The purpose of this research was to determine whether all-purpose flour could be partially replaced with locust bean gum (LBG) and guar gum, and produce an acceptable bread product. A pilot study determined that up to 4% gum replacement for flour was feasible. All bread treatments were evaluated objectively by standing height, texture, color, and cell size. Moisture determinations were obtained for each bread variation. Sensory quality was examined by consumer testing. The amount of heat required to break the hydrogen bonds in amylopectin, indicative of bread staling, was measured by differential scanning calorimetry (DSC) for all bread treatments. Two percent LBG replacement significantly increased standing height. Firmness of bread increased with an increase in gum; the 4% guar bread was significantly firmer. Crumb color was not significantly different for any of the five bread treatments. Crust color, however, was significantly lighter for the control in comparison to the 2 and 4% guar, and 4% LBG breads. Two percent guar produced a more even cell size distribution throughout the bread crumb. For all 5 bread formulations moistures were not significantly different. Sensory evaluation determined a significant difference between the control and 4% LBG. The 4% LBG bread was preferred, although not significantly. Both gums were found to retard bread staling and 2% LBG was the most effective in lengthening the shelf life of the bread product. Objective and sensory evaluation indicated both gums produced acceptable bread products for consumer consumption and possible use in further research. / Master of Science

Water powered mills were a very important part of life in early America, and Augusta County, Virginia had an abundance of milling activity. Excellent records of milling activity, farm production, and road and farm locations for the period of 1880-1885 allowed a geographic information system (GIS) database to be formed so that spatial patterns could be verified and identified in the Riverheads district of the county. Service areas of 21 mills were identified by using a GIS to calculate the shortest road distance to surrounding farms. It was found that wheat, the main crop, was most likely shipped from the 369 farms to the closest mills. A correlation was also found between wheat production and distance from the mill, thus farmers closer to a mill were more likely to grow wheat. The study also demonstrates the usefulness of GIS analysis and computer cartography in historical, geographic research which has traditionally used theoretical approaches or lacked adequate data for GIS analysis. / Master of Science

Contaminated wheat flour has been identified as the probable vehicle of a multi-state outbreak of Escherichia coli O157:H7 associated with ready-to-bake cookie dough. Several cookie dough manufacturers are currently using heat-treated flour for ready-to-bake products, although data on thermal inactivation of foodborne pathogens in wheat flour remains scarce. The objective of this research was to first determine appropriate methods and parameters for bacterial inoculation and thermal treatment of wheat flour, and to subsequently determine the population reductions of E. coli O157:H7 and Salmonella Agona in artificially contaminated wheat flour following thermal treatment for 1, 5, 15 or 30 minutes at 55, 60, 65 or 70°C in a shaking water bath. Flour samples (aw = 0.55) in sterile plastic bags were individually inoculated (~109 CFU/g), pulsified to distribute cultures, and pressed to a uniform thickness (1mm) prior to heat treatment. Following treatment, samples were rapidly cooled and diluted with peptone water; then plated onto Tryptic Soy Agar (TSA) and incubated at 37°C for 24 h prior to enumeration. The minimum heat treatments required for a 5-log reduction in microbial populations (~ 109CFU/g to ~ 104CFU/g) were 5 minutes at 70°C and 30 minutes at 70°C for E. coli O157:H7 and S. Agona, respectively. This research supports the hypothesis that the microbiological safety of ready-to-bake products may be improved by the use of heat-treated flour. / Master of Science in Life Sciences

Submitted by Angela Maria de Oliveira (amolivei@uepg.br) on 2018-12-20T16:06:34Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Marcel Adriano Jobbins.pdf: 799698 bytes, checksum: 9bb4362171f6c452c9c0332d5169dd9e (MD5) / Made available in DSpace on 2018-12-20T16:06:34Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Marcel Adriano Jobbins.pdf: 799698 bytes, checksum: 9bb4362171f6c452c9c0332d5169dd9e (MD5) Previous issue date: 2018-09-28 / Este estudo foi desenvolvido para determinar os coeficientes de digestibilidade aparente (CDA) de matéria seca (MS), energia bruta (EB), proteína bruta (PB), amido, lipídios, fibra bruta (FB), cinzas (CZ) e de aminoácidos (AA) essenciais e não essenciais de farinha de feijão in natura (FI) e feijão extrusada (FE) para juvenis de tilápia do Nilo utilizando dois marcadores de digestibilidade: óxido crômio (Cr2O3) ou cinza insolúvel em ácido (CIA). Foi elaborada uma dieta referência peletizada (DR) contendo 35,19% de PB e 17,78 MJ/ kg de EB. As dietas testes constituíam-se de 70% da DR e 30% de FI ou FE. Grupos de 15 individuos (150,16 ± 20,32 g) foram distribuídos em seis aquários de digestibilidade de 200 L, em um esquema fatorial 2 x 2, onde foram avaliados dois métodos de processamento (FI ou FE) e dois marcadores (Cr2O3 ou CIA), com duas repetições, compondo o “pool” de fezes de cada dieta testada. Os maiores CDA, referentes a interação (processamento x marcador), foram encontrados para MS, EB, PB, CZ e AA essenciais como: arginina (Arg), histidina (His), isoleucina (Ile), leucina (Leu), lisina (Lys), metionina (Met),fenilalanina (Phe), treonina (Thr) e nos AA não essenciais: ácido aspártico (Asp), cisteína (Cys), ácido glutâmico (Glu), glicina (Gly), serina (Ser) e tirosina (Tyr). O CDA de amido e para os AA essencias triptofano (Trp) e valina (Val) foi maior no FE em comparação ao FI, deferenciando dos lipídios que apresentaram melhores resultados para FI. Para FB e o AA não essencial alanina (Ala), por sua vez, não houve influência dos tratamentos dietéticos e marcadores. Independentemente do processamento a Met, His e Arg foram os AA limitantes para dietas contendo farinhas de feijão. Em conclusão, a FE apresentou -se como sendo boa fonte de energia e nutrientes, porém, os teores de Met e Cys devem ser considerados para as necessidades dietéticas de AA contendo enxofre e o marcador CIA não se mostrou sendo confiável para tilápia do Nilo. / The trial aimed to evaluate the apparent strain digestibility coefficients (ADC) of dry matter (DM), gross energy (GE), crude protein (CP), starch, lipids, crude fiber (CF), ashes (AS) and essential and non-essential amino acids (AA) of in natura bean flour (FI) and extruded bean flour (FE) for juvenile Nile tilapia using two digestibility markers: chromium oxide (Cr2O3) or acid insoluble ash (AIA). It was elaborated a pelleted reference diet (RD) containing 35.19% CP and 17.78 MJ / kg GE, the test diets consisted of 70% RD and 30% of FI or FE. Groups of 15 individuals (150.16 ± 20.32 g) were distributed in six digestibility aquariums of 200 L, in a 2 x 2 factorial scheme, two processing methods (FI or FE) and two markers (Cr2O3 or AIA) were evaluated, with two replicates, composing the faeces pool of each diet tested. The highest ADC referring to the interaction (processing x marker) were found for DM, GE, CP, As and essential AA as: arginine (Arg), histidine (His), isoleucine (Ile), leucine (Leu), lysine (Lys), methionine (Met), phenylalanine (Phe), threonine (Thr) and for non-essential AAs: aspartic acid (Asp), cysteine (Cys), glutamic acid (Glu), glycine (Gly), serine (Ser) and tyrosine (Tyr). The CDA of the starch and the essential AA tryptophan (Trp) and valine (Val) was higher in FE compared to FI, different from lipids, which presented better results for FI. For GE and nonessential amino acid alanine (Ala) there was no influence of dietary treatments and markers. Regardless of the processing, Met, His and Arg were the limiting AAs for diets containing bean flours. In conclusion, FE proved to be a good source of energy and nutrients, however, the low levels of Met and Cys should be considered for the dietary requirements of AA containing sulfur. The AIA marker proved to be unreliable for Nile tilapia.

Master of Agribusiness / Department of Agricultural Economics / Vincent R. Amanor-Boadu / The intent of this thesis is to conduct a case study on the optimization of blending soft red winter wheat, prior to processing into flour, in order to meet specific solvent retention capacity, SRC, specifications, based on predetermined customer specifications. The thesis will provide the company with a greater understanding of how to effectively manage the customer’s demands, and the costs associated with these activities in order to create greater customer value. If optimizing wheat blends is successful, the company will be able to provide similar SRC information to other customers as a value added service. (Solvent retention capacity) is a test that provides analytical data that measures three specific physical components within soft wheat flour. Traditionally, wheat flour is sold according to moisture, ash, protein content, and basic dough characteristic data; though this information is important, SRC provides specific flour functionality information that will aid customers. SRC examines the: glutenin characteristics of the flour, pentosan content and gliadin characteristics, and the starch damage from the milling process. These values describe the functionality of the flour and provide information regarding the flour’s ability to absorb water during the mixing process and the flour’s ability to release that water during the baking process. SRC quality endpoints include: reduced mixing and baking times, reduced levels of breakage after baking, and greater overall ingredient consistency throughout all the customer’s commercial bakeries. This thesis develops a process that the company may use to meet SRC quality specifications determined by the customer. The company gains customer loyalty by supply a consistent product to the customer. This product in turn yields savings for the customer in the areas of lower water use, shorter baking time and consequently lower energy use.

Master of Science / Department of Entomology / Frank H. Arthur / Kun Yan Zhu / Experiments were conducted to assess the effects of direct and indirect exposure scenarios, different degrees of residual flour, open and obstructed positions, and seasonal temperature variations on the efficacy of synergized pyrethrin against the red flour beetle, Tribolium castaneum (Herbst) and the confused flour beetle, Tribolium confusum Jacquelin du Val. To evaluate effects of direct and indirect exposures of T. castaneum and T. confusum eggs, larvae, pupae, or eggs to the insecticide aerosol within a flour mill, the following treatments were made to each life stage: insects treated with aerosol and transferred to treated or untreated flour, untreated insects transferred to treated flour, and insects and flour combined and treated together. Different degrees of harborage or sanitation levels were created by exposing T. confusum larvae, pupae, and adults to pyrethrin aerosol in Petri dishes containing 0, 0.1, 1, 5, and 10 g of wheat flour. Effects of pyrethrin dispersal in open and obstructed positions and seasonal temperature variations were assessed by exposing T. confusum pupae and adults in open positions and inside wooden boxes (1 m long, 20 cm wide, and 5, 10, or 20 cm high) inside experimental sheds maintained at target temperatures of 22, 27, and 32 °C. Results showed that when T. castaneum and T. confusum were directly exposed to aerosol without the flour source, or with a low amount of flour at open exposed areas, the aerosol provided good control against all life stages of T. castaneum and T. confusum. However, when insects were indirectly exposed (treated together with flour or untreated insects were transferred to treated flour), or treated together with deeper flour amounts, and exposed inside the boxes, the efficacy was greatly reduced. Eggs and pupae of both the species were more susceptible compared to larvae and adults. Additionally, the moribund adults initially observed in indirect exposure treatments, or at the deeper flour depth and exposure positions insides the boxes, were better able to recover. Generally, temperatures in the range of 22-32 °C had no significant effects on overall efficacy of pyrethrin aerosol.

Call number: LD2668 .T4 1985 S245 / Master of Science

Master of Science / Department of Grain Science and Industry / D.L. Wetzel / Chemical imaging enables displaying the distribution of different substances within a field of view based on their fundamental vibrational frequencies. Mid-IR bands are generally strong and feature direct correlation to chemical structure, while near IR spectra consist of overtones and combinations of mid-IR bands. Recently, mid-IR microspectroscopy has enabled determination of the relative substitution of hydroxyl groups with the modifying agent for individual waxy maize starch granules by using synchrotron source. The brightness and non-divergence of the synchrotron source and confocal masking enabled obtaining individual spectra with 5 [mu]m[superscript]2 masking and 1 [mu]m raster scanned steps. Each 1 [mu]m step results from the coaddition of hundreds of scans and lengthy data collection is required to produce data. The recent breakthrough at the Synchrotron Research Center uses a multi-beam synchrotron source combined with a focal plane array microspectrometer. This major improvement in localized detection of the modifying agent within single waxy maize starch granules is the increased efficiency of focal plane array detection and an effective spatial resolution of 0.54 [mu]m. Mixtures of granular solids represent an analytical challenge due to the range of heterogeneity and homogeneity within samples. Near IR imaging provides deeper sample penetration allowing for solid mixture analysis. However, the broad, overlapping bands present in the near IR necessitates statistical data treatment. This requires imaging specimens representative of the individual components to create spectral libraries for classification of each component. Partial least squares analysis then allows characterization and subsequent pixel analysis provides quantitative results. The primary break system for wheat milling was studied as it is key in releasing endosperm to be further ground into fine flour in subsequent processes. The mass balance of endosperm throughout individual unit processes was determined by obtaining flow rates of incoming and outgoing millstreams and calculating endosperm content through pixel identification. The feed milling industry requires the use of a tracer to determine adequate mixing and mix uniformity to limit the time and energy in processing. Near IR imaging allows individual components of a formula feed to serve as a self-tracer, eliminating the need of an inorganic tracer.

Doctor of Philosophy / Department of Biology / Susan J. Brown / RNA interference (RNAi) is a natural gene-silencing phenomenon triggered by dsRNA (dsRNA). While RNAi is an endogenous process that plays essential roles in regulating gene expression it can also be harnessed as a tool for the study of gene function. Introducing dsRNA that is homologous to target mRNA into a cell triggers the RNAi response causing the destruction of the homologous mRNA and a loss of function phenotype. In some organisms, such as the nematode Caenorhabditis elegans, once dsRNA is introduced into the body cavity, the RNAi effect is seen throughout the organism because the dsRNA is taken up by individual cells and is then spread from cell to cell. This process has been termed the systemic RNAi response. For other organisms, such as the fruit fly Drosophila melanogaster, introduction of dsRNA into the body cavity does not result in a systemic RNAi response. This may be due to the cell’s inability to take up dsRNA or spread that dsRNA from cell to cell. For other organisms, including mammals, introduction of dsRNA into the body cavity does not result in a systemic RNAi response because the immune response causes dsRNA destruction before it can be utilized in the RNAi pathway. For organisms that do not exhibit a systemic RNAi response, complex genetic methods are needed to introduce dsRNA into cells to induce the RNAi response. Therefore, one of the challenges in utilizing RNAi as a genetic tool is introducing the dsRNA into individual cells. In recent years, systemic RNAi responses have been documented in both model and non-model organisms, making RNAi an accessible genetic tool. The red flour beetle, Tribolium castaneum is an emerging model organism that has a robust systemic RNAi response. However, the mechanism of systemic RNAi and the specific parameters required to obtain a strong systemic RNAi response in this organism have not been thoroughly investigated. The aim of this work is to provide data that can allow RNAi to be better utilized as a genetic tool in Tribolium and to use this information as a basis for the use of RNAi in other insects in which it can be performed. Specifically we provide data on the essential parameters necessary to achieve an effective systemic response in Tribolium, we describe differences in the systemic RNAi response between Drosophila and Tribolium, we analyze the conservation and function of RNAi machinery genes in Tribolium and we provide information on the genes critical for a systemic RNAi response in Tribolium.

Master of Agribusiness / Department of Agricultural Economics / John A. Fox / The cost of wheat is the largest input cost for a flour mill, and as a result, profitability in wheat flour milling is determined in large part by milling efficiency – i.e., the amount of flour extracted per unit of wheat milled. In this project the objective was to quantify the influence of several measurable variables on flour mill efficiency. Data was collected from two commercial milling units of similar size. Linear regression was then used to estimate the relationship between flour yield and variables measuring grain characteristics and environmental factors. The analysis suggests that increasing ambient temperature and the occurrence of downtime both have a significant negative effect on flour yield. A significant difference in flour yield efficiency was also found between the two mills.