bluuebunny/crossref_metadata_2025_split huggingface dataset:
Properties of Flavobacterium odoratum KU Isoamylase
Authors: Hizukuri S. , Kozuma T. , Yoshida H. , Abe J. , Takahashi K. , Yamamoto M. , Nakamura N. 
Published: November 2006

AbstractIsoamylase was purified from the culture filtrate of Flavobacterium odoratum KU to a single protein by starch adsorption and gel‐permeation chromatography on a Toyopearl HW‐55S column. The molecular weight and isoelectric point of the enzyme were found to be 78000 and 8.7, respectively. The enzyme was stabilized and stimulated by Ca2+. Its optimum temperatures for activity were 50 and 45°C in the presence and absence of CaCl2 (1mM), respectively, and the optimum pH was 6.0 in the presence of CaCl2 (1mM). The enzyme debranched amylopectin and glycogen completely. The Km and It values of the enzyme for amylopectins and glycogens were similar but were slightly lower than the values for the β‐limit dextrins of these polysaccharides. The k0 values for the β‐limit dextrins of potato amylopectin and rabbit liver glycogen were slightly lower and higher than those of the mother polysaccharides, respectively. Pullulan was practically not hydrolyzed. Flavobacterium isoamylase did not hydrolyze (1→6)‐α‐D‐glucosylcyclodextrins (CDs), and it debranched branched CDs having longer (1→4)‐α‐glucan side chains than maltotriosyl residues, and maltosyl CDs with difficulty. The enzyme practically did not hydrolyze raw starches but it enhanced the raw‐starch digestion of glucoamylases synergistically.
Viscosity Prediction of Starch Hydrolysates from Single Point Measurements
Authors: D'Haene Pol , van Liederkerke Beatrijs 
Published: November 2006

AbstractA mathematical model is presented which allows the accurate prediction of the viscosity‐concentration‐temperature relationship of starch hydrolysates. The model is valid in a dry substance range between 60% and 85% and in a temperature range between 20°C and 80°C. The only input the model requires is a single viscosity value at a defined concentration and temperature or the composition of the sample up to a degree of polymerization of 10. The model is based on the fact that the temperature dependence of the viscosity of a glass forming material, just above its glass transition temperature, can be descibed using the WLF kinetics. Hence, the viscosity is only dependent on the difference between the actual temperature and the glass transition temperature of each starch hydrolysate.
Gas Chromatographic Determination of Free Adipic Acid in Adipyl Cross‐linked Starches
Authors: Sanders Peter , Brunt Kommer 
Published: November 2006

AbstractThe performance of two different procedures for the extraction of the free adipic acid present in acetylated adipyl cross‐linked starches, was compared. It concerns a single extraction with a methanol‐acetic acid mixture and, a two step extraction procedure based upon a single aqueous extraction of the starch, followed by four extractions with ethyl acetate of the obtained aqueous extract. Apparently, some compounds ‐ probably sodium salts ‐ were present in the dry residue of the methanolic extract, which interfered with the silylation reaction of the adipic and pimelic (internal standard) acid. This resulted in a less reliable gas chromatographic determination of the adipic acid content in the dry extraction residues. The aqueous/ethyl acetate extraction procedure results in a better isolation of the alkanedioic acids from the interfering residues present in the starch sample.The standard deviation in the determination of the free adipic acid in the starch adipates, based on 55 independent duplicates, is 1.6ppm. The free adipic acid concentrations in the analyzed wheat and corn starch samples varied from 0–360ppm.
Effect of Longer Heating Time on Depolymerization of Low Moisturized Starches
Authors: Igura N. , Hayakawa I. , Fujio Y. 
Published: November 2006

AbstractLow moisturized potato, sweet potato, corn and wheat starches were treated with a flow tester under heated and heated‐sheared conditions. The starches depolymerized into lower molecule by longer heating time at 150°C. With an increase in heating time, the cold water solubility of starches increased and the degree of depolymerization progressed. Comparing heated treatment with longer heating time and heated‐sheared treatment, 60—120min heating was necessary for heated specimens to obtain similar cold water solubility and degree of depolymerization of heated‐sheared specimens. These results conducted that heated‐sheared treatment strongly promoted the depolymerization of low moist starches under high temperature as compared with heated treatment only. From the results of λmax of iodine‐polysaccharide complex, there was almost same molecular state between heated for longer time and heated‐sheared treatment. Both amylose and amylopectin depolymerized into lower molecule by both treatments.
Production of Trehalose from Starch by Maltose Phosphorylase and Trehalose Phosphorylase from a Strain of Plesiomonas
Authors: Yoshida M. , Nakamura N. , Horikoshi K. 
Published: November 2006

AbstractThe cooperative concomitant action of maltose phosphorylase (MP), trehalose phosphorylase (TP), β‐amylase and a starch debranching enzyme (pullulanase, isoamylase) was investigated to develop a more efficient method for preparing trehalose from starch.About 40 and 51—56% as solid basis of 25% (w/v) liquefied potato starch were converted to trehalose by the combination of soybean β‐amylase and the crude enzyme preparation (MTA) containing MP, TP and a saccharogenic amylase from a strain (SH‐35) of Plesiomonas in the absence and presence of a starch debranching enzyme, respectively.A stable maltose syrup (70%, w/w) containing about 30% trehalose in the dry solid was prepared from starch directly, and about 36% as dry basis of the mother liquor (70%, w/w) containing about 56% trehalose was obtained as crystals of this non‐reducing disaccharide by conventional crystallization.Trehalose in the by‐product obtained after removing crystals increased up to almost that of the mother liquor by reacting with MTA again.By the method reported here, trehalose was produced from starch on an industrial scale without any remaining by‐products.
Characterization of Starch Isolated from Plantain (Musa paradisiaca normalis)
Authors: Pérez‐Sira Elevina 
Published: November 2006

AbstractStarch isolated from unripe plantain (Musa paradisiaca normalis) was evaluated for their chemical, physical, physicochemical, rheological and morphometric characteristics. The average yield of starch was 10–12%, the granules were irregularly shaped and the size varied from 10 to 50μm. The average chemical composition (% of dry matter) of the starch was as follows: crude fat 0.09, crude fiber 0.26, ash 0.02, and total sugar 0.03 (as non reducing sugar). Excluding crude fiber content all these characteristics were smaller than those of commercial corn starch. The pH of both starches ranged from 5.6 to 6.7, while acidity contents were 0.010 and 0.012 for corn and plantain starch, respectively. Absolute density, gel consistency, color and syneresis were similar in both starches, while the reducing value and gel strength were higher in plantain starch than in corn starch. Except for the initial gelatinization temperature, all the rheological parameters of plantain starch also were higher than those of corn starch.
Functional Properties of Cassava (Manihot esculenta Crantz) Starch Modified by Physical Methods
Authors: Pérez‐Sira Elevina , González‐Parada Zurima 
Published: November 2006

AbstractIn general terms, the extrusion‐cooking performed at 150°C in the two extruders caused a reduction in water absorption capacity, solubility percentage and swelling power with respect to native starch, while the process carried out at 10.21% moisture in the 2 screws extruder produced the contrary effect. The screws number increase and/or moisture content and temperature reduction caused an increment of water absorption capacity, solubility percentage and swelling power values. The pregelatinization by drum drying produced the highest values of all these parameters and for the apparent viscosity. The thermal treatments caused a decrease of apparent viscosity values at 30 and 50°C and the lowest data for these viscosities corresponded to pregelatinized starch.
Latentiation of Chemotherapeutics Agents Part 2: Synthesis of Oxidized Cellulose Imine Derivatives With Antimalarials
Authors: Cruz Maria Luiza , Ferreira Elizabeth Igne , Korolkovas Andrejus 
Published: November 2006

AbstractOxidized cellulose derivatives with sulfonamides and sulfone were synthesized in order to obtain antimalarials better than the now available. Derivatives of dapsone (ML14), sulfadiazine (ML17), sulfamethoxazole (ML18), sulfisoxazole (ML19), sulfamethoxypiridazine (ML20), sulfameter (ML22) were identified by usual spectrometric analysis (IR, UV, 1H‐NMR). Submitted to preliminar biological assay, only three compounds avoided the parasitemia on the 5th day after treatment and of these, sulfadiazine derivative showed activity on the 30th day after treatment of mice infected with Plasmodium berghei.
Production of Branched Cyclodextrins by Reverse Reaction of Microbial Debranching Enzymes
Authors: Yim Dong K. , Park Yong H. , Park Yong H. 
Published: November 2006

AbstractFormation of maltosyl cyclodextrins from mixtures of maltose and cyclodextrins by reverse reactions of Flavobacterium isoamylase and Klebsiella pullulanase was experimented and it was found that Klebsiella pullulanase produced 50.4mg maltosyl α‐cyclodextrin, 35.0mg maltosyl β‐cyclodextrin and 55.4mg maltosyl γ‐cyclodextrin per ml of reaction mixture, whereas Flavobacterium isoamylase did not form maltosyl cyclodextrins. Optimum conditions for formation of maltosyl β‐cyclodextrin by Klebsiella pullulanase were pH 4, 50°C reaction temperature and proportion of substrate 100mg β‐cyclodextrin/600mg maltose per ml.
Comparison of the Brabender Viskograph and the Rapid Visco Analyser. 1. Statistical Evaluation of the Pasting Profile
Authors: Thiewes Harm J. , Steeneken Peter A. M. 
Published: November 2006

AbstractA statistical evaluation was made of the pasting profiles of starches registered with the Brabender Viskograph and the Rapid Visco Analyser (RVA). Fourteen sets of native and modified starches, with a total of 71 samples, were tested in both instruments at the same concentration. When starch samples with only slightly different pasting profiles were measured, e.g., in quality control, the Brabender Viskograph remains the first choice because of its better discriminating ability. For most of the modified starches, good correlations between both instruments were obtained for the viscosity data. When different concentrations were used in both instruments, which is common practice, correlation of viscosity data was poor for those sets, in which the order of viscosities varied as a function of concentration. Correlation of the temperature data was poor. In many cases, the Brabender analysis can be appreciably shortened because of the good correlation between peak and end viscosities.
Pasting and Thermal Properties of Potato and Bean Starches
Authors: Kim Young S. , Wiesenborn Dennis P. , Grant Linda A. 
Published: November 2006

AbstractStarches from potato (Mainechip, ND651‐9 and Commercial) and Navy and Pinto bean were isolated and the pasting and thermal properties examined. Analysis by Rapid Visco‐Analyzer (RVA) showed potato starches had lower pasting temperatures, higher peak viscosity, and lower setback than bean starches. High intrinsic viscosity values obtained for the potato starch indicated higher average molecular weight for the potato starches compared to the bean starches. Characterization of thermal (gelatinization and retrogradation) properties of starches by Differential Scanning Calorimetry (DSC) showed that potato starches had sharp, well‐defined gelatinization thermograms, while bean starches had broad, shallow thermograms with higher peak temperature (Tp). Potato starches required higher gelatinization enthalpies than bean starches. In comparison with gelatinization, the retrogradation thermograms of starches stored at three different temperatures (23,4 and −10°C) were broader and occurred at the lower temperatures. Compared to potato starches, Navy and pinto bean starches showed a higher retrogradation enthalpy at 4 and 23°C storage temperatures, but a lower enthalpy at −10°C.
Characterization of Starch Isolated from White and Dark Sorghum
Authors: Pérez Elevina E. , Lares Mary , González Zurima M. 
Published: November 2006

AbstractStarch isolated from two varieties of sorghum; white and dark grain, have been examined and compared for chemical, physical, physicochemical and rheological properties. Additionally, this study tested starch isolation laboratory scale method for dark sorghum grain. The levels of crude protein, crude fat and ash contents were lower in white sorghum than in dark sorghum starch. No difference was observed between apparent amylose content in both starches. The physicochemical and rheological behavior reveals differences in functional properties and it can be attributed to isolation procedures.
An Evaluation of Confocal Microscopy for the Study of Starch Granule Enzymic Digestion
Authors: Lynn Andrew , Cochrane M. Patricia 
Published: November 2006

AbstractIndustrially prepared wheat starch granules were stained with the fluorochrome Nile Blue A, and subjected to digestion with human saliva. Using a confocal microscope, the degradation of two granules was recorded in sets of optical sections gathered over a seven hour period. Each set of these optical sections was digitally processed to produce a reconstructed 3 dimensional image of the starch granules. Using this technique it was therefore possible to follow the internal and external digestion of each wheat starch granule in real time.
Purification of Cyclodextrin Glycosyltransferase by Immunochromatography
Authors: Han Nam Soo , Tao Bernard Y. 
Published: November 2006

AbstractCyclodextrin glycosyltransferase (CGTase) was produced in recombinant Escherichia coli which contains the cgt gene of Bacillus macerans in the pTCGT1 plasmid. Antiserum against CGTase was prepared in rabbits. Anti‐CGTase IgG in Serum was purified using an immobilized Protein A affinity column and an immobilized E. coli cell lysate affinity column. The purified anti‐CGTase IgG was coupled to Sepharose 4B (5.3mg IgG/mL gel), which was activated with cyanogen bromide. Crude CGTase was purified with this immunoadsorbent with CGTase binding capacity of 0.27 mg/mL and eluted with 0.1M glycine buffer, pH 10.6. Approximately 65% of enzyme activity was recovered from the crude CGTase preparation by this method. The purified CGTase was electrophoretically and antigenically homogeneous, appearing as a single band. After 10 cycles, the recovery yield was not reduced significantly. There was no cross reaction between anti‐CGTase IgG and other tested amylolytic enzymes. This immunoaffinity column is, therefore, effective, efficient, and convenient to use, and can be used widely to purify CGTase from various sources.
Starch Modification: Challenges and Prospects
Authors: Bemiller James N. 
Published: November 2006

AbstractEach starch is unique. Recognition of this fact provides opportunities for new products, while nonrecognition may delay progress in understanding the specific natures of granules. Each starch needs to be modified to increase its usefulness and value, but it is unlikely that any new derivatives or degrees of substitution will be allowed. Four possibilities for new modified‐starch products other than physically modified products, are offerred: (1) control of reaction sites within granules, (2) control of reaction sites on molecules, (3) new commercial starch sources, (4) biological modification of existing, commercial, base starches. Because means of accomplishing the former two are not now available, the latter two hold the greatest promise at this time.
Isolation and Physicochemical Characterization of Fonio (Digitaria exilis Stapf) Starch
Authors: Carcea Marina , Acquistucci Rita 
Published: November 2006

AbstractFonio (Digitaria exilis Stapf) starch was isolated from the seeds of two varieties denominated Hothia and Koulli and its physicochemical properties were compared with those of commercial wheat starch. Fonio starch granules seen under a SEM had polygonal shapes and small size (about 8μm). Amylose content of Hothia (22.6%) was significantly lower than that of Koulli and wheat (26.1% and 25.0%, respectively). there was not any significant difference in lipid content of fonio starches (2.8% and 2.9%), whereas significant differences were observed in their water binding capacity (88% and 80%). Protein and ash were also determined. The swelling power and solubility of wheat and fonio starches within the 50°C‐90°C temperature range were also studied. Brabender amylograms of 5% fonio starch slurries showed similarly shaped, single‐step curves. However, the two fonio varieties reached quite different viscosity values during the heating and cooling cycle.
Rheological Properties of Calcium Treated Hydroxypropyl Rice Starches
Authors: Islam M. Nurul , Azemi B. M. N. Mohd. 
Published: November 2006

AbstractUnisolated rice starch was used for hydroxypropylation and calcium complexation. Viscosity was measured at different starch concentrations, temperatures, and shear rates. The viscosity decreased with increase of calcium concentrations and shear rates. Temperature, starch concentrations and levels of Molar Substitution (MS) enhanced the viscosity. Hysteresis behaviour was markedly influenced by levels of calcium and MS. Higher viscosity was observed in hydroxypropyl starch. It is assumed that starch molecules exist in an expanded and/or extended forms which may result in higher viscosity. Calcium treated starch shows lower viscosity. Calcium ions possibly squeezed the starch molecules into a tighter configuration and/or calcium may compete with starch for water causing the limitation of water thus resulting in reduction of viscosity. Higher viscosity was observed at higher temperatures. Higher temperature cause the starch granules swelling thus produce higher frictional forces responsible for higher viscosity.
Arabinose‐Containing Oligosaccharides from Tamarind Xyloglucan
Authors: Niemann Claudia , Carpita Nicholas C. , Whistler Roy L. 
Published: November 2006

AbstractOligosaccharide mixtures were obtained by enzymatic degradation of tamarind xyloglucan from the seeds of Tamarindus indica by commercial Aspergillus niger endo‐(1→4)‐β‐D‐glucanase, and their composition analyzed by HPAE‐PAD liquid chromatography revealing two major groups of oligosaccharides. The first group contained oligomers of DP 7, 8 and 9, while the second group consisted of a large variety of oligomers of DP 12 to 18. After purification by SEC and HPLC in semi‐preparative scale, single oligomers were characterized by glycosyl‐residue composition, glycosyl‐linkage analysis and plasma desorption mass spectrometry. Beside β‐D‐Glucosyl, β‐D‐galactosyl and α‐D‐xylosyl units, some higher oligomers contained β‐D‐galactosyl‐(1→5)‐α‐L‐arabinosyl units, linked to O‐6 in the glucosyl units of the (1→4)‐β‐D‐glucan backbone. Other L‐arabinosyl residues were located in terminal positions of α‐D‐xylosyl side chains. The variety of isolated oligomers reflected a complicated random distribution of side chains in tamarind xyloglucan. Based on the characteristics of the oligomers, four structure forming units for the polysaccharide are proposed.
Structural Changes of Cassava Starch Granules after Heating at Intermediate Water Contents
Authors: Garcia Véronique , Colonna Paul , Bouchet Brigitte , Gallant Daniel J. 
Published: November 2006

AbstractDSC thermograms of cassava starch granules heated at two intermediate moisture contents of 35 and 45% of the total weight (w.t.) reveal the existence of two endothermic steps in their progressive disorganization. Structural changes have been studied by combining polarized light microscopy and electron microscopy (scanning and transmission electron microscopy). An instability of starch granule behaviour, both at granular and crystalline levels is observed at each treatment temperature. As temperature and moisture content increase, the loss of birefringence was observed in an increasing number of granules, suggesting that there is a competition of granules for water. The loss of birefringence initiates first at the hilum and is associated with the formation of cavities in the central region of the granules, showing that the disorganization first affects the less organized areas of the granule. In limited water content conditions, the radial extension of the central cavity towards the granule surface is not observed. The limited crystalline disorganization which is restricted to the inner part of the granule does not allow either a major swelling of granules or an extensive leaching of macromolecules out of granules. Increasing temperatures progressively induced the loss of granular integrity and the development of an homogeneous matrix. These structural changes are in agreement with the cooperative disorganization model of starch crystallites following which the crystalline disorganization is facilitated by the presence of water or by the plasticization of the amorphous regions connected to these crystallites.
Hydrothermische Behandlung von Stärke in Gegenwart von α‐Amylase. Teil 3. Veränderung der rheologischen Eigenschaften von Weizenstärke durch hydrothermisch‐enzymatische Behandlung
Authors: Stoof Gisela , Anger Horst , Schmiedl Detlef , Bergthaller Wolfgang 
Published: November 2006

AbstractMit dem Ziel der Veränderung funktioneller Eigenschaften einer Weizenstärke wurden die Möglichkeiten zur hydrothermisch‐enzymatischen Modifizierung bei Wasserüberschuß (Temperung) unter weitestgehender Erhaltung der granulären Struktur der Stärke überprüft. Da Weizenstärke wegen der niedrigen Quellungstemperatur unter den üblichen Temperungsbedingungen (T=50°C) nur geringfügig verändert werden kann, wurde zum Abbau des bei höherer Temperungstemperatur irreversibel gequollenen Stärkekornanteils Bakterien‐α‐Amylase eingesetzt. Das hierbei entstehende Saccharid‐Spektrum, das zu ca. 50% aus Maltose gebildet wird, vermag die Matrix der Weizenstärke selbst bei größeren Temperungstemperaturen (54°C) zu schützen. Das Verkleisterungs‐ und Gelbildungsverhalten wird aber in charakteristischer Weise verändert, und zwar insbesondere durch starke Steigerung der Heißkonsistenz bei 95°C. Nachfolgend bricht die erzielte Konsistenz wiederum stark zusammen und liegt unter Abkühlung unter den entsprechenden Daten der Ausgangsstärke. Für die Ausbeute an getemperter Stärke ist bei höherer Temperatur die Reaktionszeit maßgeblich. Um die Schutzfunktion der gebildeten Saccharide, insbesondere der Maltose in größerer Konzentration aufzuzeigen, wurde in Maltosesirupen variabler Konzentration (6, 12, 25%) getempert. Bis zu 12% und einer Reaktionstemperatur von 50°C konnte der Konsistenzverlauf um 300 bis 500‐BE angehoben werden; bei 54°C blieb die Modifizierung begrenzt. In 25%igem Maltosesirup konnte allerdings auch bei 54°C erfolgreich getempert werden. Die Ausbeuteverluste waren erwartungsgemäß klein (< 10%). Bei der Anwendung eines gestuften Temperatur‐Zeit‐Programms in Gegenwart von α‐Amylase bzw. 25% Maltosesirup traten die jeweils erwarteten Konsistenzverschiebungen auf, allerdings in begrenzterem Umfang. Markant waren schließlich die Unterschiede in den Ausbeuten an modifizierter Stärke.