ABSTRACT
Crescimento e características de carcaça do jundiá (Rhamdia quelen) foram avaliados após 60 dias de alimentação com diferentes proporções de amilose:amilopectina na dieta. Foram criados 240 peixes (peso inicial de 34,3±4,3g) em sistema de recirculação de água constituído de 12 unidades experimentais de 280L. Foram testadas três dietas com as proporções amilose:amilopectina de: T417 = com 26 por cento de amilose, T416 = com 16 por cento de amilose e TMOCHI = com 0 por cento de amilose. Os peixes foram alimentados duas vezes por dia, às 8h e 30min e às 16 horas. A cada 15 dias, foram feitas biometrias para ajuste da quantidade de alimento ofertado. A proporção amilose:amilopectina no amido das dietas não influenciou o crescimento, os rendimentos de carcaça e a composição corporal dos peixes. Conclui-se que o jundiá tem potencial para utilizar fontes de amido compostas por até 26 por cento de amilose sem alterar a digestibilidade dos nutrientes e a deposição de gordura.
The growth and carcass traits of jundiá (Rhamdia quelen) after 60 days being fed with different amylose:amylopectin ratio in diet were evaluated. Two hundred and forty fish (initial weight of 34.3±4.3g) were raised in water re-use system with 12 units of 280L. Three diets were tested with amylose:amylopectin ratios: T417 = 26 percent amylose, T416 = 16 percent amylose and TMOCHI = 0 percent amylose. The fish were fed twice a day at 8:30 and 16:00h. Every 15 days the amount of food offered was ajusted. The amylose:amylopectin ratio in the starch of the diet did not affect growth, carcass and body composition of fish. This demonstrates that the jundiá has the potential to use starchy sources consisting of up to 26 percent amylose without altering the digestibility of nutrients and fat deposition.
Subject(s)
Animals , Amylopectin/administration & dosage , Amylose/administration & dosage , Fishes/growth & development , Animal Feed , Diet/veterinary , Fisheries , Water RecirculationABSTRACT
Devido aos escassos trabalhos brasileiros sobre a estrutura dos grânulos de amido, o objetivo desta revisão foi demonstrar os avanços atuais na elucidação da arquitetura e da estrutura química desse polímero. Muitas pesquisas sobre a avaliação da relação existente entre a estrutura molecular do amido e seu comportamento em algumas propriedades físico-químicas sugerem que diversas características estruturais, tais como teor de amilose, distribuição de comprimento das cadeias de amilopectina e grau de cristalinidade no grânulo, estejam intimamente relacionadas a eventos associados à gelatinização e retrogradação, como inchamento do grânulo, lixiviação de amilose e/ou amilopectina, perda da estrutura radial (birrefringência), supra-molecular (cristalinidade) e molecular e recristalização. O foco principal desta revisão foi a compilação de estudos a fim de obter melhor entendimento da estrutura e das características dos componentes do amido e sua relação com propriedades físico-químicas, principalmente no que diz respeito à gelatinização e retrogradação, as quais apresentam grande importância nutricional e tecnológica.
Due to poor Brazilians work on the structure of starch granules, the purpose of this review was to demonstrate the advances in current understanding of architecture and chemical structure of this polymer. Many studies evaluating the relationship between the molecular structure of starch and its behavior in some physicochemical properties, suggest that several structural features, such as amylose content, amylopectin chain length distribution and the degree of crystallinity in the granule, are closely related to the events associated with gelatinization and retrogradation as starch granule swelling, amylose and/or amylopectin leaching, loss of radial structure (birefringence), supra-molecular (crystallinity) and molecular order, and recrystallization. The main focus of this review was to make a compiler of studies in order to gain better understanding of the granule structure and characteristics of starch components and physicochemical properties (gelatinization and retrogradation) that could play a significant role in improving the quality of different food products.
Subject(s)
Amylopectin , Amylose , Starch/chemistryABSTRACT
A banana é considerada um bom modelo para o estudo da transformação amido-sacarose, já que acumula um alto teor de amido durante o desenvolvimento que é rapidamente degradado durante o amadurecimento. Várias enzimas e provavelmente mais de uma via metabólica estão envolvidas neste processo. Com isso, o objetivo deste trabalho foi estudar as características estruturais dos grânulos, bem como, a atuação das enzimas envolvidas em sua degradação. Os grânulos de amidos foram isolados de bananas controle (não tratadas) e submetidas a diferentes tratamentos: etileno, 1-MCP, frutos mantidos a 13'graus'C e frutos tratados com etileno e mantidos a 13'graus'C. Os resultados obtidos mostraram alta atividade de enzimas 'alfa' e 'beta'-amilases ligadas ao grânulo tanto por ensaios in vitro como por géis de eletroforese contendo amilopectina como substrato...
Subject(s)
Amylopectin , Enzymes/metabolism , Food Chemistry , Musa , alpha-Amylases/metabolism , beta-Amylase/metabolism , Electrophoresis/methods , Microscopy, Electron, Scanning/methodsABSTRACT
<p><b>AIM</b>To prepare amylopectin anchored dipyridamole (DIP) liposome and to study its tissue distribution in mice.</p><p><b>METHODS</b>The regular DIP liposomes were prepared by film-scatter method. The amphiphilic O-palmitoyl amylopectin was synthesized and added to modify the surface of liposome. The entrapping efficiency, zeta potential, mean diameter, span of modified and regular liposomes were assayed. The RP-HPLC was used for the determination of DIP concentration in mice tissue.</p><p><b>RESULTS</b>After modification, the entrapping efficiency depressed, zeta potential was raised, mean diameter and span had no obvious change. The level of DIP in lung, liver and spleen for regular liposomes were higher than that of injections. Compared with regular liposomes, the modified liposomes increased the DIP level in lung, and decreased the DIP level in liver, spleen, moreover, lengthened the retention time of DIP in lung.</p><p><b>CONCLUSION</b>The distribution of modified liposome in mice was markedly changed as compared with regular liposomes and injections. The modified liposomes had obvious lung targeting property.</p>
Subject(s)
Animals , Male , Mice , Amylopectin , Chemistry , Area Under Curve , Dipyridamole , Chemistry , Pharmacokinetics , Drug Delivery Systems , Liposomes , Lung , Metabolism , Palmitates , Chemistry , Particle Size , Tissue DistributionABSTRACT
Este estudo teve como objetivo padronizar e adaptar um método de determinação da amilose baseado no princípio da colorimetria, em bancada laboratorial, e, posteriormente, elaborar escalas de cores que possibilitassem as determinações qualitativa/semiquantitativa no campo, para seleção, após a colheita, de raízes de mandioca por teores de amilose/amilopectina. Os experimentos foram conduzidos no Laboratório de Ciência e Tecnologia de Alimentos da EMBRAPA Mandioca e Fruticultura, utilizando como referencial o método preconizado pela INTERNATIONAL ORGANIZATION FOR STANDARDIZATION. Foi elaborada uma curva padrão de amilose/amilopectina com dezenove pontos e uma posterior Escala de Cor correspondente, baseada nos valores da escala Pantone®. Duas outras escalas de cores foram elaboradas a partir da Escala de Cor da curva padrão, sendo uma por faixa de teores baixos, médios e altos e uma outra pelos valores médios dessas faixas de concentração de amilose. As análises espectrofotométrica e sensorial foram realizadas em seis variedades de mandioca do Banco Ativo de Germoplasma da EMBRAPA Mandioca e Fruticultura.
Subject(s)
Amylopectin/analysis , Amylose/analysis , Colorimetry/methods , ManihotABSTRACT
Ultrathin sections of tissue cysts isolated from the brain of Toxoplasma gondii infected mice were submitted to two different methodologies derived from the periodic acid - Schiff's reagent (PAS) technique. The use of osmium tetroxide vapor as a developing agent of the aldehyde oxidation to reveal polysaccharides with periodic acid resulted in positive reaction in amylopectin granules in bradyzoites, as well as in the wall and matrix of the cysts, with excellent increment of the ultrastructural morphology. This technique can be used for study of T. gondii-host cell intracellular cycle, the differentiation tachyzoite-bradyzoite, and also for the formation of cysts into the host cells.
Subject(s)
Animals , Mice , Amylopectin , Brain , Cysts , Toxoplasma , Toxoplasmosis, Animal , Cysts , Histocytochemistry , Microscopy, Electron , Osmium Tetroxide , Toxoplasma , Toxoplasmosis, AnimalABSTRACT
PURPOSE: Postoperative hyperamylasemia and pancreatitis may sometimes follow abdominal surgery but the significance and cause of hyperamylasemia after colorectal surgery were not studied enoughly. Our study was designed to identify the incidence of hyperamylasemia after colorectal surgery, to investigate the effect of hyperamylasemia on postoperative hospital course, and to clarify the causes such as extent of colorectal resection or intraoperative events. METHODS: The serum amylase was determined in post operative first day in random sampled 72 patient among whom underwent elective colorectal resection from March 2000 to July 2001. If a hyperamylasemia was evident, repeated check the level till it returned to within normal range. Other factors that seemed to affect serum amylase such as traction of pancreas during operative manupulation, intraoperative hypotensive episode or infused drug and volume expanders etc. were reviewed and analysed. RESULTS: Hyperamylasemia occurred in 25 patients (34.7%) after colorectal surgery. Serum amylse level returned to normal in all but nine patients (12.4%) by third postoperative day, two patients (2.8%) by the fifth postoperative day. Pancreas manupulation and intraoperative use of volume expander, amylopectin were found to be significantly associated with postoperative hyperamylasemia by 2-test and pearson correlation analysis. The developement of hyperamylasemia did not adversely influence the postoperative hospital course. CONCLUSIONS: Twenty-five (34.7%) in seventy-two patients who underwent colorectal surgery developed hyperamylasemia after operation. The incidence was significantly high in a group who underwent surgical procedure with more pancreas manupulation and infused hydroxyethyl starch (amylopectin) containing volume expander. The development of postoperative hyperamylasemia did not seem to influence adversely the postoperative hospital course in this study.
Subject(s)
Humans , Amylases , Amylopectin , Colorectal Surgery , Hyperamylasemia , Incidence , Pancreas , Pancreatitis , Reference Values , Starch , TractionABSTRACT
BACKGROUND: This study was carried out to determine the effect of the kinds and concentration of cryoprotectants and freezing temperature on the survival rate of frozen erythrocytes. METHODS: Erythrocytes mixed with three different concentrations of amylopectin, k-carrageenan, dextran and hydroxyethylstarch as cryoprotectants were frozen at -10, -30, -50 and -196degrees, respectively, and thawed at 35degrees. The survival rate of frozen erythrocytes was determined by hemoglobin concentration of supernatant of thawed erythrocytes. Morphological changes were observed by scanning electron microscopy. RESULTS: Frozen erythrocytes with amylopectin or k-carrageenan showed relatively low survival rate (<40%). In case of erythrocytes with dextran, the survival rate of erythrocytes with 30% dextran showed significantly increased survival rate compared with 20% or 25% dextran (p<0.05). The survival rates of erythrocytes with 30% dextran and freezing temperature of -10degrees, -50degrees and -196degrees showed 80.44%, 73.61% and 88.84%, respectively. Frozen erythrocytes with hydroxyethylstarch showed significantly high survival rate with freezing temperature of -196degrees (hydroxyethylstarch conc. 20%: survival rate 66.26%, 25%: 64.51%, 30%: 86.22%) compared with other freezing temperature. Most of frozen erythrocytes with amylopectin of k-carrageenan were changed to spherocytes by freezing process. The change to echinocytes of erythrocytes with dextran was decreased according to the increasing concentration of dextran. The change to stomatocytes of erythrocytes with hydroxyethylstarch was decreased according to the increasing concentration of dextran. CONCLUSION: It was found that the kinds and concetration of cryoprotectants and freezing temperature affected the survival rate and morphological change of erythrocytes. Dextran or hydroxyethylstarch could increase the survival rate of frozen erythrocytes over 80% by protection of erythrocytes from the physical, chemical stress during freezing process.
Subject(s)
Humans , Amylopectin , Cryopreservation , Dextrans , Erythrocytes , Freezing , Microscopy, Electron, Scanning , Spherocytes , Survival RateABSTRACT
Cristalinidade, atividade de água, textura, estado físico, temperatura de transição vítrea, isotermas de sorção e parâmetros de relaxação nuclear, foram usados para o estudo das interações entre os componentes e a mobilidade molecular dos seguintes sistemas: amido ceroso de milho (basicamente amilopectina) natural, glicerol e água; amido ceroso de milho amorfo e água; e, amido ceroso de milho amorfo, glicerol e água. Os resultados indicam que misturando-se amido ceroso de milho cristalino, glicerol e água ocorre uma interação entre os componentes. Há um movimento das moléculas pequenas da solução para a matriz sólida do sistema e vice-versa. A atividade de água da mistura diminui enquanto a mobilidade aumenta...
Subject(s)
Food Quality , Food Technology , Glycerol/analysis , Chemical Phenomena , Starch/analysis , Water/analysis , Zea mays , Amylopectin , Humidity , Magnetic Resonance Spectroscopy/methodsABSTRACT
A strain of Rhizopus sp. screened among more than 800 filamentous fungi showed great ability to produce a thermostable alfa-amylase by solid state fermentation. The best production was obtained with a bran moisture content of 40 per cent when the enzyme activity reached 60 EU/g. of medium. During the purification procedures, a column of DEAE- Sephadex A-50 separeted the enzyme in two fractions and the larger (85 per cent of the total activity) showed optimum pH in a range from 4.0 to 5.6. Optimum temperature was found at 60-65§ C and in this range no loss of activity was observed after 60 min. of treatment in pH 5,0. Its Km and Vm are, respectively, of 5.0 mg/ml of starch and 10,01 uMol of reducing sugar/min./mg. of protein. Its molecular weight was calculated in 64.000 by gel filtration in Sephadex G-200. The dextrinization power of the enzyme was observed preferentialy on substrates compound by chain with higher ramifications, traht is: amylopectin > starch> amylose. Other aspects of the enzyme pattern action are also discussed