bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies on the Susceptibility of Granular Cassava and Corn Starches to Enzymatic Attack. Part 2: Study of the Granular Structure of Starch
Authors: Franco Célia M. L. , Ciacco C. F. , Tavares Débora Q. 
Published: November 2006

AbstractThe starch granules remaining after enzymatic hydrolysis were analyzed. Enzymatic corrosion efficiency was related to granule diameter. The intrinsic viscosity of enzymatically treated cassava and corn starches was gradually lowered by hydrolysis. X‐ray analysis and observation under a polarizing microscope suggested that enzymatic corrosion must occur in amorphous areas of the granules. Scanning electron microscopy showed that, for cassava granules, enzymatic corrosion occured mainly at the surface. Corn starch granules displayed considerable surface corrosion, as well as deep radial corrosion channels.
Molecules to Granules: A Comprehensive Starch Review
Authors: Zobel H. F. 
Published: November 2006

AbstractThe molecular composition and physical aspects of starch structure are examined in relation to starch properties and utility. The structures and molecular properties of amylose and amylopectin are further considered for their effects on properties of starch granules and pastes, and whether or not they act independently or in concert with one another. Discussion of amylopectin focuses on models featuring clusters of short chain molecules that are interlinked and regularly spaced. Low and wide angle X‐ray diffraction studies are cited to confirm the cluster model and the role of amylopectin in starch crystallinity. The diversity of starch is evident by its depostion in one or more sites within a plant and by the variety of plants in which the starch is found. In addition, starches differ widely in size, shape and composition.
Molecular Structure of Corn Starch
Authors: Takeda Y. , Shitaozono T. , Hizukuri S. 
Published: November 2006

AbstractThe molecular structures of corn starches, which were prepared from kernels steeped in water, and sulfite and alkaline solutions, and a commercial product from kernels of the same source, were investigated. The amyloses obtained were small molecules (number and weight average degrees of polymerization, respectively: 930‐990, and 2270–2550), and comprised nearly equal numbers of branched (5.3 chains on average) and unbranched molecules. The amylopectins had average chain lengths of 21–22 and ß‐amylolysis limits of 58–60%. Their relatively high iodine affinities (1.05–1.25 g/100 g) and chain length distributions suggested the presence of long B‐chains with widely spaced side chains. All the starches showed similar structures, but their phosphorus contents (5‐122 ppm) varied with the steeping conditions.
Simultaneous Solid Phase Fermentation and Saccharification of Cassava Fibrous Residue for Production of Ethanol
Authors: Jaleel S. A. , Srikanta S. , Ghildyal N. P. , Lonsane B. K. 
Published: November 2006

AbstractA total of 16.5% reducing sugars in the saccharified pulp of cassava fibrous residue are achieved with the use of 30% slurry. The yield of ethanol was highest and the amount of residual reducing sugars was lowest with the use of 2.5% acid. The increase in dose of glucoamylase leads to improved yields of ethanol without any lowering in the residual reducing sugars. The ethanol yield and productivity were better and the residual reducing sugars were lower in solid phase fermentation as compared to the fermentation of liquid hydrolysate obtained by hydraulic pressing of the saccharified pulp. The slightly lower yield of ethanol in large batch static fermentation probably due to poor mass transfer and limited contact of yeast cells as well as enzyme with their substrates could be effectively overcome by employing appropriate strategies.
Effects of Attrition Milling on Air Classification Properties of Hard Wheat Flours
Authors: Sosulski F. W. , Nowakowski D. M. , Reichert R. D. 
Published: November 2006

AbstractEffects of attrition milling on yield and composition of air‐classified fractions from fifth break and first middling flours of HRS wheat were investigated using image analysis to characterize flour particle size distributions. Roller‐milled flours had high proportions of particles < 45 μ diameter but particles > 105 μm diameter constituted most of the flour volume. Attrition milling caused less starch damage than pin milling but increased the degree of reduction (<45 μm diameter), based on volume, from 10.3 to 100% for fifth break and from 6.9 to 100% for first middling flours. Two cuts on the air classifier produced a high protein fraction with high ash (30.5% protein, 41% starch, 2% ash, 14% moisture basis), which would have application as a gluten substitute in baking, and a medium protein fraction (14% protein, 66% starch, 0.65% ash) which could be blended into Bakers Patent. The major fraction of air classified middlings flour contained 6.5% protein, 77% starch and 0.3% ash.
The Properties of Glucoamylase Soluble and Immobilized on DEAE‐Cellulose. Part I. Kinetics and Thermodynamics of Enzyme Reaction
Authors: Przybyt M. , Sugier H. 
Published: November 2006

AbstractThe hydrolysis kinetics of starch and maltose solution with soluble and adsorbed on DEAE‐cellulose glucoamylase were examined. The observed changes of kinetic and thermodynamic properties of enzyme in the course of its immobilization were tried to be explained on the ground of conformation changes of glucoamylase and diffusion limitation of starch.
Insect‐Damaged Wheat – Effects on Starch Characteristics
Authors: Lorenz K. , Meredith P. 
Published: November 2006

AbstractDamage to the baking quality of wheat due to attack by insects has been reported in many countries. The insects responsible for the problem have been identified as Eurygaster integriceps and Aelia rostrata in Europe and the Near East and as Nysius huttoni in New Zealand. Damage to the protein in affected wheats in very apparent and damage to the starch seems possible. It was the purpose of this study to look for damage to the starch of wheat caused by specific insects.At the flowering stage of wheat, cages were placed over the wheat plots and different insects were introduced and kept in the respective cages until harvest. Starch was isolated from affected wheats for determination of physico‐chemical properties and functional characteristics. Scanning electron micrographs showed that starch granule damage due to insect attack can be severe. However, the damage was confined to a rather small area around the bite mark. This damage was not extensive enough to cause adverse effects on physico‐chemical properties of the starch. Bread baking potential of the starch was not significantly affected.
Chemical Factors Affecting Preparation of Carboxymethyl Starch
Authors: Hebeish A. , Khalil M. I. 
Published: November 2006

AbstractPreparation of carboxymethyl starch using chloroacetic acid and sodium hydroxide was investigated under different conditions. The carboxymethylation reaction was studied with respect to the degree of substitution (D. S.) of the carboxymethyl starch and the reaction efficiency (R. E.) of carboxymethylation variables studied included concentration of reactants and liquor ratio as well as reaction time and temperature. D. S. and R. E. were greatly enhanced by decreasing the liquor ratio. D. S. and R. E. increased also by increasing the reaction time. On the other hand, increasing the monochloroacetic acid concentration was accompanied by enhancement in the D. S. and decrement in the R. E., while both the D. S. and R. E. exhibited maximum values at 4N sodium hydroxide. The combined effect of increasing both monochloroacetic acid and sodium hydroxide concentrations was to bring about increased D. S. and decreased R. E. irrespective of the reaction temperature. Of particular interest were the results obtained at 100°C for 1 h; carboxymethyl starch of D. S. 0.436 with R. E. of ca. 79% could be achieved using solid reactants/liquor ratio of 1: 1.
The Properties of Glucoamylase Soluble and Immobilized on DEAE‐Cellulose. Part II. Thermostability of Glucoamylase
Authors: Przybyt M. , Sugier H. 
Published: November 2006

AbstractThe stability of glucoamylase as a catalyst of starch hydrolysis reaction against heat denaturation was examined for enzyme adsorbed on DEAE‐cellulose as well as in solution. The protective action of the substrate against inactivation of enzyme and the influence of the amount of enzyme adsorbed on its stability was studied.
Synthesis of Vinyl Polymer‐Starch Composites to Serve as Size Base Materials
Authors: Hebeish A. , El‐Alfy E. , Bayazeed A. 
Published: November 2006

AbstractStarch was polymerized independently with acrylamide, acrylic acid, methacrylic acid and acrylonitrile (AN) using potassium persulphate (K2S2O8) as initiator. The products of the polymerization reaction consisted of free starch, grafted starch, homopolymer and oxidized starch. The ratios of these composite constituents were found to differ considerably depending upon the nature of monomer as evidenced by differences in viscosity curves (amylograph‐viscograph) as well as sizeability of the composites and their ease of removal from cotton yarns during desizing. Also studied was the dependence of the extent of polymerization (grafting and homopolymerization) of AN to starch on K2S2O8 and AN concentrations, polymerization temperature, starch/AN ratio and starch + AN/liquor ratio; and the onset of these factors on the apparent viscosity of the composite obtained thereof. Results indicated that the extent of polymerisation increased by increasing the persulphate concentration to 6 g K2S2O8/100 g starch then levelled off; the same held good for apparent viscosity but the latter decreased upon using concentrations higher than 6 g K2S2O8/100 g starch. While the extent of polymerization increased over a range of 8‐32g AN/100 g starch, apparent viscosity decreased. Raising the polymerization temperature from 30 to 60°C caused significant enhancement in the extent of polymerization but with the certainty that maximum apparent viscosity was attained at 50°C. The extent of polymerization was much favoured at higher AN ratio, but maximum apparent viscosity was attained at starch/AN ratio of 83:17. On the other hand, the extent of polymerization decreased by increasing starch + AN/liquor ratio upto 1:75 then remained almost constant upto a ratio of 1:12.5; meanwhile maximum apparent viscosity was observed at a material/liquor ratio of 1:7.5. The results were interpreted in terms of differences in the magnitude of constituents of the poly (AN) ‐ starch composite and their affinity for and swellability in water.
Influence of Germination on Physico‐chemical Properties of Amaranth Flour and Starch Microscopic Structure
Authors: Paredes‐López O. , Cárabez‐Trejo A. , Pérez‐Herrera S. , González‐Castañeda J. 
Published: November 2006

AbstractA basic procedure was developed to germinate amaranth seeds (Amaranthus hypochondriacus). The “true” protein/total crude protein ratio decreased slightly after 36 h of germination. However, some of its rheological properties (e. g., farinographic and viscographic performances) were substantially improved by such simple treatment. Ultrastructural changes of the starch, as assessed by scanning electron microscopy, were also followed during this process. The smooth surface and dense packing of the starch in untreated seeds were outstandingly modified during germination. This procedure might contribute to widen the restricted food uses of this nutritious crop.
Extrusion Cooking of Cassava Starch for Ethanol Production
Authors: Grossmann M. V. E. , El‐Dash A. A. , Carvalho J. F. 
Published: November 2006

AbstractResponse surface methodology was used to study the effect of extrusion variables on gelatinization and viscosity of cassava starch with the aim to reduce energy consumption in alcohol production. None of the variables significantly affected the degree of gelatinization and moisture content of starch was the only significant variable affecting cold viscosity. Torque was affected by all the variables moisture being the most important. Extrusion was an efficient pre‐treatment for simultaneous saccharification and fermentation of cassava starch, resulting in 92.4% ethanol conversion. The best conditions for continuous process were: 100°C. 70 rpm, 4 mm die opening and 25‐27% moisture. For discontinuous process, when the extruded starch would be dried and ground 200°C, 190 rpm, 4 mm die opening and 20% moisture is recommended.
Presence of Starch/Protein Aggregates in the Endosperm of Corn
Authors: Goossens J. , Derez F. , Bahr K. ‐H. 
Published: November 2006

AbstractIt is common knowledge that the presence of so called “grits” and other structures in process streams of the corn wet milling process leads to starch yield losses by incomplete starch/gluten separation. The nature of these problematic structures was investigated by isolating them from the process streams and analysing their morphology by means of epifluorescence microscopy using specific dyes. Additional evidence was obtained by specific enzymatic degradation and subsequent microscopic observation. Using the same technique on thin cross sections from whole corn kernels, the location and source of these structures could be identified. Grits are dense particles from the horny endosperm, consisting of a three dimensional honeycomb like protein matrix filled with small starch granules. Many grits show the regular cell shape found in endosperm cells and are still enclosed by the fibrous cell wall. In other process streams, aggregates of protein lumps with trapped large and small starch granules occur frequently. A small fraction of fibrous material was also found to be enclosed in the protein matrix. These “sticky” aggregates often occur along with a large percentage of extremely small starch granules or fragments. Occasionally, very small “grits”‐like particles were present. Based on these findings, explanations can be found for the loss of starch and for the difficulties in the starch‐gluten separation stage in the industrial corn wet milling process.
The Development and Properties of the Tuber of the Potato (Solanum tuberosum) Part I: Variability of Tubers
Authors: Meredith P. , Meredith Peter 
Published: November 2006

AbstractA series of studies that show the great variability of tubers between plants and within one plant. “Twinning”, the tendency for a plant to bear several tubers of similar size, is introduced, and a relationship between size and specific gravity of tubers is shown briefly.
Sugar and Sucrose Ester Effects on Maize and Wheat Starch Gelatinization Patterns by Differential Scanning Calorimeter
Authors: Buck J. S. , Walker C. E. 
Published: November 2006

AbstractThe gelatinization of various starch‐sugar‐sucrose ester combinations was examined by differential scanning calorimetry. Onset and peak temperatures and enthalpy of maize starch were higher in all cases than of corresponding wheat starch samples (67.8°C. 71.6°C and 2.42 cal/g vs. 59.1°C, 63.5°C and 1.94 cal/g, respectively). The addition of any of the three sugars tested, sucrose. glucose and fructose. at 50% of the starch weight increased onset and peak temperatures but decreased enthalpy required for gelatinization.The addition of sucrose ester at 1 and 3% to the starches and starchsugar combinations affected both gelatinization temperature and enthalpy only in the case of the wheat starch/sucrose combination. With increasing ester concentration the onset and peak temperatures increased and the enthalpies decreased in this sample. This has interesting implications for the baking industry, which uses mainly wheat starch in combination with sucrose.
Effects of Hydroxypropylation on Themal Properties, Starch Digestibility and Freeze‐Thaw Stability of Field Pea (Pisum sativum cv Trapper) Starch
Authors: Hoover R. , Hannouz D. , Sosulski F. W. 
Published: November 2006

AbstractField pea starch with an amylose content of 34.2% was hydroxypropylated with propylene oxide and sodium hydroxide to give products with molar substitutions (MS) ranging from 0.04 to 0.12. Increasing the degree of MS resulted in progressive decreases in enthalpy of gelatinization. gelatinization temperatures, pasting temperatures and syneresis. and increases in paste viscosities at 95 and 50°C. The digestibility with a‐amylase decreased with increases in MS only up to the level of 0.08 and further increases in MS caused an increase in digestibility which was higher than that observed for native starch. These results were confirmed by scanning electron microscopy on hydrolyzed starch.
Hydrolytic Depolymerization of Starch Raw Materials
Authors: Abraham T. Emilia , Krishnaswamy C. , Ramakrishna S. V. 
Published: November 2006

AbstractThe common commercially available starchy sources in India namely cereals like wheat, corn, rice, sorghum were taken for the studies and compared with cassava. Starches from various sources need different type of liquefaction and saccharification procedures. The relative depolymerization procedures with viscosity and oligosaccharide profiles are reported. Rice flour gives very good conversion percentages, but the liquefaction step should be more drastic than other starchy raw materials. Wheat flour, maize flour, and maize starch could be hydrolysed by both acid‐enzyme and enzyme‐enzyme methods to give good conversion rates. Sorghum starch was found to be most difficult to hydrolyse and gave only 84% conversion.
Dextrose Equivalent Measurements on Commercial Syrups
Authors: Delheye G. , Moreels E. 
Published: November 2006

AbstractThe difficulties in the calculation of the dextrose equivalent of industrially prepared syrups from HPLC and Freezing Point Depression measurements arise from the unknown molecular weight distribution of the oligo‐ and polysaccharides. We therefore investigated the influence of the molecular weight distribution of acid‐enzymatic, enzymatic‐enzymatic prepared syrups on the results of the Lane‐Eynon oxydation‐reduction titration, HPLC and Freezing Point Depression measurements.
The Interaction Between Cibacron® Blue 3G‐A Dyed Amyloses and Microcrystalline Cellulose
Authors: Stevenson D. L. , Kennedy J. F. , White C. A. 
Published: November 2006

AbstractIt has been shown with the aid of chemical analysis, gel permeation chromatographic analysis of malto‐oligosaccharide mixtures produced by the action of α‐amylase (1, 4,‐α‐D‐glucan glucanohydrolase, E. C. 3. 2. 1. 1.) and photomicroscopy, that dyed amylosic fragments, produced by the conventional action of α‐amylase on Cibacron® Blue 3G‐A dyed amylose substrates, can become adsorbed by microcrystalline cellulose. The adsorption occurs between the aromatic residues of the dye molecule and the surface of microcrystalline cellulose, and only when the amount of solubilisation of the dyed amylose substrate is high. Thus, under these circumstances erroneously low values for α‐amylase activity will be obtained when using such a chromogenic substrate due to adsorption of soluble dyed fragments onto the surface of microcrystalline cellulose, thereby escaping detection. When α‐amylase levels are low, thereby causing little solubilisation of the dyed substrate, as is frequently the case in clinical chemistry, the amount of absorption cannot be detected and therefore the use of microcrystalline cellulose as a tablet binder to facilitate the routine use of these dyed amylose chromogenic substrates is permissible.
Production of a Novel Inulin Fructotransferase (DFAI producing) by Arthrobacter globiformis S14‐3
Authors: Seki K. , Haraguchi K. , Kishimoto M. , Kobayashi S. , Kainuma K. 
Published: November 2006

AbstractA microorganism producing a novel inulin fructotransferase was isolated from a soil sample. The enzyme converted inulin into di‐D‐fructofuranose 1,2':2,1' dianhydride (DFAI) and a small amount of oligosaccharides. Through taxonomical studies, the microorganism was identified as Arthrobacter globiformis S14‐3. The method for preparation of DFAI from inulin was investigated and established. The enzyme showed maximal activity at pH 6.0 and 40°C. The enzyme was stable up to 70°C at pH 6.0.
New Carbohydrate Derivatives from Biotechnical and Chemical Processes
Authors: Röper H. , Koch H. 
Published: November 2006

AbstractStarch, its derivatives and hydrolysis products are well established as industrial products for the food and technical industries. More advanced products, based on starch, are available today, manufactured by biotechnical and chemical processes. They comprise a variety of monomeric compounds like polyols, hydroxycarboxylic acids, glycosides and their derivatives obtained by esterification, etherification and amination. In addition, interesting oligomeric and polymeric products are accessible, based on starch and its derivatives. Selected examples of these products are described as well as their respective production methods. For some products the chemicals synthesis will be compared with the fermentation route, analysing the relative advantages and disadvantages of both. The wide application potential of these “new” products is illustrated with reference to their use in different industries, e. g. in the manufacturing and processing of resins, polymers, detergents, cosmetics, pharmaceuticals and processed foods. Special emphasis will be given to the structural peculiarities of these carbohydrate derivatives, for example chirality, which enables them to act as unique intermediates in the production of biologically active products.
Synthesis of O‐Glycopeptiden
Authors: Paulsen H. , Adermann K. , Merz G. , Schultz M. , Weichert U. 
Published: November 2006

AbstractGlycosyl halides of 2‐azido‐2‐deoxy‐D‐galactose derivatives can be selectively coupled to α‐glycosides with the hydroxyl groups of L‐serine and L‐threonine derivatives. Using adequate protecting groups further reactions with any amino acid are possible with the obtained carbohydrate amino acid compounds after the deprotection of the N‐ or C‐terminus. Among others examples from the field of glycophorines and interleukine‐2 are described. This method is also suitable for the synthesis of glycopeptides on solid support.
Perspektiven für zuckerhaltige Amphiphile mit Amid bindung
Authors: Pfannemüller Beate 
Published: November 2006

AbstractFür die Herstellung von zuckerhaltigen Amphiphilen ist die Amidverknüpfung der präparativ einfachste Weg. Durch Reaktion der Aldonsäurelactone von Glucose und Maltose mit Alkylaminen, bzw. der N‐(2‐aminoethyl)aldonamide mit Fettsäuren im Bereich c6‐C20 wird die molekulare Struktur und die hydrophil‐hydrophobe Zusammensetzung systematisch variiert. Es wurden Produkte mit ein oder zwei nicht substituierten Amidbindungen sowie N‐methylierte Produkte hergestellt.Aufgrund der starken Wasserstoffbindungen zwischen den Amidbrücken und den Zuckerkopfgruppen im hydrophilen Teil bilden sich in wäßriger Lösung hochgeordnete Aggregate: (a) Stabile Monolayer (C12‐C20), die für die Herstellung von technischen Membranen geeignet sind; (b) Gele aus verdünnter Lösung (C6‐C10), die nach elektronenmikroskopischen Untersuchungen aus einem lockeren Netzwerk von regelmäßig vertwisteten helicalen Strängen bestehen; (c) Lyotrop flüssig‐kristalline Phasen in konzentrierteren Lösungen, besonders ausgeprägt bei den N‐methylierten Proben (C10), oder Produkten mit einer Disaccharid Kopfgruppe und längeren Alkylkette (C16‐C18). Im letzteren Fall dominiert der Einfluß der hydrophoben Wechselwirkung zwischen den Alkylketten.Die Versuche geben ein Beispiel, wie man die Eigenschaften von Produkten für verschiedene Anwendungsbereiche durch chemische Modifizierung nach Wunsch einstellen kann. Man erkennt ebenfalls, welch wichtige Rolle die Zuckerkopfgruppen der Glycolipide in biologischen Systemen spielen.