bluuebunny/crossref_metadata_2025_split huggingface dataset:
GPC‐Analyse von Stärkepolysacchariden
Authors: Praznik W. 
Published: November 2006

AbstractEine kurze Darstellung der bisher in der Literatur beschriebenen Trennsysteme für die Analytik und molekulare Charakterisierung von Stärkepolysacchariden wird gegeben. Die von uns verwendeten bzw. weiterentwickelten Trennsysteme, die sich durch hohe mechanische Stabilität auszeichnen und auch im hochmolekularen Trennbereich reproduzierbare Ergebnisse liefern, werden vorgestellt. Für die Bestimmung der molekularen Verteilung mittels GPC muß eine Kalibrierung der Säulensysteme durchgeführt werden. Synthetische Amylosen und Dextrane, die sich jedoch strukturell unterscheiden, können zur Eichung herangezogen werden. Ihr unterschiedliches Trennverhalten und ihre Anwendbarkeit als Eichsubstanzen werden diskutiert. Es werden Zusammenhänge zwischen strukturellem Aufbau und molekularer Größe in Bezug zum Trennverhalten der Polysaccharide festgestellt. Statistische, rechnerische Verfahren erlauben sowohl eine Bestimmung der quantitativen Zusammensetzung der Stärken als auch die Bestimmung der mittleren Molekulargewichte (Zahlen und Gewichtsmittel) sowie der molekularen Uneinheitlichkeit von Stärkepolysacchariden. In Folge werden Anwendungsbeispiele aufgezeigt, die von der Grundlagenforschung (z. B. strukturelle Untersuchungen) über die Verwendung bei der Pflanzenzüchtung (Sortenwahl), bis hin zur Beurteilung von nativen und modifizierten Stärken im technologischen und pharmazeutischen Bereich reichen.
Some Studies on Modified Starch for Low Humidity Application
Authors: Hari P. K. , Bhalla S. 
Published: November 2006

AbstractStarch was chemically modified by substitution with hydroxyethyl groups to three levels (0.05, 0.1, 0.15 molar substitution) to reduce the brittleness of starch film for low humidity application. Substitution with hydroxyethyl groups reduced the density and sonic modulus and increased the moisture regain of the film. The brittleness of hydroxyethyl starch film at low humidity is reduced as the flexural rigidity, intermolecular friction, tensile modulus and breaking strength is decreased and breaking extension is increased.
The Effect of Physical Damage on Large and Small Barley Starch Granules
Authors: Stark J. R. , Yin X. S. 
Published: November 2006

AbstractBarley starch from a Scottish brewing barley (Golden Promise) has been isolated, purified and fractionated into two populations according to the granule sizes. The effects of physical damage on the two types of granules have been examined by iodine staining, debranching, gel chromatography, viscosity measurements and scanning electron microscopy. The amylose content of large starch granules was slightly greater than that of the small granules and the effect of physical damage did not differ significantly between the two types of granules. Physical damage to both types of granules in the dry state followed by extraction with cold water resulted in the preferential solubilization of low molecular weight amylopectin.
Purification and Characterization of Extremely Thermostable Exo‐oligo‐1,6‐glucosidase from a Caldoactive Bacillus sp. KP 1228
Authors: Suzuki Y. , Fujii H. , Uemura H. , Suzuki M. 
Published: November 2006

AbstractA p‐nitrophenyl‐α‐D‐glycopyranoside‐hydrolyzing oligo‐1,6‐glucosidase (dextrin 6‐α‐glucanohydrolase, EC 3.2.1.10) of a caldoactive Bacillus sp. KP 1228 capable of growing at 51–82°C was purified to homogeneity. The molecular weight was estimated as 140,000. The enzyme consisted of two identical subunits each comprising a threonine residue at the NH2‐terminus. The enzyme was most active at 85°C and pH 5.1, and stable for 10 min up to 85°C at pH 6.8. The enzyme had no antigenic determinant common to oligo‐1,6‐glucosidases from Bacillus cereus ATCC 7064 (mesophile), Bacillus coagulans ATCC 7050 (facultative thermophile) and Bacillus thermoglucosidasius KP 1006 (DSM 2542) (obligate thermophile). A strong correlation between the increase in proline content and the rise in thermostability of these 4 proteins was observed.
Alkaline Degradation of Monosaccharides Part VIII. A13C NMR Spectroscopic Study
Authors: De Bruijn J. M. , Touwslager F. , Kieboom A. P. G. , van Bekkum H. 
Published: November 2006

AbstractThe analysis of alkaline degradation products of monosaccharides has been performed by 13C NMR spectroscopy. The 13C chemical shifts of several carboxylic acids produced by alkaline degradation of monosaccharides have been determined. The application of these data to the identification and quantification of products in an alkaline degradation mixture of D‐glucose is presented. Carboxylic acid products up to 6 carbon atoms have easily been identified in such complex reaction mixtures. Furthermore, information on the different functional groups present in the oligomeric reaction products has been obtained from the alkaline degradation of 1‐13C‐D‐glucose.
Mobility of Water in Corn Starch Suspensions Determined by Nuclear Magnetic Resonance
Authors: Richardson S. J. , Baianu I. C. , Steinberg M. P. 
Published: November 2006

AbstractThe mobility of water in corn starch suspensions and high‐moisture powders (10 to 70% corn starch) was investigated by Nuclear Magnetic Resonance (NMR) spectroscopy, in water and deuterium oxide. Both oxygen‐17 (17O) and deuterium (2H) nuclei were probed with a single pulse. The standard isotropic two‐state model with fast exchange was used to interpret these data by means of a physical model (I) and a chemical activity model (II). According to I plots of relaxation rate against concentration indicated three regions of decreasing water mobility. According to II, the relaxation rate was linear with chemical activity over the entire concentration range. The correlation time calculated for the bound water showed high mobility.
Effects of Water Stress on Starch and Sucrose Metabolism in Cotton Leaves
Authors: Chang Ch. W. , Ryan R. D. 
Published: November 2006

AbstractStudies of starch and sucrose metabolism as influenced by water stress in cotton plants (Gossypium hirsutum L.) have been meager. Therefore, metabolic enzyme activities and metabolites from well hydrated control and partially dehydrated plants were analyzed. Water stress decreases cotton leaf starch content directly by enhancing α‐amylase activity and indirectly by altering sucrose metabolism. In inhibition of sucrose synthetase causes an sucrose in the cytoplasm and also contributes to excess orthophosphate amassment in the chloroplasts. Orthophosphate inhibits ADP‐glucose pyrophosphorylase activity which is responsible for starch synthesis in the chloroplasts. The generally accepted metabolic relationship that leaf starch content is indirectly controlled by sucrose phosphate synthase activity was not observed.
Production of Ethanol from Tapioca (Manihot esculenta Crantz)
Authors: Srikanta S. , Jaleel S. A. , Sreekantiah K. R. 
Published: November 2006

AbstractEthanol production from fresh tubers, flour and starch of tapioca was studied by simultaneous saccharification and fermentation procedure. A 20% enzyme‐liquefied slurry showed about 2–3% reducing sugars, which increased to 10% on enzymic saccharification for 4h. Alcoholic fermentation of this hydrolysate with Saccharomyces cerevisiae, Var. ellipsoideus, yielded 8–9% alcohol showing about 95% fermentation efficiency. Large scale fermentation of tapioca flour by this process also showed fermentation efficiency of 90% thereby indicating the economic viability of the process.
Hafer, Gerste und Triticale — Eigenschaften und Chancen für die technische Stärkegewinnung
Authors: Wilhelm E. , Kempf W. 
Published: November 2006

AbstractDie Entwicklung von Verfahren zur Gewinnung neuer Rohstoffe aus Agrarerzeugnissen für chemische und technische Anwendungsgebiete ist ein Schwerpunkt im Forschungsprogramm „Nachwachsende Rohstoffe”︁ des Bundesministeriums für Ernährung, Landwirtschaft und Forsten. Hafer, Gerste und Triticale wurden in vergleichenden Untersuchungen auf die Möglichkeiten der technischen Stärkegewinnung geprüft. Dabei standen der Vermahlungsprozeß und Verfahren zur Trennung von Stärke, Protein und Faser im Vordergrund, mit Auswasch‐, Sieb‐ und Zentrifugier‐Techniken, die im technischen Maßstab realisiert werden können. Durch Absenken des pH‐Wertes der Prozeßwässer bis zum isoelektrischen Punkt und Abtrennen der Proteine wurden die CSB‐Werte um 50% reduziert. Stärken mit hohen Feinkorn‐Anteilen werden für neue technische und chemische Derivate Bedeutung erlangen. Methoden zur Anreicherung und Isolierung von Feinkornfraktionen wurden erprobt und durch Rasterelektronenmiktroskopie kontrolliert. Die Stärken zeigten Unterschiede im Verhalten gegenüber Alkalibehandlung und in den Viskositätscharakteristika.
Novel Technique for Saccharification of Cassava Fibrous Waste for Alcohol Production
Authors: Srikanta S. , Jaleel S. A. , Ghildyal N. P. , Lonsane B. K. , Karanth N. G. 
Published: November 2006

AbstractA novel technique, involving the hydrolysis of starch present in cassava fibrous waste in shallow layers in stainless steel trays, is developed to facilitate the use of higher slurry concentrations. The use of slurry containing 30% solids, 4% sulphuric acid, 30 min saccharification time at 121°C resulted in the complete conversion of the starch into reducing sugars. The spent residue, after separation of the hydrolysate, contained about 24% of the total sugars formed and these were recovered to the extent of 90–94% by using a counter‐current extraction technique. A large scale saccarification of a 75 kg batch gave 75 1 pooled hydrolysate containing 15% reducing sugars. An overall process efficiency of 76.4% was observed with the fermentation of hydrolysate pooled with the counter‐current extract for alcohol production. However, fermentation of the whole saccharified pulp without the separation of the hydrolysate and acid‐enzyme hydrolysis of the waste gave lower efficiencies.
Physico‐chemical Properties of Sorghum Starch Thermally Treated by Different Methods
Authors: Glennie C. W. 
Published: November 2006

AbstractSeparate samples of sorghum were pressure cooked, extruded and popped and the physico‐chemical properties of the starches compared. Pressure cooking and extrusion increased the water solubility of the samples more than did popping. Popping lead to a significant increase in beta‐amylase susceptibility. Gel permeation chromatography revealed a decrease in starch molecular weight after both extrusion and popping.
Estimation of Phosphorus in Native and Modified Starches. Improvement in the Molybdovanadophosphoric Acid Method
Authors: Singh Vasudeva , Zakiuddin Ali S. 
Published: November 2006

AbstractThe spectrophotometric method for estimation of phosphorus based on molybdovanadophosphoric acid complex has been improved for its sensitivity (8–10 fold) by reducing the reagents concentrations to one‐third and measuring the absorbance at its λ max (355 nm). The range of the method is brought down to 0.5 μg to 7 μg/ml for 1 cm light path. Phosphorus content of potato starch remained unchanged upon acid modification or oxidation with hypochlorite. Maize and tapioca starch, on the other hand, lost about 30–40% of their phosphorus upon acid modification. The difference probably lays in the state of phosphorus in the respective starch granules.
Properties of Residual Maize Starches Following Acid Hydrolysis
Authors: Inouchi N. , Glover D. V. , Fuwa H. 
Published: November 2006

AbstractThe properties of residual starches following initial acid hydrolysis were investigated. Starch granules of several endosperm mutants of maize, namely opaque‐2 (o2), amylose‐extender; opaque‐2 (ae o2), waxy; opaque‐2 (wx o2), dull; opaque‐2 (du o2), and sugary‐2; opaque‐2 (su2 o2) were used. Initial rate of hydrolysis for su2o2 was fastest and that for aeo2 was slowest. Following the acid hydrolysis by the enzymatic and chromatographic method, in the initial phase of hydrolysis amylose was preferentially hydrolyzed in the starches, except in the case of wx o2. In the case of wx o2 the long B chains of amylopectin were preferentially hydrolyzed. The rate of decrease in chain length of ae o2 was relatively fast and that of su2o2 was slow. Fine structures of amorphous regions in these starch granules are discussed.
Synthesis and Applications of Reactive Carbohydrates Part I: Behaviour of Carboxymethyl Starch Before and After Acid Hydrolysis Toward Grafting with Acrylamide
Authors: Bayazeed A. , Higazy A. , Hebeish A. 
Published: November 2006

AbstractCarboxymethyl starch (CMS) was subjected to acid hydrolysis at 50°C for different periods of time. The CMS sample and the hydrolyzed CMS samples were then subjected to two independent reactions, namely grafting with acrylamide using K2S2O8 as initiator and oxidation using K2S2O8 under the grafting condition but in absence of the monomer. The samples were analyzed for copper number and carboxylic content before and after these two reactions. Acid hydrolysis resulted in creation – in CMS structure – of aldehydic groups which underwent partial conversion to carboxylic groups during drying. Grafting reduced significantly the copper number and so did the oxidation. The latter increased the carboxylic groups but grafting exerted opposite effect. Hydrolysis of CMS for shorter or longer periods of time enhanced the susceptibility of CMS during the initial stages of grafting. The opposite held true for the later grafting stages. Methylolation and application of grafted prehydrolyzed CMS to cotton fabrics were reported.
Chain Length Distribution of Amylopectins of Double‐ and Triple‐Mutants Containing the Waxy Gene in the Inbred Oh43 Maize Background
Authors: Fuwa H. , Glover D. V. , Miyaura K. , Inouchi N. , Konishi Y. , Sugimoto V. 
Published: November 2006

AbstractStarch granules were isolated from mature kernels of double‐ and triple‐mutant combinations of the waxy (wx) gene with other starchmodifying genes in the inbred Oh43 maize background. The amylose content and the distribution of unit chain‐length of amylopectin were determined by enzymatic‐chromatographic methods. Starches of the mutants containing the wx gene comprised 100% amylopectin. Amylopectin of the amylose‐extender;waxy (ae wx) mutant had an increased proportion of long B chains and decreased proportion of short B chains, compared with wx amylopectin, whereas amylopectin of the dull;waxy (du wx) mutant had a decreased proportion of long B chains and an increased proportion of short B chains. Therefore, the ae wx and du wx mutants amylopectins were novel. The A:B chain ratios for amylopectins examined, namely for ae wx, amylose‐extender;waxy;floury‐2 (ae wx fl2), amylose‐extender;waxy;sugary‐1 (ae wx su1), amylose‐extender;waxy;sugary‐2 (ae wx su2), brittle‐1;waxy (bt1wx). dull;waxy (du wx), and sugary‐2;waxy (su2wx) amylopectins, were in a range of 1.1 to 1.4 and similar to the wx amylopectin. Thus, starches of double‐mutant combinations of the wx gene with other starch‐modifying genes are good sources for elucidating the fine structure of amylopectin, in regards to long‐ and short‐B chains, which is affected by a single recessive gene coupled with the wx gene.
Chemical Modification of Starch via Reaction with Acrylamide
Authors: Khalil M. I. , Bayazeed A. , Farag S. , Hebeish A. 
Published: November 2006

AbstractReaction of starch with acrylamide was carried out under different conditions including reaction medium, catalyst, acrylamide concentration, reaction time and temperature as well as liquor ratio. Organic solvents, namely, isopropyl alcohol, dimethylformamide and cyclohexane alone and in admixture with water at different ratios were used as reaction medium. Catalysts used include sodium hydroxide, trisodium phosphate, sodium carbonate, sodium benzoate, sodium acetate and sodium formate. Acrylamide concentration ranged from 25% to 200%, based on weight of starch. The reaction was studied over a wide range of temperature and duration. Results obtained showed that the extent of reaction of starch with acrylamide is governed by each of these factors. Furthermore, this reaction yields mixed starch ethers, namely carbamoylethyl starch and carboxyethyl starch. Solubility, viscosity and moisture content of these starch ethers are determined by the sum of the amide and carboxyl contents.
Synthesis and Applications of Reactive Carbohydrates Part II: Graft Polymerization of Starch and Hydrolyzed Starches with Acrylamide
Authors: Higazy A. , Bayazeed A. , Hebeish A. 
Published: November 2006

AbstractStarch and different hydrolyzed starch samples were subjected to two independent reactions, namely, grafting with acrylamide using K2S2O8 as initiator and oxidation with K2S2O8 under the grafting condition but in absence of the monomer. Copper number and carboxylic group measurements showed that both grafting and oxidation decrease outstandingly the copper number of the hydrolyzed samples and diminish completely the copper number of the original starch sample. On the contrary, grafting and oxidation cause significant enhancement in the carboxylic content, indicating partial conversion of the aldehydic to carboxylic groups under the oxidative action of K2S2O8; but it is certain that higher amounts of carboxylic groups are created in absence than in presence of acrylamide. Polymerization studies showed that the hydrolyzed starch samples are much more susceptible than the original starch sample toward grafting with acrylamide only during the initial stages of the reaction. Preliminary experiments describing introduction of methylol groups into the molecular structure of grafted sample and application of the methylolated product to cotton fabric were also reported.
Absorbents from Saponified Starch‐g‐poly (acrylonitrile‐co‐2‐acrylamido‐2‐methyl‐propanesulfonic acid). Some Practical Considerations
Authors: Fanta G. F. , Burr R. C. , Doane W. M. 
Published: November 2006

AbstractCeric‐initiated graft polymerizations of monomer systems containing 90–99 mole % acrylonitrile and 1–10 mole % 2‐acrylamido‐2‐methyl‐propanesulfonic acid onto gelatinized starch, followed by alkaline saponification of the polyacrylonitrile (PAN) moiety, were carried out under more practical conditions. Highest absorbencies of both water and 0.9% NaCl were obtained when starch was gelatinized either by stirring in water at 95°C or by jet cooking and when the temperature of the exothermic graft polymerization was not allowed to exceed 30°C. Saponifications should be run at the lowest practical polymer concentration and for a period of time somewhat longer than that required for loss of the red color characteristic of alkali‐treated PAN. Moreover, the alkaline saponificate should not be neutralized prior to methanol precipitation. Increased conversions of monomers to polymer were obtained by adding a second equal portion of ceric ammonium nitrate initiator.
Extrusion Cooking of Starches for Semi‐Products
Authors: Wiedmann W. 
Published: November 2006

AbstractExtrusion cooking is introduced as a modern high‐temperature‐short‐time process. The cooking time at high temperatures is a matter of seconds, which has a favourable effect in maintaining the properties of the ingredients and active substances, while giving high rates for the destruction of micro‐organisms. The end‐products have a long shelf‐life on account of their low process moisture content. The quality of extruder‐cooked products depends on the extrusion system. The self‐cleaning co‐rotating twin‐screw extruder with its narrow residence time spectrum is the optimum system. However, the counter‐rotating intermeshing machine has certain advantages for products of low viscosity. Continuous extrusion cooking has economic advantages mainly because it replaces many batch processes and because extrusion is carried out entirely or almost entirely with the final moisture content, thus avoiding the necessity to evaporate huge quantities of water.
Biomolecular Modelling: An Interactive Program for the Visualization and Modelling of Carbohydrate (Starch and Oligosaccharide) Complexes in Solution
Authors: Neszmélyi A. , László E. , Holló J. 
Published: November 2006

AbstractComputer aided molecular modelling has been used to study the solution‐conformation of various complexes of amylose. The preferred conformation of the complexes is determined by the HSEA Hard‐Spheres Exo‐Anomeric effect) method using the interactive computer program CAOS (Conformational Analysis of Oligosaccharides). NMR spectroscopy (nOe experiments, relaxation time measurements and the observation of local shielding) can follow and prove the conformation changes in solution.
Comparative Acid Modification of Various Starches
Authors: Singh Vasudeva , Ali S. Zakiuddin 
Published: November 2006

AbstractEight starches (maize, sorghum, finger millet, waxy and nonwaxy rice, chick pea, tapioca and potato) were acid modified with 0.5N HCl at 50°C. Alkali fluidity number (AFN) increased progressively with time of modification, and was highest in cereal followed by root, legume, and tuber starches. However, reduction in the number average molecular weight (M̄n) was in the reverse order. Potato starch had the highest M̄n, among the nonwaxy native starches and showed the greatest fall upon modification, whereas cereal starches had the least M̄n in native form and showed the least fall. In fact, there was a clear proportionality between the M̄n, of native starch and the extent of its hydrolysis under any given set of conditions. This relationship could be expressed by two intersecting lines, one for grains and one for root and tuber starches. When acid modified starches were recovered and dried without neutralization, hydrolysis still continued strongly in potato starch and slightly in tapioca, finger millet and sorghum starches. Other starches showed no change.
Measurement of the Starch Content of Commercial Starches
Authors: Moreels E. , Amylum N. V. 
Published: November 2006

AbstractFor the EC starch regulation 2169/1986 a minimum purity of 97% starch on dry substance is required to obtain the new end‐use refunds. Three different methods for the determination of starch were tested. Two polarimetric methods (EC L123/72, AOAC 14031‐032) and an enzymatic method (EC L158/86) were used to determine the high starch content of commercial unmodified starches. The results of a ring test between six laboratories shows that the AOAC method, solubilizing the starch in the presence of calcium chloride, has the smallest standard deviation. An explanation for the differences observed between the three methods is given, based on the sugar spectrum of the hydrolyzed starch. An independent ring test in France shows a modified enzymatic method, developed by AFNOR (the French standards organization) produces satisfactory results.
Studies on the Susceptibility of Granular Cassava and Com Starches to Enzymatic Attack Part I: Study of the Conditions of Hydrolysis
Authors: Franco Célia M. L. , Preto São José Dorio , Ciacco C. F. 
Published: November 2006

AbstractIn this research, the susceptibility of starch granules to enzymatic hydrolysis was studied. Cassava and corn starches were hydrolysed by bacterial α‐amylase with and without amyloglucosidase under several conditions of incubation. The highest percentage of hydrolysis was obtained in the presence of both enzymes. Elimination of the soluble hydrolysis products by dialysis increased the degradation of the starch granules, especially with cassava starch.