Master of Science / Food Science Institute / Fadi Aramouni / Flour from the fruit of breadfruit trees (Artocarpus altilis) holds the potential to serve as an alternative to gluten-containing flour and may aid in alleviating food insecurity. This study assessed the effects breadfruit flour contributes to gluten-free bread quality. Breadfruit flour was included at a baker’s percentage (0, 20, 35, 50%) of a gluten-free flour blend, and was treated with various leavening agents (yeast, 15% baking powder, 20% baking powder) to create varying gluten-free bread formulas. Density and pH of each batter was assessed along with loaf density, yield, specific volume, pH, water activity, crust color (L*, a*, b*), crumb color (L*, a*, b*), and texture. Additionally, a consumer sensory study was performed to ascertain degree of liking of appearance, color, flavor, texture, aftertaste, likelihood to purchase, and overall acceptability. Significant differences (p < 0.05) were found in batter pH, loaf density, yield, specific volume, color (crust b*, crumb L*, a*, b*), pH, water activity, and texture among flour inclusion and leavening treatments. Consumer testing yielded significant differences (p < 0.05) between the control and a yeast leavened 20% breadfruit formula in appearance, color, flavor, aftertaste, likelihood to purchase, and overall acceptability. While most consumers rated the breadfruit treatment lower than the control, five celiac panelists rated it higher. Among all treatments, loaves produced from 20% breadfruit flour inclusion had significantly lower density, yield, hardness, adhesiveness, gumminess, chewiness, and crumb yellowness (b*), as well as higher specific volume, springiness, crust yellowness (b*) and darkness (L*), crumb darkness (L*), and magenta hue (a*) compared to other breadfruit flour inclusion levels. Similarly, loaves leavened with yeast had significantly lower batter pH, loaf pH, density, yield, hardness, chewiness, crust yellowness (a*), crumb darkness (L*), magenta hue (a*), and yellowness (b*) as well as higher loaf water activity, volume, springiness, and crust darkness (L*) compared to other breadfruit flour inclusion levels. These results indicate breadfruit flour can be used at ≤ 20% in gluten-free bread formulas to replace rice flour and has potential as a fiber supplement. Further research is needed to assess how breadfruit flour affects the quality of other gluten-free product formulas.

Master of Science / Department of Grain Science and Industry / Yong-Cheng Shi / Jon Faubion / The rheological properties of two waxy and two normal wheat flours were investigated and the observed differences between them were explained by biochemical analysis. Protein analysis showed that waxy flour had lower polymeric to monomeric ratio (0.70 and 0.58 for waxy flour compared to 0.75 and 0.76 for normal flour) and higher gliadin content in waxy wheat dough (43.9 and 47.3 for waxy wheat dough compared to 41.0 and 41.7 for normal wheat dough). Waxy flour had high amounts of insoluble (IPP) and unextractable (UPP) polymeric protein despite the poor dough forming properties of the waxy flours, contrary to previous correlations made between IPP, UPP and dough strength. Gluten index determination showed a clear difference between waxy and normal flour; there was no gluten aggregation when the waxy samples were tested. The determination of gluten index done on a variety of water washed flour samples indicated that the water-extractable fraction may contain compounds that affect gluten aggregation. HPLC analysis coupled with arabinose/xylose ratio and viscosity determination of the water extractable portion of the flour indicated that water extractable arabinoxylans (WEAX) in waxy wheat flour were different in composition and conformation. Further research is needed to determine if they could be responsible for the lack of gluten aggregation in waxy flour.

Made available in DSpace on 2014-10-09T12:33:09Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:06:17Z (GMT). No. of bitstreams: 0 / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Made available in DSpace on 2014-10-09T12:33:09Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:06:17Z (GMT). No. of bitstreams: 0 / O amido de bananas tem sido pesquisado na área de nutrição a partir da introdução do conceito de Amido Resistente (AR). O amido de Musa AAA-Nanicão e Musa AAB-Terra já foram caracterizados quanto as suas respostas fisiológicas. A banana verde possui boa quantidade de amido resistente. O principal interesse em relação ao amido resistente é o seu papel fisiológico. Por não ser digerido no intestino delgado, este tipo de amido se torna disponível como substrato para fermentação pelas bactérias anaeróbicas do cólon Dessa forma, essa fração compartilha muitas das características e benefícios atribuídos à fibra alimentar no trato gastrintestinal. O processo de irradiação por radiação gama pode causar uma variedade de modificações nas macromoléculas, algumas de aplicação industrial, como é o caso de perda de viscosidade e alteração de textura. No presente trabalho, farinhas de banana verde (FBV) de duas origens, foram utilizadas para estudar a sensibilidade a radiação por meio de medidas de viscosidade, textura, colorimetria e pH. As amostras de farinha de banana verde foram irradiadas com raios gama em doses de 0 a 10 kGy e taxa de dose em torno de 2kGy/h. As soluções de FBV apresentaram-se como fluidos não-newtonianos, A irradiação não alterou significativamente o pH dos hidrogéis das farinhas de banana verde FBV1 e FBV2. A viscosidade, de maneira geral, diminuiu com a dose de radiação aplicada. Quando analisada a textura a força máxima de ruptura dos hidrogéis de FBV1 e FBV2 decresceu conforme aumento da dose de irradiação. Entretanto, em particular quando irradiada a dose de 3 kGy, a FBV2 apresentou força de ruptura aumentada. / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

M.Tech. / Sorghum (Sorghum bicolour (L) Moench) and millets are drought resistant cereals (Kent and Evers, 1994) that can grow in areas with poor soils and inconsistent rainfall (Dendy, 1995) where other crops fail. They serve as staple food for many people in tropical sub- Saharan Africa and Asia (Klopfenstein and Hoseney, 1995). Traditionally, bread is made from wheat, which is a temperate cereal not able to grow well in these tropical regions. Leavened bread is seldom made from anything other than wheat (Alais and Linden, 1991) and this is because of the unique visco-elastic property of wheat flour (Hoseney, 1994). Unfortunately in tropical regions such as South Africa wheat is imported at a premium price. The aim of this study was to produce a wheat-finger millet composite flour which is suitable for bread making. Finger millet grain (FMV6) was milled with a laboratory hammer mill fitted with a 0.8 mm screen. The following wheat-finger millet composite doughs were made using standard bread making methods, 0:100 (Control); 90:10; 80:20; 70:30, respectively. Selected quality attributes of the composite dough and the bread thereof were analysed using standard methods. The formulation with 10% finger millet showed better results than other formulations. One formulation (80:20) was selected for improvement which included mixing ingredients at elevated temperatures (50°C and 93°C) and addition of 0.002% of a lipase enzyme, lipopan F; 0.3% vital wheat gluten and a combination of 0.002% lipopan F and 0.3% gluten. All formulations (including the basic formulation) contained Fungamyl Super MA (enzyme combination which contained fungal a-amylase and a xylanase). As the mixing temperatures were elevated, loaf volume decreased but when the industrial baking enzymes were introduced there was an improvement in peak time, dough stability and loaf volume. Image analysis showed that there was an improvement in crumb structure and bubble size distribution after the application of enzyme lipopan F. The crumb colour was lighter and softer when a combination of enzyme lipopan F and vital wheat gluten was applied. The bread made from formulation 80:20 with addition of a combination of enzyme lipopan F and vital wheat gluten (WFM2GL) was more acceptable than other formulations except the control bread. The bread had a high score in taste, crust appearance and mouth feel. The results suggest that there is a potential for producing a composite bread by substituting wheat flour with finger millet flour (up to 20%); mixing at 25°C with application of a combination of a lipase and vital wheat gluten. However, more work is needed to improve the quality of the bread to a greater extent.

No description available.

Viscosity of 30 and 48% soy isolate (Promine-D) dough is determined using an Instron capillary rheometer at 298K, 333K and 363K. Thermal transitions of 10 to 100% soy isolate dough are measured using a Perkin-Elmer Differential Scanning Calorimeter (DSC-2) over 310 to 350K. The observed behavior of the soy isolate doughs is explained in terms of a network based on temporary crosslinks, possibly hydrogen bonds. Additionally, factors which complicate viscosity measurement of these doughs are discussed including yield stresses, melt fracture and sample reservoir pressure losses. / Master of Science

The goal of this research is to determine the effects of added soybean lipoxygenase (LOX) on bread dough rheological properties and physical properties of bread loaves compared to controls, and to determine sensory attributes of bread loaves using quantitative descriptive analysis (QDA). Protein fractions were obtained through the use of isoelectric precipitation. The pH 4.8 precipitate was found to yield the greatest LOX activity when compared with other fractions (p<0.05). The addition of pH 4.8 precipitate improved rheological properties of bread dough, examined in a farinograph, when compared to the all-purpose control (p<0.05). Addition of soy flour also increased the gluten strength of all-purpose flour (p<0.05). The addition of pH 4.8 precipitate to all-purpose flour did not improve bread loaf volume or texture. Sensory panelists described pH 4.8 supplemented bread as having firmer crumb when compared with controls (p<0.05). There were slight color differences among the loaves. The crust and crumb of bread flour loaves was lighter in color than any other sample. It was concluded that the addition of pH 4.8 precipitate to all-purpose flour greatly improved the rheological properties when compared with all-purpose flour alone. / Master of Science

In South Africa there is a need within the milling industry for controlling food safety especially due to customer's demands and government's regulations. The best way to ensure food safety is with the implementation of a HACCP based food safety system. Therefore, the principal aim of this study was to develop a generic HACCP model for the flour milling industry. Afterwards this generic model can then be adapted for each specific mill and its needs.

Ampliar os usos da farinha de arroz foi o objetivo da substituição parcial de farinha de trigo por farinha de arroz em um produto de panificação teste, o \"sonho\", que visou obter um produto com características físico-químicas e sensoriais similares às de sonhos produzidos exclusivamente com farinha de trigo e com isso reduzir custos com ingredientes. Também foi objetivo verificar a influência da inclusão de farinha de arroz na formulação, sobre a absorção de óleo pelo produto. Foram produzidos em escala piloto e em condições padronizadas 16 lotes de sonhos contendo entre 10 e 40% de farinha de arroz de diferentes características (polido e parboilizado, teores variáveis de amilose), além de um lote do produto controle, elaborado somente com farinha de trigo. Os sonhos foram analisados em relação ao peso, volume, volume específico, teores de umidade e lipídios e também em relação à aspectos sensoriais. O sonho produzido com arroz parboilizado apresentou maior aceitação do que o produzido com arroz polido. Observou-se que a qualidade do produto final varia em função do tipo e da quantidade de arroz e dentre as diversas formulações testadas o melhor resultado foi obtido com a substituição de 30% da farinha de trigo por arroz parboilizado, que teve um rendimento 5,7% superior e foi aceito sensorialmente da mesma forma como o produto elaborado apenas com farinha de trigo. O uso de arroz na formulação e maior rendimento implicou em redução de 25% no custo da produção. O sonho produzido com arroz polido, tanto com baixo como elevado teor de amilose, não apresentou características sensoriais adequadas e apenas a substituição de no máximo 10% do trigo, gerou um produto com nível de aceitação similar ao controle e com redução de custos em torno de 7%. Em relação à absorção de óleo sugere-se estudos adicionais visto que a substituição de farinha de trigo por arroz não mostrou um comportamento uniforme de absorção de óleo durante a fritura do sonhos, possivelmente devido à fatores não controlados durante a fabricação dos sonhos. / Expanding the uses of rice flour has been the focus of the partial replacement of wheat meal by rice meal in a test baked food product, aiming to produce donuts showing physicochemical properties and overall sensory acceptance similar to those produced with wheat flour only. The replacement implies also lower costs of ingredients. Furthermore, another objective was to verify the effect of the inclusion of rice flour on the oil absorption of the product during the frying process. Sixteen different batches of dough containing among 10 and 40% rice flour of different types (milled and parboiled; high and low amylose contents) and one wheat-based batch (control) were produced in a laboratory scale. The fried donuts were analyzed regarding weight, loaf volume, specific volume, water and oil retention as well their sensory acceptance. In any case, donuts produced with parboiled rice presented better results than those produced with milled rice. It was outstanding that the quality of the fried product was dependent on type and amount of rice and it was observed that the replacement of 30% of wheat by parboiled rice resulted in product with a 5.7% higher yield, due to a higher water retention and the overall sensory acceptance was comparable to that of the wheat-based control donut. In this case, the incorporation of rice flour implied a 25% reduction in costs. Donuts produced with high-amylose milled rice flour were only acceptable when they contained a maximum of 10% of rice, thus the costs reduction reached only 7%. The replacement of wheat by rice flour did not show a reproducible and an uniform behavior of oil absorption during the frying process, may be due to uncontrolled factors and further studies have been suggested.