bluuebunny/crossref_metadata_2025_split huggingface dataset:
Neue Erkenntnisse über den Abbau der Stärke mit Hypochlorit 6. Enzymatischer Abbau von oxydierter Stärke
Authors: Fischer S. K. , Piller F. 
Published: November 2006

AbstractNew Knowledge on Degradation of Starch by Hypochlorite. Part 6. Enzymatic Degradation of Oxidized Starch. For the detection of structural changes in hypochlorite‐oxidized potato starch starches of variously high degrees of oxidation were enzymatically degraded by amyloglucosidase and a mixture of α‐ and β‐amylase. As a function of the number of functional groups, and, therefore, of the degree of oxidation an increased number of non‐degradable glucose units (GU's) was traced in the starch molecule. According to the results, not only the GU with a functional group but also the two neighbouring GU's were not affected by enzymatic degradation.
Crosslinking of Starch Xanthate IV. Epoxy Resin and Diepoxide Thickeners for Xanthate and Starch
Authors: Maher George G. 
Published: November 2006

AbstractAqueous solutions of starch xanthate (of varying degree of substitution), butanediol dixanthate or alkali‐gelatinized starch were reacted with a diepoxide, such as butanediol diglycidyl ether to get viscous gels. Epoxy resins were likewise reacted with xanthate to form viscous media. Alkaligelatinized starch of varying alkali ratio content similarly produced gels with diepoxides. Solids were precipitated from the gels and their compositions were deduced from their elemental contents and infrared spectra.
Diffusion of Gases in Amylose Acetate
Authors: Patel V. M. , Patel K. C. , Patel R. D. 
Published: November 2006

AbstractDiffusion of helium, oxygen, nitrogen and carbondioxide in amylose acetate in the temperature range 30°–60°C has been reported. The Arrhenius parameters have been evaluated and the solubility of the gases in the polymer has been discussed in terms of condensing tendency of the gases studied.
Some Human Physiological Responses to the Consumption of Glucose Syrups and Related Carbohydrates
Authors: Birch G. G. , Kearsley M. W. 
Published: November 2006

AbstractAlthough the chemical composition of glucose syrups determines their physiological response, such effects may be difficult to establish using conventional methods. Experimental design, and especially carbohydrate loading, are important factors in any attempt to distinguish physiological response in relation to chemical structure. This paper presents details of changes in blood chemistry after ingestion of different carbohydrates at different loadings by human subjects over short time periods. Similarly, psychophysical aspects of glucose syrups and related carbohydrates are investigated in relation to chemical structure.
Scanning Electron Microscopy of Saponified Starch‐g‐Polyacrylonitrile
Authors: Fanta G. F. , Baker F. L. , Burr R. C. , Doane W. M. , Russell C. R. 
Published: November 2006

AbstractA series of starch‐g‐polyacrylonitrile (PAN) copolymers was prepared by ceric ammonium nitrate initiation, the only differences being in the degree of swelling and gelatinization of starch granules. This variable was governed by the temperature at which starch‐water slurries were heated before graft polymerization. Graft copolymers were then saponified with sodium hydroxide to convert the nitrile substituents of PAN to sodium carboxylate and carboxamide. Comparison of scanning electron micrographs of each starch‐g‐PAN copolymer with those of the corresponding saponified product showed particles which retain the outward appearance of graft polymerized starch granules. Since starch is soluble in alkali and PAN is also rendered soluble on alkaline saponification, a crosslinking reaction either during graft polymerization or during base saponification is proposed to account for the observation that granules are not totally disrupted or dissolved.
Substituent Distribution in Hydroxyethyl Starch
Authors: Merkus H. G. , Mourits J. W. , De Galan L. , De Jong W. A. 
Published: November 2006

AbstractThe substituent distribution of hydroxyethyl starch has been determined at various degrees of substitution (MS = 0.03–1.9) by capillary gas chromatography of the silylated hydrolysate. In the monosubstituted derivatives 70–80% of the hydroxyethyl groups is attached to the C2 atom. The ratio of C3 to C6 monohydroxyethylated products changes from 2 to 0.2 when increasing the MS from 0.03 to 1.9. At high MS (around 2) the disubstituted products consist for about 50% of 2‐hydroxyethoxyethyl derivative, which indicates a strong preference for the consecutive reaction of the newly formed hydroxyl group of 2 hydroxyethyl‐anhydroglucose. The distribution of mono‐ and polysubstituted products is in agreement with a model of consecutive reactions with average relative rate constants for mono‐, di‐ and higher substitution of 1.30, 1.05 and 0.85 respectively.
Interaction of Hydrochloric Acid with Cyclodextrin
Authors: Szejtli J. 
Published: November 2006

AbstractThe first order rate constant for the hydrochloric acid catalyzed hydrolysis of β‐cyclodextrin increases during the reaction, because the α‐1,14‐bonds present in the macrocycle and in linear dextrins (formed by opening of the macrocycles) are split at different rates. The activation energy for hydrolysis of the glycosidic bond of maltose is 30,5 kcal/mole, while the opening of the cyclodextrin macroring is characterized with a value of 34,2 kcal/mole. At lower temperatures and higher HCl concentrations a rather stable crystalline HCl‐cyclodextrin complex is formed with good yield. This complex contains 1,8 molecules of HCl per cyclodextrin unit. After storage at room temperature for one year it still retains 1 mole of HCl. Storing the product in sealed vials for one year leads to no change in the composition.
Production and Physicochemical Properties of Hydrogenated Glucose Syrups
Authors: Kearsley M. W. , Birch G. G. 
Published: November 2006

AbstractAn obvious and as yet little explored alternative to glucose syrups, for use in foods, is a series of hydrogenated derivatives of the commercial glucose syrups. Sorbitol is already widely used in the food industry and like maltitol offers certain metabolic advantages in foods for diabetics. It is relatively easy to produce a series of partially or totally hydrogenated glucose syrups based on this form of modification. This paper presents details of the production of some hydrogenated glucose syrups and a selection of their physicochemical properties.
The Importance of Hydrogenation in the Processing of Carbohydrates
Authors: Haidegger E. 
Published: November 2006

AbstractAfter a brief introduction the importance of hydrogenation products like sorbitol, xylitol, mannitol, polyol mixtures and hydrogenated glucose syrup is discussed. Then the theoretical aspects of hydrogenation and the various hydrogenation technologies are described. Finally, a comparison is made between the discontinuous low pressure CRS (Chemical Recycling Systems) process and the continuous hydrogenation technology under high pressure developed earlier by the author.
Practical Process Conditions for the Use of Immobilized Glucose Isomerase
Authors: Delft J. V. Hupkes 
Published: November 2006

AbstractThe present world‐wide rush into the production of high fructose corn syrups has increased the demand for the enzym glucose isomerase for the isomerization process. Economics have forced producers of these sweeteners to use the immobilized enzyme in a continuous process. The most suitable way of performing continuous isomerization turned out to be a process in a fixed‐bed column. However, a downflow mode of the substrate through the enzyme bed required special properties of the beads, especially when using very high enzyme beds.Practical process conditions are described for the use of immobilized Maxazyme glucose isomerase in a continuous fixed‐bed column operation procedure, e. g. pH, temperature, concentration of activators, quality of the substrate and enzyme bed dimensions. Special attention is paid to compressibility of the enzyme particles and the characteristical pressure drop of this product. Improvements are described for the production of this immobilized enzyme, which make it possible to use Maxazyme Gl‐Immob in columns up to 5 m bed height.
The Lipids of Various Sizes of Wheat Starch Granules
Authors: Meredith P. , Dengate H. N. , Morrison W. R. 
Published: November 2006

AbstractStarches have been prepared from two wheat cultivars having contrasted hot‐pasting characteristics. The granules have been separated by successive sedimendations into several size classes and their lipid compositions determined. In agreement with previous work, the lipid is mainly lysophosphatidylcholines of palmitic and linoleic acids in nearly equal quantities. The saturated acid predominates in the smallest granules. The amounts of lipid per granule tend to be proportional to the granule surface areas of the larger granules but proportional to the volumes of the smaller granules. There was no distinction between contents or types of lipid in the two cultivars, suggesting that their contrasted pasting qualities were not a function of lipid composition.
Cyclodextrinpolymere
Authors: Szejtli J. , Fenyvesi É. , Zsadon B. 
Published: November 2006

AbstractMakromolekulare Cyclodextrine sind entweder Homopolymere oder Copolymere, die bis zu einem bestimmten Molekulargewicht wasserlöslich sind. Bei höherem Polymerisationsgrad erfolgt Vernetzung, und es entsteht eine Gelstruktur. Für die Charakterisierung der Polymere dienen die physikalischen Eigenschaften, wie Wasserbindungsvermögen, Dichte, Gelbettvolumen, Korngröße sowie mechanische Stabilität der Gelpartikel, Molekulargewicht und Farbstoffbindungskapazität bzw. Sorptionsisotherme. Polymerisierte Cyclodextrine sind sowohl für chromatographische Trennungen als auch zur Stabilisierung, Anreicherung und Reinigung von Substanzen geeignet, und sie können bestimmte Reaktionen katalysieren.
On the Relationship between Regain and Crystallinity of Starch
Authors: Nara S. 
Published: November 2006

AbstractA formula for the relationship between regain and crystallinity of starch is given. Accessibility of crystalline portion of starch is in the range of that of cellulose. The saturated moisture state shows six molecules of water per glucose residue. The sorption cannot take place at the inside of crystalline portion of starch.
Susceptibility of Various Starch Granules to Amylases as Seen by Scanning Electron Microscope
Authors: Fuwa H. , Sugimoto Y. , Tanaka M. , Glover D. V. 
Published: November 2006

AbstractStarch granules were observed by a scanning electron microscope in order to provide information concerning the types and extent of damage of the surface and internal structure of starch granules attacked by amylases. Granules resistant to the action of amylases, namely, potato, yamanoimo, and high‐amylose maize starches showed shapes and surfaces similar to the intact granules after the action of either Rhizopus glucoamylase or crystalline bacterial α‐amylase. Granules susceptible to amylases, namely, normal, waxy, soft starch, and soft starch opaque‐2 maize starches showed numerous pin holes on the surface layer and pores penetrated into the inner layers of the granules during the attack with amylases. In the case of α‐amylolysis, it is apparent that once the enzyme has penetrated into the inner layers of a granule, the layers are more readily attacked than the peripheral layers.
Studies on the Gelatinization of Starches. Part 2. Effect of Lower Alcohols on the Gelatinization of Cereal Starches
Authors: Hizukuri S. , Takeda C. 
Published: November 2006

AbstractThe effect of lower alcohols (methyl to amyl alcohol) on the gelatinization of cereal starches was studied by means of amylography and the determination of degree of gelatinization by glucoamylase digestion and iodine affinity. The straight chain primary alcohols other than methyl alcohol considerably decreased the transition temperature of the amylograms of these starches with the increase of molecular weight. The characteristic modification of the amylograms by these alcohols was inferred to be due to the exchange of the alcohols for the lipids in the amylose‐lipids complex of starch.
Molecular Weight Distribution in Starch Solutions when Hydrolised with alpha‐Amylase and when Oxidised with Sodium Hypochlorite
Authors: Henriksnäs H. , Bruun H. 
Published: November 2006

AbstractThe time course for hydrolysis of starch with α‐amylase and oxidation of starch with Na‐hypochlorite was studied with the aid of gel chromatography. It was found that the initial steps in the hydrolysis can be described as a consecutive reaction in which the fractions Mw > 5 · 105, 5 · 105 > Mw > 1 · 105 and Mw < 1 · 105 are contained. The reaction in the course of decomposition with α‐amylase is one of the first order, while decomposition by means of hypochlorite is a second order reaction. There are considerable differences in the changes in molecular weight distribution between the two methods. Hydrolysis with α‐amylase gives a solution with a symmetrical molecular weight distribution whereas hypochlorite oxidation obviously causes splitting of some of the starch molecules, which results in solutions with two molecular weight maxima.
Absorbent Polymers from Starch and Flour Through Graft Polymerization of Acrylonitrile and Comonomer Mixtures
Authors: Fanta G. F. , Burr R. C. , Doane W. M. , Russell C. R. 
Published: November 2006

AbstractPolyacrylonitrile (PAN)‐containing graft copolymers of corn starch were prepared from monomer mixtures and then saponified, and dried. Incorporation of selected comonomers lead to shorter saponification times and higher yields of adsorbent products. Substitution of flour for starch gave products which had a higher absorbency than saponified starch‐g‐PAN.
Zur biotechnischen Erforschung der Herstellung von Glucose‐Fructosesirupen. Teil 2. Reaktionskinetische Untersuchung des Mechanismus der Glucoseisomerisierung
Authors: Läszló E. , Hoschke Á. , Holló J. 
Published: November 2006

AbstractDer Mechanismus der enzymatischen Isomerisierung von Glucose wurde durch reaktionskinetische Methoden untersucht. Die kinetischen Konstanten wurden unter Verwendung von Glucose, 6‐Desoxyglucose, bzw. Sorbitol und 2‐Desoxysorbitol bestimmt. Es wurde festgestellt, daß der die Geschwindigkeit bestimmende Schritt der enzymatischen Reaktion die Bindung der Glucose in acyclischer Struktur ist. Die Aldehydgruppe weist die größte Bindungsenergie auf, so daß die Ringöffnung von der Enzymwirkung unabhängig abläuft. Dies ist der Grund für die relativ langsame enzymatische Glucoseisomerisierung. Die Geschwindigkeit der Isomerisierung kann nur durch Induzierung der Aufspaltung des Pyranoseringes erhöht werden. An eine industrielle Verwirklichung dieser Induzierung ist zur Zeit noch nicht zu denken.
Alkalizahlen thermisch dispergierter Stärken
Authors: Čeh M. , Stropnik Č. , Leskovar S. 
Published: November 2006

AbstractVon sechs nativen Stärken und ihren Kleistern wurden die Alkalizahlen potentiometrisch bestimmt. Analoge Versuche wurden auch mit thermisch dispergierten Stärken ausgeführt. Alle nativen Stärken besaßen höhere Alkalizahlen als ihre Kleister. Bei weiterem thermischem Dispergieren steigen die Alkalizahlen unterschiedlich stark an, was als Folge verschiedener thermischer Degradationsgeschwindigkeiten in den Stärkemolekülen anzusehen ist. Eine gute Korrelation konnte zwischen den reziproken Alkalizahlen thermisch dispergierter Stärken und ihren Molekulargewichten beobachtet werden.
Trägergebundene xylanolytische Enzyme. I. Wirkungsweise xylanolytischer Enzyme
Authors: Puls J. , Sinner M. , Dietrichs H. H. 
Published: November 2006

AbstractEs wird die Wirkungsweise der bei der Hydrolyse natürlich vorkommender Xylane beteiligten Enzyme beschrieben. Xylane, die ausschließlich aus Xylose aufgebaut sind, werden durch das Zusammenwirken von ß‐1,4‐Xylanasen und ß‐1,4‐Xylosidasen zu Xylose hydrolysiert. Endo‐ß‐1,4‐Xylanasen hydrolysieren die Bin‐dungen innerhalb der Xylankette mit Ausnahme der Bindungen am Kettenende und setzen dabei Xylooligomere frei. Exo‐ß‐1,4‐Xylanasen wirken am Kettenende der Xylane und spalten jeweils Xylose ab. Die durch die Wirkungsweise der Endo‐ß‐1,4‐Xylanasen freigesetzten Xylooligomeren werden von ß‐1,4‐Xylosidasen zu Xylose hydrolysiert. Bei Laubholzxylanen besitzt im Durchschnitt jeder 10. Xyloserest eine 1,2‐gebundene 4‐O‐Methyl‐ä‐D‐Glucuronosylseitengruppe. Seitengruppen wirken sich auf die enzymatische Hydrolyse blockierend aus. Endo‐1,4‐Xylanasen setzen in diesem Fall neben neutralen Xylooligomeren auch saure Xylooligosaccharide frei, die von ß‐Xylosidasen nicht weiter hydrolysiert werden können, ehe nicht die Seitengruppe von ä‐1,2‐Glucosiduronasen abgespalten worden ist.
Comparison of Starch Extraction from Tapioca Chips, Pellets and Roots
Authors: Meuser F. , Smolnik H.‐D. , Rajani Ch. , Giesemann H. G. 
Published: November 2006

AbstractThe extraction of starch from tapioca chips and‐pellets was studied in comparison to the extraction from tapioca roots especially with regard to the starch yield and ‐quality as well as to the use of by products on a laboratory scale. It was observed that the extraction of starch from the dried raw materials was more complicated than from fresh roots. Impurities were difficult to remove from chips and pellets, so that mostly mineral substances were found in the starch which reduce its quality. A wet cleaning is possible only with chips, because they have a sufficient mechanical stability.
Comparative Studies on Glucoamylases Isolated from a Strain of Aspergillus
Authors: Finch P. , Leonard P. A. 
Published: November 2006

AbstractTwo glucoamylase fractions have been isolated from an Aspergillus culture preparation by anion‐exchange chromatography and characterised by physico‐chemical and biochemical methods. The fractions were homogeneous on electrophoresis, molecular sieve chromatography and ultracentrifugation with molecular weights of 81,000. Both fractons were shown to be devoid of endo‐amylase activity and to possess similar activities towards wheat amylopectin (15–17 IU mg−1) and maltose (3–4 IU mg−1) at the optimum pH of 4.6. The fractions catalysed extensive, but not complete, conversion of wheat amylopectin to D‐glucose which was liberated with β‐anomeric configuration.
D‐Fructose – Struktur und Eigenschaften
Authors: Heyns K. 
Published: November 2006

AbstractEs wird eine Übersicht über die Struktur und die wichtigsten Eigenschaften der D‐Fructose gegeben. Insbesondere werden erörtert: Konfiguration und Konformation, der Kristallaufbau, das chemische Reaktionsverhalten in Lösung, beim Erhitzen, bei verschiedenem pH, bei der Karamelisierung, in Gegenwart von Aminosäuren (Ketosylamin‐Umlagerung, Pyrazinbildung). Erwähnt werden ferner einige Vorstellungen über die Beurteilung des Süßgeschmacks im Vergleich mit anderen Zuckern. Von Interesse ist fernerhin ein Vergleich der Eigenschaften der D‐Fructose mit denen der D‐Glucose, vor allem im Hinblick auf die Mutarotation, grundlegende Unterschiede im chemischen Verhalten, z. B. bei der Reversion. Über das Verhalten im Stoffwechsel werden einige grundlegende Zusammenhänge kurz dargestellt und im Hinblick auf die physiologischen Auswirkungen zusammenfassend diskutiert.
Rohstoffe für Fermentationen
Authors: Dimmling W. 
Published: November 2006

AbstractDie Biotechnologie hat heute vor allem Bedeutung für Lebensmittel und alkoholische Getränke, für die chemische Industrie und Pharmazie, die Biomasseproduktion sowie für Abwasserreinigung und Biogasgewinnung. Die in den 80er Jahren zu erwartenden Veränderungen auf dem Rohstoff‐ und Energiesektor sowie bei Ernährung und Umweltschutz werden hier neue Aufgabenstellungen bringen. Dazu gehören z. B. die Erzeugung proteinhaltiger Futtermittel und die stärkere Verwendung von Neben‐ und Abfallprodukten z. B. für Fermentationsäthanol als Benzinzusatz und für die Biogasgewinnung. Die möglichen Rohstoffe für Fermentationsreaktionen werden hinsichtlich Verfügbarkeit und Wirtschaftlichkeit diskutiert.
Neue Untersuchungsmethoden in der Cyclodextrinchemie
Authors: Szejtli J. 
Published: November 2006

AbstractZur Optimierung der Herstellungstechnologie von Cyclodextrinen und ihren Einschlußverbindungen ist die Kenntnis des Kristallisationsprozesses unerläßlich. Durch Registrierung der Trübung während der Komplexbildung können entsprechende Informationen gewonnen werden. Die Komplexbildung selbst läßt sich durch Dünnschicht‐Chromatographie nachweisen. Zur Untersuchung der Stabilität von Einschlußverbindungen eignet sich die TAS‐Technik (Thermomikro‐, Abtrenn‐, Transfer‐ und Auftragsverfahren von Substanzen).
Properties of Lintnerized Starch Granules from Rices Differing in Amylose Content and Gelatinization Temperature
Authors: Maniñgat C. C. , Juliano B. O. 
Published: November 2006

AbstractA study was made on the properties of starch granules of eight rices differing in amylose content and gelatinization temperature subjected to hydrolysis in 2.2‐N HC1 at 35°C for 15 days. The recovery of lintnerized starch was greater for samples with high gelatinization temperature and, to a lesser extent, high amylose content. Lintnerized starch had sharper X‐ray diffraction peaks than native starch. Their DP ranged from 18.8 to 30.3 glucose units, and the β‐amylolysis limit ranged from 74.5 to 92.1%. Gel chromatography showed two peaks corresponding to DP 29–34 and 14–7. Varietal differences were noted in the ratio of the two amylodextrin peaks.
Temperature Dependence of Stability and Activity of an Immobilized Glucose Isomerase in a Packed Bed
Authors: Roels J. A. , van Tilburg R. 
Published: November 2006

AbstractA mathematical model describing the kinetics of the conversion of glucose to fructose by an immobilized glucose isomerase has been developed. The model is a straight‐forward one and based on known kinetic behaviour of glucose isomerase and on limitations posed by diffusional resistance when a spherical particle containing the enzyme is considered.The model has been used to derive a relationship between initial enzyme activity and temperature. It can be demonstrated that the relationship between activity and temperature shows deviations from the familiar Arrhenius plot. The same holds for the activity half life time in a packed bed column.Experimental material confirming the theoretical considerations is presented. The experimental results have been applied to estimate some important parameters of the material used. An Arrhenius‐type relationship is shown to hold for the estimated enzyme activity as well as for the kinetics of the deactivation process. The parameters obtained can be used in temperature optimization studies for the packed bed conversion process. The influences of initial activity, particle size and temperature on the production of fructose are discussed.
Der Energieaufwand in der Reibenstation bei der Kartoffelstärkefabrikation
Authors: Gladkowski J. , Sroczyśki A. , Bielarz H. 
Published: November 2006

AbstractDrei Typen von Kartoffelreiben, die zur Zeit in der polnischen Kartoffelstärkeindustrie verwendet werden, wurden überprüft: ZT‐300 “Spomasz” (Polen), Holthius (Holland) und RU 80‐500 Nivoba (Holland). Es wurde die optimale Kartoffelverarbeitungsfähigkeit in Abhängigkeit vom Energieaufwand und vom Zerkleinerungsgrad der Reibsel für das Verreiben einer Tonne Kartoffeln festgestellt. Die Untersuchungsergebnisse haben die Annahme bestätigt, daß eine Vergrößerung der Reibenbelastung eine Energieaufwandverminderung zur Folge hat. Diese Belastung wird aber durch den Zerkleinerungsgrad der Reibsel (min. 90%) begrenzt. Der Reibselzerkleinerungsgrad hat einen entscheidenden Einfluß auf den Gehalt gebundener Stärke in der Kartoffelpülpe und demzufolge auf die Höhe der Stärkeausbeute. Für die drei Reiben wurde die optimale Reibenbelastung ermittelt.