bluuebunny/crossref_metadata_2025 huggingface dataset:
The Starch of Amaranthus — Physico‐chemical Properties and Functional Characteristics
Authors: Stone L. A. , Lorenz K.
Published: November 2006

Starch from four varieties of amaranth grain were examined by scanning electron microscopy. Physico‐chemical properties, including swelling power, solubility, water binding capacity, enzyme susceptibility, amylograph viscosity, and amylose, were determined. Functional characteristics, including bread and cake baking performance were studied. The granules of starch isolated from seeds of Amaranthus cruentus and Amaranthus hypochondriacus were found to be very small in size. They were angular and polygonal in shape. Compared to corn starch, the amaranth starches had a higher swelling power, a lower solubility, a greater water binding capacity, a lower susceptibility to α‐amylase, a higher amylograph viscosity and much lower amylose content. The amaranth starches produced very poor quality breads and cakes. The breads and cakes were low in volume, lacked symmetry, and had inferior grain, texture and crumb color.
Konduktometrische Aschebestimmung in Stärkehydrolysaten
Authors: Tegge G. , Richter G.
Published: November 2006

Seit etwa 70 Jahren wird in der Zuckerindustrie die Aschebestimmung mit Hilfe von konduktometrischen Verfahren durchgeführt; dagegen wendet man in der Stärkeverzuckerung immer noch die zeit‐ und energieaufwendige Sulfatasche‐Methode an. Daher wurde ein Vorschlag erarbeitet, nach dem die konventionelle Sulfataschebestimmung in Stärkehydrolysenprodukten durch ein konduktometrisches Meßverfahren ersetzt werden kann. Die neu entwickelte Methode beruht auf der elektrischen Leitfähigkeitsmessung in stark verdünnten Stärkehydrolysaten und der Umrechnung der spezifischen Leitfähigkeit auf den entsprechenden Sulfataschewert. Der Vorteil dieser Methode liegt in ihrer einfachen und schnellen Durchführbarkeit. Die physikalischen Zusammenhänge, von denen konduktometrische Messungen abhängig sind, werden erläutert.
Glucose Oxidation by Modified Mould Mycelium
Authors: Döppner T. , Hartmeier W.
Published: November 2006

A new strain of Aspergillus niger containing a high intracellular glucose oxidase and catalase activity could be isolated. The glucose oxidase of this strain showed some favourable properties with regard to enzymatic glucose oxidation in industrial scale. The mycelium was permeabilized by treatment with iso‐propanol. Then, additional catalase was bound to the mycelium so that a coimmobilizate, resulted. The enzymatic characteristics of this coimmobilizate, as compared with former immobilized glucose oxidase/catalase preparations, showed higher temperature stability and lower Km‐value for glucose. Some basic trials were done for glucose oxidation in a stirred tank reactor where oxygen supply was carried out by controlled addition of hydrogen peroxide instead of conventional aeration. The influence of temperature on the stability of both, glucose oxidase and catalase, was investigated under these application conditions.
A Thermodynamic Study of the Starch‐Water Surface Interaction
Authors: Wurster D. E. , Peck G. E. , Kildsig D. O.
Published: November 2006

The heats of immersion, in water, of corn starch U. S. P. and a directly compressible corn starch were determined as a function of moisture content. This study, in conjunction with an equilibrium vapor phase adsorption study, allowed the thermodynamic parameters characterizing the two systems to be calculated. In both cases, hysteresis was observed in the heat of immersion data. Plots of the differential enthalpies provided evidence that both starches swell in water at room temperature. Average adsorbate‐solid hydrogen bond energies were calculated for the two starch‐water systems ( ‐ 8.57 Kcal/mole, corn starch U. S. P. ‐water; ‐ 7.80 Kcal/mole, Starch 1500‐water).
Brewing Beer with Enzymes and Starch Analysis
Authors: Tóth M. , László E. , Holló J.
Published: November 2006

The method of HPLC carbohydrate analysis allows a stepwise and controlled alteration of the mashing technology. Our aim was to find a method for altering a given mashing technology by increasing the amount of digested corn grits by 40% using reduced mashing time and an up‐to‐date technology with simultaneous application of brewing‐enzymes. In the course of these experiments, by means of the HPLC method, the critical stages of carbohydrate decomposition could be revealed; after systematic application of industrial enzyme products under HPLC control the process has been short‐cut and, on the basis of analytical data, the entire mashing technology has been simplified and rationalized. As result of industrial‐scale experiments mashing time, including the cooking process of the surrogates, was cut down to 5.5 h. The wort produced by means of the elaborated well‐controllable combined infusion‐decotion mashing process has an attenuation of 85‐87% and shows the same carbohydrate composition, organoleptic properties and characteristics observed for the original wort. The results are also supported by tests of significance.
Production and Measurement of Starch Damage in Flour. Part 3. Effect of Type of Damage on Baking Performance
Authors: Evers A. D. , Stevens D. J.
Published: November 2006

Baking trials were conducted on two blends of 10% starch and 90% high protein flour. In both blends the flour component was identical but the starches had been ground in different ways to produce high levels of different types of damage. The levels of damage in the starches, and hence the blends, were similar if measured enzymically but different if measured by an amylose extraction method. Only small differences in baking properties were revealed.
Chlorination of Cake Flour and Its Effect on Starch Gelatinization
Authors: Telloke G. W.
Published: November 2006

The influence of a defined chlorination on the gelatinization behaviour of different cake flours in sucrose solutions (30–60% w/w) was investigated. Besides microscopic examinations, methods were developed for the estimation of hot paste viscosity and “amylose”

“Amylose” will throughout this paper mean linear polymers of glucose long enough to give a blue colour with iodine, but not necessarily native amylose as exists within the starch granule.

exudation from starch granules. The findings have shown that the amount of “amylose” which is exuded from starch granules during heating, as well as paste viscosity, increases with the chlorination of flour. High positive correlations were obtained between “amylose” exudation, hot paste viscosity and cake crumb firmness. It is proposed that this increased “amylose” exudation is, via an increase of gel strength, to a large extent responsible for the prevention of high ratio cake collapse. Besides reducing “amylose” exudation the high sucrose concentrations prevailing in cake batters were also found to inhibit greatly starch breakdown by malt and fungal amylase activity.
Stufenweise Elutionsanalyse elektrodialysierter Fraktionen von Mais‐Sorghum‐, Kartoffel‐ und Weizenstärke
Authors: Čeh M. , Stropnik Č. , Leskovar S.
Published: November 2006

Die 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

From 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

Cereal 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

By 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

Bei 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

A 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

The 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

A 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

A 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

Gelatinization 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

Cassava 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

Coleus 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

The 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

Ziel 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

Refined 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

Gelatinization 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

Coexistent 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

Cotton 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

Die 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

Die 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

Thermal 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

Cyclodextrins 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

Definiert 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.
Saccharification of Tapioca Starch Residue with a Multienzyme Preparation of Aspergillus ustus
Authors: Shamala T. R. , Sreekantiah K. R.
Published: November 2006

Enzyme preparation obtained cultivating Aspergillus ustus on rice straw‐wheat bran mixture (7:3) possessed cellulase, D‐xylanase, β‐D‐glucosidase, α‐amylase, amyloglucosidase and pectinase activities. Used at 2% level with tapioca starch residue (TSR) slurry gelatinized at 80°C or pressure cooked, it yielded 45–60% reducing sugar and degraded 52–65% of the fiber material. Enhanced saccharification (72%), fiber degradation (75%) could be achieved by pretreating the substrate with mineral acid. Fermentation of the hydrolysates with Saccharomyces cerevisiae produced 29–36 ml alcohol per 100 g of sun dried TSR. Data on TSR hydrolysis by α‐amylase and amyloglucosidase, A. ustus enzyme preparation individually and in combination with amyloglucosidase, in acid pretreated or untreated TSR are presented.
The Starch of Cassimiroa edulis ‐ Comparison with Maize Starch
Authors: Soni P. L. , Sharma H. W.
Published: November 2006

Starch from the seed of C. edulis is isolated, purified and its physicochemical properties are compared with maize starch. Scanning electron microscopy of the granules show that they are either smaller round or polygonal in shape. It has low phosphorus and amylose content and water binding capacity while methanol soluble lipids and proteins are more than in maize starch. Galatinization temperature and swelling power of C. edulis starch is almost comparable, but it has less solubility when compared with maize starch. Brabender viscosity shows high peak for C. edulis starch and lesser retrogradation.
Chemical Characteristics and Physicochemical Properties of the Extruded Mixtures of Cereal Starches
Authors: Fornal Ł. , Soral‐Śmietana M. , Śmietana Z. , Szpendowski J.
Published: November 2006

The results suggest that starch quality significantly determined the expansion coefficient, density, and physico‐chemical properties of the extruded starch mixtures. Unique properties of buckwheat starch were most important in this case. Attention should also be given to the effect of the extrusion conditions on chemical composition of the product, and especially to the decrease of starch and dietary fiber content.
Thermostabile Bindung von Aromastoffen an Stärke Teil 1: Bindung durch Gefriertrocknen
Authors: Maier H. G. , Rümmler U. , Moritz K.
Published: November 2006

Durch Gefriertrocknen wässriger Lösungen, Emulsionen oder Suspensionen von Menthol, Pyrazin, Thymol, Vanillin oder Pfefferminzöl und Lösungen von nativen oder modifizierten Stärken, Amylose, Amylopektin oder β‐Cyclodextrin und Erhitzen auf 180°C wurden Sorbate hergestellt, in denen der Aromastoff thermostabil und auch weitgehend extruderstabil gebunden ist. Im allgemeinen nahmen die gebundenen Mengen in der Reihe Cyclodextrin, Amylose, Kartoffelstärke, Wachsmaisstärke, Mais‐ oder Tapiokastärke, Weizenstärke, Amylopektin ab. Einige modifizierte Maisstärken sorbierten größere Mengen als native Maisstärke. Menthol und Thymol wurden besser an amylosereiche Stärken gebunden, Vanillin und Pyrazin besser an amylopektinreiche, doch Vanillin am besten an Cyclodextrin und Pyrazin an Maltodextrin (DE 4–5). Die Freisetzung der Aromastoffe beim Kauen im Mund war geringer, wenn sich Kanaleinschlußverbindungen mit Amylose gebildet hatten.
Isolation and Characterization of Starch from Bamboo Culm (Guadua flabellata)
Authors: Toledo M. C. F. , Azzini A. , Reyes F. G. R.
Published: November 2006

Starch was isolated from bamboo culm in 8.5% yield. The starch was characterized by poligonal granules ranging in size from 1 to 12 μm and an amylose content of 24%. The granules were compact, with a density of 1.531 g/cm3. This, probably, reflected in low swelling power and solubility in water and poor solubility in dimethyl sulfoxide (DMSO). Brabender amylogram indicated an initial pasting temperature of 75°C and a high susceptibility to breakdown by thermal and/or mechanical shear.
An Improved Method of the Purification of Bacillus stearothermophilus Exo‐α‐1,4‐glucosidase Active on Soluble Starch by the Use of an Immunosorbent
Authors: Suzuki Y. , Shinji M.
Published: November 2006

A p‐nitrophenyl‐α‐D‐glucopyranoside‐hydrolyzing exo‐α‐1,4‐glucosidase (α‐D‐glucoside glucohydrolase, EC.3.2.1.20) highly active on soluble starch of Bacillus stearothermophilus ATCC 12016 was 366‐fold purified to homogeneity with a yield of 31% by a simple five‐step procedure containing as the most efficient step the enzyme elution from immunosorbent with a pH 11 medium including 50% (w/v) glycerol. The enzyme specific activity was 148 μmol p‐nitrophenyl‐α‐D‐glucopyranoside hydrolyzed/min/mg protein at 60°C and pH 6.8. The enzyme cleft 71% of glucosidic linkages in α‐limit dextrin (average polymerization degree = 9) made from potato amylopectin with Bacillus subtilis α‐amylase. The products of α‐limit dextrin were hardly hydrolyzed by Bacillus thermoglucosidasius oligo‐1,6‐glucosidase (dextrin 6‐glucano‐hydrolase, EC.3.2.1.10).
Varietal Differences in Physicochemical Properties of Waxy Rice Starch
Authors: Juliano B. O. , Villareal R. M. , Baños Los
Published: November 2006

High‐gelatinization temperature (GT) waxy rice starch amylopectin has higher sedimentation coefficient than low‐GT waxy rice amylopectin. Get filtration on Sepharose CL‐2B and TSK‐Gel G‐6000PW also showed higher mean molecular weights for high‐GT amylopectins than for low‐GT amylopectins. The harder texture of cooked rice products from high‐GT waxy rices, compared to the texture of products from low‐GT waxy rices, may be due to the higher molecular weight of their amylopectins.
Die molekulare Charakterisierung von hydrolytisch abgebauten Stärken mittels Hochleistungs‐GPC‐Analyse
Authors: Praznik W. , Beck R. H. F. , Berghofer E.
Published: November 2006

Für die Erfassung der molekularen Zusammensetzung niedermolekularer Stärkepolysaccharide wird ein neues leistungsfähiges HPGPC‐System vorgestellt. Als Trennsystem wird ein druckstabiles, speziell vernetztes Agarosegel verwendet. Die Kalibrierung erfolgte mit selbst synthetsierten, durch Laserkleinwinkellichtstreuung (LALLS) molekular charakterisierten Amylosen. Zum Vergleich wurden käufliche Kalibrationsstandards getestet. Bei den strukturähnlichen Pullulanen konnte ein annähernd identisches Trennverhalten im wäßrigen System gefunden werden. Hingegen lag bei den Dextran‐ und Polyäthylenoxidstandards ein Trennverhalten vor, das dem strukturellen Aufbau und der Steifheit dieser Moleküle entspricht. – Das HPGPC‐System wurde zur Untersuchung von hydrolytisch abgebauten Stärken eingesetzt. Die molekulare Verteilung von nach verschiedenen Verfahren hergestellten niedrig abgebauten Stärkehydrolysaten, Maltodextrinen und SHP, wurde untersucht und in Bezug zu den funktionellen Eigenschaften dieser Produkte gebracht. Die Assoziatbildung der Stärkepolysaccharide konnte durch GPC‐Trennung in einem rein wäßrigen System im Vergleich zu einem salzhaltigen Eluenten beobachtet werden. Es zeigte sich, daß im Assoziatbildungsprozeß Polysacccharide mit einer Kettenlänge von 300–500 Glucoseeinheiten bevorzugt beteiligt sind. Die Gelfestigkeit der hydrolytisch abgebauten Stärken steht in direktem Zusammenhang mit der Menge an hochpolymeren Assoziaten. Als Mindestmenge an Assoziaten wurde 35% der Gesamtmenge der Produkte gefunden, die die Ausbildung von Gelen erlaubt.
Unique Physico‐chemical Properties of Sal (Shorea robusta) Starch
Authors: Soni P. L. , Sharma H. W. , Bisen S. S. , Srivastava H. C. , Gharia M. M.
Published: November 2006

Starch from sal seeds cake was isolated, bleached and purified. Scanning electron microscopy of the starch showed round to oval shaped granules of the size 3.5 to 12.3 μm. The starch has more nitrogen, phosphorus, lipids, amylose and water binding capacity in comparison to the other starches of forest origin. Despite its low and seemingly restricted swelling, the sal starch is much more soluble at any particular degree of swelling. Paste viscosity curve showed no drop in viscosity after full gelatinisation had taken place, i. e. the paste is stable on continued cooking.
Starch Crystal Transformations and Their Industrial Importance
Authors: Zobel H. F.
Published: November 2006

The structures and transformations of the starch crystal forms A, B, C and V are reviewed from the viewpoint of their industrial importance. Reviewed also is the non‐crystalline or amorphous state of starch and its role in determining the physical properties of native and gelled starches.
Physico‐chemical and Functional Properties of Common Bean (Phaseolus vulgaris) Starches
Authors: Paredes‐López O. , Maza‐Calviño E. C. , González‐Castañeda J. , Montes‐Rivera R.
Published: November 2006

Starch was isolated by a simple procedure from two varieties of Phaseolus vulgaris with outstanding agronomic performance. These varieties were negro queretaro and bayocel which have black and light brown colored seeds, respectively. The starch yields were 31.5% for negro qro. and 28.5% for bayocel. Commercial maize starch was used as reference. The granule size followed the order: negro qro. > bayocel > maize. Compared to maize starch, the legume starches had at least a similar water absorption capacity, formed a stable gel at lower concentrations and showed a Hunter total color closer to the employed white standard. The swelling and solubility were both temperature and pH dependent. Effects of pH on the pasting properties were also examined with the Brabender Viscograph. The viscosity of legume starches was increased after holding the paste at 90°C for 15 min. The retrogradation tendency of maize starch was much higher than that of legume samples. The physico‐chemical and functional properties of common bean starches might suit some food industrial applications.
A Study of Starch‐Lipid Interactions for Some Native and Modified Maize Starches
Authors: Eliasson A. C. , Finstad H. , Ljunger G.
Published: November 2006

Starch‐lipid interactions of five maize starches varying in amylose content and chemical modification were investigated by differential scanning calorimetry (DSC). The high‐amylose maize starch gave the greatest endotherm due to the amylose‐lipid complex in presence of cetyltrimethylammonium bromide (CTAB). This endotherm was decreased in an acetylated high‐amylose maize starch, and the waxy varieties did not give rise to such an endotherm. However, when the gelatinization enthalpies were compared it was found that these values decreased also for waxy varieties in the presence of CTAB. Dynamic rheological measurements showed that CTAB increased the storage modulus (G′) for all the starches investigated (normal maize starch, acetylated high‐amylose maize starch and crosslinked waxy maize starch), whereas saturated monoglycerides increased G′ for normal maize starch, decreased G′ for the crosslinked waxy maize starch and left acetylated high‐amylose maize starch unaffected. Lecithin and soybean oil either decreased G′ or had no effect.
Characterization of the Reaction Products for Starch and Acrylonitrile
Authors: Hebeish A. , Khalil M. I.
Published: November 2006

Rice starch was reacted with acrylonitrile in presence of sodium hydroxide under different conditions including liquor/starch ratio, sodium hydroxide concentration and acrylonitrile concentration as well as reaction time and temperature. The reaction products were analyzed for nitrogen and carboxylic contents and the results obtained were used for calculation of the degree of substitution (D. S.), reaction efficiency (R. E.) and total extent of etherification. Reaction products refered to mixed starch ethers, namely, cyanoethyl starch, carbamoyl ethyl starch, and carboxyethyl starch. Due to analytical difficulties to differentiate between the first two ethers, they were looked upon as cyanoethyl starch. The D. S. of the latter and the R. E. of cyanoethylation were greatly favoured at temperature not exceeding 40°C using lower liquor ratios for reaction time up to 4h provided that certain acrylonitrile and sodium hydroxide concentrations were used. Specifiably, the most appropriate conditions for preparation of cyanoethyl starch comprized:starch/acrylonitrile ratio 1 : 1, liquor/starch ratio 1:7.5 and sodium hydroxide 0.5N at 40°C for 4 h. Under these conditions a D. S. of 1.2 and R. E. of 40% could be achieved. Higher temperatures, i. e. 50 and 60°C, acted in favour of carboxyethyl starch formation particularly when the reaction was allowed to proceed for more than 3 h at 50°C and 0.5 h at 60°C.
Gelatinization Characteristics of Starch from du, wx, ae, and ae wx Endosperm of Sweet Corn Inbred la5125
Authors: Brockett E. , Thompson D. , Davis T. , Boyer C.
Published: November 2006

Starch gelatinization in excess water was studied by differential scanning calorimetry for the mutants dull (du), waxy (wx), and amylose extender (ae), and the double mutant amylose‐extender, waxy (ae wx) from the Ia5125 sweet corn inbred background. Onset temperature (To), peak temperature (Tmax), and enthalpy (ΔH) were determined. For du and wx starches Tmax was within 1°C of the value for the normal starch (Tmax = 69.4°C). For starches from ae and ae wx mutants, Tmax was 7–8°C higher than the normal starch. The highest enthalpies were observed for wx (3.26 cal/g) and ae wx (3.39 cal/g) starches; ae (2.93 cal/g) and normal (2.52 cal/g) starches were intermediate, and du (2.32 cal/g) starch had the lowest enthalpy. The endotherm of the ae starch was completed at just above 100°C, in distinction to reports for ae mutants from dent lines. Although the ae wx endotherm occurred at a higher temperature than the wx, the endotherm was sharpened relative to the ae endotherm, and was complete at 90°C.
Comparative Performance of Zymomonas mobilis and Saccharomyces cerevisiae in Alcoholic Fermentation of Saccharified Wheat Starch B in a Continuous Dynamic Immobilized Biocatalyst Bioreactor
Authors: Wayman M. , Chen S. , Parekh R. S. , Parekh S. R.
Published: November 2006

Glucose derived from an industrial, enzymatically saccharified wheat starch fraction (B starch) was investigated for ethanol production using free and immobilized cells of Saccharomyces cerevisiae and Zymomonas mobilis. Batch cultures of these organisms could successfully ferment this substrate within 24 h giving 7% ethanol by volume and over 96% sugar conversion.

Fermentation with S cerevisiae and Z. mobilis immobilized on rotating fiber discs in a continuous dynamic biocatalyst bioreactor (CDIBB) resulted in very rapid and efficient fermentation and concurrent high ethanol productivity. Z. mobilis loaded at 30g/I cell density (based on bioreactor volume, 31) fermented saccharified wheat starch B slurry at 15% solids and having 128g/I glucose, in 0.9 h with 92% sugar utilization; and volumetric productivity based on liquid hold up was 65.5 g/I‐h, being threefold higher than that obtained with immobilized yeast cells. Z. mobilis appears to be the preferred organism for the rapid fermentation of glucose rich solutions in the CDIBB. Advantages and the possible application of this bioreactor system to alcoholic fermentation of industrial derived substrates associated with high suspended solids are discussed.
Die aus einer industriellen, enzymatisch verzuckerten Weizen‐B‐Stärke gewonnene Glucose wurde unter Verwendung von freien und immobilisierten Zellen von Saccharomyces cerevisiae und Zymomonas mobilis hinsichtlich der Ethanolgewinnung untersucht. Chargenweise Kulturen dieser Organismen vergoren dieses Substrat erfolgreich 24h; sie ergaben 7 Vol.% Ethanol bei 96% iger Zuckerumwandlung. Die Vergärung mit auf rotierenden Faserplatten immobilisierten S. cerevisiae und Z. mobilis in einem kontinuierlichen, dynamischen Biokatalysator‐Bioreaktor (CDIBB) führte zu sehr schneller und wirksamer Gärung und vergleichbar hoher Ethanolproduktivität. Mit einer Zelldichte von 30g/1 (bez. auf das Bioreaktorvolumen, 31) gepackte Z. mobilis vergor eine Weizen‐B‐Stärkesuspension mit 15% Feststoff und 128g Glucose/1 in 0,9h bei 92% Zuckerverwertung. Die Volumenproduktivität, bezogen auf die Flüssigkeitsrückhaltung, betrug 65,5 g/1‐h und war damit dreimal so hoch wie bei immobilisierten Hefezellen. Z. mobilis dürfte der bevorzugte Organismus für die rasche Vergärung von glucosereichen Lösungen im CDIBB sein. Die Vorteile und die mögliche Anwendung dieses Bioreaktorsystems für die alkoholische Vergärung von industriellen Substraten in Verbindung mit hoch suspendierten Feststoffen werden diskutiert.
Synthesis and Characterization of Leucaena glauca Gum Esters
Authors: Raval D. K. , Patel R. G. , Patel V. S.
Published: November 2006

Aliphatic esters of Leucaena glauca gum with different acid anhydrides were prepared using pyridine as catalyst employing same reaction conditions. The products were analyzed for the degree of substitution and confirmed by infrared spectroscopy. The esters were also characterized by evaluating different thermal parameters using thermogravimetric analysis. The reactivity of the anhydrides and the thermal stability of the corresponding gum esters with respect to their structures have been discussed.
Production and Measurement of Starch Damage in Flour. Effect of Starch Damage on Hot Pasting Properties
Authors: Evers A. D. , Stevens D. J.
Published: November 2006

Aqueous suspensions were made of wheat starches damaged, by different methods, to varying degrees. Apparent viscosities of the hot pastes declined as damage levels increased and the relationships between these factors were examined. Measured as “extractability”, starch damage had a linear relationship with apparent viscosity for starches damaged by both methods. Starch damage measured as “digestibility” had different relationships with apparent viscosity for each type of damage involved. Evidence was found for the association of amylolytic enzymes with the starches used in the experiments.