bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanische Eigenschaften stärkegefüllter Polymerverbunde
Authors: Endres Hans‐Josef , Pries Andreas
Published: November 2006

In Fortführung der in [10] beschriebenen Untersuchung wurden wichtige mechanische Kenngrößen nativer Kartoffel‐, Mais‐ und Weizenstärkekörner ermittelt. Daraus konnten unter Voraussetzung einer ausreichenden Grenzflächenqualität die resultierenden mechanischen Eigenschaften der stärkegefüllten Verbundwerkstoffe theoretisch vorhergesagt werden. Diese theoretisch berechneten mechanischen Eigenschaften wurden abschließend durch Zugversuche an verschiedenen stärkegefüllten Verbundwerkstoffen verifiziert. Zur Bewertung der Grenzflächenqualität wurde ein Versagensmodell unidirektional verstärkter Werkstoffe herangezogen, auf die untersuchten partikelverstärkten Verbundwerkstoffe übertragen und am Beispiel weniger, ausgewählter, biologisch abbaubarer Verbundwerkstoffe näher diskutiert.

Die Ergebnisse der hier vorgestellten Untersuchungen zeigten, daß durch das Füllen von Kunststoffen mit nativen Stärkekörnern die mechanischen Eigenschaften der Matrixwerkstoffe z.T. verbessert werden können. Parallel dazu läßt sich aufgrund des günstigen Stärkerohstoffpreises von ca. 1 DM/kg [1] mit zunehmendem Stärkefüllgrad der endgültige Werkstoffpreis des Verbundwerkstoffes gegenüber dem reinen Matrixwerkstoff reduzieren und das Abbauverhalten deutlich beschleunigen.

Der maximale Stärkefüllgrad war jedoch auf Werte um 40 wt‐% begrenzt. Bis zu diesem Stärkefüllgrad konnten die untersuchten thermoplastischen Werkstoffe nahezu problemlos verarbeitet werden.
Preparation and Characterization of Starch Acetate
Authors: Khalil M. I. , Hashem A. , Hebeish A.
Published: November 2006

Acetylation of native hydrolyzed and oxidized, maize starch has been studied. The different factors affecting acetylation process were investigated. These factors include liquor ratio, acetic anhydride, perchloric acid concentration, reaction time and temperature. Also investigated were characterization and application of the acetylated starches in textile warp sizing. The acetyl content increases to reach a maximum and then decreases on increasing either liquor ratio or perchloric acid concentration. Also it increases with increasing acetic anhydride concentration within the range examined whereas the actylation reaction efficiency % decreases. Hydrolysis of starch prior acetylation inhances the susceptibility of the starch towards acetylation whereas oxidation do the reverse. The solubility of acetylated starches derived from hydrolyzed or oxidized starches increases more than that of acetylated native starch. The solubility depends on the extent of acetylation and of the modification prior acetylation. Acetylation of starch improves its sizeability of cotton yarns.
Some Selected Physicochemical Properties of Buffalo Gourd (Cucurbita foetidissima HBK) Root Starch
Authors: Toufeili Imad , Baydoun Elias
Published: November 2006

The starch granules of buffalo gourd contained 30.5% apparent amylose, showed a high swelling power and gelatinised over 57‐70.8°C with an enthalpy of 4.26cal·g−1. The starch pastes had a stable peak viscosity with a resistance to fragmentation intermediate to those of cassava and potato starches during holding at 95°C. The starch gels displayed a higher storage modulus (G′) than that of corn starch and a viscous character similar to that of potato starch. These properties differ from the maize‐like characteristics reported for this type of starch.
Studies on Isolation, Carbohydrate Make‐up and Rheological Properties of Galactomannan of Sesbania (Sesbania aculeata Poir.) Seeds
Authors: Wankhede D. B. , Sawate A. R. , Patil H. B. , Ismail S. , Deshpande H. W. , Hashmi S. H.
Published: November 2006

Isolation, carbohydrate make‐up and rheological characteristics of galactomannan of the sesbania seeds have been investigated. The galactomannan gum yield was 36.5±1.5%, on whole seed basis. The galactomannan had [a]D30+46.5°, on acid hydrolysis yielded galactose and mannose in the proportion of 1.2:2.2. Rheological properties of aqueous solutions of the galactomannan were investigated over a wide range of shear rates. The power law model, T=KDn, was employed to describe flow behaviour of the galactomannan. The magnitude of flow behaviour index ‘n’ values lower than 1.0, and found to decrease as the concentration increased, indicating pseudoplastic flow. Similarly, consistency index (K) values were increased with increased concentrations of galactomannan. Thus, the galactomannan exhibited good thickening capacity.
Structure and Physicochemical Properties of Endosperm Starches of a Waxy Allelic Series and Their Respective Normal Counterparts in the Inbred Oh43 Maize Background
Authors: Inouchi Naoyoshi , Glover David V. , Fuwa Hidetsugu
Published: November 2006

Research over the past three decades has greatly increased our understanding of the biochemical genetics of various waxy (wx) alleles of maize, but our knowledge about the structure and physicochemical properties of endosperm starches obtained from the wx alleles is still incomplete. We further investigated the structure and physicochemical properties of endosperm starches from a wx allelic series and their normal counterparts in the Oh43 inbred background.

Starch granules were prepared from mature kernels of wx mutant alleles; wx‐C31, wx‐R, wx‐90, wx‐a, wx‐B3, wx‐m‐1, wx‐m‐8, and wx‐S5, and their respective normal counterparts in the inbred Oh43 maize background. Measurements of absorption spectra of starch‐iodine complexes and by gel permeation chromatography of Pseudomonasisoamylase‐debranched starches showed that all of the starches from the wx allelic series were uniquely waxy type in characteristics, and their normal counterparts were characteristically normal type. Pasting characteristics of starch granules and retrograded starches of the wx allelic series and their respective normal counterparts were investigated by differential scanning calorimetry (DSC). The peak temperature (Tp) and conclusion temperature (Tc) values from starches of the wx allelic series were slightly higher than those of their respective normal counterparts and the ΔHs of starches of the wx allelic series were greater than those of their respective normal counterparts. The onset temperature (To), Tp, and Tc of all retrograded starches were very similar, however, the ΔHs of the retrograded starches of the wx allelic series were greate than those of their respective normal counterpart. Starch granules of the wx allelic series were hydrolyzed more rapidly than those of their respective normal counterparts.
Determination of the Intrinsic Viscosity of Native Potato Starch Solutions
Authors: Heitmann T. , Mersmann A.
Published: November 2006

The influence of shear rate and concentration on the viscosity of solutions of native potato starch in water was investigated. The concentration dependence of viscosity was expressed by the Huggins equation with shear rate independent intrinsic viscosity. On the other hand the Huggins parameter is strongly influenced by the shear rate and decreases with the reciprocal square root of increasing shear rate in the range from 50.1/s to 1000‐1/s.
Comparative Morphology of Starch of Three Andean Tubers
Authors: Cortella Alicia R. , Pochettino Maria L.
Published: November 2006

The starch of three Andean tubers have been studied (Oxalis tuberosa, Ullucus tuberosus, Tropaeolum tuberosum). Qualitative optical methods, scanning electron microscopy and quantitative analytical microscopy have been used. Statistical tests have been applied to the results. The comparative study of starch grains morphology provides important characters for their identification. As a result, starch would be an element of high value in the determination of material recovered from archaeological sites in different preservation conditions or used in food elaboration.
Thermal Behaviour of Calcium‐Hydroxypropyl Rice Starch Complexes
Authors: Islam M. Nurul , Azemi B. M. N. Mohd.
Published: November 2006

Thermal behaviour of hydroxypropyl rice starches and their calcium complexes were determined by using Differential Scanning Calorimetry (DSC) with starch: water in the ratio of 1:1. Glass transition and gelatinization temperatures were reduced by hydroxypropyl groups and enhanced by calcium treatment. Gelatinization enthalpies were reduced by both hydroxypropyl groups and calcium treatment. The interaction of hydroxypropyl groups and calcium with starch altered the two endothermic peaks observed in native starch into a single melting peaks.
Distribution of Partial Digestion Products of Hydroxypropyl Derivatives of Maize (NM), Waxy Maize (WM) and High Amylose (HA) Maize Starches
Authors: Azemi B. M. N. Mohd. , Wootton M.
Published: November 2006

Porcine pancreatic α‐amylase digests of native and hydroxypropyl derivatives of maize, waxy maize and high amylose maize starches were subjected to ethanolic fractionation into oligosaccharide and polysaccharide fractions. Both fractions of the partial digests were analysed for blue values, reducing values, total carbohydrate, average degree of polymerisation and molar substitution (MS). Distribution of hydroxypropyl groups between the fractions varied depending on starch type and level of substitution with the polysaccharide fraction being higher in MS. Blue values (BV) and average degree of polymerisation (DP) tended to decrease with digestion while reducing (RV) increased.
Abbaubare Polymerwerkstoffe auf der Basis nachwachsender Rohstoffe — Möglichkeiten und Grenzen
Authors: Fritz H. G. , Aichholzer W. , Seidenstücker T. , Widmann B.
Published: November 2006

Der Beitrag beschreibt Rezeptierungs‐ und Aufbereitungsmöglichkeiten für die Herstellung bioabbaubarer Polymerwerkstoffe unter Einbeziehung nachwachsender Rohstoffe. Diskutiert werden die Inkorporierung nativer Stärke in aliphatische Polyesterurethane sowie das Abbauverhalten derartiger gefüllter Polymersysteme. Erörtert werden weiterführend die Generierung Thermoplastischer Stärken (TPS) mittels Zweischneckenkneter und deren Einsatz als Matrixkomponenten für flachsfaserverstärkte Composites. Die Aufbereitung von Polymerblends aus Thermoplastischer Stärke und biochemisch abbaubaren, synthetischen Thermoplasten führt zu interessanten Zweiphasenwerkstoffen, denen ein beträchtliches Entwicklungs‐potential zugeschrieben werden kann. Aufrund enggeknüpfter Struktur/Eigenschaftsbeziehungen kommt der Morphologieausbildung beim Compoundierungsprozeß entscheidende Bedeutung zu. Dimensionslose Kennzahlen zum Abschätzen und Beurteilen der sich einstellenden Phasenstruktur werden vorgestellt.
Kinetics of Cowpea Starch Gelatinization Based on Granule Swelling
Authors: Okechukwu Paul E. , Anandha Rao M.
Published: November 2006

Granule size measured by laser diffraction was employed to describe the gelatinization kinetics of cowpea starch. During isothermal heating of the starch suspensions over the temperature range 67‐86°C, the granule mean diameter increased rapidly initially and gradually leveled off to an equilibrium value that showed both power law and exponential dependency on temperature. Gelatinization of the starch followed pseudo first‐order kinetics after an initial time lag that diminished with increased heating temperature. The gelatinization rate constant increased with temperature and could be described by the Arrhenius model with an activation energy of 233.6 kJ/mole.
Effect of Moisture Content on the Melting of Wheat Starch
Authors: Jang J. K. , Pyun Y. R.
Published: November 2006

The effect of water on heating wheat starch‐water mixtures of water content (between 2.8% and 90%) has been observed by differential scanning calorimetry. Four endothermic transitions were observed for wheat starches heated in the presence of limited water (moisture levels of 40,50%). These transitions appears to be due to melting of amylopectin crystallites, amylose‐lipid, and amylose. The heat decomposition temperature range of wheat starch were 253‐302°C and the plasticization effect according to the amount of water was small. The melting temperature obtained by extrapolation to zero volunme fraction of water were 234°C for M1 DSC endotherm, 254.3°C for M2 DSC endotherm, 267.8°C for M3 DSC endotherm.
Rheologische Untersuchungen zum Einfluß von Hydrokolloiden auf die Gefrier‐Tau‐Stabilität von Stärkekleistern
Authors: Liehr M. , Kulicke W.‐M.
Published: November 2006

Beim Auftauen tiefgefrorener stärkehaltiger Lebensmittel, zeigen diese häufig eine unerwünschte Wasserabscheidung (Synärese), die offensichtlich auf Strukturveränderungen zurückzuführen ist. Um das Ausmaß solcher Synäreseerscheinungen nach Gefrier‐Tau‐Zyklen (GTZ) zu beschreiben, wurden an einer Kartoffelstärke, einer Wachsreisstärke und 4 Varietäten Maisstärke rheologische Messungen durchgeführt. Als Kenngröße für die Gefrier‐Tau‐Stabilität (GTS) wurde die relative Zunahme des Speichermodul G'spez durch einen GTZ definiert, wobei ein Wert unter 1 gute GTS bedeutet. Der Vergleich verschiedener Mais‐ und Wachsmaissorten ließ keine Korrelation der GTS mit dem Amylosegehalt zu. Die ausgeprägt GT‐in‐stabile Kartoffelstärke wurde zur Untersuchung der Auswirkung einer Hydrokolloidadditivierung auf das Gefrier‐Tau‐Verhalten herangezogen. Zunächst wurde in der Reihenfolge Tara‐Gummi, l‐Carrageenan und Johannisbrotkernmehl keine bis mäßige GT‐Verbesserung gefunden. Für die Mischungssysteme mit l‐Carrageenan und Johannisbrotkernmehl wurde bei 10%igem Hydrokolloidanteil in einem 5%igem Gel eine maximale GTS erzielt. Die Wirkungsweise der Hydrokolloide konnte aus den viskoelastischen Materialfunktionen einem kombinierten Mechanismus aus Netzwerkkopplung und Exklusionseffekt zugeschrieben werden.
Hydrocolloids and Rheology: Regulation of Visco‐elastic Characteristics of Waxy Rice Starch in Mixtures with Galactomannans
Authors: Kulicke Werner‐Michael , Eidam Dirk , Kath Franziskus , Kix Martin , Kull Arne H.
Published: November 2006

Texture and sensory properties of starch solutions or gels, resp., can be influenced by regulating the visco‐elastic properties that cannot be adjusted by simply varying the waxy rice starch concentration. Therefore, the hydrocolloid galactomannans guar gum and locust bean gum were used for addition. A total polymer concentration of c = 5% was maintained through all tests, the hydrocolloid fractions varied (cHK = 0.5%, 1%, 2%).

The mixtures were entirely decomposed in an autoclave at 130°C resulting in an almost complete destruction of the granular starch structure. With rheomechanical oscillation measurements in the linear‐visco‐elastic range the influence of the galactomannans onto viscosity yield and visco‐elasticity was determined quantitatively. It was found that the influence on the viscosity is depending on the deformation rate. At low frequencies and with increasing galactomannan fraction the viscosity decreases, while above a critical frequency ωkr an increase in viscosity could be detected compared to pure starch. The mixtures also displayed an increase in viscous fractions versus elastic fractions compared to pure starch. With increasing galactomannan fraction, the ratio storage modulus/loss modulus is reduced continuously from G′:G″ > 10 (definitely mainly elastic) to G′:G″ = 1 with simultaneously decreasing influence of the frequency.

Based on the presented data and knowledge on solution structure of the individual components, a model for describing network structures in mixtures was developed. Changes in viscous‐elastic properties are based on a thermodynamic incompatibility between starch and galactomannan fractions. The mixtures contain mixed network structures, with waxy rice starch (permanent network points) and galactomannans (temporary network points) contributing individually and characteristically to the resulting flow behaviour.
Isolation of Sorbitol‐6‐Phosphate from Hydrogenated Tapioca Starch Hydrolysate
Authors: Sharma Rajesh K. , Shah Nilesh K. , Kothari Raman M.
Published: November 2006

Chemical characterization of hydrogenated tapioca starch hydrolystate (TSH) of 95±1% DE contained 0.2‐0.5% organic entity which was water‐soluble and acid‐resistant phosphate, later identified as sorbitol‐6‐phosphate from its response to (a) pentaacetyl derivative formation, (b) GC profiles and (c) tracing its origin to G‐6‐P from TSH.
Gelatinierungsverhalten von Weizenstärke in einem zweiwelligen Knetgerät
Authors: Potente H. , Liu J. , Rücker A.
Published: November 2006

Nativen Stärke kann unter der Zugabe von Gelatinierungsmitteln (z.B. destilliertes Wasser oder Glyzerin) in einem zweiwelligen Kneter gelatiniert werden. Der Gelatinierungsgrad der Stärke hängt wesentlich von den Parametern Verweilzeit, Temperatur, Druck, Drehzahl und dem Anteil des Gelatinierungsmittels ab. Bei den Versuchen, die diesem Aufsatz zugrunde liegen, wurden die Proben in einem Plastograph mit verschiedenen Anteilen destillierten Wassers (20%, 30%, 40%) und unterschiedlichen Knetzeiten hergestellt. Der Gelatinierungsgrad dieser Proben wurde durch ein DSC‐Analysegerät bestimmt. Die Ergebnisse zeigen, daß der Gelatinierungsgrad der Stärke mit steigender Verweilzeit und steigender spezifischer mechanischen Energieeinleitung zu Beginn stark und dann langsam zunimmt, bis der Gelatinierungsgrad der Stärke von 100% erreicht wird. Mit dem steigenden Anteil des destillierten Wassers verzögert sich jedoch die Gelatinierung der Stärke. Weiterhin wird eine mathematische Behandlung des Gelatiniervorganges durchgeführt. Die Übereinstimmung zwischen dem berechneten und gemessenen Gelatinierungsgrad ist zufriedenstellend.
Carbohydrate Digestibility and Resistant Starch of Steamed Bread
Authors: Wen Q. B. , Lorenz K. J. , Martin D. J. , Stewart B. G. , Sampson D. A.
Published: November 2006

Sixteen Australian hard and soft wheats and two U.S. hard wheats were milled into flours (break and reduction) for preparation of steamed breads. Chemical composition and rheological properties of the flour were determined. Steamed breads were analyzed for carbohydrate digestibility and resistant starch. There was no relationship between flour type, protein content and specific volume of steamed breads. Carbohydrate digestibility of steamed breads from soft wheat flour was higher than that of breads from hard wheat flour. Reduction flours produced steamed breads with higher carbohydrate digestibility than break flours. Resistant starch was higher in steamed breads from soft wheat flours than in those from hard wheat flours. Reduction flour produced higher resistant starch levels than break flours. Commercial white bread had resistant starch levels similar to those of steamed breads from soft wheat flour and hard wheat reduction flour.
Synthesis of Cyanoethyl Inulin, Aminopropyl Inulin and Carboxyethyl Inulin
Authors: Verraest Dorine L. , da Silva Lara P. , Peters Joop A. , van Bekkum Herman
Published: November 2006

Inulin was cyanoethylated by reaction with acrylonitrile in the presence of aqueous sodium hydroxide. Products with a degree of substution (ds) from 0.2 to 1.6 were prepared. The materials were analyzed using NMR spectroscopy and GPC analysis. The nitrile groups of cyanoethyl inulin were converted into amino groups by reduction with sodium borohydride in the presence of a transition metal chloride (CoCl2.6H2O). Furthermore, the nitrile groups were hydrolyzed towards carboxylates using hydrogen peroxide in alkaline medium. The polycarboxylate obtained by this means was shown to possess good calcium carbonate crystallization inhibition properties.
Isolation and Physico‐chemical Properties of Enset Starch
Authors: Gebre‐Mariam T. , Abeba Addis , Schmidt P. C.
Published: November 2006

Enset starch (Ensete ventricosum, Musaceae) has been examined for its chemical composition, amylose content and physico‐chemical properties. The proximate composition of the starch on dry weight basis was found to be 0.16% ash, 0.25% fat, 0.35% protein, and 99.24% starch. The amylose content was 29%. Scanning electron microscopy (SEM) of enset starch granules showed characteristic morphology that was somewhat angular and elliptical. The starch has normal granule size distribution with a mean particle size of 46μm. It exhibits typical X‐ray diffraction pattern of B‐type with a distinctive maximum peak at around 17° 2θ Its moisture sorption pattern was similar to that of potato starch but much higher than maize starch. DSC parameters obtained from starch‐water mixtures (1:2), namely, the enthalpy of gelatinization (ΔH: 21.6mJmg−1), the onset temperature (T0: 61.8°C), the peak temperature (Tp: 65.2°C) and the endset temperature (Te: 71.7°C) were higher than those obtained for potato starch. Brabender viscosity curves of 6% starch paste showed lower peak viscosity (884 BU) than potato starch (1668 BU) but greater than maize starch (302 BU). The breakdown was also lower than potato starch but higher than maize starch. Retrogradation of enset starch was substantially greater than potato starch but less than maize starch.
An Aqueous Alcoholic‐Alkaline Process for Cationization of Corn and Pea Starches
Authors: Kweon M. R. , Bhirud P. R. , Saskatoon F. W. Sosulski
Published: November 2006

To develop a more efficient process for cationization of corn and pea starches, the effects of gelatinization inhibitor, type of solvent and solvent concentration, starch: water ratio, reaction temperature and 2‐chloro‐3‐hydroxypropyltrimethylammonium chloride (CHPTAC) concentration on rate and efficiency of cationization of corn und pea starches in an aqueous alcoholic‐alkaline solvent were studied during 24h of reaction time. The use of watermiscible organic solvents in the aqueous alkaline media eliminated the requirement for a gelatinization inhibitor to minimize starch swelling. The alcohol concentrations which produced high reaction efficiencies were 35‐75% ethanol or 2‐propanol. Optimum conditions for the reaction included 65% ethanol, 50°C and a starch:water ratio of 1:1 (w/w). The degree of substitution (DS) value increased linearly with CHPTAC concentration up to O,2M CHPTAC, but reaction efficiency (RE) decreased at the O,2M CHPTAC concentration. Cationization of starch in the aqueous alcohol solvent would be an alternative to aqueous processes because of the higher DS and reaction efficiencies that were achieved more rapidly and without the aid of other gelatinization inhibitors.
Changes of Carbohydrate Composition During Enzymatic Hydrolysis of Starch with Mycolase Participation
Authors: Nebesny E. , Pierzgalski T. , Brzeziński S.
Published: November 2006

33% in d.s. potato starch liquefied with bacterial α‐amylase to DE 20 was saccharified 48 h with Mycolase alone to DE 55.5. In adequate conditions at different enzyme dosages hydrolyzates of the maltose content of 50.4 to 65.8% in d.s. could be obtained. When potato starch liquefied to DE 20 was saccarified 48 h with mycolase in cooperation with glucoamylase at different ratios of enzyme dosages to DE 64.9‐72.3, hydrolyzates of the glucose contents of 37.3‐49.8% and the maltose contents of 54.9‐34.2% in d.s. could be obtained. Characteristic were hydrolyzates saccharified to DE 69 which had gloncose content 41.3% and maltose content 42.8% in d.s., that are practically similar contents of those sugars.
Hydrolysis of Poly(acrylamide) ‐ Starch Graft Copolymer
Authors: Khalil M. I. , Farag S. , Fattah S. Abd El
Published: November 2006

Poly(acrylamide)‐starch graft copolymer was treated independently with sodium hydroxide and different acid solutions. The different acids include phosphoric, hydrochloric and sulphuric acid. The treatment was carried out under a variety of conditions including sodium hydroxide concentration, time and duration of hydrolysis as well as type of acid used. The extent of hydrolysis was assessed by estimating amide and carboxyl content as well as the acrylate and starch content before and after treatment. It was found that the increment in carboxyl content is equal to the decrement in amide on using sodium hydroxide concentration up to 1n, while using higher concentrations than 1n lead to differences in formed carboxyl and decreased amide groups. The magnitude of this difference depends on sodium hydroxide concentration as well as temperature and duration of hydrolysis. The maximum value of carboxyl content obtained was 593 m‐eq/100g sample. The acidic treatment of the starch copolymer does not affect the conversion of amide groups to carboxyl groups and the lonely effect was hydrolysis of starch component of the copolymer. Evaluation of the alkali teated copolymer as cation exchanger was carried out. The absorption efficiency % of different cations depends on the associated anions and follow the order: Cu2+ > Zn2+ > Co2+ Mg2+.
Properties of Flavobacterium odoratum KU Isoamylase
Authors: Hizukuri S. , Kozuma T. , Yoshida H. , Abe J. , Takahashi K. , Yamamoto M. , Nakamura N.
Published: November 2006

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

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

The performance of two different procedures for the extraction of the free adipic acid present in acetylated adipyl cross‐linked starches, was compared. It concerns a single extraction with a methanol‐acetic acid mixture and, a two step extraction procedure based upon a single aqueous extraction of the starch, followed by four extractions with ethyl acetate of the obtained aqueous extract. Apparently, some compounds ‐ probably sodium salts ‐ were present in the dry residue of the methanolic extract, which interfered with the silylation reaction of the adipic and pimelic (internal standard) acid. This resulted in a less reliable gas chromatographic determination of the adipic acid content in the dry extraction residues. The aqueous/ethyl acetate extraction procedure results in a better isolation of the alkanedioic acids from the interfering residues present in the starch sample.

The standard deviation in the determination of the free adipic acid in the starch adipates, based on 55 independent duplicates, is 1.6ppm. The free adipic acid concentrations in the analyzed wheat and corn starch samples varied from 0–360ppm.
Effect of Longer Heating Time on Depolymerization of Low Moisturized Starches
Authors: Igura N. , Hayakawa I. , Fujio Y.
Published: November 2006

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

The cooperative concomitant action of maltose phosphorylase (MP), trehalose phosphorylase (TP), β‐amylase and a starch debranching enzyme (pullulanase, isoamylase) was investigated to develop a more efficient method for preparing trehalose from starch.

About 40 and 51—56% as solid basis of 25% (w/v) liquefied potato starch were converted to trehalose by the combination of soybean β‐amylase and the crude enzyme preparation (MTA) containing MP, TP and a saccharogenic amylase from a strain (SH‐35) of Plesiomonas in the absence and presence of a starch debranching enzyme, respectively.

A stable maltose syrup (70%, w/w) containing about 30% trehalose in the dry solid was prepared from starch directly, and about 36% as dry basis of the mother liquor (70%, w/w) containing about 56% trehalose was obtained as crystals of this non‐reducing disaccharide by conventional crystallization.

Trehalose in the by‐product obtained after removing crystals increased up to almost that of the mother liquor by reacting with MTA again.

By the method reported here, trehalose was produced from starch on an industrial scale without any remaining by‐products.
Characterization of Starch Isolated from Plantain (Musa paradisiaca normalis)
Authors: Pérez‐Sira Elevina
Published: November 2006

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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