings. With increasing the feeding mass and fixed values of moisture content and die openings surface, the expected value of the extrusion temperature decreases. With increasing the dosage of raw materials into the extruder, the largest expected value for the energy, spent per kilogram of production (soybean cake + soybean oil), decreases. By increasing the dosage of raw materials in the extruder, the largest expected value for the energy, spent per kilogram of soya cake production, is reduced. With increasing the dosage of raw materials in the extruder, the lowest expected value of energy, spent per kilogram of soybean oil production, increases</p>
82

Avaliação da modificação da composição e textura de um produto obtido por transesterificação enzimática da gordura de leite com óleo de soja / Evaluation of the modification on the composition and texture of a product obtained by enzymatic transesterification of milkfat with soybean oil

Nunes, Gisele Fátima Morais 29 August 2008 (has links)
As características nutricionais de produtos alimentícios têm sido cada vez mais valorizadas pelo mercado consumidor em função da constante preocupação com os efeitos dos alimentos na saúde. O sucesso de um produto alimentício no mercado, entretanto, depende também de suas características físicas, tais como espalhabilidade, aparência e impressões sensoriais dos alimentos na boca. Estas características desempenham papel fundamental no processamento industrial e na aceitabilidade do produto pelo consumidor. Neste contexto, o presente projeto teve como objetivo avaliar o efeito da transesterificação enzimática da gordura de leite com óleo de soja na composição e na textura do produto alimentício obtido, empregando como catalisador lipase de Aspergillus niger previamente imobilizada em suporte híbrido polissiloxano-álcool polivinílico. Em uma primeira etapa, as matérias-primas foram caracterizadas quanto à umidade, índices de acidez, saponificação, peróxido e iodo, propriedades reológicas e térmicas. Em seguida, os materiais de partida foram misturados em diferentes proporções seguindo um planejamento experimental estatístico de misturas, e empregados nas reações de transesterificação. As variáveis resposta foram os índices de acidez, saponificação, iodo e peróxido, as propriedades de textura consistência e dureza, e o grau de transesterificação. Os resultados obtidos mostraram que os índices de acidez, saponificação, peróxido e iodo apresentaram uma dependência linear em função da fração mássica de gordura de leite tanto para a mistura das matérias-primas como para os produtos transesterificados. Com relação às propriedades de textura, modelos estatísticos foram compostos e permitiram verificar que a transesterificação promoveu uma diminuição tanto da consistência quanto da dureza nas misturas contendo proporções superiores a 50% de gordura de leite. As misturas preparadas com frações de gordura inferiores a este valor praticamente não sofreram alterações de textura após a reação. A avaliação da composição dos produtos obtidos demonstrou que as amostras correspondentes à gordura de leite pura e às misturas contendo 67 e 75% desta, apresentaram modificações no perfil de triacilgliceróis (TAGs), mostrando de forma geral diminuição na concentração dos TAGs C34-C38 e C54 e aumento dos TAGs C24-C30 e C44-C50. A reação empregando gordura de leite pura resultou em um grau de transesterificação (5,20%) mais elevado em relação ao óleo puro (3,33%), o que pode estar diretamente relacionado à especificidade da enzima pelos ácidos graxos presentes nesta gordura. O grau de transesterificação mais elevado (10,75%) foi obtido para a mistura contendo 67% de gordura de leite. Os resultados indicaram que a transesterificação de misturas contendo 50-67% de gordura de leite resultou em produtos com melhores propriedades de textura (espalhabilidade) sob temperatura de refrigeração em comparação à manteiga, à gordura de leite ou à simples mistura física com igual composição, sendo os valores de consistência e dureza pelo menos 32% menores em comparação à manteiga. Portanto, o desenvolvimento experimental deste trabalho permitiu demonstrar a viabilidade da transesterificação enzimática de uma mistura contendo elevados teores de gordura de leite, o que resultou na preservação de parte de suas características organolépticas, obtendo-se como resultado um produto com melhores características de textura (maior espalhabilidade) e nutricionais (maior teor de ácidos graxos insaturados). / The nutritional food characteristics have been highly considered by consumers due to the constant worries with their effects on health. However, the success of a new food product in the market depends also on its physical characteristics, such as spreadability, appearance and mouthfeel. These properties are very important for industrial processing and acceptability of the product by the consumer. In this context, the objective of present project was to assess the effect of the enzymatic transesterification of milkfat with soybean oil on the composition and texture of the obtained product. For this reaction Aspergillus niger lipase previously immobilized in polysiloxane-polyvinyl alcohol hybrid matrix was chosen as catalyst. The work was carried in three steps. Firstly, raw materials were characterized regarding their humidity, acid, saponification, peroxide and iodine indexes, rheological and thermal properties. Following these, raw materials were mixed at different proportions according to a statistical mixture factorial design and used as substrate in the transesterification reactions. The response variables were acid, saponification, iodine and peroxide indexes, texture properties (consistency and hardness) and transesterification yields. Acid, saponification, peroxide and iodine indexes showed a linear dependence on the milkfat mass fraction for both physical raw materials blends and transesterified products. Regarding the texture properties, statistical models were composed and allowed verifying that the transesterification reaction decreased both consistency and hardness for substrates containing more than 50% of milkfat. No alteration in these properties was noted for substrates containing lower milkfat fraction. The evaluation of the product compositions showed that samples containing pure milkfat and mixtures containing 67 to 75% of milkfat yielded modifications in the triacylglycerols profile (TAGs) such as decreased on the C34-C38 and C54 TAGs concentrations and increased on the C24-C30 and C44-C50 TAGs concentrations. Reactions carried with pure milkfat resulted in higher transesterification yield (5.20%) as compared with pure soybean oil (3.33%), and this was related to the specificity of the enzyme for fatty acids presented in the milkfat. The highest transesterification yield (10.75%) was obtained for mixtures containing 67% of milkfat. Theses results indicated that the transesterification reactions of substrates containing 50-67% of milkfat gave products having better properties regarding the texture (more spreadability) under cooling temperature than butter, milkfat or simple physical blend at the same composition. Consistency and hardness values were at least 32% lower than data for butterfat. Therefore, the proposed experimental work allowed demonstrating that the enzymatic transesterification of a mixture containing high milkfat levels besides partially preserving the milkfat organoleptic characteristics also rendering a product with better texture (higher spreadability) and nutritional properties (higher amount of unsaturated fatty acids).
83

Factors Affecting the Oxidative Stability of Foods-Interesterified Soybean Oil with High Intensity Ultrasound Treatment and Trona Mineral in Packaged Fresh Meats

Lee, Jiwon 01 May 2013 (has links)
Oxidation in oils and muscle foods has been studied for many years to understand its mechanism and furthermore to control and manage it. A series of different processing steps or different packaging techniques can alter oxidative stability. The objective of the current study was to examine oxidative stability of processed oil and to evaluate the effect of carbon dioxide generating mineral on quality of beef and chicken under different storage conditions. In Study 1 (Chapter 3), the effect of ultrasound on oxidative stability of interesterified soybean oil and soybean oil was examined. Sonication did not affect oxidation rate until the oils were highly oxidized. Sonicated interesterified soybean oil exhibited a slightly but significantly lower oxidation rate than non-sonicated oil during long-term storage, while sonication of non-interesterified soybean oil led to a significantly higher oxidation rate than in non-sonicated soybean oil after induction period. In Study 2 (Chapter 4), the feasibility of trona as a CO2 producing product in a model system and in modified atmosphere packaging of beef steaks was investigated. Trona was able to generate more carbon dioxide than sodium bicarbonate with salicylic acid in model systems. Steaks stored with trona/acid mixture had similar color stability and delayed lipid oxidation compared to those stored in high oxygen packaging. In Study 3 (Chapter 5), the effect of packets containing trona and acid placed in a simulated self serve retail case and closed butcher case on the quality of ground beef was studied. Mineral packets did not affect color, lipid oxidation, or microbial growth of ground beef since there was not a sufficient amount of moisture to generate CO2 effectively. In Study 4 (Chapter 6), the quality of chicken breast/thigh portions stored with mineral packets was compared to those without mineral packets during extended storage, and mineral packets had an antimicrobial effect of CO2 only on day 15. In conclusion, high intensity ultrasound did not affect the rate of oxidation of oil until the oil had already become noticeably rancid, and mineral packets containing trona and an acid with low water solubility can be used as CO2 generating sachet if sufficient moisture is given.
84

An Oxidized Fat Containing Diet Decreases Weight Gain but Increases Adiposity in Mice Fed a Low Fat Diet

Schneider, Mary Katherine 14 September 2009 (has links)
Introduction: Fast and convenience foods are abundant, relatively inexpensive, and accommodating to the fast-paced lifestyle of many Americans. One popular method of cooking used by many fast food establishments is deep-fat frying. Soybean oil is commonly used for frying and is rich in polyunsaturated fatty acids (PUFA) such as linoleic acid (LA). When soybean oil is used for deep-fat frying, LA becomes oxidized (Ox-LA). Endogenous Ox-LA has the capacity to be a ligand to peroxisome proliferator-activated receptor gamma (PPAR¥ã), a nuclear transcription factor that regulates adipocyte maturation. It is not yet known whether or not dietary Ox-LA has the same capacity with respect to PPAR¥ã. Considering the fact that dietary oxidized lipids are abundant in the typical American diet, it is important to know if they regulate weight gain and especially adipose tissue mass. In this study, we investigate the effects of fresh and heated soybean oil on weight gain and adiposity in mice fed isocaloric low fat diets. Methods: Soybean oil was heated on a hot plate, under a hood, at 190¨¬C for three hours. Fresh soybean oil served as the source of unoxidized oil (Unox-oil) and the heated oil served as the source of oxidized oil (Ox-oil). Both the Ox-oil and Unox-oil were incorporated into a low-fat (10% of calories) mouse chow by Research Diets, Inc. (New Brunswick, NJ). Sixteen C57BL/6J mice were divided into two groups and fed low fat diets with Ox-oil (low fat oxidized, LFO) or with Unox-oil (low fat unoxidized, LFU). Another group of 8 mice were pair fed to the LFO group with the Unox-oil containing chow (PLU). Mice in the LFO and LFU groups were fed ad libitum and known amounts of fresh food was added to the cages every three days. Leftover food was weighed. Body weights were measured once a week. After 16 weeks mice were euthanized and epididymal white adipose tissue (EWAT), retroperitoneal white adipose tissue (RWAT), inguinal white adipose tissue (IWAT), and intrascapular brown adipose tissue (IBAT) samples were collected, weighed and stored at -80 degrees Celsius until further analysis. Fat pads were homogenized and cytosolic and nuclear proteins were extracted by standard methods. These extracts were subjected to Western blotting to determine the amount of PPAR¥ã in the cytosol and nuclear compartments of the fat pads. Differences in group means were analyzed by Mann Whitney U test. Comparisons were considered statistically significant at a p-value of < 0.05. Results: Final mean body weights were significantly different when comparing the mice in the LFU group to the pair fed mice (PLU) (mean ¡¾ SD; 29.52 ¡¾ 1.09 grams (g) and 26.85 ¡¾ 1.44 g, respectively; p < 0.05). Mice fed a low fat diet consisting of Ox-oil (LFO) had a final mean body weight of 27.88 ¡¾ 2.03 g. Mice in the LFU group gained significantly more weight on average than did mice in the LFO or PLU groups (mean ¡¾ SD; 8.86 ¡¾ 1.37g, 7.10 ¡¾ 1.47 g, and 5.71 ¡¾ 1.13 g, respectively). Although mean food intakes were not significantly different between any of the three groups, the average food intake was greatest for the LFU mice in comparison to the LFO and the PLU mice (mean ¡¾ SD; 20.65 ¡¾ 0.09 g/week, 18.40 ¡¾ 0.05 g/week, and 18.38 ¡¾ 0.19 g/week, respectively). Feeding efficiency (g of weight gain/g of food consumed) was the highest in the LFU mice compared to the PLU mice (mean ¡¾ SD; 0.031 ¡¾ 0.005 g/g and0.022 ¡¾ 0.004 g/g) and this difference was statistically significant. The LFO mice gained less weight per gram of food consumed than did the LFU mice (mean ¡¾ SD; 0.028 ¡¾ 0.006 g/g). Mean weights of all fat pads in the LFO group were significantly greater than those of the LFU and PLU mice (mean ¡¾ SD; 0.329 ¡¾ 0.109g, 0.199 ¡¾ 0.055g, and 0.219 ¡¾ 0.041 for EWAT, 0.091 ¡¾ 0.039g, 0.050 ¡¾ 0.026g, and 0.051 ¡¾ 0.017 for RWAT, 0.221 ¡¾ 0.065g, 0.135 ¡¾ 0.053g, and 0.144 ¡¾ 0.038 for IWAT, and 0.079 ¡¾ 0.012g, 0.055 ¡¾ 0.013g, and 0.062 ¡¾ 0.011 for IBAT, respectively). PPAR¥ã protein in the cytosol of EWAT fat pads was analyzed and quantified in comparison to the amount of Glyceraldehyde-3-phosphate dehydrogenase (GAPDH; loading control) present. Mean PPAR¥ã /GAPDH ratios for LFU mice was 0.226 ¡¾ 0.082, for LFO mice was 0.264 ¡¾ 0.122, and for PLU mice was 0.234 ¡¾ 0.108. Mean PPAR¥ã:GAPDH ratios were not significantly different between any of the groups. Conclusion: It appears that the consumption of oxidized oil caused a significant decrease in weight gain and food intake (although not significant) and a significant increase in fat pad mass in mice compared to those consuming a diet with unoxidized oil. The lack of difference in the amount of PPAR¥ã among the three groups of mice suggests that the changes in weight gain and fat pad mass among the oxidized oil consuming animals is not mediated through regulation of PPAR¥ã protein. To our knowledge, ours is the first study to report that mice consuming a low fat diet inclusive of dietary oxidized lipids exhibit greater adiposity than do mice consuming a low fat diet consisting of unoxidized lipids.
85

Einfluss der variierenden Nährstoffzusammensetzung einer stärkebetonten Ration auf die Glucose- und Insulinreaktion beim gesunden Pferd / The effect of a varying nutrient composition in a starchy meal on glycaemic and insulinaemic responses in healthy horses

Klein, Sara, Klein, Sara 25 June 2010 (has links) (PDF)
Die Abdeckung des Energiebedarfs ist insbesondere bei Sport- und Zuchtpferden mit einer Aufnahme hoher Stärkemengen gekoppelt. Daraus können jedoch sowohl fermentative Störungen, bedingt durch das Abfluten von Stärke in den Dickdarm, als auch metabolische Veränderungen resultieren, wobei letztere insbesondere in Form von gesteigerten Glucose- und Insulinreaktionen zum Ausdruck kommen und nicht zuletzt in der Entstehung einer Insulinresistenz münden können. In der vorliegenden Arbeit sollte der Einfluss verschiedener Nährstoffe bzw. Futtermittel in Kombination mit der Aufnahme einer stärkereichen Mahlzeit auf die Glucose- und Insulinreaktion bei gesunden Pferden überprüft werden. Für die Versuche standen insgesamt zwölf Wallache (Alter: 6 ± 4 Jahre, Gewicht: 552 ± 84 kg) zur Verfügung. Die Untersuchungen unterteilten sich in drei Fragestellungen, bei denen die jeweiligen Futtermittel randomisiert oder blockweise angeboten wurden. Als stärkereiche Mahlzeit wurde einmal täglich morgens Bruchmais in einer Dosierung von 2 g Stärke / kg KM verfüttert. Im ersten Versuchsabschnitt erhielten die Pferde verschiedene Heuzuteilungsformen (ad libitum oder restriktiv (0,6 kg / 100 kg KM)) in der Nacht vor Bruchmaisaufnahme sowie nach der Fütterung des Bruchmaises. Im zweiten Versuch wurde der Bruchmais in Kombination mit extrahierten Rohfaserquellen (0,2 g / kg KM Cellulose / Hemicellulose oder 0,1 g / kg KM Apfelpektin) oder 0,2 g Rohprotein / kg KM (in Form von Maiskleber) verfüttert. Im dritten Versuchsabschnitt erfolgte die Zulage von 0,2 ml Soja- oder Fischöl / kg KM zum Bruchmais. Je nach Fragestellung durchliefen die Pferde eine acht- bis elftägige Adaptationsphase, nach welcher sich ein- bis zweitägige Blutprobenentnahmetage anschlossen. Hierbei wurde den Pferden über einen Venenverweilkatheter bis 510 Minuten ppr. jeweils in halbstündigen Abständen Blut entnommen. Im Plasma wurden die Blutparameter Glucose (GOD-Methode) und Insulin (Radioimmunoassay) bestimmt. Es konnte gezeigt werden, dass die Zufuhr von Rohfaser in Form von Heu vor und nach Aufnahme einer stärkereichen Ration keinen wesentlichen Einfluss auf die Glucosereaktion hatte. Hierbei wurden die Glucosekonzentrationen nach zwölfstündiger Nüchterung durch die Heufütterung während der Blutentnahme nicht beeinflusst (AUCHeu restriktiv nachts, Heu restriktiv tags 132 ± 72,5 mmol x min / l, AUCHeu restriktiv nachts, Heu ad libitum tags 144 ± 114 mmol x min / l, Behandlung p > 0,05). Die Heuaufnahme während der Blutentnahme führte zu signifikant höheren Glucosekonzentrationen (Behandlung p = 0,02) wenn die Pferde vor der Bruchmaisaufnahme ad libitum Zugang zu Heu hatten (Heu ad libitum nachts, Heu ad libitum tags). Die Flächen unter den Glucosekurven wiesen jedoch keine signifikanten Unterschiede zwischen den Behandlungen auf (AUCHeu ad libitum nachts, Heu restriktiv tags 89,5 ± 50,5 mmol x min / l, AUCHeu ad libitum nachts, Heu ad libitum tags 113 ± 62,7 mmol x min / l, Behandlung p > 0,05). Die Heufütterung während der Blutentnahme ließ nach zwölfstündiger Nüchterung signifikant höhere Insulinkonzentrationen (AUCHeu restriktiv nachts, Heu ad libitum tags 5996 ± 4460 µU x min / ml) erkennen als ohne Heufütterung (AUCHeu restriktiv nachts, Heu restriktiv tags 1626 ± 1040 µU x min / ml, Behandlung p = 0,02). Die Pferde zeigten weiterhin signifikant höhere Insulinwerte, wenn nach der Fütterung des Bruchmaises Heu ad libitum aufgenommen werden konnte (AUCHeu ad libitum nachts, Heu restriktiv tags 1275 ± 845 µU x min / ml, AUCHeu ad libitum nachts, Heu ad libitum tags 3701 ± 2163 µU x min / ml, Behandlung p = 0,04). Die Zugabe extrahierter Rohfaserquellen wie Cellulose / Hemicellulose sowie Pektin zu einer definierten Maisaufnahme zeigte keinen signifikanten Einfluss auf die Glucose- (AUCBruchmais 230 ± 163 mmol x min / l, AUCCellulose / Hemicellulose 259 ± 215 mmol x min / l, AUCPektin 274 ± 106 mmol x min / l, Behandlung p > 0,05) und Insulinreaktion (AUCBruchmais 8885 ± 4024 µU x min / ml, AUCCellulose / Hemicellulose 8767 µU x min / ml, AUCPektin 10657 µU x min / ml, Behandlung p > 0,05). Durch die additive Supplementierung von Sojaöl- und Fischöl zu einer stärkehaltigen Mahlzeit ließen sich keine signifikanten Unterschiede in der Glucose- (AUCSojaöl 268 mmol x min / l, AUCFischöl 234 mmol x min / l, AUCBruchmais 257 ± 113 mmol x min / l) und Insulinreaktion (AUCSojaöl 4640 µU x min / ml, AUCFischöl 3653 µU x min / ml, AUCBruchmais 4703 ± 3365 µU x min / ml) im Vergleich zur isolierten Bruchmaisaufnahme erkennen. Die Ergänzung von Protein zu einer stärkehaltigen Mahlzeit zeigte sehr variable Reaktionen innerhalb der Einzelpferde, wobei zwei Pferde keine Reaktion und zwei Pferde erhöhte Insulinreaktionen zeigten. Unterschiede in den Glucosereaktionen wurden nicht beobachtet. Zusammenfassend ist hervorzuheben, dass die gewählten Fütterungskonzepte (Zulage extrahierter Faserquellen, Protein oder Fett) bei einer Stärkezufuhr von 2 g Stärke / kg KM keinen signifikanten Einfluss auf die Glucose- und Insulinreaktionen hatten. Dagegen führte die Fütterung von Heu ad libitum nach Aufnahme einer stärkereichen Ration zu erhöhten Insulinkonzentrationen. Um die Glucose- und Insulinreaktion nachhaltig abschwächen zu können, ist als effiziente Maßnahme eine Reduktion der aufgenommenen Stärkemenge pro Mahlzeit zu empfehlen, wohingegen die Zulage von Rohfaser und Fett bei standardisierter Stärkeaufnahme keine Abschwächung der postprandialen Glucose- und Insulinreaktion bewirkt. / In order to meet horses’ requirements of work and exercise feeding high amounts of starch is common practice. However, a high intake of starch can increase the risk of either fermentative disorders due to an overload of starch in the hindgut, or of metabolic disorders leading to exaggerated blood glucose and insulin concentrations which possibly could induce insulin resistance. The aim of this study was to investigate the effects of different nutrients in combination with the intake of a starchy meal on blood glucose and insulin concentrations in healthy horses. Twelve geldings (age: 6 ± 4 years, body weight (BW): 552 ± 84 kg) were fed the respective diets either in a randomized order or in a block design. The experiment was divided into three feeding trials. In each trial, horses received cracked corn (2 g starch / kg BW) in the morning (0800 h). In the first trial horses were fed cracked corn and grass hay in four different orders (hay ad libitum or hay restrictive (0.6 kg / 100 kg BW)), in the night before and after the intake of cracked corn. In the second trial cracked corn was mixed with extracted diatary fibers (cellulose / hemicellulose (0.2 g / kg BW) or apple pectin (0.1 g / kg BW)) or with corn gluten (2 g crude protein / kg BW). In the third trial cracked corn was fed either in combination with soybean oil (0.2 ml / kg BW) or in combination with fish oil (0.2 ml / kg BW). Each feeding period consisted of eight to eleven days of acclimatization to the different diets followed by one or two blood collection days. Blood samples were taken via a venous catheter in half-hour intervals up to 510 minutes ppr. Plasma glucose concentrations were measured by a glucose oxidase assay, and insulin levels were determined using a radioimmunoassay. There was no influence of hay feeding during blood collection after a 12 h overnight fast on plasma glucose concentrations (AUChay restriktive night, hay restriktive day 132 ± 72.5 mmol x min / l, AUChay restriktive night, hay ad libitum day 144 ± 114 mmol x min / l, treatment p > 0.05). In contrast, hay feeding during the blood collection period led to significant higher plasma glucose concentrations (treatment p = 0.02) when horses had ad libitum access to hay in the night before the intake of cracked corn. There was no significant difference in the AUC (AUChay ad libitum night, hay restriktive day 89.5 ± 50.5 mmol x min / l, AUChay ad libitum night, hay ad libitum day 113 ± 62.7 mmol x min / l, treatment p > 0.05). Furthermore, horses which were fed hay ad libitum after the intake of cracked corn demonstrated significant higher insulin concentrations (AUChay restriktive night, hay ad libitum day 5996 ± 4460 µU x min / ml) than horses without hay feeding (AUChay restriktive night, hay restriktive day 1626 ± 1040 µU x min / ml, treatment p = 0.02). In case of ad libitum hay feeding during the night significant higher insulin concentrations were found in horses which had ad libitum access to hay after intake of cracked corn when compared to horses without hay feeding during blood collection (AUChay ad libitum night, hay restriktive day 1275 ± 845 µU x min / ml, AUChay ad libitum night, hay ad libitum day 3701 ± 2163 µU x min / ml, treatment p = 0.04). The addition of extracted cellulose / hemicellulose and extracted apple pectin did not change the glycaemic (AUCcracked corn 230 ± 163 mmol x min / l, AUCcellulose / hemicellulose 259 ± 215 mmol x min / l, AUCpectin 274 ± 106 mmol x min / l, treatment p > 0,05) and insulinaemic responses (AUCcracked corn 8885 ± 4024 µU x min / ml, AUCcellulose / hemicellulose 8767 µU x min / ml, AUCpectin 10657 µU x min / ml, treatment p > 0.05) in comparison to isolated intake of cracked corn. There were no differences in postprandial glucose (AUCsoybean oil 268 mmol x min / l, AUCfish oil 234 mmol x min / l, AUCcracked corn 257 ± 113 mmol x min / l, treatment p > 0,05) and insulin responses (AUCsoybean oil 4640 µU x min / ml, AUCfish oil 3653 µU x min / ml, AUCcracked corn 4703 ± 3365 µU x min / ml, treatment p > 0.05) between feeding either cracked corn alone or in combination with soybean oil or fish oil. Protein supplementation of a starchy meal resulted in highly individual insulin responses. Two horses showed higher insulin concentrations after addition of protein to the corn meal, whereas two horses showed no reaction to the respective diet. There were no differences in the glycaemic responses. In conclusion, the results demonstrated no influence of the applied feeding strategies including supplementation of a starchy meal (2 g / kg BW) by extracted dietary fibers, protein or fat on postprandial glucose and insulin responses. In contrast, hay feeding increased the plasma insulin concentrations after the intake of cracked corn. To attenuate the glycaemic and insulinaemic responses in the horse efficiently, a reduction of starch intake per meal to quantities below 1 g starch per kg BW and meal is recommended, whereas feeding strategies like the addition of fiber or fat to a standardised starch intake do not improve glucose metabolism in healthy horses.
86

Avaliação de dietas lipídicas fornecidas em duas frequências de suplementação na terminação de novilhas em pastejo /

Santana, Márcia Cristina Araújo. January 2010 (has links)
Resumo: Objetivou-se avaliar o efeito de suplementos lipídicos disponíveis em diferentes formas (soja em grão moído, óleo de soja, e sais de cálcio - SC) no consumo de matéria seca total; comportamento ingestivo; desempenho corporal; parâmetros de fermentação ruminal; características de carcaça; desenvolvimento e composição corporal; e na qualidade da carne de novilhas mantidas em pastagens de Brachiaria brizantha cv. Marandu suplementadas em duas frequências (diária ou segunda, quarta e sexta - SQS). O experimento foi realizado nos meses de julho a novembro de 2007. Foram utilizadas novilhas mestiças (1/4 Nelore x 1/4 Santa Gertrudis x 1/2 Braunvieh), alimentadas com três suplementos lipídicos na quantidade de 0,75% do peso corporal. Os dados foram analisados em delineamento inteiramente casualisados com os tratamentos em arranjo fatorial (3x2 - três suplementos lipídicos e duas frequências alimentares). O consumo de matéria seca total foi maior nos meses de agosto e outubro em relação ao mês novembro. Houve efeito das formas de fornecimento da fonte lipídica sobre o consumo em kg de matéria seca total, forragem e nutrientes. Durante o período seco e início das águas os animais obtiveram ganhos médios totais de 0,577g dia-1, que não foram influenciados pelas suplementos lipídicos e frequências de suplementação utilizadas. A redução na frequência de suplementação alterou o tempo de pastejo em função dos suplementos lipídicos. Não houve influência dos suplementos lipídicos e das frequências de suplementação sobre o balanço de compostos nitrogenados, na síntese e eficiência de proteína microbiana. Houve influência das formas de fornecimento dos suplementos lipídicos sobre os valores de pH ruminal. A menor frequência de suplementação proporcionou diferenças nas concentrações de nitrogênio amoniacal ruminal... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This research aimed to evaluate total dry matter intake, feeding behavior, growth performance, rumen fermentation parameters; carcass characteristics, development and body composition, and meat quality responses of steers grazing Brachiaria brizantha cv. Marandu supplemented at two frequencies (daily or Monday, Wednesday and Friday - MWF), under different forms of lipid supplements (soybean grain, soybean oil, and calcium salts - CS). This research was conducted throughout a four month period during the dry season (July to November 2007). Crossbred heifers were used (1/4 Nellore x 1/4 Santa Gertrudis x 1/2 Braunvieh) fed with three lipid supplements in the amount of 0.75% of body weight. The experiment was completely random, using a 3x2 factorial arrangement (3 supplements and 2 supplementation frequencies). The total dry matter intake was higher in August and October compared to November. There was effect of the lipids forms supplied on total dry matter, forage and nutrients intake. During the dry season and beginning of the wet season the animals showed average daily gain of 0.577 g day-1, which were not affected by dietary lipid supplementation and frequencies used. The kind of lipid diet under reduction on the frequency of supplementation alter grazing time. There was no influence of diet lipid and frequencies supplementation on nitrogenous compounds, in the synthesis and efficiency of microbial protein. There was influence of the lipids forms diets on values of rumen pH. Supplementation provided under frequency differences in the concentrations of ammonia in the rumen. There was influence of the lipids forms diets on weight hot carcass, and weight and dress percentage. Supplementation with dietary lipids under different forms and frequencies does not provide differences in body composition... (Complete abstract click electronic access below) / Orientadora: Telma Teresinha Berchielli / Coorientador: Ricardo Andrade Reis / Banca: Alexandre Amstalden Moraes Sampaio / Banca: Ana Cláudia Ruggieri / Banca: Marco Antonio Alvares Balsalobre / Banca: Juliano José de Resende Fernandes / Doutor
87

Novo catalisador heterog?neo magn?tico SiO2/KI/?Fe2O3 para rea??o de transesterifica??o em ?leos vegetais para produ??o de biodiesel

Macedo, Alice Lopes 21 February 2017 (has links)
Data de aprova??o retirada da vers?o impressa do trabalho. / Incluir a Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM) como ag?ncia financiadora. / Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2017-12-13T16:15:41Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) alice_lopes_macedo.pdf: 5251789 bytes, checksum: e988c8abc173c91e128980414db14ef9 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2018-01-03T12:17:24Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) alice_lopes_macedo.pdf: 5251789 bytes, checksum: e988c8abc173c91e128980414db14ef9 (MD5) / Made available in DSpace on 2018-01-03T12:17:24Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) alice_lopes_macedo.pdf: 5251789 bytes, checksum: e988c8abc173c91e128980414db14ef9 (MD5) Previous issue date: 2017 / Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM) / A crescente demanda global por combust?veis l?quidos para transporte, gera??o de eletricidade, atividade industrial e produ??o agropecu?ria tem imposto planejamento de a??es direcionadas ao uso de fontes ambientalmente limpas de energia. Os derivados da biomassa s?o alternativas econ?mica e tecnicamente vi?veis aos de origem f?ssil, n?o renov?vel, ora dominantes na matriz energ?tica global. O biodiesel, l?quido formado por uma mistura de ?steres de ?cidos graxos, ? adequado ? opera??o em motores de combust?o interna de ciclo Diesel, em substitui??o ou em complemento ao petrodiesel, ou em outras m?quinas t?rmicas. O prop?sito central do presente trabalho foi o desenvolvimento de um catalisador s?lido economicamente vi?vel, quimicamente eficiente e ambientalmente limpo para a produ??o de biodiesel via processos de transesterifica??o de triacilglicer?is dos ?leos de maca?ba ou de soja, com metanol. Foi preparado o catalisador heterog?neo baseado em iodeto de pot?ssio impregnado em s?lica amorfa (SiO2; derivada de areia da constru??o civil) e misturada a um componente magn?tico sint?tico (maghemita, ?Fe2O3). As estruturas qu?mica, cristalogr?fica e hiperfina essenciais e as propriedades magn?ticas dos materiais precursores e do catalisador s?lido foram investigadas. O teor de ?steres e a composi??o dos biodieseis produzidos foram determinados por cromatografia de fase gasosa acoplada a espectr?metro de massa. A composi??o qu?mica do catalisador, verificada por espectroscopias de energia dispersiva sob feixe de el?trons e por fluoresc?ncia de raios X (FRX), confirmou a ocorr?ncia de Si, Fe, K, e I. As ?reas espec?ficas BET encontradas para os componentes individuais, SiO2, ?Fe2O3 e do catalisador SiO2/KI/?Fe2O3, foram 352, 102, e 19 m2 g-1, respectivamente. A significativa redu??o da ?rea espec?fica do catalisador aponta que os componentes foram efetivamente impregnados no suporte. A morfologia das part?culas visualizadas por microscopias eletr?nicas de varredura e de transmiss?o revela a textura esponjosa do catalisador SiO2/KI/?Fe2O3, similarmente ao suporte de s?lica; o ?xido de ferro magn?tico aparece como material altamente organizado, cristalino, disperso no suporte. Os dados M?ssbauer e da magnetometria do ?xido de ferro magn?tico puro e no catalisador confirmam ser a maghemita, resultando em uma magnetiza??o de satura??o do catalisador de 4,6 emu g-1. O catalisador SiO2/KI/?Fe2O3, usado na transesterifica??o de triacilglicer?is, na propor??o em massa em rela??o ao ?leo da am?ndoa de maca?ba de 4,5% e raz?o molar ?leo:metanol de 1:35, levou ? produ??o de 94,3 massa% de ?steres, ap?s 8 h de rea??o. Foi experimentalmente observado que a maghemita tem comportamento qu?mico-catal?tico sin?rgico com os demais componentes do catalisador. O SiO2/KI/?Fe2O3 foi reutilizado em seis rea??es consecutivas com ?leo de soja, na mesma propor??o do catalisador e raz?o molar ?leo:metanol de 1:35, com rendimentos de 94,5% e tempo reacional de 110 min, para o primeiro ciclo, e de 61,2% e 150 min, para o ?ltimo ciclo. O catalisador, antes e ap?s cada ciclo de reuso, e as al?quotas das rea??es foram analisados por FRX, que mostrou que n?o h? perda significativa dos componentes do catalisador. Os resultados demonstram uma perspectiva tecnol?gica que permite redu??o substantiva do volume de efluentes poluentes e utiliza??o de diferentes mat?rias-primas oleaginosas de alto potencial para a produ??o de biodiesel. / Tese (Doutorado) ? Programa de P?s-gradua??o em Biocombust?veis, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2017. / The global demand for liquid fuels destined to propel automobile motors and for all other types of transport has been growing significantly over the last decades in response to the needs of the population for mobility. These fuels are also necessary for the generation of electricity to support industrial and agricultural activities. However, the principal concern involved in the generation of mechanical work involves the threat that the effluents from burning fuels, particularly those from fossil origin, impart to the environment. Biomass-derived fuels are energetically, economically and environmentally interesting alternatives to the non-renewable fossil fuels, which still dominate the global energy matrix. Biodiesel, a liquid that is composed of a mixture of esters of fatty acids, is mainly suitable for use in Diesel-cycle internal combustion engines, totally replacing or partially complementing petrodiesel. The main purpose of the present work was the development of an economically viable, environmentally clean and chemically efficient solid catalyst for the production of biodiesel via the transesterification reaction of triacylglycerols from maca?ba or soybean oil with methanol. The proposed heterogeneous catalyst was based on potassium iodide-impregnated particles of amorphous silica (SiO2; derived from construction sand) mixed with a synthetic magnetic iron oxide (maghemite, ?Fe2O3). The essential chemical, crystallographic and hyperfine structures and magnetic properties of the starting materials and of the solid catalyst mixture were assessed by physical laboratory techniques. The ester content and the chemical composition of the biodiesel produced were determined by gas chromatography coupled with mass spectrometry. The chemical composition of the catalyst, as determined by electron energy dispersive and X-ray fluorescence (FRX) spectroscopies, confirmed the occurrence of Si, Fe, K, and I. Specific BET surface areas for the SiO2 and ?Fe2O3 components and for the SiO2/KI/?Fe2O3 catalyst were found to be 352; 102 and 19 m2 g-1, respectively. The significant reduction in the specific area of the catalyst indicates that the solid components were intimately mixed and that KI was indeed impregnated on the support. The morphology of the particles, as visualized from the scanning and transmission electron microscopy images, reveals the spongy texture of the SiO2/KI/?Fe2O3 catalyst, which was quite similar to that of the initial silica support. The atomic framework of the magnetic iron oxide appeared to be a highly organized, crystalline nano-material, relatively well dispersed on the silica support. The M?ssbauer and magnetometric data for the pure magnetic iron oxide and for the catalyst confirm that the component is essentially maghemite. The resulting saturation magnetization of the catalyst mixture was 4.6 emu g-1. From the chemical point of view, this maghemite was found to act synergically with the other components of the catalyst and to significantly improve its catalytic activity. The transesterification reaction of triacylglycerols using the SiO2/KI/?Fe2O3 catalyst at a mass ratio corresponding to 4.5 mass% relative to the maca?ba kernel oil and a methanol:oil molar ratio 30:1 yielded 94.3 mass% of esters after 8 h of reaction. The SiO2/KI/?Fe2O3 catalyst was reused for six consecutive transesterification reactions of triacylglicerols in soybean oil employing the same mass proportion of the catalyst and a methanol:oil molar ratio 35:1. A 94.5% yield of esters was obtained after 110 min of reaction in the first cycle, and a 61.2% yield was obtained in the last reaction cycle after 150 min. The compositions of the catalyst before and after each reaction cycle, along with detection of residual chemical elements in the liquid mixture of esters formed, were duly monitored by FRX. There was no significant leaching of the catalyst components during the reactions. These results open a perspective for (i) a substantial reduction in the volume of polluting effluents and (ii) the use bio-oils from native Brazilian flora (maca?ba) as raw materials for the industrial production of biodiesel.
88

Seleção de catalisadores a base de estanho (IV) para a produção de ésteres etílicos via transesterificação / Selection based catalysis tin (IV) for the production of ethyl esters via transesterification

Silva, Eleny Pires da 29 March 2012 (has links)
The aim of this study was to investigate the catalytic activity of three complexes exhibiting Lewis acid character: butylstannoic acid, di-n-butyl-oxo-stannane and ibutyltin dilaurate. These catalysts were tested in ethanolysis of soybean oil in order to obtain a mixture of alkyl esters, known as biodiesel. The interest of this study is to verify the efficiency of catalysts in reactions of ethanolysis and determine the yield of biodiesel. Ethanol was employed as alcoholysis agent due their renewable nature and be less toxic than methanol. In all conditions tested the following order of activity can be established: DBTO> DBTDL> BTA. All experiments performed in the closed reactor shown higher yields compared to those obtained employing one reactor operating under reflux conditions. In the reactions carried out in the presence of ethanol, lower yields were obtained compared to methanol. / O objetivo deste trabalho foi investigar a atividade catalítica de três complexos metálicos exibindo caráter ácido de Lewis: ácido butilestanóico, óxido de dibutil estanho e dibutildilaurato de estanho. Esses catalisadores foram testados na etanólise do óleo de soja visando a obtenção de uma mistura de ésteres alquílicos, denominada biodiesel. O interesse desse estudo é verificar a eficiência dos catalisadores em reações de etanólise e determinar o rendimento em biodiesel. O etanol foi empregado como agente de alcóolise por ser proveniente de fontes renováveis e ser menos tóxico que o metanol. Em todas as condições testadas a seguinte ordem de atividade pode ser estabelecida: DBTO > DBTDL > BTA. Todos os experimentos realizados no reator fechado apresentaram rendimentos superiores comparados ao reator operando em condições de refluxo. Nas reações conduzidas na presença do etanol, foram obtidos rendimentos inferiores, comparativamente ao metanol.
89

Avaliação de dietas lipídicas fornecidas em duas frequências de suplementação na terminação de novilhas em pastejo

Santana, Márcia Cristina Araújo [UNESP] 09 August 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:33:32Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-08-09Bitstream added on 2014-06-13T21:06:23Z : No. of bitstreams: 1 santana_mca_dr_jabo.pdf: 2076387 bytes, checksum: c69287a57df1d91e1c872d6cfdf584d5 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Objetivou-se avaliar o efeito de suplementos lipídicos disponíveis em diferentes formas (soja em grão moído, óleo de soja, e sais de cálcio - SC) no consumo de matéria seca total; comportamento ingestivo; desempenho corporal; parâmetros de fermentação ruminal; características de carcaça; desenvolvimento e composição corporal; e na qualidade da carne de novilhas mantidas em pastagens de Brachiaria brizantha cv. Marandu suplementadas em duas frequências (diária ou segunda, quarta e sexta - SQS). O experimento foi realizado nos meses de julho a novembro de 2007. Foram utilizadas novilhas mestiças (1/4 Nelore x 1/4 Santa Gertrudis x 1/2 Braunvieh), alimentadas com três suplementos lipídicos na quantidade de 0,75% do peso corporal. Os dados foram analisados em delineamento inteiramente casualisados com os tratamentos em arranjo fatorial (3x2 – três suplementos lipídicos e duas frequências alimentares). O consumo de matéria seca total foi maior nos meses de agosto e outubro em relação ao mês novembro. Houve efeito das formas de fornecimento da fonte lipídica sobre o consumo em kg de matéria seca total, forragem e nutrientes. Durante o período seco e início das águas os animais obtiveram ganhos médios totais de 0,577g dia-1, que não foram influenciados pelas suplementos lipídicos e frequências de suplementação utilizadas. A redução na frequência de suplementação alterou o tempo de pastejo em função dos suplementos lipídicos. Não houve influência dos suplementos lipídicos e das frequências de suplementação sobre o balanço de compostos nitrogenados, na síntese e eficiência de proteína microbiana. Houve influência das formas de fornecimento dos suplementos lipídicos sobre os valores de pH ruminal. A menor frequência de suplementação proporcionou diferenças nas concentrações de nitrogênio amoniacal ruminal... / This research aimed to evaluate total dry matter intake, feeding behavior, growth performance, rumen fermentation parameters; carcass characteristics, development and body composition, and meat quality responses of steers grazing Brachiaria brizantha cv. Marandu supplemented at two frequencies (daily or Monday, Wednesday and Friday - MWF), under different forms of lipid supplements (soybean grain, soybean oil, and calcium salts - CS). This research was conducted throughout a four month period during the dry season (July to November 2007). Crossbred heifers were used (1/4 Nellore x 1/4 Santa Gertrudis x 1/2 Braunvieh) fed with three lipid supplements in the amount of 0.75% of body weight. The experiment was completely random, using a 3x2 factorial arrangement (3 supplements and 2 supplementation frequencies). The total dry matter intake was higher in August and October compared to November. There was effect of the lipids forms supplied on total dry matter, forage and nutrients intake. During the dry season and beginning of the wet season the animals showed average daily gain of 0.577 g day-1, which were not affected by dietary lipid supplementation and frequencies used. The kind of lipid diet under reduction on the frequency of supplementation alter grazing time. There was no influence of diet lipid and frequencies supplementation on nitrogenous compounds, in the synthesis and efficiency of microbial protein. There was influence of the lipids forms diets on values of rumen pH. Supplementation provided under frequency differences in the concentrations of ammonia in the rumen. There was influence of the lipids forms diets on weight hot carcass, and weight and dress percentage. Supplementation with dietary lipids under different forms and frequencies does not provide differences in body composition... (Complete abstract click electronic access below)
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Fornecimento de fontes lipídicas na dieta de poedeiras e seus efeitos sobre o desempenho, qualidade dos ovos, perfil de ácidos graxos e colesterol na gema

Faitarone, Ana Beatriz Garcia [UNESP] 17 August 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:33:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-08-17Bitstream added on 2014-06-13T19:04:39Z : No. of bitstreams: 1 faitarone_abg_dr_botfmvz.pdf: 754134 bytes, checksum: 45dd71e6381045c73eb898cfbd217a7f (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Universidade Estadual Paulista (UNESP) / O presente experimento teve duração de 112 dias e teve por objetivo avaliar o desempenho e qualidade dos ovos de poedeiras leves alimentadas com dietas suplementadas com óleos vegetais. As aves foram distribuídas em um delineamento experimental inteiramente casualisado com 10 tratamentos - (T1 – Controle; T2 – inclusão de 2,5% de óleo de linhaça; T3 – inclusão de 2,5% de óleo de canola; T4 – inclusão de 2,5% de óleo de soja; T5 – inclusão de 5% de óleo de linhaça; T6 – inclusão de 5% de óleo de canola; T7- inclusão de 5% de óleo de soja; T8 – inclusão de 2,5% de óleo de linhaça + 2,5% de óleo de soja; T9 – inclusão de 2,5% de óleo de canola + 2,5% de óleo de soja e T10 – inclusão de 2,5% de óleo de linhaça + 2,5% de óleo de canola) - e seis repetições de oito aves por parcela experimental, perfazendo um total de 480 aves. Foram avaliadas o consumo de ração, a produção de ovos, o peso dos ovos, a massa de ovos, a conversão alimentar por dúzia e por quilograma de ovos produzidos, a gravidade específica dos ovos, a resistência da casca à quebra, a cor de gema, as percentagens de gema, albúmen e casca, a espessura de casca e o índice gema. Não foram observadas diferenças significativas entre os tratamentos para peso e massa de ovos, conversão alimentar por dúzia de ovos produzidos, gravidade específica dos ovos, resistência da casca à quebra, espessura de casca, percentagens de gema, albúmen e casca. Concluiuse que a suplementação de óleos vegetais, na ração de poedeiras comercias leves não promoveu melhoras no desempenho e na qualidade dos ovos / The present experiment lasted 112 days and aimed to weigh up the performance and eggs quality of light laying hens fed with diets supplemented with vegetal oil. The light laying hens were distributed on an completely randomized design with 10 treatments (T1 - control, T2- inclusion of 2.5% of linseed oil in the diet, T3- inclusion of 2.5% of canola oil in the diet; T4-inclusion of 2.5% of soybean oil in the diet; T5- inclusion of 5% of linseed oil in the diet; T6- inclusion of 5% of canola oil in the diet; T7-inclusion of 5% oil soy in the diet; T8- inclusion of 2.5% of linseed oil +2.5% soybean oil in the diet; T9- inclusion of 2.5% canola oil + 2.5% soybean oil in the diet and T10- inclusion of 2.5% of linseed oil + 2.5% of canola oil in the diet) and six repetition of eight birds by experimental sector, adding up to 480 birds. The ration consumption, the eggs production, the weight and mass, the alimentary conversion per dozen and per kilogram of produced eggs, specific gravity of the eggs, the strength egg shell to break, the yolk color, proportion of yolk, albumen and shell, shell thickness and yolk index were weighed up. Significant differences among the treatments for weight and eggs mass, food conversion by produced dozen eggs, specific eggs gravity, resistance to shell break, shell thickness, percentages of yolk, albumen and shell were not observed. It was concluded that the vegetal oils supplementation on the given diets to light laying commercial hens doesn’t affect the performance and the eggs quality

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