Thesis (Ph. D.)--University of Wisconsin--Madison,1984. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographies.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1981. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

No description available.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1966. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin--Madison, 1968. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Submitted to the faculty of Indiana University In partial fulfillment of the requirements for the degree Master in Bioinformatics In the School of Informatics, Indiana University, December 2004 / The aggregation rate of B-Lactoglobulin (BLG) was studied using turbidimetry and dynamic light scattering in the range 5.8<pH,3.5 at a fixed ionic strength of 4.5 mM, and in the range 4.5 - 500mM NACl at a fixed pH of 5.0. The initial slope of turbidity vs time curve was used to define an initial rate. The highest initial rates of aggregation were observed in the pH range 4.50 to 4.75 but the increase in aggregation rate when the pH was reduced from 5.0 to 4.69 was large compared to its decrease when the pH was reduced from pH 4.69 to 4.20; i.e. the dependence of initial rate on pH was highly asymmetric. The rate of aggregation at pH 5.0 strongly increased with decrease in ionic strength I from 100 to 4.5 mM and was found to be nearly linear with 1/ I. QELS measurements at pH 5.22 and 5.40 at I = 4.5mM revealed that particle size increased with time. Eventual appearances of bimodal distributions showed fast and slow modes corresponding to the BLG dimer and to hydrodynamic diameter 100-800 nm. Measurements at 4.0 and 4.2 indicated the consumption of dimers in the first few minutes to form higher order aggregates. Electrostatic modeling via Delphi was used to visualize the electrostatic poetnetial around the BLG dimer in order to elucidate the pH and ionic strength dependence of BLG aggregation rates. The aggregation process appears to comprise firstly an initial fast consumption of dimer, whose dependence on pH and I arises from the interaction of the positive and negative domains of interacting dimers; and secondly, the slow formation of much larger aggregates with relatively little sensitivity to pH and I. The open-ended nature of BLG aggregation is thought to arise from the asymmetry of the dimer charge distribution in the range 4.2<pH<5.2. Polyanions appear to inhibit aggregation. However, the role of polyanions in minimizing BLG aggregation was observed immediately after the addition of polyanioin to the protein. / Bioinformatics

In recent years there have been two cycloterpenals, molecules consisting of a cyclohexadienal core, isolated from nature. Cyclocitral, the condensation product of citral, has been isolated from the North Sea bryozoans Flustra foliacea. In the human eyes, cycloretinal has been isolated and is a toxic by product of the vision cycle. This retinal dimer is believed to contribute to age related macular degeneration, the leading cause of blindness in the elderly. In 1992, it was discovered that if [beta]-ionylideneacetaldehyde was incubated with beta-lactoglobulin ([beta]-LG), the principal whey protein in dairy milk, that it would mediate the formation of cyclo-[beta]-ional. No follow up studies were performed on this protein mediated reaction or what biological activities these cycloterpenals may possess. This dissertation investigates the biological roles of substituted cyclohexadienes including cycloterpenals and cyclohexadiene enaminonitriles. To mimic the protein mediated reaction, we developed a synthetic procedure to produce a wide array of cycloterpenal by utilizing L-proline. Over 100 cycloterpenals were synthesized and screened for their biological activities against an array of cell based screens. The phenotypic effects of these cycloterpenals were screened against a PC12 assay where dramatic effects were observed on neurite outgrowth. During the synthesis of starting materials for the production of our cycloterpenal library, it was discovered that if excess base was added to the Horner-Wadsworth-Emmons reaction between a methyl-ketone and diethyl-(cyanomethyl)-phosphonate, conversion of the [alpha]-[beta]-unsaturated nitrile into an enaminonitrile was observed. This new synthetic procedure was optimized to generate a library of enaminonitriles as well as their quinazoline derivatives. The work within also includes the investigation of the [beta]-LG mediated reaction formation of cycloterpenals with natural and unnatural [beta]-methyl aldehydes. We were able to demonstrate that [beta]-LG could mediate the conversion of [alpha],[beta]-unsaturated aldehydes into their corresponding cycloterpenal. In vitro analysis was also performed with store bought milks and the [beta]-LG present was able to mediate the formation of cyclocitral. An in vivo experiment was also performed by utilizing New Zealand White rabbits to demonstrate the formation of cycloretinal within the blood stream by feeding a source of [beta]-LG with retinal. Interestingly, in human blood, [beta]-LG is present at concentrations of 0.7-1.2 g/dL. The protein has been identified within drusen pigments and lipofuscin granules that accumulate in the retina of macular degeneration patients. As humans do not produce beta-lactoglobulin, the source of this protein is from milk and milk products. With these experiments, we clearly demonstrate that under the appropriate conditions, cycloretinal can be produced with [beta]-LG. We have clearly established a direct link between [beta]-LG chemistry and age-related macular degeneration.

Orientador: Carlos Alberto Gasparetto / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-03T18:07:35Z (GMT). No. of bitstreams: 1 Guimaraes_DanielaHelenaPelegrine_D.pdf: 1470612 bytes, checksum: ba6feee7cf8f1d21e4fb3eb2315b6ebb (MD5) Previous issue date: 2003 / Resumo: Este é um trabalho sobre a incrustação de proteínas de origem animal, b-lactoglobulina e ovoalbumina, sobre superfícies cilíndricas aquecidas, comuns nos equipamentos de tratamento térmico e de concentração por evaporação. A incrustação é um fenômeno de transferência de massa que é uma função da solubilidade dessas proteínas. Para descrever a cinética da incrustação foi desenvolvido um algoritmo de cálculo que teve como subsídio a solubilidade das proteínas. A solubilidade foi determinada experimentalmente na faixa de 40-60°C, incluindo a dependência do pH na faixa de 3,5 a 7,8 para a b-lactoglobulina e 6,0 a 9,0 para a ovoalbumina. O algoritmo foi desenvolvido para aplicação no interior de tubos cilíndricos permitindo um modelo matemático unidimensional, mais simples devido à simetria. O sistema de equações foi resolvido pelo método de diferenças finitas com a aplicação de um algoritmo desenvolvido na linguagem Fortran 77. Os resultados mostram que a solubilidade protéica depende da temperatura e do pH da solução e que a cinética de incrustação é dependente da temperatura do fluido e da sua vazão mássica. O tempo necessário para o decréscimo de 30% no raio interno do tubo foi menor para maiores valores de temperatura e vazão. A deposição das proteínas foi mais acentuada na região de entrada do tubo / Abstract: This is a research work on b-1actoglobulin and ovalbumin fouling over cylindrical heated surfaces, present on heat transfer equipments and evaporators. Fouling is a mass transfer phenomenon which is a function of protein solubility. To describe fouling kinetics an algorithm was developed based on the protein solubility. The protein solubility was determined experimentally in the range of 40-60°C, including dependence with pH in the range of 3.5-7.8 for b-1actoglobulin and 6.0-9.0 for ovalbumin. The algorithm was developed for cylindrical tubes thus leading to a less complex one-dimensional mathematical model, due to symmetry. The system of equations was solved by the finite differences method with an algorithm developed in Fortran 77 language. Experimental results showed that protein solubility depends on the solution temperature and pH and the fouling kinetics was dependent on the fluid temperature and flow rate. The time needed for 30% decrease on the tube internal radius was smaller for higher values of both temperatures and flow rate. Protein deposition was more intense in the tube entrance / Doutorado / Doutor em Engenharia de Alimentos

No description available.

ABSTRACT Characterization Of Raw Milk Fouling On Plate-Type Heat Exchangers Using Different Alloys And Cow PhenotypeS Stephen Ernest Nelson Milk and other dairy products are widely used in many households today. Milk is a popular beverage that is seen as a healthy alternative to other synthetic beverages such as soda pop and other sugar based drinks. It became law that milk, and milk products are pasteurized before its release to the general public (FDA 2003). Pasteurization is a thermal process where the intent is to lower the concentration of microorganisms in the milk to render it safe to drink with heat (Bansal and Chen 2006). With all the thermal processing of the raw milk, this leads to thermal efficiency degradation of the heat exchangers used to pasteurize the milk (Bansal and Chen 2006) due to direct fouling of the heating surface. The buildup of organic and inorganic matter onto a metal surface from the constant heating of the milk on a stainless steel surface is called fouling. The exact mode on which the fouling layers nucleate and grow is unknown by the date of this writing. Milk fouling has been around as long as the pasteurization process. (Visser and Jeurnink 1997) Fouling rate is related to a function of variables. Fouling rate is a function of milk type, time, and temperature, age of the milk, seasonal variations, process equipment design and more. The main consensus of milk fouling initiation is that of the whey protein b-Lactoglobulin which constitutes about 0.32% in whole milk (de Jong 1997; Bansal and Chen 2005a; Bansal and Chen 2006). Table III shows the general compositions of the constituents in milk. In order to look for dependence between milk phenotypes and heated surface alloys, a design of experiment (DOE) was made. The experiment used three types of milk phenotypes to test for fouling differences. Also, four alloy compositions were also tested against the milk phenotypes. This produced a three by four matrix of variable combinations or 3x4 factorial design. It was hoped that these combinations will show a certain, but repeatable process condition which will produce lower fouling rate versus the control milk type. The milk phenotypes used in this experiment are phenotype AB-AB (control), AB-AA, and AB-BB. The phenotype of label before the hyphen was the k-casein phenotype, the label after the hyphen represented the b-Lacto globulin phenotype. The four metal types tested were stainless steel 304 (control), stainless steel 316, stainless steel 430, and titanium 6V 4Al. It was not feasible to change out the plates in the pilot scale milk pasteurizer at the pilot plant at the Dairy Products Technology Center (DPTC), or to make special replacement plates that exposed each metal to be tested on a single heat exchanger plate (AOAC-c 1995). The manufacturing of a complete laboratory scale milk pasteurizer for the study of milk fouling on metal plates proved to be very successful. The model flow cell heat exchanger produced high enough quality of milk foulant on the test coupons in comparison to the large scale fouling layers found in full scale dairy heat processing equipment. Although generally speaking, there was not a significant technology breakthrough of using different alloys as the material for the plates in milk pasteurizer heat exchangers, a method of creating the milk fouling layer on a smaller scale can be very useful in future works studying milk fouling. The titanium alloy showed a significantly lower fouling rate, this was probably mostly due to the highly passivated surface of the Titanium. It was also seen that the actual breed of cow could have played a significant role in fouling. The new FCHE model was produced to show the viability of creating a biofilm or milk fouling layer on any material provided that it is rigid enough. Microorganisms were also briefly studied on the foulant layer that was produced with the flow cell. This new approach should provide a basis for new and more advanced research of the mechanisms and nature of milk fouling in heat processing equipment.