bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation and Characterization of Starch Acetate
Authors: Khalil M. I. , Hashem A. , Hebeish A. 
Published: November 2006

AbstractAcetylation 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

AbstractThe 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

AbstractIsolation, 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

AbstractResearch 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

AbstractThe 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

AbstractThe 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

AbstractThermal 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

AbstractPorcine 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

AbstractDer 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

AbstractGranule 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

AbstractThe 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

AbstractBeim 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

AbstractTexture 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

AbstractChemical 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

AbstractNativen 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

AbstractSixteen 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

AbstractInulin 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

AbstractEnset 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

AbstractTo 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

Abstract33% 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

AbstractPoly(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+.