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Thesis (M.S.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 56-62). Also available on the World Wide Web.

Alternative methods to reduce the variation caused by pale, soft, and exudative (PSE) and dark, firm, and dry (DFD) conditions in meat tissues need to be examined. The objective of this dissertation was to determine if functional ingredients, like hydrocolloids and bicarbonates, improved the quality of PSE and DFD meat. This was accomplished by examining the rheological characteristics of meat model systems and products after enhancement with hydrocolloids and bicarbonates ingredient solutions. These results will be used to formulate and manufacture either enhanced beef steaks, beef roasts, or frankfurters to test the efficacy of use to improve the quality of DFD or PSE meat. The flow behavior, steady-shear viscosity, and dynamic testing of hydrocolloid solutions were determined. Torsion Analysis (TA) and Texture Profile Analysis (TPA) were performed on PSE muscle tissue gel samples and frankfurters. Raw and cooked CIE color space values, pH, and sensory evaluation determination were made on meat gel samples, beef steaks, roast beef, and frankfurters. Hydroxypropyl methylcellulose (1.0%HPMC), methylcellulose (1.0%SGMC), and konjac flour (0.125%KF) were found to be Newtonian in behavior. The dynamic moduli of these ingredients were resistant to changes in ionic strength and were tested for viability in a meat model system. Potassium bicarbonate (KHCO) was a viable substitute for sodium bicarbonate. The synergistic effect of combining KHCO with hydrocolloids, salt and sodium phosphate (SP) improved the color, pH, and textural properties of PSE ground pork and frankfurters, but did not effect sensory characteristics. Acetic acid (AA), KF, and xanthan gum (XG) were added to beef steaks and bottom rounds to reduce the meat quality variation caused by high pH and animal age. The addition of AA and hydrocolloid treatments improved the color and pH of high pH muscles and did not appreciable affect shelf-life flavor of cooked roast beef. Solutions of AA, KF and XG were viable enhancement treatments for use in high pH beef bottom rounds to produce a fully cooked roast beef product.

Thesis (Ph. D.)--University of Wisconsin--Madison, 2001. / Includes bibliographical references. Also available on the Internet.

This dissertation explores the changes in structure of colloidal systems on the introduction of repulsive interactions. Colloidal gels are well understood when all particle interactions are attractive, but their structure is fundamentally changed when repulsive interactions compete with those attractive interactions, as in the case of a binary gel of oppositely charged particles. Similarly, colloidal crystals are well understood when interactions are approximately hard-sphere, but again, the structure and material properties change when a long-range repulsion is introduced, giving a colloidal `Wigner' crystal. My research quantitatively investigates these effects in experimental model systems. I use confocal microscopy to directly image in three dimensions suspensions of micron-scale colloidal particles which are monodisperse, index- and density-matched, fluorescent, and electrostatically charged. I use standard image-processing techniques to obtain the precise location of each particle in the imaging volume in order to analyze both global and local structure. In the case of the binary gel, I observe gelation of oppositely charged particles, controlled by varying the total particle volume fraction, the interaction strength, and the mixing ratio of the two particle species. I find that contrary to commonly studied purely attractive gels, in which weakly quenched gels are more compact and less tenuous, particles in these binary gels form fewer contacts and the gels become more tenuous as we approach the gel line, and the average attractive bond number emerges as a critical parameter for gelation. This suggests that a different mechanism governs gel formation and structure in binary gels, in which attractive and repulsive interactions compete. In the case of the long-range-repulsive colloidal `Wigner' crystals, I find a body-centered-cubic crystalline phase at particle volume fractions near 15%, in contrast to the face-centered-cubic crystalline phase found at volume fractions above 50% for hard spheres. The soft interactions in these repulsive crystals permit large fluctuations, with typical particle displacements up to 20% of the nearest-neighbor spacing. I determine the three independent crystalline elastic constants, and find that the crystals are very compliant (c ~ 5-40mPa), and strongly anisotropic at all volume fractions studied. I also observe a sharp interface between the fluid and crystalline phases. / Physics

Ο σκοπός της παρούσης εργασίας είναι να εξετάσουμε την κινητική απελευθέρωσης υδρόφιλων και λιπόφιλων μορίων που εγκλωβίζονται σε λιποσώματα, όταν τα λιποσώματα διασπείρονται σε συστήματα φορέων- υδρογελών. Στην παρούσα εργασία μελετάται η απελευθέρωση της υδατοδιαλυτής ουσίας καλσεΐνης και της λιποδιαλυτής γκριζεοφλουβίνη τόσο από σταθερά λιποσώματα (DSPC:Chol) όσο και από ασταθή (PC) διεσπαρμένα σε φορείς υδρογελών. / Release of calcein and griseofulvin (GRF) from control (gels in which solutes are dissolved in) and liposomal gels was studied using agarose-assisted immobilization as a technique to separate gels from drug-receptor compartments.Results show that calcein release from liposomal gels is slower compared to control gels, and can be further retarded by using rigid-membrane liposomes (faster release from PC-liposome compared to DSPC/Chol-liposome gels).Additionally, calcein release is not affected by the lipid amount loaded (in the range from 2 to 8 mg/ml), therefore solute loading can be controlled according to needs. Oppositely, GRF release from liposomal gels is determined by drug loading. At high drug loading levels (compared to GRF aqueous solubility), GRF is released with constant rate from liposomal gels irrespective of liposome type (PC or DSPC/Chol). Thereby, for amphiphilic/lipophilic drugs, drug properties (solubility, log P) determine the system behavior. Calcein and GRF release from control carbopol gels is faster compared to HEC and mixture gels. The same is true for calcein in liposomal gels. Carbopol gel rheological properties were found to be significantly different (compared to the other gels), implying that these characteristics are important for drug diffusion from gels.

Lanksti vanadžio pentoksido kserogelio struktūra, susidedanti iš vanadžio-deguonies sluoksnių, atskirtų vandens molekulėmis, leidžia įterpti tarp sluoksnių ne tik atskirų elementų jonus, bet ir molekulinius darinius. Šio darbo tikslas yra sukurti naujų vanadžio – gliukozės pagrindu metalo-bioorganinių junginių sintezės technologiją, ištirti jų paviršiaus dangas, Rentgeno fotoelektronų spektrus bei cheminę sudėtį. Darbe trumpai aprašyti Skenuojančio elektronus, atominių jėgų ir Rentgeno fotoelektronų spektroskopijos metodų pagrindai, vanadžio oksidų savybės, V2O5 gelių struktūra ir sintezės metodai. V2O5/xGL junginiai buvo gamina trimis etapais: vanadžio pentoksido kserogelio sintezė, naudojant zolis-gelis technologija; gliukozės (C6H12O6) įterpimas į kserogelio struktūrą ir V2O5/xGL kserogelio atkaitinimas prie 580 0C, siekiant pašalinti chemiškai surišta vandenį. Gauta V2O5/xGL junginiai buvo tiriami Rentgeno fotoelektronų spektroskopijos, skenuojanti elektronus mikroskopijos, atominių jėgų mikroskopijos metodais. Vanadžio-deguonies ir anglies sričių RFS spektrų pokyčiai, įvedus į gryno vanadžio pentoksido kserogelio struktūrą gliukozės molekules, leidžia tvirtinti, kad mes gavome ne paprastą vanadžio ir gliukozės mišinį, o buvo susintetintas V2O5/GL junginys, kuriame susidarė tam tikri cheminiai ryšiai tarp V2O5 ir C6H12O6 molekulių. Tuom mes įrodome, kad gliukozės molekulę (C6H12O6) įterpėme į vanadžio pentoksido struktūrą. Gauti rezultatai leidžia tvirtinti, kad... [toliau žr. visą tekstą] / Flexible structure of vanadium pentoxide xerogel, consisting of vanadium-oxygen layers, separated by water molecules, allows to insert ions of separate elements, as well as molecular formations, between the layers. The purpose of this work is to produce a new vanadium – glucose based metal – bioorganic compounds fusion technology, to explore the surface of coating, X – ray photoelectron spectra and chemical composition. In this work the basics of the Scanning electron, Atomic force and X-ray photoelectronic spectroscopy methods, features of vanadium oxides, structure of V2O5 and synthesis methods are briefly described. V2O5/xGL compounds was produced in three stages: synthesis of vanadium pentoxide xerogel, using zol-gel technology; inserting glucose into the structure of xerogel and annealing of the obtained vanadium hydrochinon xerogel at 580°C, in order to remove the chemically linked water. The obtained V2O5/xGL was analyzed using the Scaning electron, Atomic force and X-ray photoelectronic spectroscopy methods. Vanadium-oxygen and carbon XPS spectra of the fields changes shows that using of sol-gel technology methods, we synthesized V2O5/xGL compounds.

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Diss. (sammanfattning) Uppsala : Univ., 2003. / Härtill 7 uppsatser.