Master of Science / Department of Animal Sciences and Industry / James S. Drouillard / Three studies evaluated effects of high-amylase corn (Enogen® Feed Corn, EFC) on ruminal digestive characteristics using different processing methods; a 4th study evaluated performance of finishing cattle fed steam-flaked EFC. In study 1, mill-run corn (CON) and EFC were ground through 9-, 6-, or 4 -mm screens, blended to contain 0, 33.3, 66.7, or 100% EFC, and heated to 50, 75, or 100⁰C (plus a non-heated control). No 2- or 3-way interactions occurred (P > 0.05). Increasing EFC in blends linearly improved in situ dry matter disappearance (ISDMD; P < 0.01) and in vitro gas production (IVGP; P = 0.02). Study 2 used blends of EFC and CON containing 0, 25, 50, 75, or 100% EFC, which were reconstituted to 27, 30, or 33% moisture, and ensiled. High-amylase corn did not affect ISDMD (P = 0.19) but IVGP increased linearly (P < 0.01) in response to greater amounts of EFC. Acetate:propionate ratio and total volatile fatty acid (VFA) production by in vitro fermentation improved linearly by increasing EFC (P < 0.02). Study 3 used the same blends of EFC and CON as study 2. Grains were tempered with 0, 3, or 6% moisture, steam conditioned 15, 30, or 45 min, and flaked. No 2- or 3-way interactions occurred. Starch availability, ISDMD, IVGP, and in vitro production of acetate, propionate, and total VFA increased linearly (P < 0.01) with greater flaked EFC in blends. Study 4 fed finishing diets consisting of steam-flaked CON, or EFC, for 136 d to 700 crossbred beef heifers (394 ± 8.5 kg initial BW). Compared to CON, cattle fed EFC had similar DMI (P = 0.78) but had greater ADG (P < 0.01) and a 5% improvement in feed efficiency (P < 0.01). Carcass weight was 6 kg greater for EFC cattle (P < 0.01), which also had 8% fewer liver abscesses (P = 0.03) than CON. Marbling score was greater in CON cattle (P = 0.04) than EFC; no differences in USDA Quality Grade (P = 0.33), Yield Grade (P = 0.13), LM area (P = 0.89), or 12th-rib fat thickness (P = 0.21) were evident. Improvements in digestion associated with EFC are likely confined to that component of grain mixtures due to a lack of quadratic effects. Improvements in feed efficiency, carcass weight, and potential liver abscess mitigation may be of advantageous use for producers.

Call number: LD2668 .T4 1963 M67 / Master of Science

No description available.

No description available.

Abstract Recent decades have experienced a sharp increase in the incidence and prevalence of diabetes mellitus. One antidiabetic therapeutic approach is to reduce gastrointestinal glucose production and absorption through the inhibition of carbohydrate-digesting enzymes such as α- amylase and α-glucosidase and α-amylase. The aim of the current study was to screen six medicinal plant species, with alleged antidiabetic properties for α-glucosidase inhibitory activities. Powdered plant materials were extracted with acetone, and tested for ability to inhibit baker's yeast α-glucosidase and α-amylase activities. The largest mass (440 mg from 10 g) of the extract was obtained from Cassia abbreviata, while both Senna italica and Mormordica balsamina yielded the lowest mass of the extracts. Extracts of stem bark of C. abbreviata inhibited baker's yeast α-glucosidase activity with an IC50 of 0.6 mg/ml. This plant species had activity at low concentrations, with 1.0 mg/ml and above resulting in inhibition of over 70%. The other five plant extracts investigated had IC50 values of between 1.8 and 3.0 mg/ml. Senna italica only managed to inhibit the activity of enzyme-glucosidase at high concentrations with an IC50 value of 1.8 mg/ml, while Tinospora fragosa extracts resulted in about 55% inhibition of the activity of the enzyme at a concentration of 3.5 mg/ml, with an estimated IC50 value of 2.8 mg/ml. The bark extract of C. abbreviata was the most active inhibitor of the enzyme, based on the IC50 values (0.6 mg/ml). The bark extract of C. abbreviata contains non-competitive inhibitor(s) of α-glucosidase, reducing Vmax value of this enzyme from 5 mM·s–1 to 1.67 mM·s–1, while Km remained unchanged at 1.43 mMfor para-nitrophenyl glucopyranoside. Antioxidant activity of the extracts was also investigated. The C. abbreviata extract was more active as an antioxidant than the positive control, trolox. The extracts did not inhibit alphaamylase activity more than about 20% at the highest concentration tested.

Amylase activities and patterns were compared in extracts from mature seeds and from different parts of seedlings at various stages of seed germination of various varieties of different legume species. Apart from soyabean, all varieties had low levels of amylase activities in extracts from mature seeds, while the former had a remarkably high level. Amylase activities and the number of bands increased during seed germination and showed time and tissue specifity. The extracts from cotyledons had the highest activities and the largest number of bands as compared to that of the various parts of embryonic axes. Amylase activities and patterns had time specific changes during the various stages of seed development of the 7 varieties of different legume species studied. All the different varieties showed changes in zymogram patterns and decreased amylase activity during seed development, except soyabean where amylase activity remained high at all stages. The different components of amylase were characterised in pea (var. Feltham First). One band of a -amylase activity, restricted to the cotyledons, was present in the middle stages of seed development only, then reappeared at the third day of seed germination. The embryonic axes β -amylase activity decreased as the seed developed, to reach zero level in mature seeds, and reappearred during seed germination. The reverse sequence occurred for the cotyledonary β -amylase. The pea a -amylase was partially purified using ethanol precipitation, glycogen complex and hydroxyapatite column chromatography. The purified protein had three major bands with few faint bands on the SDS polyacrylamide gel. The embryonic axes β -amylase of pea was partially purified using the conventional method, ammonium sulphate precipitation, ion exchange chromatography and gel filtration. The purified protein contained two thick bands and many faint bands on the SDS polyacrylamide gel. The zymogram patterns of phosphorylase, EST, GDH, GOT, LDH, ADH and MDH were investigated during seed development of various varieties of different legume species. The most noticeable changes as the seeds developed were the decrease in activities and number of bands of EST in pea and soyabean, shift in GDH activities between isoenzyme forms in pea (var. English Wonder), increase in GDH activities and number of bands in dwarf French bean and soyabean and increase in activities and number of bands of MDH in pea (var. Feltham First).

Univ., Diss.--Marburg, 2000.

A strain of Aspergillus niger, isolated from rotting cassava tubers, has been immobilised in beads of calcium alginate (1 percent, w/v) and used to produce amylolytic enzymes. The optimal operating conditions (cell concentration and gel composition of the immobilised system, temperature of incubation, initial pH of the medium) have been investigated. Amylolytic enzyme production was associated with the cell growth within the calcium alginate beads. The growth pattern of Aspergillus niger cells trapped in the calcium alginate gel has been studied. An early phase of exponential growth followed by a phase of decelerating growth rate was observed. The explanation for this growth pattern has been discussed. By operating the immobilised cell system under optimised conditions a higher level of amylolytic enzyme production than that obtained with a free cell system was achieved. A better operational stability for the immobilised system was demonstrated. The continuous production of amylolytic enzymes by the immobilised cells of Aspergillus niger has been investigated. Using a nitrogen-limited medium, it was possible to maintain a relatively high enzyme productivity during a 12 day- period of continuous operation. The thermostability, storage stability, pH and temperature activity profiles of the crude enzyme broth from the immobilised cell culture, and their comparison with these characteristics for enzyme broth from a free cell culture, have been studied. The conversion of raw (uncooked) cassava starch to glucose syrup and, in the presence of yeast cells, its further fermentation to ethanol, have been investigated using culture liquid from immobilised cells. Also, the immobilised cell system has been employed as a possible treatment system for starch-containing wastewater.

The food industry has responded to the American Heart Association's overwhelming concerns about the complications of obesity with an array of fat reduced products that maintain the functionality of fat in given systems. In baked products, it appears that no one single ingredient effectively mimics these functions. The present study investigated the effect of liquid or dry honey as a partial replacement for sugar on the baking and keeping qualities of fat reduced muffins. The fat reduced muffins also utilized a hydrocolloid fat replacer, bacterial and fungal amylases, and an emulsifier (DATEM). Results showed that both liquid and dry honey significantly (p<0.05) increased crust and crumb color at all replacement levels, however the use of 25% liquid honey was shown to favorably increase the crust color of fat reduced muffins. Volume was not significantly (p>0.05) affected but appeared to decrease with the addition of honey due to either premature starch gelatinization or a decrease in batter pH. The addition of honey increased moisture content, and decreased water activity, but did not decrease firmness or staling rates especially after prolonged frozen storage. Sensory panelists noted that the addition of liquid or dry honey increased the cohesive forces and decreased tenderness. The addition of moisture to the fat reduced system did not appear to improve the perceived moistness of the product. / Master of Science

Made available in DSpace on 2014-06-11T19:31:00Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-07-31Bitstream added on 2014-06-13T20:01:21Z : No. of bitstreams: 1 tavano_ol_dr_araiq.pdf: 761592 bytes, checksum: 1c98a6250ff1a76b1380af40256bd7b4 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Neste trabalho estudou-se a possibilidade de imobilização de uma amilase produzida por cepa de Neurospora crassa (mutante exo-1), e produção de derivados ativos e estabilizados. Foram testados diferentes suportes sólidos, incluindo-se diferentes suportes de agarose e suportes epóxidos preparados com Eupergit e Sepabeads. Além da agarose 10BCL foi utilizada a agarose 4BCL para que se verificasse possíveis dificuldades difusionais do substrato desta enzima, o amido. O acompanhamento das cinéticas de imobilização com a maltose como alternativa ao amido, também colaborou em evidenciar a dificuldade de difusão do amido através de ambos os suportes glioxil-agarose. O derivado obtido com agarose 10BCL, assim como aquele produzido com uso de suporte Eupergit foram os derivados mais estáveis, capazes de manter 100% de suas atividades após 12 horas de incubação à temperatura de 60°C, quando na forma solúvel a enzima conservou apenas 12% de sua atividade inicial. Quando incubados a 70°C destacou-se o derivado de glioxil-agarose (10BCL) como mais estável, mantendo cerca de 30% de sua atividade inicial após 4 horas de incubação. Quando testada a utilização de uma agarose comercial alternativa, sem percentual de crosslink conhecido, de menor custo, sua aplicação mostrou-se promissora e os derivados produzidos além de ativos se apresentam estáveis frente à temperatura. Em conjunto, as informações contidas no presente estudo indicam que a amilase de Neurospora crassa apresenta-se promissora em comparação às amilases de mercado aqui estudadas, tanto em sua utilização na forma solúvel quanto no que se relaciona a produção de derivados estáveis. / In this work were studied the immobilization of amylase from Neurospora crassa (Mutant Exo-1). This amylase showed easily production, purification and high capacity of immobilization on agarose and epoxy supports. It was used crosslinked agarose with two polymer concentration: 4 and 10%. The 4BCL agarose presents bigger porous diameter than 10 BCL agarose, so, in this case, possible diffusion problems of the starch across the supports could be reduced. Also, in this study, we have tested two epoxy supports for this amylase immobilization, using Eupergit and Sephabeads supports. The activies of the obtained derivatives were measured using two substrates - maltose and starch. Both glyoxyl agarose support prepared with 4BCl and 10BCL agarose present diffusion problems when the starch was used as substrate to measure the immobilization course. The 10BCL glyoxyl derivative presented the highest thermal stability when comparing the others derivatives. Among the epoxy derivatives the Eupergit one were better than the derivatives obtained using Sepabeads as support. In a confrontation between the two best derivatives, that is, the glyoxyl 10 BCL and Eupergit derivatives, both of them were stable at 60º incubation, maintaining 100% of activities for 12 hours, while the soluble amylase preserved about 12% of initial activity. These two amylase derivatives only showed differences at 70ºC incubation, when the glyoxyl 10BCL amylase derivative was more thermally stable, preserving about 30% of the initial activity after 4 hours.