bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gelatinization and Solubility Properties of Commercial Oat Starch
Authors: Mua John‐Paul , Jackson David S. 
Published: November 2006

AbstractGelatinization and solubility characteristics of starch contribute to unique functionality in foods. Corn and oat starch viscoamylographs (35g db) showed peak viscosities of 400 and 390B.U., respectively. Oat starch had a more rapid (89.7 vs 85.6°C) and higher set back (790 vs. 740B.U.) than corn. Data on soluble components of cooled (85°C) starch pastes, as collected and analyzed by high‐performance size exclusion chromatography (HPSEC), suggest that amylopectin plays a significant (P<0.05) role in oat paste set back; for corn starch, amylose is the dominant factor. Solubilities and apparent molecular weights (MW) of oat starch heated (65‐120°C) under shear and subsequent sonication (0‐40s) in water or 90% methyl sulfoxide (DMSO) were also determined by HPSEC. An intermediate MW fraction was eluted on the HPSEC chromatograms only when oat starch was heated in water (100‐120°C/30min) or DMSO and sonicated, suggesting that this fraction may not be inherent in the native granule. in water, polymer solubility and peak MW increased with temperature (65‐120°C), whereas in DMSO, solubility decreased with heating (65‐100°C), while peak MW remained basically constant. Aqueous (aq) leaching at 75°C solubilized more corn amylose than amylopectin, but amylopectin and amylose co‐leached from oat starch granules. Aq leaching, at 20°C above their DSC peak ends (85 and 95°C for oat and corn, resepctively), showed more amylopectin leached from oat starch granules whereas more amylose was leached from corn starch granules.
The Effects of Extrusion Conditions on the Physical Properties of Wheat Flour Extrudates
Authors: Ryu G. H. , Walker C. E. 
Published: November 2006

AbstractThe effects of extrusion conditions (feed moisture content and rate, process temperature, screw speed and geometry, and die diameter) on expansion ratio, bulk density, and breaking strength of wheat flour extrudates were investigated. Extrudate samples were prepared by using a Brabender single‐screw extruder. Higher feed moisture content and process temperature were required for proper expansion. At 3.18mm die opening, the relationship between expansion and bulk density was positive. Feed rate was the most effective factor for increasing bulk density. Breaking strength was significantly decreased with increasing process temperature.Under extrusion conditions of 22% feed moisture, 110g/min feed rate, 160°C process temperature, and 130rpm screw speed with 5:1 CR, wheat flour was puffed with low bulk density and breaking strength.
Effect of 1B/1R Translocation in Wheat on Physical and Chemical Properties of Starch
Authors: Burnett C. J. , Lorenz K. J. , Carver B. F. 
Published: November 2006

AbstractStarches were isolated from near‐isoline pairs of 1B/1R translocation wheats and their parents for determination of water binding capacity, swelling power, solubility, Amylograph viscosity, scanning electron microscopy, differential scanning calorimetry and bread baking characteristics.Translocation wheats had a statistically lower starch yield. The starches of these wheats had a lower swelling power at 60° and 80° and a reduction in Brabender viscosity after a 15 min holding period when compared with control starches. Texture scores of breads baked with starches from translocation wheats were better than those of control breads.
Nuclear Magnetic Resonance Spectroscopy of Pullulan and Isomaltose: Complete Assignment of Chemical Shifts
Authors: Arnosti Carol , Repeta Daniel J. 
Published: November 2006

AbstractOver the past decade, advances in nuclear magnetic resonance spectroscopy (NMR) and increased availability of NMR spectrometers have led to the application of NMR to a wide range of problems in many fields, including environmental chemistry. Complete assignment of carbon and proton resonances is a prerequisite for using NMR spectroscopy to monitor changes in chemical structures during the course of biochemical and biological experiments. Several corrections and additions to previously published 13C chemical shifts of pullulan and isomaltose are reported here. In addition, the 1H assignments of isomaltose are presented.
Complexes of Starch with Dioic Acids
Authors: Tomasik P. , Wang Y.‐J. , Jane Jay‐Lin 
Published: November 2006

AbstractAttempts are presented for the preparation of complexes of starch with a series of dioic acids (oxalic, malonic, succinic, glutaric and adipic). The complexes are isolated and characterized by potentiometric titration, powder X‐ray diffraction, characteristics of gelation and differential scanning calorimetry. These complexes contain dioic acids on the level of 1−3g per 1g of starch. Oxalic acid forms a surface complex with crosslinking involving both its carboxylic groups. Malonic acid forms surface complex with involvement of only one of its carboxylic groups and all three succinic, glutaric and adipic acids form inclusion complexes.
Gamma Radiation‐Induced Graft Copolymerization of Acrylonitrile Onto Sodium Salt of Partially Carboxymethylated Amylose
Authors: Patel Bipin K. , Sinha Vijay K. , Patel Chandrakant P. , Misra Bhupendra Nath , Trivedi Harikrishna C. 
Published: November 2006

AbstractThe graft copolymerization of acrylonitrile onto Sodium salt of Partially Carboxymethylated Amylose (Na‐PCMA, DA=0.313) in aqueous and in water: methanol mixed solvents system has been studied using gamma rays from Co60source as a means of initiation by the mutual method. The optimum condition for affording maximum percentage of grafting of acrylonitrile onto Na‐PCMA has been obtained by varying different reaction parameters such as total dose, monomer concentration, amount of water and composition of solvents system. The mechanism of grafting has been postulated. The resulting graft copolymer has been characterized by chemical, spectroscopic, thermogravimetric and scanning electron microscopic methods.
Concentrated Water Solution of Salts as Solvents for Reactions of Carbohydrates. Part 1: Reactions of Glucose Promoted by Concentrated Solutions of Alkaline and Alkaline Earth Metal Salts
Authors: Tyrlik Stanislaw K. , Szerszen Dorota , Kurzak Barbara , Bal Karol 
Published: November 2006

AbstractSaturated water solutions of selected alkaline and alkaline earth metal salts have been studied whether or not they catalyze the formation of levulinic acid from glucose. The most active was a solution of magnesium chloride. Activity was further increased in the system (MgCl2+H+).We observed complete inhibition of this reaction by NO3−. Contrary to the generally accepted opinion that formation of hydroxymethylfurfural is only H+ catalyzed, we observed activity of the system formed from MgO and MgCl2 when one starts from glucose. (MgCl2+ MgO) in water is alkaline.
Amylose is not Strictly Linear
Authors: Curá José Alfredo , Jansson Per‐Erik , Krisman Clara R. 
Published: November 2006

AbstractAmyloses from selected corn starches were used to measure the glucoses involved in the branching points. The number of glucose α 1,6 glycosidically linked were determined by two different methods: 1) The enzymatic one measures directly quantiatively and specifically the glucoses α, 1,6 linked. 2) The other, a chemical one that measures the different n‐methylated glucoses involved in the terminal, α 1,4 linked and α1,6 linked positions.The results obtained through both methodologies clearly indicate a good correlation. Amylose is not linear. It has very small proportion of branches and they are α1,6 glycosidically linked.
Electrochemical Synthesis of Polysaccharide‐Protein Complexes. Part 1: Preliminary Studies on Apple Pectin‐Albumin Complexes
Authors: Dejewska A. , Mazurkiewicz J. , Tomasik P. , Zaleska H. 
Published: November 2006

AbstractSolid complexes of apple pectin with egg albumin could be prepared from their aqueous solutions in the 12V gradient of potential on the stainless steel electrodes. The complexes were separated as a gel on anode. The composition of the complexes was dependent on the component ratio in solution and practically independent of pH of solution which varied from 4 to 11.6 within 90 min process.
Effect of the Heat‐Moisture Treatment on the Enzymatic Susceptibility of Corn Starch Granules
Authors: Franco Célia M. L. , Ciacco César F. , Tavares Débora Q. 
Published: November 2006

AbstractNormal and waxy corn starches were isolated, adjusted to different levels of moisture and heated at 100°C for 16h. The heat treated starches were hydrolysed with α‐amylase and amyloglucosidase. The starch samples were studied by determining their water‐binding capacity, pasting properties, X‐ray diffraction and by optical and scanning electron microscopy. The results showed that the heat‐moisture treatment produced an increase in the degree of crystallinity of normal and waxy corn starches at the level of 18% moisture. This result, in conjunction with a significant decrease in the enzymatic susceptibility, suggested a rearrangement of the starch molecules with strengthening of the linkages within the granules. On the other hand, the heat‐moisture treatment caused a rupture with further rearrangment of linkages within the granules for normal and waxy corn starches adjusted to the 27% moisture level. This produced a certain degree of starch degradation increasing the accessible regions of the granule to amylolysis.
Polymorphic Transitions of Amylose‐Ethanol Crystalline Complexes Induced by Moisture Exchanges
Authors: Le Bail P. , Bizot H. , Pontoire B. , Buléon A. 
Published: November 2006

AbstractVh‐type crystals were prepared by precipitation in pure alcohol of amylose solutions in dimethyl sulfoxide (DMSO). The respective influences of amylose chain length and final equilibrium relative humidity (E.R.H.) on the nature of transitions induced by moisture exchanges were studied extensively using X‐ray diffraction. The nature and kinetics of observed transitions depend on amylose chain length. If the Va form is always observed upon dehydration, A, B or mixtures of A and B forms are obtained according to the amylose chain length when rehydrating over higher water activities. Other specific transitions occurred when the Vh material was preliminary crystallized in mixture of ethanol and water (80/20,v/v). Some results suggest that these transitions occur through a transient disappearance of crystallinity and subsequent reorganization. Such mechanisms would be more conceivable than a solid state conversion from a single helical conformation (Vh type) to a double one (A and B types).
Starch Damage Part 1: Characterisation of Granule Damage in Ball‐milled Potato Starch Study by SEM
Authors: Baldwin Paul M. , Adler Jeremy , Davies Martyn C. , Melia Colin D. 
Published: November 2006

AbstractScanning electron microscopy (SEM) has been used to classify and quantify the types of damage evident in a population potato starch granules following ball milling. Whilst the majority of granules remained undamaged, a significant (p<0.01) increase in the number of granules with localized damage was observed (1.6% to 15.1%). A variety fo types of localised damage were discernable, ranging from areas where small amounts of granule surface material had been removed, to large areas possessing coarse surfaces caused by extensive removal of material. The generation of this latter category termed ‘rough faces’, was the most significant and predominant change following ball milling (p <0.05). Ball‐milling was therefore attributed to the penetration of an outer granule layer, via the removal of surface material at existing points of weakness. This produced rough, disrupted areas of the granule surface, which are more likely to be susceptible to hydration and enzyme attack.
Starch Damage Part 2: Types of Damage in Ball‐milled Potato Starch, upon Hydration Observed by Confocal Microscopy
Authors: Adler Jeremy , Baldwin Paul M. , Melia Colin D. 
Published: November 2006

AbstractConfocal fluorescent microscopy was used to classify the types of damage in native and ball milled potato starch granules on the basis of their response on hydration. Damage to individual granules at room temperature was assessed using the integrity of the maltese cross and with two fluorophores, congo red and acridine orange. A variety of types of damage were found, ranging from granules that appeared physically intact with localised congo red fluorescence and a corresponding deficit in the maltese cross, to granules that had ‘exploded’, as hydration of the core ruptured the granule, leaving the outer layers of the granule split but ostensibly intact. Also found were granules with obvious fractures and apparently intact granules with fluorescent areas which sometimes exuded a puff of fluorescing material. When hydrated at room temperature the interior of granules sometimes forms a gelatinous mass while the exterior of the granules remained virtually unaffected. The differentiation of the outer layers of the potato starch granule from the inner layers suggests a macroscopic model of granule structure comprising an outer layer, that is resistant to both damage and gelation, covering a less resistant interior.
Structural and Physicochemical Changes of Potato Starch Along Periodate Oxidation
Authors: Veelaert S. , Polling M. , De Wit D. 
Published: November 2006

AbstractDialdehyde starches were prepared by oxidation with periodate. The influence of the degree of oxidation of the dialdehyde starch on its microstructural and physicochemical properties such as crystallinity, granular structure, complexing capacity with iodine and lysolecithine and water absorption are discussed. Oxidation appears to cause a gradual decrease of any microstructure, meanwhile water absorption is observed to be maximal at intermediate degrees of oxidation. A structure‐swelling relationship has been developed and compared with the washing efficiency during purification.
Determinatin of the Degree of Cationicity in Cationic Starches by Solid‐State 13C NMR Spectroscopy
Authors: Killinger William E. , Murray Daniel , Hatfield Galen R. , Hassler Thord 
Published: November 2006

Abstract13C solid‐state NMR is presented as a rapid and accurate method for determining the degree of substitution in cationic starches. Data are presented for four cationic starches where the cationizing agent is a trimethyl‐substituted quarternary amine. Using a rigorous quantitative approach, NMR determined DS values can be obtained that fall within ±0.01 DS units of those obtained by traditional wet chemical methods. By employing average relaxation parameters, the analysis time can be reduced to roughly one hour at the expense of an increase in uncertainty to only ±0.03 DS units.
Gelatinization of Starch in Aqueous Alkaline Solutions
Authors: Ragheb A. A. , Abdel‐Thalouth I. , Tawfik S. 
Published: November 2006

AbstractThe effect of kind and concentration of alkali on the gelatinization of maize, rice and wheat starches were thoroughly investigated. No gelatinization could be observed on using the carbonate and/or bicarbonate of sodium and potassium even on using their saturated solutions, while both sodium and potassium hydroxides undergo gelatinization. Gelatinization of starch occurs immediately at a concentration of sodium hydroxide of 1.2%, while clear gelatinized pastes could be obtained at 4% or more. Infra‐red spectra of maize and rice starches before and after alkali treatment reveal that treatment of starch with sodium hydroxide is accompanied by some physicochemical changes in the structure of starch. The rheological properties as well as the apparent viscosity of the gelatinized starch pastes depend on the kind of starch as well as the nature and concentration of alkali used.
Formation of Maize Starch Gels Selectively Regulated by the Addition of Hydrocolloids
Authors: Eidam Dirk , Kulicke Werner‐Michael , Kuhn Klaus , Stute Rolf 
Published: November 2006

AbstractNative maize starches containing amylose are used for manufacturing gels in food technology at concentrations of about 7%. Depending on the pasting conditions chosen, several hours may be required for the final consistency to be attained. For this reason the influence of hydrocolloids was investigated with economic factors dictating an effective concentration of approximately 5% in terms of the pure starch. The gelation process was monitored quantitatively by means of rheomechanical oscillation measurements in the linear viscoelastic range. The substances investigated were polysaccharides with chemically similar structures and classified as safe under foodstuff regulations: guar gum, locust bean gum, x‐carrageenan, t‐carrageenan, xanthan and carboxymethylcellulose (CMC). The gelation process can be significantly accelerated by a range of hydrocolloids, with the effect decreasing as follows: CMC > locust bean gum > guar gum > x‐carrageenan > xanthan. The mixtures achieved between 45% and 80% of the final gelation stability of pure starch of 100Pa. The gelation process is clearly retarded by the hydrocolloid t‐carrageenan. With the aid of the rheological data it is possible to correlate the influence of the hydrocolloids on the process of self‐aggregation and also on the resulting viscoelastic properties of the mixed gels with one another. In terms of a molecular interpretation it is possible to distinguish between exclusion effects and specific interactions in the functioning of the hydrocolloids.
Modifications in the Phenolphthalein Method for Spectrophotometric Estimation of Beta Cyclodextrin
Authors: Goel Anuj , Nene Sanjay N. 
Published: November 2006

AbstractThe phenolphthalein solution used in the assay of β‐Cyclodextrin is not stable and undergoes spontaneous decolorization. There is linear decrease in absorbance of phenolphthalein with time. This causes a continuous increase in error with time which is as high as 80% after one hour. A simple procedure is described in the paper to circumvent this problem allowing reproducible and reliable results to be obtained. A single reagent assay was developed by incorporating phenolphthalein in Na2CO3 solution. This resulted in stable absorbance readings and increased the linearity of assay up to 200μg/ml of β‐cyclodextrin.
The Influence of Acid Hydrolysis of Potato Starch on the Stress‐Strain Propoerties of Thermoplastic Starch
Authors: van Soest J. J. G. , Benes K. , De Wit D. 
Published: November 2006

AbstractPotato starch has been hydrolysed lowering the molecular mass. The influence of starch molecules mass on the mechanical properties of thermoplastic starch has been investigated. Acid hydrolysis was performed with hydrochloric acid in various concentrations and time spans. Acid hydrolysis of the granular potato starch decreased both the molecular mass of amylose and amylopectin. The thermoplastic materials have been made by extrusion processing of the various starches with fixed amounts of water and glycerol.The stress‐strain properties showed to be influenced by molecular mass. The materials were rubbery at 20°C and 60% relative humidity. Although the tensile stress did not change significantly, the elastic modulus increased with an decrease in molecular mass. This increase was explained by differences in starch structure and morphology. The higher of the low molecular mass materials could result in a more rapid starch structural ordering. The elongation and tearing energy increased with incrasing molecular mass. Theses effects were explained by the higher amylose chain length and amylopectin endgroups chain length resulting in a more entangled polymer matrix.
Gelatinization of Thermally Treated Starch Mixed with Sodium Hydroxide in the Solid State
Authors: Ragheb A. A. , Abd El‐Thalouth I. , Tawfik S. 
Published: November 2006

AbstractThe effect of thermal treatment on maize starch mixed with different amounts of sodium hydroxide, in the solid state, on its gelatinization was thoroughly investigated. Besides, the rheological properties of the products which undergo gelatinization by addition of water at room temperature after treatment were also investigated. It was found that gelatinization of thermally treated starch with sodium hydroxide in the solid state starts only at a ratio of alkali: starch of 1:10 or more regardless of the temperature of treatment.The rheological properties as well as the apparent viscosity at various rates of shear were found to be dependent on both the temperature of treatment an the sodium hydroxide: starch ratio. Storing of the thermally treated gelatinized starch pastes for 7 days is accompanied by a remarkable increase in their apparent viscosity at any specific rate of shear which may be due to the effect of sodium hydroxide on starch during storing.
Determination of Amylose in Cereal and Non‐Cereal Starches by a Colorimetric Assay: Collaborative Study
Authors: Martinez Cristina , Prodolliet Jacques 
Published: November 2006

AbstractAn improved colorimetric method, based on the well‐known reaction between amylose and iodine, is described. Native starch is dissolved in ureadimethylsulfoxide and the resulting solution defatted with ethanol. An aliquot of the lipid‐free solution is then reacted with iodine and the absorbance of the blue‐coloured amylose‐iodine complex measured, thus determining the iodine‐binding capacity of starch (Blue Value). A collaborative study was conducted, according to official guidelines, to determine the method's repeatability and reproducibility: 8 participants were each sent 8 starch samples from different botanic origin for duplicate analysis. Statistical evaluation of the results gave good precision results, with an average repeatability relative standard deviation of 2.1% and an average reproducibility relative standard deviation of 5.6%. The method is, therefore, suitable to determine precisely the amylose content of native starch.
Determination of Amylose in Flour by a Colorimetric Assay: Collaborative Study
Authors: Martinez Cristina 
Published: November 2006

AbstractAn improved colorimetric method, based on the well‐known reaction between amylose and iodine, is described. During a first step, flour is dissolved in dimethylsulfoxide and the starch precipitated with ethanol. The extracted starch is redissolved in urea‐dimethylsulfoxide and the resulting solution defatted with ethanol. An aliquot of the lipid‐free solution is then reacted with iodine and the absorbance of the blue‐coloured amylose‐iodine complex measured, thus determining the iodine‐binding capacity of starch (Blue Value). A collaborative study was conducted, according to official guidelines, to determine the method's repeatability and reproducibility: 9 participants were each sent 7 flour samples from different botanic origin for duplicate analysis. Statistical evaluation of the results showed satisfactory precision, with an average repeatability relative standard deviation of 2.6% and an average reproducibility relative standard deviation of 9.1%. The proposed method can, therefore, be considered as reliable and can be used for routine analysis.
Effect of Talc on Properties of Corn Starch Extrudates
Authors: Bhatnagar Sandeep , Hanna Milford A. 
Published: November 2006

AbstractCommercially available 0, 25, 50 and 70% amylose corn starches were extruded with up to 5% talc {(OH)2Mg3(Si2O5)2} in a single screw Brabender laboratory extruder at 18% moisture content, 140°C barrel temperature, and 140rpm screw speed. Expansion ratio, unit density, percentages of closed and open pores, porosity and molecular degradation of extruded starches were measured.Addition of talc resulted in decreases in expansion ratio, unit density and percentage of open pores, and in increases in percentage of closed pores and porosity of extrudates. The extrudates became smaller with a greater number of round and uniformly sized cells with added talc. Gel permeation chromatographic fractionation of extrudates showed extensive degradation of fraction I with increasing talc concentrations. The talc appeared to have provided nucleation sites for water vaporization as the material exited the die of the extruder.