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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.
51

Investigations into the Pilot Scale Separation of Protein and Starch Biopolymers from Oat Cereal

Macdonald, Rebecca Joanne January 2010 (has links)
Cereals contain naturally occurring biopolymers (for example proteins and starches) that can be used as renewable raw materials in a variety of speciality chemical applications. The separation of protein and starch biopolymers from wheat is well established and relies on a group of proteins called glutens that have a unique network-forming functionality. Oat and other cereals do not naturally contain these gluten proteins and typically rely on chemical-based separation techniques which alter the chemical and physical structures and damage the inherent natural functionality of the biopolymers. This research study investigated the separation of the protein and starch fractions from cereals using the Al-Hakkak Process, a new aqueous process. This process involves adding water and wheat gluten protein to cereals that do not contain gluten. The wheat gluten interacts with the cereal proteins, facilitating the separation of the starch and protein fractions whilst retaining their inherent natural functionality. The aim of this research project was to investigate and optimise the pilot scale separation performance of the Al-Hakkak Process using oat flour. As very little prior research had been carried out, the focus was to characterise the oat starch and protein separation performance and gain an understanding of the mechanisms involved. A variety of techniques were employed. Large scale deformation rheology was used to gain an understanding of the oat-gluten dough rheology and establish the relationship between the rheology and the separation performance. Confocal scanning laser microscopy was used to investigate the structure of the oat-gluten protein network. The molecular interactions between the oat and gluten proteins were studied using gel electrophoresis. The network-forming functionality of the new oat-gluten protein was explored. The influence of various processing parameters on the pilot scale separation performance was investigated and the results compared with other data collected through the study to identify key processing parameters. This research programme has resulted in interesting, encouraging and some unexpected outcomes and these are discussed in detail in the thesis. It was concluded that an insoluble protein network formed in the oat-gluten dough and both kneading and extraction processes were found to contribute to the formation of this. A key conclusion was that the changes that took place in the oat-gluten dough were similar to, but not identical to, the changes that occur in wheat dough. It was proposed that the mechanism for the development of a protein network in oat-gluten dough differed from wheat dough for two main reasons: a) the presence of the oat flour disrupted the normal wheat gluten behaviour, and b) components in the oat flour altered the activity of the gluten proteins. The research identified key processing parameters for the Al-Hakkak Process including kneading time, gluten content, and sodium chloride content of the oat-gluten dough as well as sodium chloride concentration, pH, and temperature of the extract liquor. An important discovery was that the oat and gluten proteins interacted at a molecular level through reducible, covalent, bonding (most likely disulphide linkages) to form the insoluble protein network in the oat-gluten dough. It was concluded that these reducible bonds coupled the individual protein subunits to form new hybrid oat-gluten protein molecules (a combination of oat proteins and gluten proteins). Both insoluble and soluble proteins in the oat and gluten flour were involved in the formation of the insoluble protein network in the oat-gluten dough. This outcome has applications beyond the Al-Hakkak Process, as this new knowledge can be applied to the wider dough processing industry. It was concluded that the wheat gluten was the source of the protein network-forming functionality of the hybrid oat-gluten protein and that the oat proteins had a diluting effect. It was proposed that oat-gluten protein flour from the Al-Hakkak Process could be reused to replace the commercial wheat gluten flour in subsequent production batches. During spray drying of the starch stream, the soluble biopolymers in the extract liquor were found to act as an adhesive and glued individual starch granules together to form spherical agglomerates. Acidification of the extract liquor was found to enhance this agglomeration. It was proposed the acidified starch granules were sticker during spray drying due to the partial acid hydrolysis of the starch granule suface which enhanced the agglomeration.
52

Oat and Barley Variety Tests

Cluff, Ronald C., Parsons, David K., Dennis, Robert E. 09 1900 (has links)
No description available.
53

The Effects of Oat Fiber and Corn Bran on Blood Serum Cholesterol and Triglyceride Levels

Broeder, Craig E. (Craig Elliot) 08 1900 (has links)
Forty Sprague Dawley rats were randomly placed in five groups with eight rats per group. Each group varied in dietary composition for fiber type and carbohydrate source. Groups one and two received oat fiber and either sucrose or corn starch as the carbohydrate source. Groups three and four received corn bran as the fiber source and either sucrose or corn starch as the carbohydrate source. Group five (considered the control group), received Purina standard rat chow. Analysis of variance showed only significant differences for food intake, and the control group had a significantly higher food intake. Weight gain, serum cholesterol and triglyceride levels showed no significant differences.
54

Pěstování ovsa v praktických podmínkách zemědělského podniku / The oat growing in terms of selected agricultural company

ZIMMERMANNOVÁ, Zlata January 2019 (has links)
The aim of the dissertation thesis was to find out the influence of fungicide and increased amount of nitrogen on the yield components of oat. The dissertation is divided into a literary overview and the thesis as such. In 2018 a pilot research was made on the land of a farm located in the district of Tábor. Atego oat was grown in four variants there: a control variant, a variant fertilized by nitrogen (without the usage of fungicide), a variant comprising fungicide application (without nitrogen fertilization) and a variant including both nitrogen fertilization and fungicide application. The highest theoretical yield was registered in the variant which contained fungicide as well as nitrogen. Regarding the yield components of oat, the highest number of plants and panicles was registered in the variant fertilized by nitrogen (without the usage of fungicide); the highest number of stolons and the maximum weight of one thousand grains was measured in the variant including both nitrogen fertilization and fungicide application. Finally, the highest number of grains in a panicle was obtained from a control variant.
55

Manejo nutricional de vacas primíparas aos 24 meses de idade / Nutritional management of primiparous cows 24 months old

Cadó, Lucas Munareto January 2016 (has links)
O experimento conduzido na Fazenda Rancho Santa Zelina, em Júlio de Castilhos, RS, entre julho de 2014 a setembro de 2015, analisou o desempenho reprodutivo de 42 vacas mestiças Angus primíparas aos 24/25 meses de idade postas no pós-parto em pastagem cultivada de aveia (Avena strigosa Schreb) e azevém (Lolium multiflorum Lam.). Aos 80 dias pós-parto foram distribuídas conforme peso (PC) e escore de condição corporal (ECC) em dois sistemas alimentares: SS – mantidas por 23 dias na pastagem cultivada e sete dias em pastagem natural; CS – mantidas por 23 dias na pastagem cultivada e sete dias em pastagem natural com a suplementação diária de 0,8% do PC de suplemento contendo 14% proteína bruta (PB) e 70% de nutrientes digestíveis totais (NDT). O método de pastoreio foi o contínuo com massa de forragem (MF) média de 1450 kg/ha de matéria seca (MS) em pastagem cultivada e 2150 kg/ha/MS em pastagem natural. O delineamento experimental foi o inteiramente casualizado, com dois sistemas alimentares e vinte e uma vacas por sistema alimentar, sendo cada vaca considerada uma unidade experimental. Para comparar os sistemas alimentares, as variáveis que apresentaram normalidade foram avaliadas utilizando o procedimento MIXED do SAS. A variável taxa de prenhez foi avaliada pelo teste do qui-quadrado. A suplementação não influenciou o peso (PCFT) e condição corporal final (ECCFT) das vacas, porém a variação de peso diária média das vacas do CS foi superior a das em SS durante os sistemas alimentares (0,465 kg e 0,227 kg, respectivamente). Os bezerros do CS nesse período apresentaram maior ganho médio diário, 0,829 kg comparado com aqueles do SS de 0,644 kg e maior peso final (130,86 kg e 117,29 kg, respectivamente). As vacas do CS tiveram a significativa maior taxa de prenhez de 80,95%, enquanto as do SS tiveram 57,14%. Aos 42 dias de acasalamento 80,95% das vacas do CS estavam prenhes, enquanto do SS apenas 28,57% já tinham concebido. Vacas primíparas aos 24 meses de idade e que irão conceber têm maior peso e escore de condição corporal ao início do acasalamento do que as futuras falhadas. / The experiment was conducted at the Farm Rancho Santa Zelina in Julio de Castilhos, RS, from July 2014 to September 2015, examined the reproductive performance of 42 crossbred cows Angus gilts to 24/25 months old put postpartum in cultivated pasture oat (Avena strigosa Schreb) and ryegrass (Lolium multiflorum Lam.). After 80 days postpartum were distributed as weight (BW) and body condition score (BCS) in two food systems:SS – 23 days in a cultivated pasture (Avena strigosa Schreb. e Lolium multiflorum Lam.) and 7 days in a natural grassland; CS – 23 days in the same cultivated pasture and 7 days in a natural grassland receiving 0,8% BW supplement with 14% crude protein (CP) and 70% total digestible nutrients (TDN). The grazing method was continuous with herbage mass (MF) average of 1450 kg/ha of dry matter (DM) in cultivated pasture and 2150 kg/ha/DM in natural pasture. Treatments were arranged in a completely randomized design with two food systems and twenty-one cows for feeding system, where each cow was considered an experimental unit. To compare the food systems, variables with normal distribuition were assessed using the SAS MIXED procedure. The pregnancy rate was evaluated using the chi-square test. Supplementation did not affect cows‟ final body weight (FBW) and final body condition (FBC), but the daily average weight variation of cows in CS was higher than in SS (0.465 kg and 0.227 kg, respectively). The CS calves this period had higher average daily gain, 0.829 kg compared to those of the SS 0.644 kg and higher final weight (130.86 kg and 117.29 kg, respectively). The 80.95% pregnancy rate of the CS cows was higher than the 57.14 % of SS cows. After 42 days of mating, 80.95% of the CS primiparous cows had conceived, against just 28.57% from the SS. Primiparous cows at 24/25 months old and that will get pregnant have higher BW and BCS at beginning of the mating than the open ones.
56

Zamenjivači masti na bazi pšeničnih i ovsenih mekinja i njihova primena u formulaciji keksa / Wheat and oat bran based fat replacers and their application in cookie formulation

Milićević Nataša 26 November 2018 (has links)
<p>Sporedni proizvodi dobijeni u procesu mlevenja žitarica, p&scaron;enične i ovsene mekinje, hidrotermički su tretirane u cilju dobijanja gelova, koji se, kao zamenjivači masti, mogu koristiti u formulacijama prehrambenih proizvoda. Optimizacija procesnih parametara (koncentracija mekinja, vreme homogenizacije i temperatura homogenizacije) proizvodnje gelova vr&scaron;ena je primenom postupka odzivne funkcije (RSM). Gelovi od p&scaron;eničnih i ovsenih mekinja, koji su pripremljeni po prethodno utvrđenim optimalnim parametrima (za p&scaron;enične mekinje: 22,0% koncentracija mekinja, vreme homogenizacije od 11,7 min i temperatura homogenizacije od 83,2&deg;C; za ovsene mekinje: 22,0% koncentracija mekinja, vreme homogenizacije od 10,0 min i temperatura homogenizacije od 95,0&deg;C), su, dalje, kao zamenjivači masti, bili inkorporirani u formulaciju keksa na različitim nivoima supstitucije masti (30%, 40% i 50%).<br />Fizičke, teksturne i senzorske karakteristike keksa sa zamenjivačima masti ispitane su u poređenju sa kontrolnim (punomasnim) keksom, te je nivo zamene od 30% izabran kao najpogodniji u smislu sniženja sadržaja masti, sa jedne strane, i ostvarenja željenih karakteristika, sa druge strane.<br />S obzirom da su proizvedeni zamenjivači masti na bazi mekinja nutritivno vredni i bogati funkcionalnim komponentama, ustanovljeno je da je dodatak ova dva funkcionalana zamenjivača masti na nivou od 30% doprineo pobolj&scaron;anju nutritivnih i funkcionalnih svojstava keksa u pogledu povećanog sadržaja prehrambenih vlakana i minerala, povoljnijeg odnosa PUFA/SFA, kao i porasta sadržaja antioksidativno delotvornih komponenti.</p> / <p>Wheat and oat brans, by-products of grain processing, were processed by hydrothermal treatments into the form of gels for partial replacement of fat in food products.<br />Response surface methodology (RSM) approach was applied to examine the effects and to optimize process parameters (bran concentration, homogenization time and homogenization temperature).<br />Wheat and oat bran gels prepared according to the previously determined optimal parameters (for wheat bran: 22.0% bran concentration, homogenization time of 11.7 min and homogenization temperature of 83.2 &deg;C; for oat bran: 22.0 % bran concentration, homogenization time of 10.0 min and homogenization temperature of 95.0 &deg;C) were further incorporated as fat substitutes into the cookie formulation at different levels of substitution (30%, 40% and 50%).<br />The physical, texture and sensory properties of cookies with fat replacers were examined in comparison with the control (full fat) cookies, and the fat replacement level of 30% was chosen as the most suitable in terms of reducing the fat, on the one hand, and achieving the desired mentioned characteristics, on the other.<br />Knowing that the produced fat replacers are nutritionally valuable and rich in functional components, it has been found that the addition of these two functional fat replacers at the level of 30% contributed to the improvement of the nutritional properties of cookies in terms of higher content of dietary fibers, minerals and more favourable ratio of PUFA/SFA, as well as higher content of antioxidant components.</p>
57

Métodos de extração e qualidade da fração lipídica. / Extraction methods and quality of the lipid fraction.

Brum, Aelson Aloir Santana 10 January 2005 (has links)
Um estudo crítico foi realizado utilizando quatro métodos clássicos de extração de lipídios em aveia em flocos e peito de frango. Foram comparados os rendimentos, o tempo de extração, a repetibilidade de cada método e a qualidade oxidativa da fração lipídica obtida. As metodologias utilizadas foram as de Soxhlet, com n-hexano como solvente, nos períodos de quatro e oito horas de extração; Folch et al., com clorofórmio e metanol na proporção de 2:1 (v/v); Bligh & Dyer, com clorofórmio, metanol e água na proporção de 1:2:0,8 (v/v) e Hara & Radin, com n-hexano e isopropanol, na proporção de 3:2 (v/v). Os resultados obtidos indicaram que para a aveia em flocos, os métodos de Soxhlet e Bligh & Dyer apresentaram um rendimento superior (7,71 % e 7,66 %, respectivamente) em relação ao método de Hara & Radin e Folch et al. (6,61 % e 6,93 %, respectivamente). No estudo do peito de frango, os métodos de Soxhlet, Folch et al. e Bligh & Dyer apresentaram um rendimento satisfatório de lipídios totais, sendo, respectivamente, de 1,56 %, 1,56 % e 1,65 %. Apesar do bom rendimento em lipídios totais, o método de Soxhlet afetou a qualidade da fração lipídica em ambas amostras, demonstrada pela presença de peróxidos (4,39 e 4,19 meq O2/kg no peito de frango; 3,71 e 3,70 meq O2/kg na aveia em flocos) e pela acidez oléica (2,58 % de ácidos graxos livres (AGL) no peito de frango; 2,25 e 2,24 % AGL na aveia em flocos), em ambos os períodos de tempo da extração. Com base nos resultados deste trabalho, indica-se a metodologia de Bligh & Dyer para os casos em que haja interesse em uso posterior das frações lipídicas, em detrimento da de Soxhlet, não recomendável para o fim mencionado. / A critical study was carried through with four clasical methods of extraction of lipids from chicken breast and oat flakes. The yield, the extraction time, the repeatability of each method and the oxidative quality of the lipid fraction were evaluated and compared. The methodologies evaluated were Soxhlet, with n-hexane as the solvent, in periods of four and eight hours of extraction; Folch et al., with chloroform and methanol in the ratio of 2:1 (v/v); Bligh & Dyer, with chloroform, water and methanol, in the ratio of 1:2:0.8 (v/v), and Hara & Radin, with n-hexane and isopropanol, in the ratio of 3:2 (v/v). The results indicated that for oat flakes, the methods Soxhlet and Bligh & Dyer presented higher yields in total lipids (7.71 % and 7.66 %, respectively) than the methods Hara & Radin and Folch et al. (6.61 % and 6.93 %, respectively). In the study with chicken breast, the methods Soxhlet, Folch et al. and Bligh & Dyer presented the highest yields, being respectively 1.56 %, 1.56 % and 1.65 %.Despite the good yields in total lipids, the Soxhlet method affected the quality of the lipid fraction in both samples, demonstrated by the presence of peroxides (4.39 and 4.19 meq O2/kg in chicken breast; 3.71 and 3.70 meq O2/kg in oat flakes) and by the acid values (2.58 % FFA [free fatty acids] in chicken breast for both extractions; 2.25 and 2.24 % FFA in oat flakes,) for both periods of time evaluated. Based on the results obtained in this research, the authors recommend Bligh & Dyer methodology whenever there is interest in further use of the lipid fraction and strongly disencourage Soxhlet method for the purpose mentioned.
58

Effects of dietary inclusion levels of a low lignin hull, high-oil groat oat on the performance, carcass characteristics and rumen fermentation characteristics of feedlot cattle

Arya, Sushama 17 March 2010
Two experiments were conducted to evaluate the effects of dietary inclusion level of a low lignin hull, high-oil groat (CDC SO-I) oat on the performance, carcass characteristics and rumen degradation characteristics of feedlot cattle. In the first trial, 200 crossbred steers (average weight of 427.3 ± 22.4 kg) were allocated to 20 pens. Five treatments, formulated by replacing barley with increasing levels of CDC SO-I oat (Barley grain:CDC SO-I oat ratios of 100:0; 75:25; 50:50; 25:75 and 0:100 ; DM basis) were used. Four pens were randomly allocated to each treatment diet. Over the entire study there was a linear decrease (P< 0.01) in DMI and ADG with increasing inclusion level of CDC SO-I oat, whereas feed efficiency (gain:feed) decreased (P= 0.03) quadratically. Days on feed also increased (P= 0.03) quadratically for the steers fed the higher levels of CDC SO-I oat. Increasing the inclusion level of CDC SO-I oat in the diet also decreased (P< 0.01) carcass weight, dressing percentage and grade fat linearly. However, there was no effect of treatment on rib eye area and lean yield percentage. There was no significant effect of treatment on marbling score. While the results of this trial point to a negative effect of CDC SO-I oat on finishing performance, there were minimal differences between cattle fed 100% barley as the concentrate versus those fed 75% barley: 25% oat blend.<p> Trial 2 involved a metabolism trial to determine the effect of CDC SO-I oat inclusion level on rumen fermentation parameters of 5 fistulated heifers fed the same diets used in Trial 1. A 5 × 5 Latin square experiment design was used. Rumen degradation parameters (rumen pH, VFA, osmolality and ammonia nitrogen levels) and feeding behavior (time spent eating, ruminating, chewing and drinking) were measured. Mean rumen pH for the barley-based diet was 5.88 which was not different (P> 0.05) than the mean pH of 5.5 for the oat-fed cattle. Treatment did not affect (P> 0.05) time spent below pH cutoff values of 5.8, 5.5 and 5.2. No effect of oat inclusion level (P> 0.05) was observed on total VFA levels, molar proportion of individual fatty acids and osmolality while isobutyrate (P= 0.05) and ruminal ammonia nitrogen concentrations decreased linearly (P= 0.02) with the higher inclusion of CDC SO-I oat. Time spent eating was linearly (P< 0.01) increased with higher inclusion level of CDC SO-I oat.<p> Over all, the results of this study indicate that the replacement of barley by CDC SO-I oat in finishing diets decreases dry matter intake and as a result leads to reduced ADG, increased days on feed and lower slaughter and carcass weights. The reduced performance might be the result of higher fat content, high hull and/or faster degradation rate of oat starch leading to subacute ruminal acidosis in cattle fed higher levels of oat. However, replacing barley with CDC SO-I oat does not significantly change the rumen environment. The results of this study indicate that CDC SO-I oat can be successfully included up to a maximum level of 25% without any adverse effect on performance and carcass characteristics in the diets of finishing cattle.
59

The influence of microsite and seed limitation on annual weed seedling recruitment in arable agriculture

Forster, Glen Gregory 04 April 2005
The germination and emergence of a seedling, or seedling recruitment remains an essential process in the establishment of a plant. This establishment can be limited by the availability of microsites within the soil profile, or the availability of seed within a given area. Three field experiments were initiated in Saskatchewan, Canada to examine the relative effect of seed and microsite limitations on weed seedling recruitment. The first experiment examined the effect of landscape position as well as nitrogen (N) rate and tillage system (zero tillage vs. conventional tillage) on weed seedling recruitment from an indigenous weed population. Survey results indicated habitat differentiation of the weed population with wild oat and cleavers preferentially recruiting in the lower landscape positions, Russian thistle and Kochia in the upper landscape positions, while green foxtail recruited in high levels on all landscape positions. This suggested that different weed species have different microsite requirements for weed seedling recruitment across contrasting landscape positions. The second field experiment examined the effect of landscape position and moisture availability on weed seedling recruitment from an artificial hand-seeded weed seedbank. This experiment indicated that seed limitation remained a very important factor, but even when irrigated, total seedling recruitment did not reach maximum recruitment, indicating water was not the only limiting resource for weed seedling recruitment. Microsite limitations were greatest on the upper slope position for all species with green foxtail having the greatest overall recruitment of the species across all landscapes and moisture regimes. The third experiment examined the effect of tillage system and density on weed seedling recruitment of wild oat, green foxtail, and wild mustard. Again, weed seedling recruitment remained a function of both microsite and seed limitations as absolute recruitment values increased for each density examined in this experiment. The agronomic significance of microsite limitation was negligible as high weed population numbers occurred for the highest weed seeding densities. Overall, microsite limitations remained negligible in these experiments for arable agriculture with the main influence on weed seedling recruitment most often being seed limitation in the natural seedbank.
60

Weed management in reduced-input no-till flax production

Gillespie, Scott 13 September 2006 (has links)
The goal of the project was to enhance the period of weed growth prior to seeding in order to reduce weed emergence and weed competition after the crop has been planted. Weed growth was stimulated using either light tillage or by applying nitrogen fertilizer early in the spring. Light disturbance significantly increased pre-seed weed emergence while early applied nitrogen did not appear to have an effect. Post seeding weed emergence levels and weed biomass were similar among the light tillage and early nitrogen treatments. Therefore the goal of decreasing weed competition after seeding was not attained. Future research should focus on long-term strategies to reduce weed populations in field rather than seasonal strategies. / October 2006

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