NDSU Theses & Dissertations

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Research performed to achieve a formal degree from NDSU. Includes theses, dissertations, master's papers, and videos. The Libraries are currently undertaking a scanning project to include all bound student theses, dissertations, and masters papers.

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Browsing NDSU Theses & Dissertations by browse.metadata.program "Cereal and Food Sciences"

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    Enhancing Bread Using High Temperature Extruded Lentil Flours
    (North Dakota State University, 2010) Gupta, Abhay
    Wheat proteins play a major role in determination of dough rheological properties and quality of baked bread. The main objective of this study was to evaluate the effects of extrusion speeds and lentil flour concentration in wheat flour on dough rheological properties, staleness and sensory attributes. Wheat flour was fortified with 5%, 10%, 15% and 20% lentil flour extruded at 350rpm, 400rpm and 450rpm extrusion speeds. The wheat flour sample ( control) was also fortified with non-extruded lentil flour to evaluate the effects of extruded and non-extruded lentil flours on bread characteristics. Bread staling was determined by measuring hardness of the crumb and samples were compared to control. Overall consumer acceptability was evaluated using a nine-point hedonic scale sensory analysis to determine the best wheat flour to lentil flour ratio. Extrusion speeds did not have any effects on overall acceptability of bread. Breads baked from wheat flour fortified with 10% lentil flour were most accepted by sensory panelists in terms of overall acceptability. Therefore, 10% lentil flour breads were tested for staleness and compared to the control sample. Lentil breads had no significant difference in staleness on day one as compared to the control sample. However, on day four and day six, it was observed that lentil breads staled faster than the control bread. It can be concluded that bread with lentil flour had poorer shelf life as compared to breads with only wheat flour.
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    Structural, Rheological and Biological Functionality of Fiber-Rich Fractions From Beans
    (North Dakota State University, 2022) Lopez, Ana Magallanes
    egumes have been reported as a good source of dietary fiber. This research aimed to understand how soluble dietary fiber (SDF) can be extracted from dry beans to enhance human health. Raw bean samples were ground with a hammer-type mill. Cooked bean samples were boiled to their optimum cooking time, freeze-dried, and ground. Phenolic content was measured by Folin-Coilteau reaction. SDF was extracted by enzymatic digestion (α-amylase, protease, & amyloglucosidase), filtration, SDF flocculation with 95% (v/v) ethanol and freeze-dried. High-Performance Size Exclusion Chromatography (HPSEC) and high-performance anion-exchange chromatography (HPAEC) were used to study SDF composition. Flow behavior was measured at various SDF solution concentrations (2%, 4%, 6% w/v). Immunomodulatory properties were studied in vitro by quantifying the levels of selected cytokines released by RAW264.7 cells (macrophages) when treated with SDF. The impact of macrophages conditioned media (MCM) treated with the SDF on 3T3-L1 adipocyte (fat) cells differentiation (adipogenesis) was assessed. The results showed that cooking processing significantly (p < 0.05) reduced flour phenolic content and antioxidant capacity. The SDF-rich fractions monosaccharide composition indicated the presence of pectic polysaccharides, hemicelluloses and raffinose family of oligosaccharides (RFOs). The SDF molecular weight distribution showed a significant (p < 0.05) reduction of low molecular weight (LMW) fractions after the cooking process. In contrast, the high molecular weight (HMW) fractions were not affected by cooking. Studied SDF solutions were highly viscous, but the viscosity was lost when shear force was applied, thus exhibiting a shear-thinning behavior. For the immunomodulatory properties, the results indicated that the extracted SDF caused a pro-inflammatory response, suggesting its potential use as an immune system stimulator. Regardless of the SDF sample, when TLR-4 signaling inhibitor was added, cytokines production was significantly (p < 0.05) decreased, suggesting the affinity of SDF with the TLR-4 receptor. Finally, a significant (p < 0.05) decrease in lipid accumulation and reduced protein expression of adipogenic markers was detected from adipocytes cultured with MCM treated with SDF. The results suggested that the SDF extracted from dry beans has the potential to reduce adipogenesis and could be used as food supplements to reduce or prevent obesity.
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    Structure Modification to Enhance Pulse Protein Functions and Flavor Profile Opportunities in Saccharide Mediated Glycation via Maillard-Driven Chemistry
    (North Dakota State University, 2020) Zha, Fengchao
    Owing to the combined characteristics of low allergens and lipids, as well as high versatility and abundance, eco-friendly pulse-based protein has served as a critical contender to supplement animal protein. The inferior solubility and off-flavor, however, place a practical restriction on its application. Glycation via Maillard-driven reaction is a potential green chemistry to modulate protein structure and functions. The various types of protein, saccharides with different molecular mass and structural characteristics, and two reaction systems (dry and wet heating) were applied to synthesize protein-saccharides conjugates. The aims were to investigate (i) the effect of glycation on functionalities and flavor of pulse-based protein using above-mentioned elements, and (ii) mechanisms by which glycation affects the protein architectures and modulates its functionalities. SDS-PAGE, SEM and FTIR-ATR were applied to confirm the successful development of protein-saccharide conjugates. The extent of glycation was time-dependent, and 11S and 7S globulin were mainly responsible for conjugation with gum Arabic (GA) under dry heating conditions (60°C, 79% relative humidity, pH 7.0). Glycation significantly improved protein solubility at neutral pH, whereas such effect varied depending on the protein source and reaction time. The stability of emulsion against environment stress and lipid oxidation gained a significant improvement, which was attributed to electrostatic interactions and stronger steric hindrance of protein-GA conjugates. HS-SPME-GC-MS analysis indicated glycation is a promising approach to mitigate the beany flavor, presumably because of the alterations in protein structure resulting in release of unpleasant odorants. The solubility of pea protein was sufficiently improved after glycation, while its thermal stability was remarkably lowered under wet heating conditions (80°C, pH 10.0). The proposed principle involved glycation via Maillard-driven chemistry enhanced the surface hydrophilicity of protein and unfolded its spatial architectures.