965 resultados para Acid modified corn starch
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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A semente de milho doce é leve e rugosa. A rugosidade torna difícil a classificação das sementes quanto à forma e ao tamanho e isso dificulta a semeadura. Uma solução para esse problema seria a utilização da técnica de revestimento. Assim, este trabalho teve por objetivo avaliar diferentes materiais de enchimento, cimentantes e corantes na peletização de sementes de milho superdoce e verificar quais combinações de materiais seriam eficientes na manutenção da qualidade fisiológica das sementes após o armazenamento e que permitissem vazão e distribuição uniformes durante a semeadura. Foram então testados doze materiais de enchimento (calcários 1 e 2, caulim, carvão vegetal ativado, areia, vermiculita, fubá de milho, farinha de trigo, polvilho de mandioca, amido de milho, celite e terra de diatomáceas), dois cimentantes (goma arábica e cascorez extra) e seis corantes (tintas guache, acrílica, plástica e para tecido, corante para alimento e gelatina). As avaliações da qualidade física e fisiológica das sementes revestidas e nuas foram efetuadas por meio dos testes: teor de água, fragmentação, peso de mil sementes, volume aparente e plantabilidade, germinação, primeira contagem da germinação e emergência de plântulas em campo. O revestimento de sementes de milho superdoce proporciona homogeneidade de forma e tamanho às sementes, melhora a vazão e a distribuição dos péletes na semeadura e não compromete a emergência de plântulas em campo depois de quatro meses de armazenamento.
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O objetivo do experimento foi avaliar os efeitos da utilização do farelo de soja ou da glutenose sobre a degradabilidade ruminal in situ dos constituintes de dietas compostas por feno, milho e as fontes nitrogenadas fornecidas para bovinos adultos com 650 kg de peso. A glutenose foi considerada fonte nitrogenada de baixa degradabilidade e o farelo de soja, de média degradabilidade ruminal. As degradabilidades potenciais obtidas para o nitrogênio foram 39,7 e 90,3% e as degradabilidades efetivas 35,7 e 62,9%, respectivamente, para glutenose e farelo de soja. Utilizou-se a fibra mordente para determinar a taxa de passagem das dietas e obtiveram-se 6,6%/h para dietas com farelo de soja e 2,4%/h para dietas com glutenose. Não houve diferença na degradabilidade potencial da matéria seca do feno, nas frações A, B, C e na taxa de degradação, mas a degradabilidade efetiva da matéria seca foi inferior para as dietas com farelo de soja (29,3 vs 40,6%). Os demais ingredientes, à exceção do milho, apresentaram acentuadas diferenças entre as dietas nas variáveis de degradabilidade, na taxa de degradação e na degradabilidade efetiva do nitrogênio, com inferioridade na dieta com glutenose. O milho diferiu apenas quanto à degradabilidade efetiva do nitrogênio, superior na dieta com glutenose (68,7 vs 56,3%). O amido do milho apresentou menor degradabilidade efetiva na dieta com farelo de soja (52,5 vs 68,0%), sendo a degradabilidade efetiva da fibra do feno também inferior para essas dietas (27,3 vs 43,2%). Concluiu-se que fontes nitrogenadas com distintas degradabilidades podem afetar tanto a degradabilidade da fibra do volumoso quanto à do amido da própria fonte nitrogenada e do milho das dietas.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Porosity in starch consolidation casting technique is rightly related to original size and morphology of starch granules, leaving a pore structure after burning out. This work reports the results for the addition of different native potato and corn starch proportions in suspension,; with TiO(2) (rutile) powder. Gelling temperature have been defined after observation under light microscopy using a heating stage. Analysis of porous network and isolated pores have been clone from images of samples surfaces obtained by depth from focus reconstruction, revealing a qualitative correlation of pores characteristics and starches additions in suspensions, suggesting that the presence of isolated or interconnected pores can be handled by starches selection to control the amylopectin and amylose contents in slurries. Also, the analysis of porous fraction distribution shows no consistent pattern through specimens' volume according to starches in mixtures.
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Cyclodextrin glycosyltransferase (CGTase) is an enzyme that produces cyclodextrins from starch by an intramolecular transglycosylation reaction. Cyclodextrins have been shown to have a number of applications in the food, cosmetic, pharmaceutical, and chemical industries. In the current study, the production of CGTase by Paenibacillus campinasensis strain H69-3 was examined in submerged and solid-state fermentations. P. campinasensis strain H69-3 was isolated from the soil, which grows at 45 C, and is a Gram-variable bacterium. Different substrate sources such as wheat bran, soybean bran, soybean extract, cassava solid residue, cassava starch, corn starch, and other combinations were used in the enzyme production. CGTase activity was highest in submerged fermentations with the greatest production observed at 48-72 h. The physical and chemical properties of CGTase were determined from the crude enzyme produced from submerged fermentations. The optimum temperature was found to be 70-75 degrees C, and the activity was stable at 55 degrees C for 1 h. The enzyme displayed two optimum pH values, 5.5 and 9.0 and was found to be stable between a pH of 4.5 and 11.0.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Visando obter informações a respeito da estrutura dos grânulos, amidos de milho normal e ceroso foram isolados e submetidos à ação da a-amilase e amiloglucosidase. Para elucidar a estrutura dos grânulos, os resíduos desta hidrólise foram submetidos à cromatografia de permeção em gel Sephadex G-50, diretamente e após sucessivas digestões enzimáticas com pululanase e b-amilase. Os resultados mostraram que existem diferenças nos resíduos dos amidos de milho ceroso e normal, tratados com a-amilase e amiloglucosidase. No resíduo do amido de milho ceroso, os perfis de eluição mostraram duas frações a 290 e 350 ml (picos I e II) respectivamente, que não eram suscetíveis ao ataque da a-amilase e amiloglucosidase, indicando que estas frações faziam parte das zonas cristalinas do amido. Estas frações também faziam parte das áreas cristalinas no amido normal. A presença do pico V à 390 ml na a-glucana do amido de milho normal sugeriu que além das duas frações não suscetíveis à hidrólise existia outra que também participava das zonas cristalinas deste amido como regiões não suscetíveis às enzimas formando, consequentemente, rede cristalina fortemente associada. A presença deste pico a 390 ml sugeriu arranjo cristalino distinto entre o amido de milho ceroso e o normal.
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Cyclodextrins ( CDs) are cyclic oligasaccharides composed by D- glucose monomers joined by alpha- 1,4-D glicosidic linkages. The main types of CDs are alpha-,beta-and gamma-CDs consisting of cycles of six, seven, and eight glucose monomers, respectively. Their ability to form inclusion complexes is the most important characteristic, allowing their wide industrial application. The physical property of the CD-complexed compound can be altered to improve stability, volatility, solubility, or bio-availability. The cyclomaltodextrin glucanotransferase ( CGTase, EC 2.4.1.19) is an enzyme capable of converting starch into CD molecules. In this work, the CGTase produced by Bacillus clausii strain E16 was used to produce CD from maltodextrin and different starches ( commercial soluble starch, corn, cassava, sweet potato, and waxy corn starches) as substrates. It was observed that the substrate sources influence the kind of CD obtained and that this CGTase displays a beta- CGTase action, presenting a better conversion of soluble starch at 1.0%, of which 80% was converted in CDs. The ratio of total CD produced was 0: 0.89: 0.11 for alpha/beta/gamma. It was also observed that root and tuber starches were more accessible to CGTase action than seed starch under the studied conditions.
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Organic-inorganic hybrids were prepared using ureapropyltriethoxysilane, methacryloxypropyltrimethoxysilane and acrylic acid modified zirconium(IV) n-propoxide precursors and were characterized by small angle X-ray scattering, X-ray diffraction and photoluminescence spectroscopy. The results indicate an effective interaction between the zirconium-based nanoparticles and the siliceous nanodomains that induces changes in the hybrids' emission features. Planar waveguides were obtained by spin-coating of the prepared sols on sodalime and silica substrates. Refractive index, thickness, number of propagating modes, and attenuation coefficient were measured at 543.5, 632.8 and 1550 nm by the prism coupling technique. The synergism between the two hybrid precursors resulted in monomode planar waveguides with low losses in the infrared ( from 0.6-1.1 dB cm(-1)) which also support a number of propagating modes in the visible ( losses from 0.4-1.5 dB cm(-1)). Channel waveguides were also obtained by UV photopatterning using amplitude or phase masks and propagating modes were observed at 1550 nm.
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The chemical composition of corn and cottonseed meal was determined in accordance with the Cornell Net Carbohydrate and Protein System (CNCPS) in diets with forage:concentrate ratios of 80:20 (D1) and 60:40(D2) using Nellore cattle. The potential and effective degradabilities of the carbohydrate and protein subfractions were also determined. For corn. diet 2 resulted in an increase for potentially degradable dry matter (DM). An increase was observed in the effective degradation of DM (EDDM) when lag time was not considered, however, the use of Eng time increased the EDDM for both diets, 23 and 18% for DI and D2. respectively. For cottonseed meal, diet 2 determined a reduction in the potentially degradable DM: therefore, the use of lag time increased the EDDM for bath diets, 14% for D1 and 15% for D2. The availability of corn starch (fraction B1) was lower than that determined by CNCPS. The higher values for the degradability of corn and cottonseed meal protein subfractions may indicate an underestimation by the model, and, or, could be attributed to the Zebu animals used in this study.
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Organic-inorganic hybrid materials were prepared from an ureasil precursor (ureapropyltriethoxysilane designated as UPTES) and acrylic acid modified zirconium (IV) n-propoxide. Thin films containing rhodamine 6G (Rh6G) were prepared by spin-coating on glass substrates with different Zr:Si molar ratios (Zr:Si = 75:25, 50:50 and 25:75). Refractive index, thickness, number of propagating modes and attenuation coefficient were measured at 543.5, 632.8 and 1550 nm wavelengths by the prism coupling technique. Distributed feedback (DFB) laser effect was observed and studied as a function of films thickness and refractive index.
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The utilization of energetic and protein feeds, highly digestible as well, becomes more and more necessary due to the quality of formulated rations, fish performance and relationship with the environment. Apparent digestibility coefficient (ADC) of dry matter, protein, energy, phosphorus, and amino acids of corn starch, corn, wheat, rice, soybean, and cottonseed meal, corn gluten and fish meal were determined for Nile tilapia. ADC was determined using a reference diet based on albumin, gelatin and corn starch, was used inert indicator chromium III oxide (Cr(2)O(3)). Each test diet composed by 70% of reference diet and 30% of the test diet. Feces were collected using mofied Guelph system. ADC values for protein and average ADC of amino acids were as follows: corn 89.76 and 96.43%, rice meal 95.88 and 92.26%, wheat meal 93.54 and 84.41%, fish meal 82.59 and 86.36%, corn gluten 89.82 and 87.98%, soybean meal 94.13 and 91.93%, cotton meal 87.10 and 77.47%, respectively. According to the results of this work, ADC of protein is not a reliable indicator of ADC values of amino acids, even more so for wheat meal, corn, and cotton meal. Among protein feeds, soybean meal was found to have the highest ADC for protein and amino acids, while corn was the energetic feed with the highest ADC (86.15%) for energy.