Thesis (Ph. D.)--Columbia University, 1945. / "Lithoprinted." Vita. Bibliography: p. 55-56.

Thesis (Ph. D.)--Columbia University, 1925. / Vita. Bibliography: p. 25-27.

Thesis (Ph. D.)--Columbia University, 1935. / Vita. Bibliography: p. [31].

Thesis (Ph. D.)--Columbia University, 1927. / Vita. Bibliography: p. [42-43].

Thesis (Ph. D.)--Columbia University, 1923. / Vita. "Reprinted from the Journal of the American chemical society, vol. 44."

No description available.

Wheat grain quality and consumption is influenced by its constituents structure and concentrations. In the first part of the dissertation, six Canadian bread wheat cultivars; four (CDC Teal, AC Superb, AC Barrie, AC Splendor) belonging to the Canada Western Red Spring (CWRS), and two (AC Foremost, and AC Crystal) to the Canada Prairie Spring Red (CPSR) market classes were characterized for the relationship between their starch constituents and starch in vitro enzymatic hydrolysis. CPSR cultivars with relatively longer amylopectin chains of DP 37-45, reduced chain lengths of DP 15-18, and a low volume percent of small C-type starch granules, had reduced starch in vitro enzymatic hydrolysis rates. In the second part of the dissertation, near-isogenic wheat lines differing at the Waxy locus were analyzed for the influence of genome-specific granule-bound starch synthase I (GBSSI/Waxy; Wx-A, Wx-B, Wx-D) on starch composition, structure and starch in vitro enzymatic hydrolysis. Amylose concentration was more severely affected in genotypes with GBSSI missing from two genomes (double nulls) than from one genome (single nulls) of wheat, indicating dosage dependent amylose synthesis. Subtle differences in amylopectin chain length distribution were observed among non-waxy, partial and completely waxy starches, suggesting a non-limiting role of genome-specific GBSSI for amylopectin synthesis. A suppressive role of Wx-D on the short chain phenotype of wheat amylopectin was observed. In addition, Wx-D increased the volume percentage of large A-type starch granules and reduced starch hydrolysis index. Thus, among the waxy isoproteins, Wx-D might be the major contributor for reducing the rate of in vitro starch enzymatic hydrolysis in wheat. In the third part of the dissertation, endosperm starch’s physicochemical properties and structure during grain development in wheat waxy-null genotypes were analyzed. The study was conducted with pure starch isolated from wheat grains at 3-30 days post anthesis (DPA), at three day intervals. Changes in amylopectin structure were observed until 12 DPA, suggesting the formation of a basic amylopectin skeleton by this stage. A differential influence of waxy isoproteins on amylopectin structure formation has been suggested, with Wx-B and Wx-D affecting short glucan chains of DP 6-8 at 3 and 6 DPA, Wx-A being effective at 9 and 12 DPA, and Wx-D affecting DP 18-25 chains from 18-30 DPA.

No description available.

Lo scopo del presente lavoro è stato quello di esaminare il potenziale di idrolisi e degradabilità dell’amido dei cereali e co-prodotti e di valutare gli aspetti collegati. L’approccio utilizzato comprende sia test in vitro che in vivo. In particolare: - Una serie d’indagini in vitro ha fornito dati sul potenziale di degradabilità enzimatica dell’amido dei cereali e co-prodotti considerando sia l’influenza della struttura dell’amido, del tipo di cereale, del rapporto amilosio:amilopectina, del processo termico, dell’insilamento, dello stadio di maturazione e delle pratiche agronomiche. - Una valutazione funzionale basata sul calcolo del potenziale di degradabilità enzimatica dell’amido tramite la stima dell’indice glicemico in vitro, combinata con un approccio matematico di modellizzazione dei dati ottenuti, è stata proposta per fornire un metodo efficace di screening dei materiali amidacei utilizzati comunamente nella formulazione per diete destinate ai suini. - Un esperimento in vitro è stato condotto per investigare la risposta glicemica post-prandiale in suini alimentati con diete che differivano nel potenziale di idrolisi enzimatica. Infine, considerando la crescente attenzione dei nutrizionisti sulla matrice proteica dei cereali (con particolare importanza data alle prolammine), i metodi comunemente utilizzati per le tecniche di estrazione delle prolammine sono stati confrontati e ri-investigati. / In the present work, it has been attempted to examine the variability in starch hydrolysis and digestion from cereal grains and co-products and to study aspects related, in order to give a better understand of the science behind the differences in grains/feeds starch digestion potential. The general approach was to use a combination of in vitro and in vivo techniques. In particular: - A series of in vitro investigations has provided data on the degradation potential of starch from cereal grains and co-products considering the influence of starch structure, cereal type, amylose-amylopectin ratio, heat processing, ensiling, stage of maturity and of agricultural practices. - A laboratory-based functional evaluation of starch value of cereal grains based on a predicted glycemic index approach, combined with a mathematical first-order exponential model, has been proposed in order to allow an efficient screening of starchy-materials entering in the pig diet formulation. - An in vivo experiment has been undertaken to investigate the postprandial plasma glucose response in pigs fed diets containing starch with a wide range in in vitro digestion patterns. Lastly, taking into account the increasing attention of swine nutritionists on prolamin proteins, the most commonly used prolamin extraction procedures were compared and reinvestigated, in order to get useful information for routine lab analysis.

Currently there is great concern about the consumption of fossil fuels, as well as a possible depletion of traditional sources of production of raw materials mainly hydrocarbon derivatives. Parallel challenges to the preservation of the environment bring to discussions agenda every question involving biofuels and their means of obtaining. That said this issue still has major concerns about the use of raw materials that require less energy expenditure and prevent competition for land for food production, which end up entering the agenda of externalities related with this issue. In the case of the production of ethanol from starch sources, traditional processes still have high costs associated with the production of enzymes used and the great energy demand for starch gelatinisation at high temperatures. An alternative to the granular starch hydrolysis process is the use of enzymes capable of processing these starches at low temperatures which makes it unnecessary to gelatinization and reduces energy expenditure, also called simultaneous saccharification and fermentation (SSF), resulting in considerable economic advantage. Brazil is a traditional agricultural producer, and the rice production is quite significant and is as a by-product of rice bran that has low commercial value, being used for oil extraction, as an ingredient in animal feed and as fertilizer organic therefore be in perfect conditions to be used as raw starchy material to obtain ethanol. This work aims to investigate the use of this raw material and set the parameters for increased production scale-up with the use of commercial enzymes. The initial data to establish the working parameters were taken from the literature establishing this initial data for testing. In view of the large number of variables used to Plackett-Burman methodology to verify the effects of the main variables and select the ones that have most effect on the model.Thus for the job 1 in the shake flasks were selected following parameters: concentration of bran inoculum percentage, corn percentage of water macerated, soybean concentration, enzyme percentage yeast addition time and percentage of cellulase. This initial planning, among the most significant variables and, consequently, were selected for the planning application Outlining Central Composite Rotational (CCRD), are rice bran concentration, the percentage of inoculum and the percentage of cellulase. To work 2 were investigated variables agitation and temperature in ethanol production in bioreactor 3 liters. For analysis of the experiment of reducing sugar was used DNS method (Miller, 1959), and analysis of the ethanol present in the sample specimens were removed and subjected to Alcolyzer. For the tests performed in the first work the greatest amount of ethanol was obtained at 12 assay which was reached 172.70 grams of ethanol per kilogram of rice bran with 84% efficiency in the experiment. For experiments performed in the second study, with 3 liter reactor the best result is shown in Test 1 reaching 182.52 grams of ethanol per kilogram of rice bran with 89% efficiency. Thus, it was demonstrated that there is considerable potential for the production of ethanol using this raw material. Taking into account that the availability of this raw material is estimated at 1 million tonnes per year, the IRGA, we would have a much ethanol around 35 to 50 million liters per year. / Atualmente, existe grande preocupação em relação ao consumo de combustíveis fósseis, bem como um possível esgotamento das tradicionais fontes de produção de matéria-prima, principalmente os derivados de hidrocarbonetos. Paralelamente a isso, os desafios com a preservação do meio ambiente trazem para as discussões questões que envolvem os biocombustíveis e seus meios de obtenção. Isso posto, essa questão ambiental ainda traz grandes preocupações referentes à utilização de matérias primas que exijam menos gastos energéticos, bem como evitar a disputa por terras destinadas à produção de alimentos, o que acaba entrando na pauta das externalidades envolvendo o tema. No caso da produção de etanol de fontes amiláceas, os processos tradicionais ainda apresentam elevados custos de produção associados às enzimas empregadas e à grande demanda energética para a gelatinização do amido com altas temperaturas. Uma alternativa ao processo de hidrólise do amido granular é a utilização de enzimas capazes de processar esses amidos a baixas temperaturas, o que torna desnecessária a gelatinização e reduz o gasto energético, também denominado sacarificação e fermentação simultânea (SSF), apresentando considerável vantagem econômica. O Brasil é um tradicional produtor agrícola, sendo que a produção de arroz é bem expressiva e tem como um dos subprodutos o farelo de arroz. Este subproduto possui baixa valor comercial e é utilizado para extração de óleo, além de funcionar como ingrediente de ração animal e como fertilizante orgânico, estando, portanto, em perfeitas condições para utilização como matéria-prima amilácea para obtenção de etanol. A partir disso, este trabalho visa investigar a utilização e a viabilidade técnica do farelo de arroz, com a utilização de enzimas comerciais. Os dados iniciais para estabelecer os parâmetros de trabalho foram retirados da literatura. Tendo em vista o grande número de variáveis, utilizou-se a metodologia Plackett-Burman, visando verificar os efeitos das principais variáveis e selecionar as que tiveram maior efeito sobre o modelo. Dessa forma para o trabalho 1 em frascos agitados foram selecionadas as seguintes variáveis: concentração de farelo, percentual de inoculo, percentual de água de milho macerada, concentração de farelo de soja, percentual de enzima, tempo de adição de levedura e percentual de celulase. Desse planejamento inicial, entre as variáveis mais significativas e que, consequentemente, foram selecionadas para a aplicação do planejamento Delineamento Composto Central Rotacional (DCCR), estão a concentração de farelo de arroz, o percentual de inoculo e o percentual de celulase. Para o trabalho 2 em biorreator de 3 litros, foram investigadas as variáveis agitação e temperatura na produção de etanol. Para análise do açúcar redutor dos experimento foi utilizado a metodologia de DNS (Miller, 1959), e para análise do etanol presente nos ensaios foram retirados amostras e submetidas ao Alcolyzer. Para os ensaios realizados no primeiro trabalho a maior quantidade de etanol foi de 172,70 gramas de etanol por quilograma de farelo de arroz, com eficiência de 84%. Para os experimentos realizados no segundo trabalho, com reator de 3 L o melhor resultado foi 182,52 gramas de etanol por quilograma de farelo de arroz com eficiência de 89 %.Dessa forma, foi demonstrado que existe um potencial considerável para produção de etanol utilizando esta matériaprima, tendo em vista que há a estimativa de 1 milhão de toneladas por ano, com a possibilidade de produção de 35 a 50 milhões de litros adicionais de etanol por ano.