bluuebunny/crossref_metadata_2025_split huggingface dataset:
Viscosity Measurements of Potato Starch Paste with the Rapid Visco Analyzer
Authors: Haase Norbert U. , Mintus Thomas , Weipert Dorian 
Published: November 2006

AbstractViscosity behaviour of potato starch paste was measured with the Rapid Visco Analyzer (RVA, Newport Scientific, Warriewood, Australia). By reason of high viscosity properties of potato starch suspensions, starch concentration was reduced from 3.0 to 2.0 g starch weight (14% moisture) in 25 ml distilled water.In view of Brabender viscograms a short temperature profile (13 min including heating, stable hot phase, and cooling) achieved the best results. Reproducibility of RVA‐measurements was high as well with new canisters as with re‐used ones. Coefficient of variation (s%) was below 2%.A comparison of RVA and Brabender viscograms pointed out a close correlation of r=0.94 for both, the peak viscosity and the viscosity difference between peak and trough.
Two‐Steps Procedure for the Purification of Corn Flour Hydrolysate
Authors: Arasaratnam Vasanthy , Sritharan Kiburahary , Balasubramaniam K. 
Published: November 2006

AbstractWhen corn flour hydrolysate filtrate (CFHF) was treated with 100% (w/v) (NH4)2SO4 for purification, 80.5% of the protein was removed. Among the pH values studied, at pH 1.5, 90.2% of the total protein was precipitated from CFHF and supernatant was removed by decantation. The corn flour hydrolysate was purified with Amberlite and DEAE‐cellulose after precipitating the protein at pH 1.5. Charcoal was better than cation‐ and anion‐ exchange resins for the removal of proteins, amino acids and pigments from the hydrolysate.
Maize Mutants. Part 1: Studies on their Starch Components
Authors: Curá José A. , Krisman Clara R. 
Published: November 2006

AbstractThe present study was conducted in order to evaluate the starch components contained in several maize mutants. The α1,4‐α1,6 glucopolysaccharides were fractionated according to their branching degree. The determination of the wavelenght of maximum absorption (γ max) in the presence of Krisman's reagent [12] as well as the glucose α1,6 linkages involved in the branching point were determined. The mutants analyzed possess characteristics that allow us to identify them according to the composition and structural properties of their polysaccharides (phytoglycogen, amylopectin, amylose).
Kritische Situationen bei der Bestimmung des Substitutionsgrades von Amyloseverbindungen über ihren Kohlenstoffgehalt
Authors: Otto Andrè Henry 
Published: November 2006

AbstractDer Substitutionsgrad (DS) von Amyloseverbindungen ist nicht immer über ihren Kohlenstoffgehalt bestimmbar. Kritische Situationen treten für Derivate mit einem Substituenten auf, wenn die Kohlenstoffwerte des letzteren und von reiner Amylose (4/9 = 0.444) gleich sind. In der Praxis trifft man dies kaum an.Disubstituierte Amyloseverbindungen weisen eine Vielzahl kritischer Situationen auf. Das hängt vom DS des bestimmten Subsitutenten ab und ist nur möglich, wenn der zu bestimmende Substituent der kleinere ist. Der kritische DS(1)(=DSkr kann jeden Wert von 0 bis 3 annehmen. Bei trisubstituierten Verbindungen treten kritische Situationen selten auf. Dafür ist es notwendig, daß der zu bestimmende Substituent [DS(3)] seiner Größe nach zwischen den beiden bekannten Substituenten liegt. Die Summe DS = DS(1)+DS(2) der letzten ist offensichtlich immer größer als 2. Alle Paare DS(1) und DS(2) sind über lineare Gleichungen verbunden.Es wurden spezielle und allgemeine Formeln für die Voraussage von kritischen Situationen für alle Amyloseverbindugen hergeleitet.
Ethanol Production From Raw Sago Starch Under Unsterile Condition
Authors: Pranamuda Hardaning , Lee Sang‐Won , Ozawa Tetsuo , Tanaka Hideo 
Published: November 2006

AbstractIn order to utilize raw sago starch as fermentation material, mold strain (Aspergillus niger N‐10) which produces raw sago starch hydrolyzing enzyme, was isolated. Maximum raw sago starch consumption rate by the strain was obtained when the initial pH of the medium was 3.5 and the enzyme showed high stability and activity at lower pH values. Direct ethanol production from raw sago starch was investigated using a mixture of the strain and ethanol producing yeast, Saccharomyces cerevisiae IFO 0309. Neither the growth of the strains nor ethanol production was inhibited in the mixed culture of the two strains. Moreover, when fed‐batch mixed culture was conducted under unsterile condition (both the medium and the apparatus were not sterilized), about 30g/1 of ethanol was produced with ethanol yield from raw sago starch Yp/s of 0.40g ethanol/g starch.
Components of the Porous Maize Starch Granule Prepared by Amylase Treatment
Authors: Yamada Tetsuya , Hisamatsu Makoto , Teranishi Katsunori , Katsuro Kimiaki , Hasegawa Nobuyu , Hayashi Mitsugu 
Published: November 2006

AbstractPorous starch granules were prepared from normal and waxy maize starch with amylase (from Aspergillus sp.) treatment, but we failed to make it from amylostarch under the same condition. The porous normal starch samples of some digestive stage were analyzed to X‐ray diffraction, DSC and GPC after debranching process. The X‐ray diffraction patterns were changed following with proceed of digestion, but the values obtained from DSC and GPC were not changed. These observations suggest that crystal region may be more sensitive to the amylase than amorphous one, and amylose may be homogeneously distributed in the both regions.
A Rapid Method for the Determination of Amylose Content by Using Differential‐Scanning Calorimetry
Authors: Mestres Christian , Matencio Françoise , Pons Brigitte , Yajid Myriam , Fliedel Geneviève 
Published: November 2006

AbstractA calorimetric procedure to measure amylose content of various starchy raw materials has been developed. It is based on the measurement by Differential Scanning Calorimetry (DSC) of the enthalpy change of the formation of complexes between amylose and add phospholipid (L‐α‐lysophosphatidylcholine from egg yolk) observed during cooling. Contrasting to the colorimetric determination of amylose, the DSC procedure is not influenced by the presence of amylopectin or indigenous lipids. For rice and maize flours, the amylose content determinations are very similar for both colorimetric and DSC methodologies whether the starchy material was raw or pre‐cooked. But the DSC methodology is more repeatable and time saving; in particular, the defatting and starch determination steps can be omitted.
Synthesis, Characterization and Properties of Polyacrylamide‐Starch Composites
Authors: Hebeish A. , El‐Rafie M. H. , Higazy A. , Ramadan M. 
Published: November 2006

AbstractPolyacrylamide‐starch composite was prepared by polymerization of maize or rice starch with acrylamide (Aam) using potassium permangante/citric acid initiation system. Major factors affecting the polymerization reaction were studied with a view to discover appropriate conditions for preparation of the composite. Results obtained imply that the total conversion (monomer converted to homopolymer and graft) increases by increasing concentrations of potassium permanganate from 0.5‐0.20%, citric acid from 0.1‐0.15 and acrylamide from 10‐30% ows. Polymerization can easily be carried out at 40°C for 6 min at pH 4 using a material to liquor ratio 1:25 under a stirring rate of 350 rpm. The results further imply (a) that the apparent viscosity of the composite increases by increasing Aam concentration irrespective of the rate of shear, (b) that for 30% Aam concentration the composite consists of 77.7% starch and 22.3% polyacrylamide of which 10.4% are grafted, (c) that the sizeability of polyacrylamide‐starch composites is much better than that of native starches, and (d) that the kind of starch not only determines the total conversion but also the composition of the composite.
The Use of Freezing‐Point Depression for the Theoretical Dextrose Equivalent Measurement
Authors: Marchal Leon M. , Jonkers Jan , Tramper Johannes 
Published: November 2006

AbstractThe determination of the theoretical dextrose equivalent was investigated, by measuring the osmolality (mol dissolved particles/kg H2O) by freezing‐point depression. Relations for dextrose equivalent and increase in dry weight during a hydrolysis were derived as a function of molality and amount of dry weight at the start of the hydrolysis. With freezing‐point depression it was possible to determine the theoretical dextrose equivalent of oligosaccharides (dextrose to maltoheptaose), whereas a traditional titration method (Luff‐Schoorl) overestimates 20‐50%. The relation for the increase of dry weight during the hydrolysis of starch with an α‐amylase was experimentally validated. The overestimation of dextrose equivalent by Luff‐Schoorl titration was also evident in the hydrolysis of amylopectin potato starch. With freezing‐point depression it was possible to determine the theoretical dextrose equivalent fast and accurate.
Per‐O‐methylated α‐ and β‐CD: Cyclodextrins with Inverse Hydrophobicity
Authors: Immel Stefan , Lichtenthaler Frieder W. 
Published: November 2006

AbstractThe investigation focuses on the computer‐aided generation of the molecular geometries, contact surfaces, and lipophilicity patterns of per‐O‐methylated α‐CD (1) and its β‐CD homolog2, and compares them with their parent non‐substituted cyclodextrins. The molecular geometries, compared via statistical analysis of crystal structure data available, reveal1and2to be considerably more flexible than α‐and β‐CD, allowing wide variations in the tilting of the glucose units relative to the macrocyclic ring axes. The comparative evaluation of their contact surfaces not only discloses a substantial increase of the torus heights upon per‐O‐methylation (from ∼8.0Å in α‐ and β‐CD, to → 11.1Å in1and2), but also an enlargement of their cavity areas by 40% (+35Å2for α‐CD →1) and 70% (+75Å2for β‐CD →2), respectively. The hydrophobic characteristics of1and2, emerging from the molecularlipophilicitypatterns (MLPs) generated and projected onto the contact surfaces in color‐coded from, are inverse to those for α‐ and β‐CD: the most hydrophobic surface regions of1and2are located at the torus rims made up by the 2‐OMe and 3‐OMe groups at one side, and the 6‐CH2OMe moieties at the other, with a hydrophobic „band”︁ wrapping around the outside of the macrocycles; these „exo‐lipophilic”︁ topographies are opposed by pronouncedly hydrophilic central cavities. A variety of experimental findings can be rationalized on the basis of the opposite lipophilicity profiles of the CDs and their permethylated analogs, such as for example the opposite orientation of benzaldehyde,p‐nitrophenol, and 3‐iodopropionic acid in the cavities of α‐CD and of1. Thus, the notion is substantiated that the operation of dispersive interactions between guest and CD‐host cavities play a more dominant role in inclusion complex formation than hitherto appreciated.
The Starch Component of the Wood Parasite Cistanche deserticola Y. C. Ma
Authors: Naran Radna , Ebringerová Anna , Hormádková Zdena , Babor Karol 
Published: November 2006

AbstractStarch fractions have been isolated from the underground part of the parasite using hot water and alkali treatments, respectively. Chemical, enzymic and spectroscopic analyses as well as gel chromatography were used to characterize the starch fractions. Both hot water‐(HWS) and alkali‐extracted (AP) starch fractions contain amylose and amylopectin components in different proportions. The water soluble part of alkali‐extracted starch (APS) was well sparated by precipitation with cetyltrimethylammonium bromide into amylose and amylopectin compontents differing in the molecular weight. APS shows a larger contamination with cell wall constituents (protein, lignin, glucuronoxylan and pectin) in comparison with that of the other starch fractions.
Mechanische Modifizierung nativer und poröser Stärken durch Vermahlung zur Verwendung als Fettimitate. Teil 1: Eigenschaften nativer Stärken nach der Vermahlung im trockenen Zustand
Authors: Niemann Claudia , Meuser Friedrich 
Published: November 2006

AbstractZur Herstellung von modifizierten Stärken, die als Fettimitate fungieren können, wurden handelsübliche Stärken aus Mais, Weizen, Gerste, Wachsmais, Wachsgerste, Hafer, Sago und Palerbsen einer Prallmahlung oder Kugelschwingmahlung ausgesetzt. Die dadurch hervorgerufenen änderungen physiko‐chemischer Eigenschaften der Produkte, z.B. des Kaltwasserbindevermögens, der Kaltwasserlöslichkeit, des Grads der mechanischen Stärkeschädigung, des scheinbaren Amylosegehalts sowie der Partikelgrößen‐Verteilung wurden bestimmt. Die Prallmahlung hatte wenig Einfluß auf die physiko‐chemischen Eigenschaften. Die Kugelschwingmahlung bewirkte hingegen eine erhebliche Fragmentierung und Verformung der Stärkekörner. Entsprechend dem Grad der Fragmentierung und Verformung wurden die Kaltwasserbindeeigenschaften gezielt so verändert, daß die Vermahlungsprodukte Gele in kaltem Wasser bildeten, die stabil gegenüber Zentrifugalkräften und einer Gefrier‐Tau‐Behandlung, vergleichbar mit handelsüblichen Fettersatzstoffen, waren. Die Kriterien für die Verwendung mechanisch modifizierter Stärken als Fettimitate wurden ermittelt.
Kinetics of Starch Hydrolysis with Bacillus amyloliquefaciens‐α‐Amylase Under High Hydrostatic Pressure
Authors: Raabe Eduard , Knorr Dietrich 
Published: November 2006

AbstractKinetic studies on the isothermal pressure inactivation of Bacillus amyloliquefaciens α‐amylase (BAA) in Tris/HCl buffer and in 15.% (w/v) starch solution were performed at 25°C. The reaction rate of hydrolysis was studied at 25°C under high pressure conditions.The inactivation kinetics and the pressure dependence of the hydrolysis reaction could be described with a first‐order kinetic model. The activation volume of the enzyme inactivation reaction in 0.05M Tris/HCl buffer pH 7.2 was calculated as ‐28.4→2.2cm3/mole and in 1.5% (w/v) starch solution pH 7.2 the activation volume was ‐13.8→2.1cm3/mole. The difference of the activation volumes obtained confirm the protective effect of the substrate against pressure inactivation. The hydrolysis of starch was found to be retarded with increasing pressure and the resulting activation volume of the hydrolysis was +22.7→1.9cm3/mole. In preliminary studies the inactivation kinetics in buffer solution was found to strongly depend on the initial enzyme concentration.A high pressure pretreatment of the substrate resulted in no changes in the digestibility of the substrate.
Dynamic Simulation of a Simulated‐Moving‐Bed Chromatographic Reactor for the Inversion of Sucrose
Authors: Meurer Markus , Altenhöner Ulf , Strube Jochen , Untiedt Armand , Schmidt‐Traub Henner 
Published: November 2006

AbstractThe combination of a chemical or biochemical reaction and a chromatographic separation process in a single unit‐operation allows higher yields and a better separation performance not only for reversible decomposition reactions but also for irreversible reactions. A continuous Simulated‐Moving‐Bed (SMB) chromatographic reactor for the irreversible enzymatic inversion of sucrose is presented. In addition, a simulation based strategy for the design and optimization of chromatographic reactors is explained. Dynamic simulation studies using a rigorous model of the SMB process, illustrate the advantages of the continuous chromatographic reactor in comparison to conventional chromatographic processes for the inversion of sucrose. Reaching at least the same product purity as comparable conventional processes, the new reactor allows not only the reduction of capital costs but also a reduced desorbent rate and a higher productivity in terms of the converted amount of sucrose.
Modification of Microstructure of Starch Extruded With Selected Lipids
Authors: Bhatnagar Sandeep , Hanna Milford A. 
Published: November 2006

AbstractNormal corn starch was extruded with palm, peanut and coconut oils; myristic, stearic and behenic acids and three monoglycerides in a C. W. Brabender single screw laboratory extruder at 140°C barrel temperature, 140rpm screw speed and 22% moisture content. Microstructure of extrudates was studied using a scanning electron mircocope. The pore size distribution, pore volumes and shear strengths of the extrudates were also studied. Addition of lipids resulted in modification of pore size distribution and pore volumes depending on the type of lipid. Complexing lipids gave lower pore volumes, smaller size pores, lower porosities and higher shear strengths of the extrudates. Porosity correlated well with the shear strength values.
Production of Trehalose from Starch by Thermostable Enzymes from Sulfolobus acidocaldarius
Authors: Mukai Kazuhisa , Tabuchi Akihiko , Nakada Tetsuya , Shibuya Takashi , Chaen Hiroto , Fukuda Shigeharu , Kurimoto Masashi , Tsujisaka Yoshio 
Published: November 2006

AbstractThe optimum conditions for the production of trehalose from starch were investigated using two thermostable enzymes, maltooligosyl trehalose synthase (MTSase) and maltooligosyl trehalose trehalohydrolase (MTHase), from Sulfolobus acidocaldarius ATCC 33909. The optimum pH was 5.5 and the optimum temperature was 55—57°C using isoamylase from Pseudomonas amyloderamosa as a debranching enzyme. The addition of CGTase to the reaction mixture during the saccharification process caused an increase in trehalose and a decrease in maltose and maltotriose. Isoamylase was better than pullulanase as a debranching enzyme. The yield of trehalose was independent of the type of starch used. Under optimum conditions, the yield of trehalose from corn starch at 30% concentration was more than 82%.
A Comparative Study on Retrogradation of Rice Starch Gels by DSC, X‐Ray and α‐Amylase Methods
Authors: Kim Jeong‐Ok , Kim Wan‐Soo , Shin Mal‐Shick 
Published: November 2006

AbstractThe degree of retrogradation (DR) of 10 and 50% rice starch gels, which were stored at refrigerator, room temperature and freezer for 1, 3 and 6 days, were investigated by DSC, X‐ray diffractometry and α‐amylase‐iodine methods. Besides being affected by moisture content and storage conditions applied, the nonwaxy rice starch gels were retrograded faster and higher than the waxy ones. DR of 50% starch gels was higher than that of 10% starch gels. In case of 50% starch gels DR increased in the following order: refrigerated < room temperature < frozen. For 10% starch gels, no typical X‐ray pattern of the retrograded starch was shown, while DSC and α‐amylase‐iodine method gave information on DR of starch gels. Due to interpretative sensitivity of the data obtained, α‐amylase‐iodine method was suggested as an adequate mens for the DR of starch gels.
Preparation of Starch Succinates by Reactive Extrusion
Authors: Wang Linfu , Shogren Randal L. , Willett Julious L. 
Published: November 2006

AbstractThe succinylation of cornstarch by extrusion processing has been studied. Several different factors affecting the succinylation of starch were investigated including water content, succinic anhydride quantity, catalyst type and quantity, and reaction temperature. The degree of substitution (DS) increases with decreasing water content and increasing succinic anhydride quantity. Higher temperature favors higher DS using sodium bicarbonate as catalyst while the opposite is true using magnesium hydroxide as catalyst. Of the three catalysts used, sodium bicarbonate is best. Aqueous solubility and viscosity of the starch succinates tend to increase with increasing DS. Based on the results of aqueous solution viscosity, some samples appear to be promising as commercial thickening agent.
Effect of Hydrocolloids on Gelatinization and Structure Formation in Concentrated Waxy Maize and Wheat Starch Gels
Authors: Biliaderis C. G. , Arvanitoyannis I. , Izydorczyk M. S. , Prokopowich D. J. 
Published: November 2006

AbstractStarch‐hydrocolloid interactions were studied in concentrated (40% w/w starch) aqueous dispersions by differential scanning calorimetry and dynamic rheometry. At the levels commonly employed in food product formulations (1–2% w/w hydrocolloid on a starch basis), polysaccharides of varying molecular structures (xanthan, β‐glucan, arabinoxylan, guar gum) did not affect the gelatinization temperature of waxy maize and wheat starches. However, the hydrocolloids increased the phase transition temperature range (Tm‐Ti) and the melting enthalpy of starch crystallites, implying a stabilization of the granular structures during heating. There was also an enhancement in the crystallization rate of amylopection on aging gels at 5°C, the effect being more marked with the waxy maize starch gels. The most pronounced effect, however, has been the retardation of gelation kinetics of waxy maize starch by the hydrocolloids. The decrease in storage modulus (G′) development of amylopectin‐hydrocolloid gels was attributed to the interference of intermolecular associations among amylopectin molecules by the polysaccharide, which seems to be a prerequisite for establishment of a continuous network structure. In contrast, wheat starch gel rheology did not seem to be affected by the hydrocolloids.
Isolation and Partial Characterization of Starches from Dry Beans (Phaseolus vulgaris) and Chickpeas (Cicer arietinum), Grown in Sonora, Mexico
Authors: Yañez‐Farias Grelda A. , Moreno‐Valencia J. Gerardo , Falcón‐Villa Ma. del Refugio , Barrón‐Hoyos Jesus M. 
Published: November 2006

AbstractFor a better understanding of the carbohydrate components of Mexican dry legumes, in an attempt to suggest alternative processing, starches from dry beans (Phaseolus vulgaris var. pinto) and chickpeas (Cicer arietinum var. surutato) were isolated through sedimentation procedure. They were further characterized in their: physical characteristics of shape and size by light and Scanning Electron Microscopy (SEM); chemical characteristics by proximate analyses and amylose contents; functional characteristics of gelatinization temperature, viscosity and thermal properties by Differential Scanning Calorimetry (DSC); and nutritional characteristics, % digestibility. Starch in these two legumes was firstly isolated at over 85% recovery, with an amylose content of 52.4% and 46.5% for dry beans and chickpeas, respectively. SEM and light microscopy showed starch granules with a predominantly oval shape and size in the range of 20–25μ, for both legumes. Higher gelatinization temperatures were found for dry beans than for chickpeas. Similarly, fusion enthalpies and maximum gelatinization temperature were also higher for beans, as shown by DSC. However, chickpea starch gave a slightly higher % digestibility than bean starch. These results suggested that the difference in the amylose content, in both legumes, determine the starch granule structure, their intermolecular organization and their physical and functional characteristics.