bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stufenweise Elutionsanalyse elektrodialysierter Fraktionen von Mais‐Sorghum‐, Kartoffel‐ und Weizenstärke
Authors: Čeh M. , Stropnik Č. , Leskovar S. 
Published: November 2006

AbstractDie durch thermisches Dispergieren hervorgerufenen Veränderungen in den Sol‐ und Gelfraktionen von Mais‐, Sorghum‐, Kartoffel‐ und Weizenstärke wurden mit der stufenweisen Elutionsanalyse verfolgt. Die Sol‐ und Gelfraktionen wurden durch Elektrodialyse der Kleister, bzw. ihrer Dispersionen gewonnen. Die qualitative Einschätzung der Veränderungen in den Chromatogrammen nach dem thermischen Dispergieren der Kleister stimmt mit dem Abfall der Molekülmasse der Sol‐ und Gelfraktionen überein. Zusätzliches Dispergieren der Gelfraktionen mit Lauge bewirkt Desaggregation eventuell vorhandener Spuren von Stärkefragmenten auf der Auftragsstelle. Die Chromatogramme der Solfraktionen bleiben nach Laugenzusatz praktisch unverändert. Eine Korrelation zwischen dem Prozentgehalt der Gelfraktion in der Stärke – dem Amylopektinanteil – und ihrer Molekülmasse während des thermischen Dispergierens konnte festgestellt werden. Bei verlängertem Dispergieren bei 120°C wird der Gelanteil in der Stärke geringer; ebenso verringert sich die Molekülmasse des Amylopektins. Während des dreistündigen Dispergierens fällt die Stärkemenge in der Gelfraktion des Maisstärke‐ und Sorghumstärkekleisters um ungefähr 65%. Bei Kartoffelstärkekleister wurde eine um 31% und bei Weizenstärkekleister eine um 25% verringerte Gelfraktion festgestellt.
Amylase Synthesis by Forced Heterocaryons of Aspergillus niger in Submerged Culture Conditions
Authors: Ilczuk Z. , Fiedurek J. 
Published: November 2006

AbstractFrom 43 auxotrophic mutants A. niger found earlier 21 forced heterocaryons were obtained. All were examined with respect to total amylolytic activity by the method of test‐tube microculture, whereas 12 of them (with the highest indices of this activity) were also tested with regard to glucoamylase synthesis. In most cases the amylase activity of hererocaryons was much higher than that of their component strains of lower and frequently of a higher activity. A distinct increase of this activity was also shown by heterocaryons formed from auxotrophs, originating from them in relation to prototrophic parent cultures with a weak amylase activity. However, none of the heterocaryons equalled the level of amylase synthesis, reached by a highly active prototroph A. niger C in this respect.
Extraction of Lipids from Cereal Starches with Hot Aqueous Alcohols
Authors: Morrison W. R. , Coventry A. M. 
Published: November 2006

AbstractCereal starches were extracted at 100°C with various proportions of lower alcohols and water to establish optimum conditions. Lipid yields generally exceeding 90% were obtained with one two‐hour extraction of maize starch at 100°C when using not less than 14 ml of 75–85% methanol, 10 ml of 75% ethanol, 12 ml of 74–78% n‐propanol, 14 ml of 74–78% isopropanol, or 17 ml of 84% n‐butanol per gram of starch. Similar results were obtained with wheat A‐starch ( > 8 μm granule diameter), wheat B‐starch ( < 8 μm granule diameter) and rice starch using n‐propanol‐water, and with rice starch using methanol‐water. Yields decreased if the proportions of alcohol and water were not kept within well‐defined limits, especially with butanol and ethanol. The preferred conditions for complete recovery of lipids were two 2‐hour extractions and one 1‐hour extraction at 100°C with not less than 16 ml of 75% n‐propanol per gram of starch.
The Influence of Pullulanase and α‐Amylase upon the Oligosaccharide Product Spectra of Wheat Starch Hydrolysates
Authors: Atkins D. P. , Kennedy J. F. 
Published: November 2006

AbstractBy hydrolyzing wheat starch solutions using different combinations of ä‐amylase and pullulanase it has been possible to achieve significantly different oligosaccharide product spectra in hydrolysates with the same dextrose equivalent (D. E.). Where pullulanase was used either as a pretreatment to α‐amolysis or in combination with α‐amylase starch hydrolysates were produced whose oligosaccharide product spectra differed significantly from the comparable hydrolysate at the same D.E. produced by α‐amylase alone. Throughout the range of starch hydrolysate D.E. values the following trends were observed: pullulanase involvement produced less G1, G2 and G5 oligosaccharides and less intermediate molecular weight fraction (D.P. > 12) than when α‐amylase alone was used. Where the D.E. values exceeded 20, in addition to these general differences, pullulanase involvement was found to be responsible for the increased production of G6 and G3 oligosaccharides and to significantly reduce the amount of unhydrolyzed polysaccharide both in the intermediate and high molecular weight fractions.
Reinigung von Stärkehydrolysaten mittels lonenaustausch‐Chromatographie
Authors: Berghofer E. , Tauber W. , Klaushofer H. , Steyrer W. 
Published: November 2006

AbstractBei der großtechnischen Anwendung der Ionenaustausch‐Chromatographie zur Reinigung von Stärkehydrolysaten sind noch viele Fragen und Probleme offen, zu deren Klärung die vorliegende Arbeit beitragen sollte Vorerst wurden einige wichtige Eigenschaften des verwendeten Trennharzes Lewatit TSW 40 bestimmt, und zwar das Harzporenvolumen, das Harzzwischenraumvolumen sowie die Verteilungskoeffizienten von Glucose, Maltose und Natriumchlorid an diesem Harz. Als nächstes wurde überprüft, welche Beladungsform des Ionenaustauschers am besten zur Auftrennung von Stärkehydrolysaten geeignet ist. Von den drei untersuchten Beladungszuständen (Natrium‐, Calcium‐ und Wasserstoff‐Beladungsform) erwies sich die Natrium‐Beladungsform insgesamt gesehen am günstigsten. Ein Nachteil der Ionenaustausch‐Chromatographie ist die starke Verdünnung der erhaltenen Fraktionen. In weiterer Folge wurde daher versucht, durch teilweise Eluatrückführung Produktfraktionen mit möglichst hoher Trockensubstanz zu erhalten. Es gelang eine Verfahrensweise auszuarbeiten, bei der Glucosefraktionen mit einem Trockensubstanzgehalt von 23–25% erhalten wurden. Der Reinheitsquotient dieser Produktfraktionen lag bei etwa 93–95% und die Glucoseausbeute betrug 88,7%.
Glucose Oligomers as Models to Elucidate the Starch Radiolysis Mechanism
Authors: Raffi J. , Agnel J.‐P. , Boizot C. , Thiéry C. , Vincent P. 
Published: November 2006

AbstractA comparative study of gamma irradiated glucose and glucose oligomers has been carried out in order to find a suitable model to understand the mechanism of starch radiolysis. Measurements of malonaldehyde and formic acid, produced by irradiation, showed that the quantitative comparison of radiolytic products was not significant for our purpose, which was also confirmed by a literature survey. However, an electron spin resonance kinetic study of several oligomers, irradiated in the powder state, showed that maltopentaose, and to a lesser extent, maltotriose, may be used as models in the radiolysis of starch.
Oligosaccharide Component Composition and Storage Properties of Commercial Low DE Maltodextrins and Their Further Modification by Enzymatic Treatment
Authors: Kennedy J. F. , Noy R. J. , Stead J. A. , White C. A. 
Published: November 2006

AbstractThe use of dextrose equivalent (DE) as a method of describing maltodextrin materials has been shown to be of little use in predicting the storage stability of 50% w/w maltodextrin solutions required for clinical feed preparations. The alternative method of defining maltodextrin materials in terms of their oligosaccharide component composition, obtained by gel filtration chromatography, is described and used to study the composition and storage properties of commercial low DE maltodextrin materials.The further modification of these maltodextrin materials with commercial forms of α‐amylase (1,4‐α‐D‐glucan glucanohydrolase, EC 3.2.1.1) and pullulanase (pullulan 6‐glucanohydrolase, EC 3.2.1.41) is discussed in terms of the resulting oligosaccharide component composition and storage stability of 50% w/w solutions.
Morphological Studies of Potato Starch Modified by Grafting Using Mn3+ as Initiator and by Saponification
Authors: Rodehed C. , Rånby B. , de la Bayona M. , Mehrotra R. 
Published: November 2006

AbstractA series of starch‐g‐polyacrylonitrile copolymers of starch granules and starch gel were synthesized with the Mn3+ initiating system. The samples were examined and photographed in a scanning electron microscope before and after homopolymer extraction in N, N‐dimethylformamide., The grafted starch was hydrolyzed in aqueous acid solution to remove the starch moiety. The graft copolymers were also saponified with aqueous sodium hydroxide to convert nitrile groups to carboxamide and sodium carboxylate groups. The micrographs show that polyacrylonitrile is grafted both on the surface and in the interior of the granule. At higher grafting ratios the products contain increasing amounts of grafts inside the granule, but the centre of the granule is always hollow. The saponified graft copolymer retains its granular structure, in spite of the swelling and the high temperature during the hydrolysis, although the surface of the granules becomes smoother.
Studies on the Retrogradation of Starch in Starchy Foods. Part 3. Effect of the Addition of Sucrose Fatty Acid Ester on the Retrogradation of Corn Starch
Authors: Matsunaga A. , Kainuma K. 
Published: November 2006

AbstractA model of retrograded starch molecules was proposed in our previous paper. The effect of the addition of n‐butyl alcohol or sucrose fatty acid on the retrogradation of starch was studied in this paper. The samples were prepared by repeating freeze‐thaw cycles with or without addition of complex forming agents. The samples were treated with 16% sulfuric acid as by Nägeli amylodextrin preparation or a mixture of β‐amylase‐pullulanase. The residues of the acid or enzyme treatment were chromatographed. From the results of iodine titration, degree of gelatinization, X‐ray diffraction, and chain length distribution, it is discussed how the helix forming angents react with fractions of starch and prevent the retrogradation. A schematic model of the retrograded starch with helix forming agents are also proposed.
Differential Scanning Calorimetry Study of the Wheat Grain Cooking Process
Authors: Jankowski T. , Rha C. K. 
Published: November 2006

AbstractGelatinization of wheat grain endosperm during cooking was studied under simulated cooking conditions using differential scanning calorimetry (DSC). A DSC thermogram of the wheat grain section heated in excess water shows biphasic transition characterized by peak temperatures of 64.5°C and 86°C. Similar shape and temperatures are indicated on the thermogram of isolated wheat starch heated in limited water conditions (48.8% w.b.). During the cooking process, exposure of wheat grain endosperm to heat without adequate moisture causes alteration of the starch structure, which in turn, causes a broadening of the gelatinization temperature range and shifting of endothermal transition toward higher temperatures.
Variation in Properties of Starch in Cassava Varieties in Relation to Age of the Crop
Authors: Moorthy S. N. , Ramanujam T. 
Published: November 2006

AbstractCassava starch extracted from six varieties at different period of growth was examined for various physiochemical properties. The granule size increased in all the six varieties upto 6th month from time of tuber initiation and thereafter remained almost constant. The amylose content and reducing values did not vary much at different stages of growth. The swelling volume and swelling power of starch showed large variations particularly after 10th month. Such changes of four varieties were not noticed in other varieties. Associative binding forces of starch molecules largely determine the stability characteristics of starch under varied environmental conditions.
Studies on Coleus Starch
Authors: Moorthy S. N. 
Published: November 2006

AbstractColeus starch was isolated by standard procedure and its properties studied. The granule size varies from 5 to 20 μm with majority being in the range 8–16 μm. The gelatinization temperature is 65–85°C. Viscosity of a 2% solution is 37 s (Redwood No. 1). The viscosity increases to 56 s on cooling and remains steady afterwards. The sol stability of the 2% solution is 72 h. The total amylose content is 33% of which soluble amylose is 12.8%. The sweeling volume is 25 cm3/g of starch the reducing value in terms of ferricyanide number is 2.71. The results are discussed in comparison with other tuber starches.
The Extrusion Cooking of Potato Starch Material
Authors: Senouci A. , Smith A. C. 
Published: November 2006

AbstractThe effect of extrusion cooking on the pasting properties of potato starch materials is examined using a Couette rheometer. The dispersion viscosity of aqueous dispersions of potato starch, pregelatinized potato starch and commercial potato granules has been investigated. The effect of extrusion moisture and progress down the extruder on this property has been studied. The dispersion viscosity response is related to the gelatinization and disruption of starch granules. Extrusion at high moisture levels leads to high viscosity dispersions tending to that of gelatinized starch whereas low moisture levels result in lower viscosity dispersions.
Energieverbrauch und Energiefluß einer Maisstärkefabrik
Authors: German H. , Meuser F. 
Published: November 2006

AbstractZiel der Untersuchungen war es, den Energiefluß einer Maisstärkefabrik darzustellen sowie den produktbezogenen Energieverbrauch zur Herstellung von Maisstärke, Glucosesirup und Nebenprodukten zu ermitteln. Der untersuchte Betrieb verwendete, bezogen auf die eingesetzte Primärenergie 69,3% Erdgas und 30,7% Strom. Nach der innerbetrieblichen Energiewandlung standen 84,6% der eingesetzten Primärenergie zur Herstellung von Stärke, Glucosesirup, Keimöl, Kleber und anderen Nebenprodukten zur Verfügung. Diese Nutzenergie setzte sich aus 30,2% Kraftstrom, 0,5% Lichtstrom, 46,8% Dampfwärme und 7,1% Heizgaswärme zusammen. Zur Quellung, Quellwassereindampfung und ‐trocknung wurden 15,8%, zur Stärkeextraktion und‐raffination 10,8%, zur Stärketrocknung 11,9%, zur Glucosesirupgewinnung 12,7% und zur Herstellung von Keimöl, Kleber und weiteren Nebenprodukten 22,0% der Primärenergie verbraucht. Der Anteil der Wärmerückgewinnung betrug 4,4%. Der kumulierte produktbezogene Primärenergieverbrauch zur Herstellung von Maisstärke betrug unter Einbeziehung des Energieverbrauchs für die landwirtschaftliche Erzeugung und den Transport des Maises sowie für den Produkttransport 12 060 und für die Herstellung von Maiskleber 9 520 MJ/t TS.
Effect of Cross‐Linking on Functional Properties of Legume Starches
Authors: Hoover R. , Sosulski F. 
Published: November 2006

AbstractRefined starches from lentil, fababean and field pea contained 38.5, 32.0 and 34.2% amylose, respectively, where the water binding capacities, swelling powers, susceptibilities to amylase digestibility and amylograph viscosities were in the order: lentil > fababean > field pea. This evidence and the X‐ray diffraction data suggested that the degrees of molecular association between starch chains, especially amylopectin, followed the order: field pea > fababean > lentil. Cross linking with phosphorus oxychloride decreased water binding capacity, swelling power, α‐amylase digestibility and 95°C viscosity in the amylograph but increased the degree of set‐back. X‐ray diffraction patterns indicated that cross linking occurred mainly in the amorphous regions of the starch granule. Scanning electron microscopy showed that cross linking hindered amylose exudation. The stable hot paste viscosities of cross‐linked starches would be of value where low pH and high temperature are employed during pressure cooking or sterilization while the low degree of set‐back of field pea starch should improve the freeze‐thaw stability and textural quality of frozen foods.
A Comparison between Corn Starch and Dry Milled Corn Products in their Dispersion Properties
Authors: Navickis L. L. , Bagley E. B. 
Published: November 2006

AbstractGelatinization of corn starch, flour, meal and grits has been compared. Amylograph curves show differences that can be related to particle size and to constraints on the swelling behavior, presumably due to native protein in the corn milled products. Autoclaving starch and dry milled products at 121 °C in the presence of steam alone merely hardens the particles. However, when the particles are in contact with liquid water, swelling and gelatinization readily occur and gels are formed. Above 10% loading, gels formed by autoclaved grits and meal are significantly more rigid than gels formed from corn starch alone. Flour gives gels of essentially the same properties as the starch up to 30% loading, above which flour gels become more rigid than starch gels and match the gels formed from corn meal and grits.
Effect of Citric Acid on Potato Starch Gelatinization
Authors: Yamada T. , Morimoto Y. , Hisamatsu M. 
Published: November 2006

AbstractCoexistent effects of citric acid and acetic acid on gelatinization of potato starch and corn starch are discussed and some difference was found in citric acid but not in acetic acid on potato starch, although any difference was not found between both acids on corn starch. The amylogram of potato starch with EDTA treatment and CaCl2 treatment supports a presumption that removal of calcium ions bound to phosphate in the starch with citric acid should be responsible to the above acid effect.
Effects of Water Stress on Starch and Its Metabolizing Enzyme Activities in Cotton Leaves
Authors: Chang C. W. , Wetmore J. A. 
Published: November 2006

AbstractCotton plants were subjected to water stress ranging from –1.0 to –2.2 MPa. Starch content decreased during the initial decline in water potential from –1.1 to –1.4 MPa. This change was related to an increase in soluble α‐amylase activity and a decrease in bound glucan synthetase activity. Starch content then increased sharply to nearly 200% of control levels with a decrease in water potential to about –1.6 MPa. With a further reduction in leaf water potential to –2.2 MPa, both bound glucan synthetase activity and starch content decreased rapidly, while soluble α‐amylase activity continued to increase. The enzymic data demonstrate that effects of water stress on cotton are adverse, because starch degradation products are not translocated, but accumulate as reassembled starch in the source leaves.
Zur enzymatischen Hydrolyse verschiedener Stärkearten
Authors: Tegge G. , Richter G. 
Published: November 2006

AbstractDie Arbeit beschäftigt sich mit der Frage, wie sich verschiedene handelsübliche Stärken in Verzuckerungsprozessen gegenüber amylolytischen Enzympräparaten und bei der Aufarbeitung der aus ihnen gewonnenen Hydrolysate verhalten. Im Endverzuckerungsgrad von Stärken aus Gelbmais, Waxmais, Amylomais, Kartoffeln und Weizen zeigten sich keine signifikanten Unterschiede. Die nach der Verflüssigung auftretenden niedrigeren DE‐Werte von Waxmaishydrolysaten wurden in der Endverzuckerung kompensiert. Bei Viskositätsmessungen nach Verflüssigung und Verzuckerung zeigten die Rohhydrolysate aus Weizenstärke stets die höchste Viskosität. Nach Filtration konnten dagegen keine signifikanten Viskositätsunterschiede mehr festgestellt werden. Zusätze von Pentosanase in der Verzuckerungsphase wirkten sich auf Viskosität und Filtrierbarkeit der Hydrolysate nicht aus. Glucoamylase mit erhöhter Pentosanaseaktivität beeinflußte die Filtrierbarkeit bei Weizenstärkehydrolysaten positiv; die Viskosität blieb dagegen unverändert. Der Verlauf der enzymatischen Verflüssigung der einzelnen Stärkearten wurde mit Hilfe des Brabender‐Viskographen verfolgt. Hierbei zeigten sich aufschlußreiche Unterschiede zwischen Kartoffel‐ und Waxmaisstärke einerseits und Mais‐ und Weizenstärke andererseits.
Praktische Erfahrungen mit der NIR‐Reflexionsspektroskopie beim enzyminduzierten Abbau von Weizenstärke zu Glucose
Authors: Weustink P. 
Published: November 2006

AbstractDie NIR‐Reflexionsspektroskopie bietet eine gute Möglichkeit, den enzyminduzierten Abbau der Weizenstärke vom Zeitpunkt der Verflüssigung und Verzuckerung bis zum Endprodukt Glucose während des Betriebsprozesses zu kontrollieren. Die dabei auftretenden DE‐Werte liegen im Bereich von 10–100 DE und können mit 3 voneinander unabhängigen Eichungen auf dem Infra‐Alyzer 400 L gemessen werden. Die Gerätewerte sollten in regelmäßigen Abständen durch Handtitration kontrolliert werden.
On Water in Potato Starch
Authors: Bączkowicz M. , Tomasik P. , Wiejak S. 
Published: November 2006

AbstractThermal analysis (TG and DTA) was carried out on potato starch dried in the air at room temperature as well as at 130°C, and also on that dried azeotropically with benzene. Water present in the matrix of potato starch influences the whole pathway of dextrinization up to at least 300°C. The mode of removal of water from air‐dried starch also subtly changes the route of thermal decomposition of starch and magnitudes of thermal effects. The role of atmospheric oxygen in thermolysis is also documented.
Cyclodextrins in Biotechnology
Authors: Szejtli J. 
Published: November 2006

AbstractCyclodextrins and their derivatives enhance the solubility of complexed substrates in aqueous media, but do not damage the microbial cells or the enzymes. Therefore the enzymatic conversion of lipophylic substrates can be intensified (accelerated, or performed at higher substrate concentration). Examples are the hydrolysis of triglycerides or conversion of hydrocortisone to prednisolon. In presence of an appropriate CD‐derivative (e. g. 2,6‐dimethyl‐β CD) the lipidlike inhibitor substances are complexed, therefore the propagation of Bordatella pertussis and the production of pertussis toxin increases up to 100‐fold. The tolerable level of toxic compounds at biological detoxication of sewage of organic chemical industry can be elevated by admixing small amount of β‐cyclodextrin to the system, because the complexed toxic substances do not kill the detoxicating microbes.
Modelle für Struktur und Eigenschaften der Stärke
Authors: Pfannemüller B. 
Published: November 2006

AbstractDefiniert aufgebaute Modellsubstanzen können zum Verständnis der Eigenschaften der Stärke beitragen. Geeignete lineare und verschiedenartig verzweigte Produkte mit Amyloseketten einheitlicher Länge werden durch phosphorolytische Synthese mit freien und trägergebundenen Maltooligomeren als Starter hergestellt.Der erste Teil dieser Arbeit gibt einen Überblick, in welcher Weise Löslichkeit, Retrogradation und Gelbildung durch Kettenlänge, Kettenlängenverteilung und Verzweigungsdichte beeinflußt werden, und welche Folgerungen sich für die speziellen Beiträge der natürlichen Stärkekomponenten ergeben.Im zweiten Teil wird über Untersuchungen an reinen Maltooligomeren berichtet, die die synthetischen Modelle im kurzkettigen Bereich ergänzen. Die Röntgen‐Pulveraufnahmen der aus wäßriger Lösung ausgefallenen Proben zeigen den B‐Typ im Bereich DP 20 bis 13, den A‐Typ im Bereich DP 12 bis 10. Die Grenze zur Retrogradation und Kristallisation scheint bei DP 8 bis 9 zu liegen. Bei diesen reinen Substanzen wird der C‐Typ nicht beobachtet. Die Ergebnisse lassen vermuten, daß zwischen der Länge der Amylopektinzweige, die von den Clusterregionen ausgehen, und dem Röntgentyp ein möglicher Zusammenhang besteht. – In Gegenwart von Amylose werden aus iodidfreier Iodlösung langsam I3‐‐Ionen gebildet. Entsprechende Untersuchungen an der Serie von Maltooligomeren zeigen, daß die I3‐‐Bildung korreliert ist mit der Tendenz zur Helix‐Bildung, wie zu erwarten war. In dieser Reihe nimmt Maltotriose eine Sonderstellung ein und verhält sich ähnlich aktiv wie α‐Cyclodextrin. Dieser Befund legt nahe, daß beide Substanzen in wäßriger Lösung eine ähnliche Konformation besitzen.