Thesis (M. Phil.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 134-145).

Thesis (M.S.)--Florida State University, 2003. / Advisor: Dr. Shridhar K. Sather, Florida State University, College of Human Sciences, Dept. of Nutriton, Food and Excercise Sciences. Title and description from dissertation home page (viewed 5/4/04). Includes bibliographical references.

Thesis (Ph. D.)--University of Missouri-Columbia, 2002. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2002. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.

Canola protein isolate (CPI) has tremendous potential as a protein alternative to soy within the global protein ingredient market. The overall goal of this thesis was to compare and contrast the gelling mechanism of CPI with a commercial soy protein isolate (SPI) ingredient. Specifically, the gelation properties of CPI and SPI were evaluated as a function of protein concentration (5.0–9.0%), destabilizing agent [0.1 – 5.0 M urea; 0.1 and 1.0% 2-mercaptoethanol], ionic strength (0.1, 0.5 M NaCl) and pH (3.0, 5.0, 7.0, 9.0). The fractal properties of CPI were evaluated as a function of protein concentration (5.0 – 9.0%) and pH (3.0, 5.0, 7.0, 9.0). In the first study, the gelling properties of CPI and SPI as a function of concentration were evaluated, along with the nature of the interactions within their respective gel networks. Overall, the magnitude of the storage modulus (G') of the gel was found to increase with increasing concentration at pH 7.0, whereas the gelling temperature (Tgel) remained constant at ~88ºC. As the NaCl level was increased from 0.1 to 0.5 M, the zeta potential was found to be reduced from ~-20 to -4 mV, but with little effect on Tgel or network strength. In the presence of 2-mercaptoethanol, networks became weaker, indicating the importance of disulfide bridging within the CPI network. Disulfide bridging, electrostatics and hydrogen bonding are all thought to have a role in CPI gelation. In the case of SPI, the magnitude of the storage modulus (G') and Tgel were found to increase and decrease (~80ºC to 73ºC), respectively, with increasing urea concentration at pH 7.0. Increases in NaCl from 0.1 to 0.5 M reduced the zeta potential from ~-44 to -13 mV and caused a shift in Tgel from ~84ºC to 67ºC, and increased G'. No gels were formed in the presence of 2-mercaptoethanol. In the second study, the effect of pH on the gelling properties of CPI and SPI was evaluated. Surface charge (i.e., zeta potential) measurements as a function of pH found CPI to be positively (+18.6 mV), neutral and negatively (-32 mV) charged at pH 3.0, ~5.6 and 9.0, respectively. On the other hand, SPI was observed to be positively (+35.4 mV), neutral and negatively (-51 mV) charged at pH 3.0, 5.0 and 9.0, respectively. An increases in NaCl concentration from 0 M to 0.1 M resulted in a reduction in surface charge at all pHs for both CPI and SPI. Differential scanning calorimetry was performed to determine the thermal properties of CPI. The gelation temperature was found to be above the onset temperature for denaturation. For CPI, the onset of denaturation was found to occur at ~68ºC and then increased to ~78-79ºC at pH 7.0-9.0. With respect to rheological properties, SPI did not gel at pH 9.0, and G' declined as pH increased from 3.0 to 7.0. CPI did not gel at pH 3.0, however the network formed at pH 5.0 became stronger (higher G') as pH increased. The SPI gelling temperature at pH 3.0, 5.0 and 7.0 was observed to be ~85.6, ~46 and ~81ºC, respectively. SPI gels formed at pH 5.0 earlier due to increased protein aggregation near its isoelectric point (pI). The gelation temperature for CPI at pH 5.0 and 7.0 were similar (~88ºC), then declined at pH 9.0 (~82ºC). Network structure of CPI as a function of pH also was investigated using confocal scanning light microscopy (CSLM). As the pH became more alkaline from pH 7.0 to pH 9.0, there was a decrease in lacunarity (~0.41->~0.25). However, the fractal dimension was found to increase (from ~1.54 to ~1.82) showing that increasing the pH resulted in a more compacted CPI network. In summary, protein-protein aggregation induced either by increasing concentration or changing the pH resulted in network formation for both CPI and SPI, where both networks were thought to be stabilized by disulfide bridging and hydrogen bonding. SPI underwent protein aggregation earlier than CPI near its pI value, whereas CPI gels formed the strongest networks away from its pI under alkaline conditions. In all cases, CPI grew in diffusion-limited cluster-cluster aggregation to from the gel network.

Native and pressure-treated (600 MPa) soy protein isolates (SPI) were subjected to in vitro digestion to study the effect of pressure processing on the digestibility of SPI and the antioxidant activity of the hydrolysates and isolated low molecular weight (<1 kDa) peptides. The digestibility of SPI increased significantly (P < 0.05) with pressurization following 10 min of pepsin digestion. The total peptide content in the pepsin-pancreatin hydrolysates was unaffected by pressurization; however, the peptide profiles were altered. Peptides from hydrolysates of pressurized SPI showed higher antioxidant activity than peptides from native SPI hydrolysates as measured by the FRAP assay. In contrast, peptides from native SPI hydrolysates exerted higher antioxidant activity than peptides of hydrolysates of pressurized SPI as assessed by the DPPH assay. These results indicate that peptides from hydrolysates of native and pressurized SPI produce differential in vitro antioxidant activities that might impact their in vivo antioxidative effects.

The effects of the fenretinide and genistein as single or combined drugs on ovarian cancer proliferation and viability were investigated. Hypothesis: Co-treatment with genistein will enable a lower dose of fenretinide to be effective in inhibiting the proliferation and survival of ovarian cancer cells. Methods: Low and high doses of genistein and fenretinide were tested on A2780s and A2780cp cells using trypan blue viable cell count, MTS assay. Results and conclusions: Unlike low doses of fenretinide, genistein had anti-proliferative effects on both cell lines. There were no additive or synergistic effects of the two compounds. Higher dose treatments induced anti-proliferative effects and apoptotic cell death in both A2780s and A2780cp cells, with a greater sensitivity of A2780s cells to both test compounds. Overall Conclusion: Genistein and higher doses of fenretinide similarly impair cell cycle progression and induce apoptosis. The anti-proliferative effects of genistein can be affected by co-treatment with fenretinide

Chicken nuggets are commonly made with varying levels of textured vegetable proteins such as soy and wheat, for their ability to bind water and their meat like conformation. This project compared textured wheat proteins and soy proteins at 10%, 20%, 30%, and 40% in both emulsified and non-emulsified chicken nuggets. A total of 6,048 chicken nuggets were evaluated in replications for batter breader pickup (%), par fry yield (%), cook loss (%), L*, a*, b* color value, texture profile analysis, and sensory analysis. Analysis was conducted for all four concentrations of wheat and soy treatments then compared to each other and an all-white meat chicken nugget control. All data was analyzed with a α <0.05 using SAS with PROC GLM and Duncan’s MRT, except for sensory data which was analyzed as a complete randomized block design using analysis of variance with a α <0.05, and was analyzed using SAS with PROC GLM. Results indicated that no notable trends were apparent in the quality testing. A trained sensory panel determined that Soy flavor was more detectable at 20% and 30% than wheat flavor was at similar levels. The results indicate that wheat proteins can replace soy proteins for functional properties in both emulsified and non-emulsified chicken nuggets at all concentrations evaluated. It was also determined that wheat proteins could be used at levels up to 30% without imparting a noticeable flavor.

Thesis (Ph.D.)--University of Delaware, 2007. / Principal faculty advisor: Richard P. Wool, Dept. of Chemical Engineering. Includes bibliographical references.

Thesis (Ph. D.)--University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed May 6, 2009). Vita. Includes bibliographical references.