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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.
1

Nutritional and Microstructural Responses in Cereal Grains to Heat-Related Processing Methods

2015 October 1900 (has links)
Cereal grains share many common traits, but they also have different internal structures, nutrient values, degradation kinetics and digestion features. Heat treatments are commonly used in the feed industry. It is known that heat is able to change the nutrient values of the feed but the effect could be equivocal. In order to understand the effects of heat processing on internal structure and nutrient availability of cereal grains, two batches of wheat, triticale and corn were divided into three groups (control/raw (unheated), dry heating and moist heating) and processed at 121 °C for 80 min. Basic chemical analysis and in situ, in vitro assays were conducted and CNCPS, DVE/OEB and NRC-2001 models were used to determine the nutrient availability of the grains. In addition, two mid-IR molecular spectroscopy techniques (Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) and Synchrotron Radiation Infrared Microspectroscopy (SR-IMS)) were used to gain an insight into the heat-induced changes in the functional groups. Significant (P<0.05) differences were found between the cereal grains in their nutritional availabilities, including their chemical characteristics, protein and carbohydrate fractions, energy values, the ruminal degradation kinetics, hourly effective rumen degradation ratios, potential N-to-energy synchronization, and intestinal digestion of cereal grains. Compared to dry heating, moist heating had more impact on altering the nutrient profiles and showed the potential to increase the nutrient availability of wheat and triticale for dairy cattle. Significant differences (P<0.01) were detected between different feeds and heat treatment groups by using the ATR-FTIR technique. Results were found in consistency with the conventional chemical and animal studies mentioned above despite when using the SR-IMS technique. Significant (P<0.05) correlations were detected between some structure spectral characteristics and nutrient digestion traits. In conclusion, the moist heating had more profound impact than the dry heating in increasing nutrient supplies to ruminants in wheat and triticale. The heat-induced effects found in corn were less positive. The ATR-FTIR technique could detect the internal structural changes in cereal grains, while the sensitivity and accuracy of the SR-IMS technique were not proved in this study.
2

Commercial Production of Wheat Grain Irrigated with Municipal Wastewater

Day, A. D., McFadyen, J. A., Tucker, T. C., Cluff, C. B. Unknown Date (has links)
Authors' manuscript; no date on item. / Experiments were conducted in southern Arizona to study the effects of irrigating wheat (Triticum aestivum L.) with a mixture of pump water and wastewater and pump water alone on wheat growth, grain yield, grain quality, soil properties, and irrigation water quality. In small plot research, wheat irrigated with a mixture of pump water and wastewater produced taller plants, more heads per unit area, heavier seeds, higher grain yields, and higher straw yields than did wheat grown with only pump water. When large fields were compared, wheat grown with a mixture of pump water and wastewater had taller plants, more lodging, lower grain volume-weights, and higher grain yields than did wheat produced with pump water. The pH and exchangeable sodium of soil irrigated with pump water alone or a mixture of pump water and wastewater were similar. Electricalconductivity and nitrate-nitrogen were higher in soils irrigated with pump water than they were in soils irrigated with a mixture of pump water and wastewater. Extractable phosphorus was higher in soils irrigated with a mixture of pump water and wastewater than in soils irrigated with pump water. Total soluble salts and nitrate-nitrogen were higher in pump water than they were in the pump water and wastewater mixture; however, the pump water and wastewater mixture had a higher level of phosphorus than did pump water.
3

Potential of Wastewater for Commercial Barley Production

Day, A. D., McFadyen, J. A., Tucker, T. C., Cluff, C. B. 21 March 2014 (has links)
No date on item; authors' manuscript. / Experiments were conducted in southern Arizona to investigate the effects of irrigation with pump water and a pump water-wastewater mixture on barley (Hordium vulgare L.) growth, grain yield, and grain quality; soil properties; and irrigation water quality. In 1974 and 1975, on small plot research, barley irrigated with a 50:50 mixture of pump water and wastewater significantly exceeded barley irrigated with pump water alone in plant height, number of heads per unit area, number of seeds per head, seed weight, grain yield, and straw yield. In large field studies conducted from 1970 through 1977, barley irrigated with the mixture had taller plants, more lodging, lower grain volume-weights and higher grain yields than barley irrigated with pump water alone. Soils irrigated with both types of irrigation water had similar pH. Soluble salts (ECx103), exchangeable sodium percentage, nitrate-nitrogen, and extractable phosphorus were significantly higher in soils irrigated with the pump water-wastewater mixture than in soils irrigated with pump water. Water quality analyses showed that the pump water-wastewater mixture had lower total soluble salts, lower nitrate-nitrogen, and higher phosphorus levels than pump water alone.
4

Absorption and accumulation of cadmium from cereal grains

Moberg Wing, Anncatherine January 1993 (has links)
Cadmium (Cd) is a potentially toxic trace element. Cereal grains contribute one-third to one-half of the Cd exposure via the diet. Among cereal grains, wheat generally contains the highest Cd concentration and the bran and germ fractions contain more Cd than the endosperm. An increase in the consumption of unrefined grains may cause an increase in the body burden of Cd if an increase in the exposure to Cd via the diet leads directly to increased Cd absorption and accumulation. However, there is evidence that certain factors may reduce the availability of Cd for absorption from the diet. The purposes of these studies were to refine an atomic absorption spectrometric method for measuring the accumulation of Cd from diets with low, naturally occuring concentrations of Cd, to evaluate the extent to which Cd is accumulated from different milling fractions of wheat and from different cereal grains, and to determine to what extent the presence of certain minerals and mineral-binding factors in the diet and the iron (Fe) status of the individual affect Cd accumulation from cereal grain diets. The results of the method studies showed that the amount of Cd in the liver and kidneys of rats after six weeks on different diets and the retention of 109Cd in these organs three weeks after the ingestion of 109Cd-labelled test meals of the diets were in agreement on the fractional and total accumulation of Cd from the diets. To a first approximation, the accumulation of Cd in the liver and kidneys in rats appears to be the product of the separate effects of the concentration of Cd in the diet which is available for absorption and the Fe status of the rats. The Cd concentration in grains varied by a factor of five between whole wheat and rye and the amounts of Cd accumulated in rats from diets with whole grains were nearly proportional to the Cd concentrations in the grains. The fractional accumulation of Cd was lower in rats given diets with whole grains or wheat fractions high in fiber and phytic acid than in rats fed endosperm wheat diets. This lower fractional Cd accumulation did not compensate for the high Cd concentrations in whole wheat and wheat bran. The fractional accumulation of Cd in the liver of rats is inversely related to their Fe status. The fractional Cd accumulation in the liver of rats with low Fe status was as much as ten times that in rats with high Fe status. The Cd accumulation in the kidneys appears to be even more sensitive to Fe status. The accumulation of Cd in human placenta supports these conclusions. Women who eat diets with less cereal grain fiber and who also maintain their Fe stores during pregnancy generally accumulate less Cd in the placenta than those who eat more grain fiber and/or have lower Fe status. On the basis of these results, it is recommended that as much as possible of the dietary fiber from cereal grains should derive from grains with low Cd concentrations. It is also imperative that the diet provide sufficient Fe and other nutrients to promote Fe status and thereby limit Cd accumulation. / <p>Diss. (sammanfattning) Umeå : Umeå universitet, 1993, härtill 5 uppsatser.</p> / digitalisering@umu
5

Characterisation of chemical components in manually isolated aleurone and associated layers from maize, wheat and barley kernels

Ndolo, Victoria Uchizi January 2015 (has links)
Health benefits related to consumption of whole grains have been attributed in part to phytochemical and micronutrient composition. Understanding the composition, structure and distribution of these components in different cereal grains is of potential importance in aiding the selection of whole grains and their processed fractions for inclusion in the diet, and as ingredients in development of new food products. The aim of this research was to characterise the chemical components in the botanical fractions of yellow corn, barley, wheat. Manual separation, a tedious and laborious technique that yields pure fractions, suitable for compositional analysis, was used to separate whole grains into pericarp, aleurone layer, germ and endosperm fractions. Component identification and quantification of tissue components was accomplished by several techniques. The study also explored the possibility of using spectral characteristics fluorescence intensity values to provide rapid estimates of the concentrations and distribution of ferulic acid (FA), a major phenolic compound in cereal grains. While composition of phenolic acids and carotenoids was similar, the distribution was significantly different (P < 0.05) among cereal types and grain fractions. Phenolic acids were concentrated in pericarp and aleurone fractions, followed by the germ and the endosperm had the lowest levels. Yellow corn exhibited the highest values. Carotenoids, lutein and zeaxanthin were concentrated in the germ and aleurone layer of wheat and barley while in yellow corn it was in the endosperm and aleurone layer. This is the first study to report on carotenoid composition of aleurone fractions. Mineral elements, thiamine and niacin were higher in wheat aleurone than in purple barley and yellow corn aleurone layers. These findings suggest that yellow corn aleurone layers have potential as a functional food ingredient despite the low micronutrient content. A positive, significant correlation (r= 0.421, p < 0.0001) was found between fluorescence intensity values and ferulic acid concentration. Thus, fluorescence intensity profiles are a promising approach for rapid assessment of FA concentration in grain in-situ. This work has provided information that would act as a database for selection of cereal fractions and guide the miller to obtain grain fractions with enriched levels of phytochemicals and micronutrients. / February 2016
6

Virus-induced gene silencing of putative Diuraphis noxia (Kurdjumov) resistance genes in wheat

Starkus, Laura January 1900 (has links)
Master of Science / Department of Entomology / C. Michael Smith / The Russian wheat aphid Diuraphis noxia (Kurdjumov) is a serious pest of world cereal grain crops, primarily barley and wheat. A phenotypic characteristic of D. noxia feeding, leaf rolling, creates a leaf pseudo gall which protects aphids, making it difficult to treat infested plants with insecticides or biological control agents. Therefore, the use of D. noxia-resistant crops is a desirable aphid management tactic. Because of the development of virulent D. noxia biotypes, the identification of new sources of barley and wheat resistance is necessary. Virus-induced gene silencing (VIGS) utilizes the plant defense system to silence viruses in inoculated plants. The accumulation of virus RNA in plants triggers the defense system to silence sequences homologous to the introduced virus and sequences of interest from a plant are inserted into the virus and silenced along with the virus. The VIGS method was tested to determine the ability of barley stripe mosaic virus (BSMV) to serve as a VIGS vector in wheat plants containing the Dnx gene for resistance to D. noxia. Dnx leaves with silenced BSMV virus yielded D. noxia populations that were significantly no different from populations produced on healthy Dnx leaves. Thus, BSMV silencing does not interfere with Dnx resistance. Several different methods were examined to determine how best to confine aphids to the silenced leaf, and a modified plastic straw cage was chosen as the optimum cage type. Microarray and gene expression data were analyzed to select two NBS-LRR type disease resistance protein genes - TaAffx.104814.1.S1_at and TaAffx.28897.1.S1 - (NBS-LRR1 and NBSLRR2), in order to assess their role in Dnx resistance. NBS-LRR1 and NBSLRR2 were silenced by inoculating leaves of Dnx plants with barley stripe mosaic virus (BSMV) containing sequences of each gene. Controls included Dnx and Dn0 plants inoculated with BSMV and non-BSMV inoculated plants. Aphids were allowed to feed on control and treatment plants to assess aphid population and mean weight of aphids surviving at the end of the experiment. There were no differences among treatments based on aphid population, but there were significant differences the mean weights of aphids reared on several different treatments.

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