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Chemical, color, and sensory attributes of sorghum bran-enhanced beef patties in a high oxygen environmentJenschke, Blaine Edward 12 April 2006 (has links)
Bottom rounds were shipped to the Rosenthal Meat Science and Technology Center, ground and enhanced with one of the following predetermined treatments: control; 0.4% sodium phosphates and 0.3% salt; 0.25% sorghum bran; 2.0% sorghum bran; 0.25% sorghum bran, 0.4% sodium phosphates and 0.3% salt; and 2.0% sorghum bran, 0.4% sodium phosphates, and 0.3% salt. The ground beef was formed into 226 g ground beef patties, packaged in an 80% O2 and 20% CO2 gaseous environment, and stored under retail display at 4 degrees for 0, 3, 6, or 9d. Measurements to determine rate and extent of oxidation, rate of discoloration, and sensory characteristics were taken to evaluate the effectiveness of sorghum bran.
Patties containing the highest amount of sorghum bran had the lowest TBARS values over 9 days of storage, lower a* values, greater amounts of discoloration, darker lean color, and less cook loss (P<0.05) than control patties. Patties enhanced with the highest level of sorghum bran had lower beefy/brothy and bloody flavor aromatics, higher sorghum flavor, more bitter and burnt aftertaste, and more sandy/gritty textures (P<0.05) when compared to control patties. Patties containing the low amount of sorghum had lower TBARS values (P<0.05), but similar amounts of cook loss as the control patties. Patties containing a low sorghum level, 0.4% sodium phosphates (SP) and 0.3% salt (S) had lower (P<0.05) amounts of cook loss when compared to control patties. Patties containing low amounts of sorghum were similar to control patties in terms of redness while the addition of low sorghum, SP, and S decreased (P<0.05) the degree of redness. Patties containing low amounts of sorghum bran had similar amounts of discoloration compared to control (CONT) patties. Also, these had less bloody flavor aromatics (P<0.05), but were similar in sorghum flavor aromatics and bitter taste when compared to control patties.
The addition of sorghum bran at low levels can retard oxidative rancidity in ground beef patties without causing detrimental color changes and negatively affecting sensory attributes, while patties enhanced with 2% sorghum bran have extensive discoloration and undesirable sensory attributes.
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Investigation of the characteristics of ammonia-oxidation bacteria and novel nitrogen removal technologiesTsai, Ruo-lin 29 July 2009 (has links)
Use of nitrifying and denitrifying bacteria to remove ammonia from waste water had been studied for a long time due to their high efficiency and low cost. Nitrifying bacteria not only grow slowly but also require high concentration of oxygen to facilitate the nitrifying process. Moreover, the followed denitrifying process needs the supply of adequate carbon sources for denitrifying bacteria to avoid greenhouse gas emission from the system. It shows the operational control to remove ammonia from waste water would be very difficult. Therefore, it is important to study the physiological and biochemical characteristics of those nitrifying and denitrifying bacteria closely. In 1995, Mulder discovered the disappearance of ammonium at the expense of nitrate and nitrogen production from their denitrifying pilot plant in the Netherlands, then van de Graaf verified an ANAMMOX reaction in the laboratory. Further studies that have revealed the combination of aerobic nitrification and anaerobic ammonium oxidation is more efficient to remove ammonia than most conventional methods. The ANAMMOX process is performed by a group of Planctomycete which involves the oxidation of ammonia anaerobically with nitrite as the final electron acceptor to yield gaseous nitrogen. Since this process is no need of supply external carbon source and oxygen, the ANAMMOX system can offer the advantages of less cost, less microbial contamination and less N2O and NO emission to the environment. This study is to summarize the bacterial species diversity, distribution in nature, their physiological characteristics, and potential biochemical pathways of those nitrogen converting microorganisms. In addition, several novel nitrogen removal technologies are also discussed for further understanding of the process optimization under both aerobic and anaerobic conditions.
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One-site addition two-metal oxidation reactions of unsymmetrical bimetallic complexes related to dioxygen binding by hemerythrin /Gavrilova, Anna Leonidovna. January 2003 (has links)
Thesis (Ph. D.)--University of Chicago, Dept. of Chemistry, December 2003. / Includes bibliographical references. Also available on the Internet.
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Development of microreactor systems for electrocatalytic studies of methanol oxidation at elevated temperatures /Arvindan, Nallakkan Subbiah. January 2003 (has links)
Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (leaves 183-191).
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Kinetics and mechanisms of redox reactions of some macrocyclic tertiary anine complexes of ruthenium /Lau, Keung. January 1988 (has links)
Thesis (Ph. D.)--University of Hong Kong, 1988.
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High-valent ruthenium and osmium oxo complexes for homogeneous and photochemical oxidations of inorganic and organic substrates /Yam, Wing-wah, Vivian. January 1988 (has links)
Thesis (Ph. D.)--University of Hong Kong, 1988.
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Oxidative chemistry on gold : unraveling molecular transformations at surfacesGong, Jinlong, 1979- 16 October 2012 (has links)
Gold has been considered catalytically inert due to its resistance to oxidation and corrosion. However, decades ago, it was discovered that gold nano-particles (<5nm) on metal oxides demonstrate superior chemical activity towards many reactions. These seminal findings spurred considerable interest in investigations of the mechanistic details of oxidative reactions on gold-based catalysts. However, the active site and structure of supported Au nanoclusters as well as the active oxygen species remains elusive. Achieving high selectivity toward partial oxidation products also remains a challenge. In this dissertation, an oxygen-covered Au(111) crystal under ultra vacuum conditions was used as a model system to gain insights into oxidative reactions in gold-based catalysis. I have been able to demonstrate that (i) surface-bound oxygen atoms are metastable at low temperature; (ii) the oxygen atoms participate in surface reactions as a Brønsted base or a nucleophilic base; and (iii) the acid-base reactions that have been observed on silver and copper may also occur on gold. Low temperature CO oxidation and the associated mechanistic aspects are investigated. CO reacts with hydroxyls formed from water-oxygen interactions to produce CO₂ on Au(111) populated with atomic oxygen at low temperatures. Directing an ¹⁶O beam toward C¹⁸O₂ pre-adsorbed Au(111), the formation of carbonate is significantly enhanced. This reaction is suggested to follow a hot-precursor-mediated mechanism. The identification of reaction pathways in oxidation of N-containing molecules such as ammonia and propylamine is presented. Abstraction of hydrogen from ammonia or propylamine by O atoms is the initial step in the surface decomposition of NHx (or RNHx-1) on Au(111). Atomic oxygen or hydroxyl-assisted dehydrogenation steps have lower barriers than the recombination steps under relevant conditions. 100% selectivity of N₂ or propionitrile can be obtained if the oxygen coverage is below the stoichiometric value. The surface oxidative chemistry of alcohols on Au(111) is also investigated. Except for methanol that is fully oxidized, alcohols initially undergo O-H bond cleavage (producing alcoxides) followed by selective β-C-H bond activation to form aldehydes or ketones. This finding reveals that the interaction of Au with the metal oxide support might not be essential to facilitate the reactions if active oxygen species are readily present, particularly at low temperatures. / text
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Molecular characterization of Chinese medicines for the regulation of the intracellular redox signalingQi, Hongyi., 齐红艺. January 2011 (has links)
published_or_final_version / Chinese Medicine / Doctoral / Doctor of Philosophy
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The effect of ammonia and its oxidation products upon the soil, its microbial population, and the growing plantDuisberg, Peter Caspar, 1919- January 1945 (has links)
No description available.
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MECHANISTIC STUDIES OF SELENIUM-DIOXIDE OXIDATIONSKlein, Howard Paul, 1941- January 1968 (has links)
No description available.
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