Thesis (doctoral)--Universität Hohenheim, 2001.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1991. / Vita. Abstract. Includes bibliographical references (leaves 75-81). Also available via the Internet.

Thesis (PH. D.)--Leland Stanford Junior University, 1925. / Cover title. eContent provider-neutral record in process. Description based on print version record. Bibliography at the end of each part.

Call number: LD2668 .T4 1951 D8 / Master of Science

No description available.

No description available.

Memoria para optar al título de Ingeniero en Alimentos / En Chile, el cultivo del árbol de olivo (Olea Europaea L.) es de gran importancia, siendo la Arbequina la variedad más cultivada. Como desecho de la industria olivícola se obtiene gran cantidad de hojas que poseen un interesante y amplio perfil de polifenoles, siendo la oleuropeína el más importante. El extracto de hojas de olivo es una interesante alternativa para la incorporación de antioxidantes naturales en alimentos. Sin embargo, la oleuropeína es susceptible a degradación frente a condiciones ambientales (luz, temperatura, entre otros) y/o condiciones en el alimento (pH, enzimas, interacción con otros componentes). La hipótesis de este trabajo plantea que la adición de micropartículas de extracto de hojas de olivo en matrices de almidón y gluten mantendrá en mayor grado el contenido de polifenoles y la capacidad antioxidante respecto a la adición de extracto sin encapsular. Se preparó un extracto hidroalcohólico de hojas de olivo (cv. Arbequina) donde la oleuropeína fue el principal polifenol encontrado. El extracto de hojas de olivo (EHO) se encapsuló utilizando inulina como agente encapsulante, a través de la técnica de secado por atomización. Las micropartículas (In-EHO) presentaron una alta eficiencia de encapsulación y recuperación de oleuropeína (>87%). Para evaluar la factibilidad del uso de extracto de hojas de olivo como fuente de polifenoles en alimentos y comparar su efectividad con la de las micropartículas, se incorporó EHO y In-EHO a matrices de almidón y gluten. Se probaron tres concentraciones de polifenoles 200, 350 y 500 ppm EAG (Equivalente Ácido Gálico). Las matrices fueron fritas bajo condiciones atmosféricas y de vacío, 170 y 116°C por 5 y 3 min, respectivamente. Las hojuelas fueron caracterizadas según su contenido de humedad, grasa libre, polifenoles totales (Folin-Ciocalteu), actividad antioxidante (DPPH, FRAP) y dureza. Las hojuelas con micropartículas (In-EHO), presentaron un mayor contenido de polifenoles totales en fritura atmosférica y una mayor capacidad antioxidante en fritura atmosférica y al vacío, respecto a aquellas hojuelas con extracto (EHO). Por su parte, a igual contenido de polifenoles, la capacidad antioxidante fue significativamente mayor en fritura atmosférica que al vacío, sugiriendo que durante la fritura atmosférica se generan metabolitos con actividad antioxidante derivados de la reacción de Maillard / In Chile, the olive tree (Olea Europaea L.) cultivation is of great importance, being Arbequina the most cultivated variety. As a discard by-product of the olive industry, lots of leaves are obtained. These leaves have an interesting and wide profile of polyphenols, being oleuropein the most important. The olive leaves extract is an interesting alternative for incorporation of natural antioxidants in food. Oleuropein, however, is sensitive to degradation by environmental (light, temperature) and food (pH, enzymes, interaction with other components) conditions. The hypothesis of this work suggests that the addition of microparticles of olive leaves extract in starch and gluten matrices will keep in a higher degree the polyphenol content and the antioxidant activity than the addition of not encapsulated extract. An hidroalcoholic olive leaves extract was prepared (cv. Arbequina) were oleuropein was the main polyphenol found. The olive leaves extract (EHO) was encapsulated using inulin as encapsulation agent by spray drying technology. The microparticles (In-EHO) showed high encapsulation efficiency and oleuropein recovery (>87%). To evaluate the feasibility of using the olive leaves extract as a source of polyphenols and compare its effectiveness with the microparticles, EHO and In-EHO were incorporated in starch and gluten matrices. Three different concentrations of polyphenols were tested 200, 350 and 500 ppm EAG (Gallic Acid Equivalent). The matrices were fried under atmospheric and vacuum conditions, 170 and 116°C for 5 and 3 min, respectively. The fried chips were analyzed according to its moisture content, fat content, total polyphenol content (Folin-Ciocalteu), antioxidant activity (DPPH, FRAP) and hardness. The chips with microparticles (In-EHO) showed higher polyphenol content in atmospheric frying and higher antioxidant capacity in both frying conditions, than those chips with extract (EHO). Furthermore, for the same polyphenol content the antioxidant activity was higher in atmosphere conditions than in vacuum ones, suggesting that during atmosphere frying Maillard reaction products with antioxidant activity are formed

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Attempts to develop dual-purpose durum wheat cultivars for both pasta and bread-making have been unsuccessful. To better understand this limitation, thirty durum genotypes, selected based on their diverse geographical origin, and five bread wheat cultivars were compared as to their flour mixing properties, dough physical characteristics and baking performance. The polymeric composition of gluten protein was determined using SE-HPLC of unreduced flour protein extracts and the size-distribution of the gluten polymer was estimated by determining the SDS-unextractable polymer (macro-polymer) content. Durum genotypes were characterized by a lower bread-making quality compared to bread wheats, in spite of higher total flour protein and gluten polymer contents. This was due to a weaker gluten and lack of dough extensibility. The stronger gluten characteristics of bread wheats were associated with a greater ability to form macro-polymers. However, two durum cultivars had a higher macro-polymer content than many of the bread wheats, suggesting that an additional property, unrelated to size-distribution of the gluten, contributes to the greater loaf volumes observed for bread wheats. Considerable variability for most quality attributes was observed among durum genotypes. Gluten strength and dough extensibility were the most important factors associated with superior baking performance. These two parameters were not inter-related. Durum genotypes expressing LMWG-1 had the weakest gluten and the poorest baking performance. This allele contributed less protein to the glutenin fraction and the sub-units produced exhibited a reduced ability to form macro-polymers. Among the durum genotypes expressing LMWG-2, those carrying HMWG-(6+8) were characterized by a better baking quality than genotypes carrying HMWG-(7+8) or HMWG-20. Genotypes carrying HMWG-20 were characterized by a comparatively weaker gluten and a lower macro-polymer content. The better baking performance of genotypes expressing HMWG-(6+8) relative to that of genotypes carrying HMWG-(7+8) was attributed to the greater dough extensibility characterizing the former group, but not to differences in gluten strength-related parameters. There was no indication of differences in the gluten polymer's size-distribution between the two groups. / Graduation date: 1997

Bread is widely consumed and is an ideal vehicle for nutraceutical delivery. Sorghum bran, flax, and inulin are nutraceutical ingredients that may be incorporated into bread to provide health benefits. Because celiacs can not consume bread containing wheat flour, a need exists for gluten-free bread containing nutraceutical ingredients. In preliminary research, bread containing 12% brown sorghum bran and 5% flaxseed was developed. In an effort to reduce rapid staling, soy flour was substituted for 0, 2, 4, and 6% of the wheat flour. Bread was evaluated based on specific volume, crumb firmness, color, moisture, nutrition content, and sensory evaluation. Sorghum bran was high in dietary fiber (45%) and antioxidants (oxygen radical absorbance capacity, ORAC). Flaxseed also contained dietary fiber (28%) and omega-3 fatty acids. Soy flour was high in protein. High levels of soy flour increased crumb firmness and decreased specific volume. The bread containing 2% soy flour was preferred, however, by panelists in sensory evaluation. Per 56 g serving, this bread provided ~3 g dietary fiber, ~396 mg omega-3 fatty acids, and ~3417 mol TE antioxidant activity. The use of low levels of soy flour in bread containing sorghum bran and flaxseed may help improve palatability and increase consumption of dietary fiber, antioxidants, and omega-3 fatty acids in bread. A gluten-free bread containing sorghum bran, flax, and inulin was also developed for consumers with celiac disease. Breads were evaluated based on the same parameters as described above. Inulin was high in soluble fiber (90%). The optimum formula was 10% inulin, 5% sorghum bran, and 5% flax. This formula had improved specific volume, reduced crumb firmness, and an attractive dark colored crumb. One 56 g serving of the bread provided ~2 g dietary fiber, ~1882 mol TE antioxidant value, and ~287 mg omega-3 fatty acids. When compared to commercially available gluten-free bread mixes, the optimum formula was significantly improved with regards to crumb firmness and provided acceptable specific volume. Because of the improved bread qualities and high levels of health-promoting nutraceutical ingredients, the optimum formula could likely compete in the gluten-free bread market.