bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of Thermal and Viscoelastic Properties of Four Waxy Starches and the Effect of Added Surfactant
Authors: Gudmundsson M. , Eliasson A.‐C.
Published: November 2006

The waxy starches used in this investigation (maize (WM), barley (WB) and two rice starches RD4 and IR29) showed different gelatinization temperatures (GT) and enthalpies (ΔHG) measured with differential scanning calorimetry (DSC). The differences in GT and ΔHG could only partially be related to X‐ray crystallinity. The high GT waxy starches WM and RD4 retrograded to a greater extent measured with DSC and the order of increased retrogradation agreed well with the order of X‐ray crystallinity of the retrograded waxy starches. The melting temperature (TC) of the retrograded waxy starches in contrast to GT was very similar for all starches. This indicates that the temperature of the glass transition (Tg) of the amorphous regions in the starch granules controlled the onset GT and perhaps also the extent of retrogradation.

Addition of cetyl trimethyl ammonium bromide (CTAB) decreased the extent of retrogradation more than 45% compared to the melting enthalpy (ΔHC) of the waxy starches without CTAB addition. The rice starch RD4 was most affected by the CTAB addition, and the WM starch the least. The viscoelastic behaviour in the temperature interval 25–90°C of 12%(w/w) gels differed between the waxy starches. The WB starch gels showed the highest storage modulus (G′) value and the lowest phase angle (δ), i. e. strongest and least viscous gels. The WM starch gels showed the lowest G′ value and the highest δ. The rice starches were in between with the RC4 starch (high GT) showing higher G′ value and lower δ than the IR29 (low GT). The viscoelastic parameters changed only slightly with increased temperature.

The addition of CTAB to the waxy starch gels changed the viscoelastic behaviour of the stronger and less viscous starch gels of the WB and RD4 as their G′ value decreased and δ increased with increased temperature. The effect on WM and IR29 was only small.
Changes of Carbohydrates and Molecular Structure of Dextrins During Enzymatic Liquefaction of Starch
Authors: Nebesny Ewa
Published: November 2006

Investigations of potato starch hydrolysis during bacterial α‐amylase “Amylogal CS” liquefaction to a different dextrose equivalent were carried out at 85deg;C and pH 6,5. DE‐values, carbohydrate compositions and molecular structure of dextrins were investigated in starch hydrolyzate samples taken at DE‐values from 3.4 to 20.6. In the progress of liquefaction, that is at increasing DE‐values, changes in carbohydrate compositions, and there the decrease only of maltoheptaose and dextrins content in hydrolyzate were observed. Simultaneously, it was found that molecular weight and number of dextrin branchings decreased particularly rapidly to a significant degree of nearly 3.4 DE. At further increase of DE‐value during starch liquefaction the decrease of dextrins molecular weight and the number of branchings was lower and not that significant.
Developmental Changes in Properties of Sweet Potato Starches
Authors: Noda T. , Takahata Y. , Nagata T.
Published: November 2006

Sweet potato starches extracted from two varieties at different stages of development were investigated for various physicochemical properties. Average granule size increased in the early stage of development. The amylose content calculated from the blue value (BV) remained almost constant. The onset temperature (To) determined by differential scanning calorimetry (DSC) was lowest in the latest stage of development. The heat of gelatinization (ΔH) was lowest in the earliest stage of development. Digestibility by two glucoamylases tendet to be lower in the later stage of development.
Effect of Acid Hydrolysis and Ball Milling on Porous Corn Starch
Authors: Niemann Claudia , Whistler Roy L.
Published: November 2006

Porous corn starch from glucoamylase hydrolysis of native corn starch was examined before and after cross‐linking, acid hydrolysis and dry ball milling. Cross‐linking does not significantly change the crystallinity, water absorption or gelatinisation properties but acid hydrolysis at 60°C increases, proportionately, crystallinity and water absorption capacity and decreases moisture adsorption at humidities less than 80%, in comparison to untreated porous corn starch. Highly crystalline porous starch has a fragile granule structure. Ball milling destroys crystallinity in both normal, porous, and cross‐linked or partially hydrolyzed starches. Particle sizes of 1–2m are obtained by milling dry starches for 48 h. Water absorption for milled starches is more than 200% (weight water/weight starch d.b.). Viscosities of these products were significantly reduced at high temperatures. Products formed stable gels in 25–30% dispersions in cold water.
Systematische GC/MS‐Analyse von 1,2‐O‐Ethylenglucose‐Derivaten in Hydrolysaten von Hydroxyethylstärke
Authors: Hildebrand Ulrich , Cech Franz , Rupp Daniela , Sommermeyer Klaus
Published: November 2006

In den Hydrolysaten von Hydroxyethylstärke konnten nach Persilylierung 16 verschiedene 1,2‐O‐Ethylen‐D‐Glucose‐Derivate mittels GC/MS nachgewiesen und identifiziert werden. Neben den üblichen Fragmenten silylierter Verbindungen bilden diese Derivate vier sehr signifikante lonen (m/z 86, 127, 229 und 227), die zur Erkennung der bicyclischen intramolekularen Glucosidierungsprodukte neben monocyclischen Hydroxyethylglucose‐Derivaten und zur Isomeren‐ und Anomeren‐Unterscheidung gut geeignet sind. Das typische Fragmentierungsverhalten persilylierter 1,2‐O‐Etn‐Glc‐Derivate wird beschrieben und die Ergebnisse durch den Vergleich mit den analogen Acetylderivaten verifiziert.
Chemical Modification of Guaran Gum Part I: Carboxymethylation in Aqueous Medium
Authors: Kamel M. , Abd El‐Thalouth I. , Amer M. Abou , Ragheb A. , Nassar S. H.
Published: November 2006

Guar gum was isolated from the seeds and subjected to modification via carboxymethylation in aqueous medium. The modification increases its solubility in cold water, and increases the stability of its pastes to microorganisms. Regardless of the DS of these products, their aqueous solutions are characterized by non‐Newtonian pseudoplastic behaviour, and their apparent viscosity at a constant rate of shear depends on the DS as well as the measuring temperature.
Some Disaccharide‐derived Building Blocks of Potential Industrial Utility
Authors: Lichtenthaler Frieder W. , Immel Stefan , Martin Dierk , Müller Volkhard
Published: November 2006

The utilization of inexpensive, bulk‐scale accessible, renewable disaccharides as organic raw materials necessitates their practice‐oriented conversion into products with different functional groups and, hence, broader application profiles. The backlog for the development of practical reaction channels to versatile building blocks from disaccharides being particularly obvious. Correspondingly, this account describes a series of examples by which the reaction potential inherent in disaccharides such as sucrose, lactose, maltose and isomaltulose is utilized towards the acquisition of versatile building blocks without cleaving the intersaccharidic linkage. ‐ The glucose portion of sucrose, e.g. can be converted into dihydropyranones with the carbonyl function at C‐2 or C‐4, the reducing glucose parts of maltose and lactose may be transformed into enediolone, enelactone, or enollactone structures, whilst the fructose moiety of isomaltulose elaborates a furan ring by threefold, acid‐induced elimination of water to yield the terminally O‐glucosylated HMF, i.e. glucosyloxymethyl‐furan‐2‐carboxaldehyde. ‐ All reaction sequences comply with criteria of practicallity and therefore being transformable to large scale without major changes. Another novel entry reaction into O‐functionalized disaccharide derivatives, the cathodic deprotonation and subsequent trapping of the mono‐anion with suitable reagents according to Hamann, was evaluated in terms of understanding the regioselectivity attainable through computer simulations of relevant conformers of sucrose in solution, and the corresponding molecular electrostatic potential (MEP) profiles.
The Effects of Enzyme Hydrolysis on the Properties of Potato, Cassava and Amaranth Starches
Authors: Gorinstein Shela , Lii Cheng‐Yi
Published: November 2006

X‐ray diffraction method and differential scanning calorimetry were used to study the effects of enzyme hydrolysis on physico‐chemical properties of potato, cassava and amaranth starches. Various hydrolysis procedures and different sources of enzymes were employed. The highest percentage of hydrolysis was obtained using the bacterial thermostable α‐amylase following by the saccharification with amyloglucosidase. Enzyme treatment showed decrease in the degree of crystallinity of all hydrolyzed starch samples of A‐type crystals. B‐and C‐types were weakened upon enzymatic hydrolysis at 60°C and completely dissappeared at 100°C. The gelatinization endotherm decreased for samples with low degree of crystallization and disappeared in samples with amorphous stage.
The Effect of Low Levels of Antioxidants on the Swelling and Solubility of Cassava Starch
Authors: Mat Hashim D. B. , Moorthy S. N. , Mitchell J. R. , Hill S. E. , Linfoot K. J. , Blanshard J. M. V.
Published: November 2006

The addition of low levels of sodium sulphite had a dramatic effect on the structure of cassava (Manihot esculenta Crantz) starch pasted at 95°C. Inclusion of 100 ppm sulphite promoted granule disintegration resulting in a reduction in measured swelling volume to nearly 10% of its value in the absence of sulphite and release of almost all the carbohydrates from the starch granule. It is suggested that sulphite addition promotes oxidative reductive depolymerization (ORD) of the polysaccharides since its effect on the granules is prevented when lower levels (around 20 ppm) of the polar antioxidant propyl gallate are added. Possible practical applications of the results and implications for the understanding of starch granule structure are discussed.
High‐Pressure Gelatinization of Barley Starch at Low Moisture Levels and Elevated Temperature
Authors: Vainionpää Jukka , Forssell Pirkko , Virtanen Teija
Published: November 2006

High‐pressure gelatinization of barley starch at low water contents and at elevated temperature was performed in a differential scanning calorimeter equipped with a pressure chamber. Microscopic examination of the samples showed complete loss of birefringence and rupture of granular structure in most samples. The results indicated that enthalpy levels much higher than those in high‐moisture gelatinization are needed to attain proper gelatinization and plastification of starch at low water contents.
Evaluation of an Enzymic Method for Starch Purity Determination
Authors: Kennedy John F. , Cabalda Vivian M.
Published: November 2006

Independent evaluation of an enzyme method (AFNOR) on a wider than original array of starch types showed incomplete conversion of some starch components (up to 2.5%) to glucose, as assayed per gel permeation chromatography. The AFNOR method uses only a single enzyme regime consisting of amyloglucosidase from Aspergillus niger. Negligible amounts of starch were found in the precipitates/residues, obtained after starch hydrolysis of the starch hydrolysates (<0.1%). Standard deviation of the method was <1% absolute for all starches studied.
Emulsifier Effects on Pasting Properties of Wheat Flour Extrudates with/without Sucrose and Shortening
Authors: Ryu G. H. , Walker C. E.
Published: November 2006

The objective of this study was to determine the effects of emulsifier types and concentrations, plus the addition of sucrose and shortening on wheat flour extrudates. Ground extrudate pasting properties were measured in the rapid viscoanalyser (RVA). Four pasting parameters were determined from the RVA curve: peak time (PT), peak viscosity (P), breakdown viscosity (H), and initial slope (IS). Emulsifier types and the addition of sucrose and shortening significantly affected PT, P, H, and IS. Emulsifier concentration significantly influenced PT and H. Emulsifiers significantly increased PT and H and decreased P and IS. Glyceryl monostearate had the greatest effects on these parameters. Sucrose and shortening generally enhanced the effects of emulsifiers on pasting properties.
Mechanism of Starch Gelatinization in Neutral Salt Solutions
Authors: Jane Jay‐Lin
Published: November 2006

DSC thermograms showed that salt affected the onset temperature (T0) and enthalpy change (AH) of starch gelatinization and that the effect differed by type of salt and concentration. Anion effects seemed to parallel the structure‐making and structure‐breaking effects of water. At all concentrations, sulfate ions increased T0 and AH, but thiocyanate suppressed them. T0 and AH were affected by cations in a complex mode. In CaCl2 (3molal) or LiCl (7–10m) solution, starch gelatinized at room temperature but did not gelatinize in NaCl or KCI solutions at any concentration. Light micrographs taken at room temperature showed that in KSCN and KI solutions (>2m) starch gelatinization began at the hilum but in CaCl2 (3m) and LiCl solutions (7–10m) starch gelatinization started at the periphery. It was concluded that the mechanism of starch gelatinization in salt solutions can be attributed to: (1) structure‐making and structure‐breaking effects on water and (2) electrostatic interactions between salts and hydroxyl groups of starch.
Studies in Carbohydrate Based Glues and Thickeners for Foodstuffs. Part I: Glucose ‐ Sucrose ‐ Apple Pectin Ternary System
Authors: Mazurkiewicz Jozef , Zaleska Hanna , Zaplotny Jozef
Published: November 2006

Viscosities are given of aqueous solutions of α‐D‐glucose, sucrose, apple pectin and Arabic gum, as well as of various binary mixtures of these solutions. Aqueous mixtures of α‐D‐glucose and sucrose exhibit a small increase in viscosity. The addition of apple pectin to the binary mixtures gives solutions of a viscosity of Arabic gum.
Screening of Gamma Cyclodextrin‐Producing Recombinant E. coli Using Congo Red Dye on Solid Complex Media
Authors: Hamaker Kent , Tao Bernard Y.
Published: November 2006

Recombinant genetic cloning of cyclodextrin glucanotransferase (EC 3.2.1.19) bacterial genes into E. coli has spurred the need for a rapid solid media screening analysis for recombinants. A number of qualitative and quantitative colorimetric assays have been previously developed for cyclodextrins (CDs) based on the changes in colored dye spectral response upon chelation in CDs. However, none are applicable at the screening conditions needed for recombinant E.coli (neutral pH, colored complex solid media). We report a qualitative colorimetric detection method for γ cyclodextrins produced from recombinant E. coli at neutral pH in complex media using congo red and xylene cyanole dyes.
Properties and Structure of Aqueous Solutions of Hydroxypropyl‐beta‐Cyclodextrin
Authors: Häusler Olaf , Müller‐Goymann Christel C.
Published: November 2006

Molecules of hydroxypropyl‐beta‐cyclodextrin (HPBCD) in aqueous solution interact with each other via hydrogen bonds. Especially for concentrations beyond 50% (w/w), a strong increase in viscosity and a considerable decrease of freezable water can be determined. The addition of substances which are able to break the water structure (urea, KSCN) reduces these effects remarkably. The formation of inclusion compounds with urea could not be detected. Endothermic phase transformations confirm the presence of liquid crystalline structures at low temperatures. These liquid crystalline structures are not detectable at room temperatures, but the freeze fracture technique shows micelle‐like associates of a size of about 20 nm. Studies on the complexation of phenolphthalein as well as surface tension measurements of HPBCD solutions indicate that a minimum concentration of HPBC is necessary for the association phenomena.
Cloning an Autonomous Replication Sequence from Aspergillus oryzae
Authors: Kudo K. , Okoshi A. , Usami R. , Horikoshi K.
Published: November 2006

DNA sequence from Aspergillus oryzae genome which, confers on pOK‐1 the ability to replicate autonomously in Saccharomyces cerevisiae is described. A hybrid plasmid pOK‐1 was constructed from pBR325 and YEp13 fragment containing Leu2+ gene. Asp. oryzae DNA and pOK‐1 were cleaved with BamHI, ligated and introduced into Escherichia coli. About 600 recombinant plasmids were obtained. One of them transforms S. cerevisiae SHY3 to Leu2+ with middle efficiency. The plasmid designated as pSB1–2 contained two BamHI fragments (4.3 kb and 4.1 kb) of Asp. oryzae DNA.
Untersuchungen an Kartoffelpülpe als Ballaststoffquelle. Die Zusammensetzung der Kartoffelpülpe nach Einwirkung von Pektinasen und Cellulasen sowie enzymatischem Stärkeabbau
Authors: Dongowski Gerhard , Stoof Gisela , Potsdam‐Rehbrücke
Published: November 2006

Die Zusammensetzung der alkoholunlöslichen Substanzen (AUS) von Kartoffelpülpe wurde untersucht nach Einwirkung von verschiedenen pektolytischen und cellulolytischen Enzymen gefolgt von stärkeabbauenden Enzymen. Die Vorbehandlung mit Pektinase/Cellulase‐Kombinationen übt einen signifikanten Einfluß auf die Menge und die Eigenschaften des nach dem Stärkeabbau verbleibenden Rückstandes aus. Weiterhin ergeben sich hier die bedeutendsten Veränderungen in der Zusammensetzung der Rückstände nach Einwirkung der amylolytischen Enzyme. Es wird ein Zusammenhang zwischen dem Gehalt an Reststärke in den Rückständen und der Wirkung der zellwandabbauenden Enzyme gefunden. Der Gehalt an Reststärke korreliert negativ mti dem Zellwandabbau. Das bedeutet, daß die enzymatische Abbaubarkeit der Stärke wesentlich von der Beschädigung der Kartoffelpülpe‐Zellwand und in diesem Zusammenhang hauptsächlich vom Abbaugrad der Cellulose abhängt. Die Wasserbindungskapazität (WBK) nimmt nach Einwirkung von Pektinase/Cellulase‐Kombinationen intensiv ab. Die anschließende Behandlung mit amylolytischen Enzymen bewirkt nur geringe Veränderungen in der WBK.
Studies on the Structure of Pea Starches. Part 1: Initial Stages in α‐Amylolysis of Granular Smooth Pea Starch
Authors: Bertoft Eric , Manelius Robin , Qin Zhu
Published: November 2006

A diluted solution of Bacillus amyloliquefaciens α‐amylase was pumped through a layer of smooth pea starch granules in a column and further into a bed of ion‐exchanger that retained the enzyme but not the solubilised dextrins. The design of the experiment prevented a secondary hydrolysis of the originally solubilised dextrins. The granules were quite resistant to hydrolysis and collected dextrins from the initial stages of the solubilisation of both large and small granules had d.p. (degree of polymerization) 2–100. Large granules that were treated with a more concentrated enzyme solution in a test‐tube, were solubilised up to 7%. The granular residues contained increased amounts of dextrins in the d.p.‐range 50–300. Scanning electron microscopy revealed an extensive fragmentation of the granules and the enzyme had preferentially attacked the starch in layers between the “growth rings”.
Structure versus Functional Relationships of a New Starch‐Based Fat Replacer
Authors: Harris Donald W. , Day Gary A.
Published: November 2006

A new starch‐based fat replacer called STELLAR, is prepared by controlled acid hydrolysis of corn starch. Fat‐like properties arise from the particle gel structure developed on shearing the insoluble starch product in water to produce a firm, deformable creme. The new fat replacer has an average molecular weight of less than 20,000 and is composed of crystallites comprised of double helical structures. Based on actual particle size analyses and calculations made on surface area data, it is concluded that the creme is comprised of loosely aggregated submicron size particles. This is corroborated by transmission electron microscopy results. Oxygen 17NMR measurements demonstrate the importance of water immobilization during creme formation. The functional properties of the new starch based fat replacer are discussed in relation to its structure.
Relationships Between Structure and Activity in the α‐Amylase Family of Starch‐metabolising Enzymes
Authors: MacGregor E. Ann
Published: November 2006

α‐Amylases are known to be multidomain proteins, i.e., the molecules consist of several folding units. Each α‐amylase is believed, however, to have a catalytic domain consisting, of a barrel of eight parallel α‐strands surrounded by eight α‐strands. with an extra helix inserted after the sixth γ‐strands. The α‐strands and helices alternate along the polypeptide chain and are linked together by irregular loops. Amino acid residues situated on the loops joining the C‐terminal end of each α‐strand to the N‐terminal end of the following helix make up the active site of the enzymes. A similar structure has been found in cyclodextrin glucanotransfcrases and it is now believed that such a (α/α)8‐barrel also constitutes the catalytic domain of enzymes active on α‐1.6‐glucosidic bonds, and of enzymes with dual specificity for both α‐1.4‐ and α‐1.6‐ bonds.

Knowledge of the three‐dimensional structure of α‐amylases and cyclodextrin glucanotransferase has made possible identification of structural features important for enzymic activity and specificity. By analogy, some general conclusions are reached concerning pullulanase, isoamylase. oligo‐1,6‐glucosidase, neopullulanase and branching enzymes.
Effect of Cellulase Addition on Hydrolysis of Sago Starch Granules by Raw Starch Digesting Amylase from Penicillium brunneum No. 24
Authors: Haska Nadirman , Ohta Yoshiyuki
Published: November 2006

Raw sago starch digesting amylase was obtained from Penicillium brunneum No. 24. with strong ability to digest sago starch granules. The crude enzyme from this strain contains CMC‐ase and avicelase. The specific activity of the enzyme did not increase proportionally with purification. We tried combination of our purified enzyme with other hydrolytic enzymes as a means of improving the hydrolysis of sago starch granules.

Addition of cellulase at the initial stage of the hydrolyzation process resulted in an increase in the ability of raw starch digesting amylase to digest sago starch granules. Adding 10 unit/g starch of cellulase. followed of our purified raw starch digesting amylase in small portion at various time intervals was found effective in the hydrolysis of untreated sago starch granules. The treatment resulted in a convertion rate of untreated sago starch granules to glucose near to complete after 120h enzymes reaction, and was also effective in reducing the reaction time of hydrolysis of treated sago starch granules. This process showed that mainly glucose was produced.
A Flow Injection System for the Determination of Starch in Starch from Different Origins with Immobilized α‐Amylase and Amyloglucosidase Reactors
Authors: Emnéus Jenny , Nilsson Gunilla , Gorton Lo
Published: November 2006

A heat stable α‐amylase (Termamyl) was immobilized on controlled pore glass (CPG) with a pore size of 1 489Å and amyloglucosidase (AMG) was immobilized on a ceramic silica support (Micropil A) with a pore size of 300Å. These enzyme supports were packed into two separate immobilized enzyme reactors (IMERs) which together with a third reactor containing co‐immobilized glucose dehydrogenase/mutarotase were incorporated into a flow injection (FI) system for the determination of the total glucose content of starch related poly‐ and oligosaccharides. Samples of maltose, a maltooligosaccharide mixture, three soluble starches, three amylopectins, two amyloses, glycogen, and native starches from different origins were injected. The degree of hydrolysis was determined by comparing the produced amount of glucose in the FI system with the calculated amount of glucose in the samples and with samples to which had been added and let to react for six hours soluble α‐amylase and AMG before injected into the FI system also containing the IMERs. Virtually complete conversion to glucose was obtained for maltose, maltooligosaccharides, two soluble starches and native potato starch. Maximum enzymatic degradation by the starch hydrolyzing enzyme reactors was obtained in most instances except for glycogen (96%), native wheat (88%), rice (93%), and corn starch (83%).
Crystalline Parts of Three Different Conformations Detected in Native and Enzymatically Degraded Starches
Authors: Gernat Christine , Radosta Sylvia , Anger Horst , Damaschun Gregor
Published: November 2006

We examined cereals and legume starches with different amylose contents, using X‐ray wide‐angle scattering. The parts of polymorphs in the crystalline regions and the crystallinity of the starches were determined. The high‐amylose starches hold 74.6%‐84.6% B‐type and 15.4%‐22.6% VH‐type.

Crystallinity of high‐amylose starches is xc = 0.154–0.17. According to phase analysis of the scattering curve of wheat starch 6.8% B‐type and 93.2% A‐type are contained. Thus, in the crystalline phase wheat starch is more heterogeneous than maize starch. The residuary substance of heterogeneous hydrolysis of wheat starch at T1 =58°C is an insoluble sediment, which does contain already 17.1 % VH‐Amylose. This is the proof of the amylose‐lipid complex in the sediment. If the temperature of hydrolysis raised to 70°C, the VH,‐amylose proportion increased to 80.5%. Since the crystalline VH‐ structures are detectable during heterogeneous hydrolysis as from T1 = 58°C, they seem to have contained already in native starch.
Properties of Starches from Australian Wheats. Part 3: In vitro Digestibility and Hydroxypropyl Derivatives
Authors: Wootton Michael , Mahdar Dedi
Published: November 2006

The in vitro digestibilities of starches isolated from 21 Australian wheat varieties were measured after gelatinisation, using porcine pancreatic α‐amylase. The starches were also converted into their hydroxypropyl derivatives and levels of substitution, and freeze‐thaw stability of the products assessed. Digestibilities varied between samples and were significantly correlated negatively with fat content of the starches. No significant correlations between digestibilities and any of amylose content, grain hardness or granule crystallinity were found. Efficiency of reagent usage during derivatisation and freeze‐thaw stability also varied between starches. Levels of substitution were not reflected in relative freeze‐thaw stabilities of the starch derivatives.
Erythritol, a New Raw Material for Food and Non‐food Applications
Authors: Röper Harald , Goossens Jozef
Published: November 2006

In response to an increasing demand from consumers for healthier and calorie controlled foods, Cerestar has developed a new food ingredient, erythritol. Erythritol can be produced from starch by a full biotechnological process, combining enzymatic and fermentative conversions. The use of an osmophilic yeast allows the fermentation step to be performed at high dry substance, giving an economic advantage. An extremely pure end product is then easily obtained by final crystallisation.

Erythritol is structurally a polyol and shares the health properties of other polyols such as being toothfriendly and safe for diabetics. However, it offers in addition two very important nutritional advantages: a lower calorific value (0.3 Kcal/g) and a good tolerance. This is due to its low molecular weight, which allows erythritol to be rapidly absorbed from the small intestine, with subsequent excretion in the urine. Fermentation in the colon is therefore excluded and any resulting gastro‐intestinal discomfort avoided. The combination of these properties makes erythritol a unique low calorie bulk sweetener.

From a functionality point of view, erythritol is a moderately sweet bulking agent with a cooling taste: workability is similar to other polyols. It has a taste profile close to that of sucrose and may therefore improve the taste quality of a blend with intense sweeteners. Its low solubility and ease of crystallisation, make erythritol very suitable for applications which require a crystalline sweetener, such as chocolate. Other potential application areas are bakery, table‐top and confectionery.

Presently erythritol is under evaluation to establish beyond any doubt its safety and to obtain food approval as a new, low calorie, bulk sweetener.

Potential non‐food applications of erythritol are in polymers, fine chemicals and pharmaceutical intermediates.
A Universal Feature in the Structure of Starch Granules from Different Botanical Sources
Authors: Jenkins Paul J. , Cameron Ruth E. , Donald Athene M.
Published: November 2006

Starch samples from different botanical species show few unifying features in either structure or function: for example both the amylose/amylopectin ratio and the amylopectin chain length are found to vary extensively with botanic source. We have applied a detailed analysis to data obtained from small angle X‐ray scattering (SAXS) of a variety of different starches which has shown the existence of a constant structural periodicity. This finding suggests the possibility of a general mechanism governing the way starch is laid down in different species.
Studies on the Structure of Pea Starches Part 4: Intermediate Material of Wrinkled Pea Starch
Authors: Bertoft Eric , Qin Zhu , Manelius Robin
Published: November 2006

β‐Limit dextrins were isolated from wrinkled pea starch, fractionated into different sizes, and their molecular weight distribution analysed by gel chromatography. A minor part of the dextrins had high molecular weight and long chains typical for amylose. The major part of the dextrins had low molecular weight and possessed unit chains of the same types as was found in the amylopectin of smooth pea starch. However, the proportion of long chains was significantly higher. The hydrolysis of wrinkled pea starch with α‐amylase was fast and reflected the large content of amylose, whereas the hydrolysis of the β‐limit dextrin was slow. The intermediate dextrin products obtained from the latter had similar molecular weights as those produced from other amylopectins, which indicated that it was build up of clusters of branchings. Structure models that show the mode of interconnection of the clusters in the intermediate material are suggested.
Beitrag zum enzymatischen Abbau von Stärkeschlichten auf einem Textilgut
Authors: Denter Ulrike , Knittel Dierk , Schollmeyer Eckhard
Published: November 2006

Es wurden Untersuchungen zum Einsatz von Cyclodextrin‐Glucosyl‐ Transferase beim enzymatischen Entschlichten von stärkegeschlichtetem Baumwollgewebe durchgeführt. Das verwendete Enzym soll beim Stärkeabbau in Lösung selektiv β‐Cyclodextrin bilden. Wie die vorliegenden Experimente zeigen, ist die CGTase in der Lage, Stärke nicht nur in Lösung, sondern auch auf einem textilen Träger abzubauen. Unter den gegebenen Randbedingungen katalysiert das Enzym die Bildung von α‐Cyclodextrin. Um eine gegenüber α‐Cyclodextrin verstärkte Anreicherung von β‐Cyclodextrin zu erreichen, ist eine genaue Analyse des Prozesses unter Variation und Optimierung der Randbedingungen erforderlich.
Characterization of Hydroxyethyl Starch by Polymer Analysis for Use as a Plasma Volume Expander
Authors: Kulicke Werner‐Michael , Roessner Dierk , Kull Wiebke
Published: November 2006

Hydroxyethyl starch is currently finding increasing use as a basis material for plasma volume expanders. In clinical applications it is desirable to have a precise knowledge of the steric and chemical structure, as these affect the pharmacokinetics and pharmacology.

Characterization involved the determination of the mean molar masses and distribution functions of various hydroxyethyl starches, with molar masses ranging from 40,000 g/mol to 200,000 g/mol and degrees of substitution from 0.38 to 0.64, by means of size exclusion chromatography followed by double detection (MALLS/RI). Hydrodynamic data (Staudinger indices, Huggins constants and equivalent diameters) were determined by viscometric means.

The chemical structure of the hydroxyethyl starches were clarified by {1H}‐13C NMR spectroscopy. Signal assignment for the {1H}‐13C NMR spectra made it possible to carry out an absolute determination of the molar, mean and partial degrees of substitution and the degree of branching. The partial degrees of substitution of the carbon atom C‐2 was found to constitute between 60 and 80% of the total degree of substitution. This value is significantly larger than the partial degrees of substitution at the atoms C‐3 and C‐6, which were found to contribute up to approximately 10% and 20% respectively of the total degree of substitution. Degrees of branching ranging from 3.1% to 5.5% were detected.
Amino Derivatives of Starch Part 1: Amination of Amylose Oxidized with Nitrogen Dioxide
Authors: Tihlérik Karol
Published: November 2006

Amylose oxidized with nitrogen dioxide, having D.O. by (C=O) 0.38 and by (COOH) 0.94 was converted into its oxime, which after reduction with sodium and isopropyl alcohol yielded (1→4)‐2‐amino‐2‐deoxy‐α‐glucopyranuronan with D.S. by (NH2) 0.30 and by (COONa) 0.85. After acetylation and O‐deacetylation (1→4)‐2‐acetamido‐2‐deoxy‐α‐d‐glucopyranuronan with D.S. by (NHCOCH3) 0.28 and by (COONa) 0.80 was obtained.
Clay as a Carrier in Starch Encapsulated Herbicides Prepared by Extrusion Processing
Authors: Carr Merle E. , Wing Robert E. , Doane William M.
Published: November 2006

Metolachlor and atrazine herbicides were separately incorporated into matrices containing all starch, all clay, and starch/clay blends by a twin‐screw extrusion process. A low‐cost clay and unmodified corn‐starch were preblended dry, processed with water and herbicide in the extruder at 70–95°C, and extruded at 65% solids using an intense mixing screw. The extrudates were dried, milled, sieved (14‐20 and 20‐40 mesh), and analyzed for level of entrapped herbicide. The effect of various levels of clay and other variables on encapsulation efficiency, swellability, and release rates of the products in water were determined. The study showed that clay in the preblends of up to 50% had rather small effects on encapsulation efficiency and release rates of the products in water. As little as 20% starch in the blends remarkably slowed the release rates compared to that of clay alone. Processing the clay, herbicide and water without starch in the extruder significantly slowed the release rate compared to an unprocessed mixture of clay, metolachlor, and water. In all cases metolachlor was released more quickly than atrazine from the products (10‐27% active ingredient).
Molecular Characteristics of High Amylose Starches
Authors: Praznik Werner , Huber Anton , Watzinger Sabine , Beck Roland H. F.
Published: November 2006

A new methodology for the analysis of starch which combines complexation/precipitation‐techniques with size exclusion chromatography and enzymatic debranching is described. Application of this methodology yields detailed information about the microstructure of starch. The non‐branched/long‐chain‐branched glucans (amylose) of wrinkled pea and high amylose corn starch proved to be different in respect to average molecular weight and branching characteristics, whereas close similarity was found for the short‐chain branched components (amylopectin) of the two starches, both of them showing a bimodal molecular weight distribution.
The Catalytic Effect of Bromide in the Hypochlorite Oxidation of Linear Dextrins and Inulin
Authors: Besemer Arie C. , van Bekkum Herman
Published: November 2006

The effect of bromide in the hypochlorite oxidation of amylodextrins (short chain amylose) and inulin on the reaction rate was investigated. It was found both in the linear dextrins and inulin oxidation that the rate increases linearly with the sodium bromide concentration, which proves the catalytic effect of this substance. The origin of the catalysis is the rapid Br−/OCl− conversion. The second‐order rate constant of the reaction

Carbohydrate + HOBr/OBr− → polycarboxylates + HBr/Br− was determined at pH 9.0 and 294‐298 K.

The activation energy for the oxidation of amylodextrins amounts to 67 kJ.mole−1. The highest rate was found at pH 8.25. The reaction rate is almost independent of pH in the region 8.5–9.5. Because of the simultaneous occurrence of bromine, Br3−. hypobromous acid and hypobromite in the pH region investigated, it is difficult to elucidate the oxidation mechanism.
Technological Evaluation of Nitrogen Containing Starch Derivatives as Sizing Agents
Authors: Hebeish A. , Ragheb A. A. , Refai R. , Saad M. A. , Dokki I. Abd El‐Thalouth
Published: November 2006

The structural changes brought about by introducing different nitrogen containing groups via cyanoethylation, carbamoylethylation and carbamation in the molecules of rice and maize starches and oxidized starches derived thereof and the onset of these changes on the technical properties of yarns sized with such starch products were investigated. It was found that the apparent viscosity of pastes prepared from those products depends on the nature of starch, the degree of oxidation prior to chemical modification, the nature of modification as well as the measuring conditions, i. e. the rate of shear and temperature. Cotton yarns sized using these starch derivatives were measured for yarn number, tensile strength, C.V.%, elongation at break and C.V.% in elongation. Besides, the weavability test expressed as the minimum number of cycles due to abrasion (St1) and average number of cycles due to abrasion (St6) were investigated. A comparison among modified starches prepared from rice starch would reveral that the highest value of St1 is obtained with yarns sized using carbamoylethylated sample derived from unoxidized starch. With maize starch, on the other hand, the highest value of St1 is obtained with cotton yarns sized using carbamoylethylated starch derived from starch oxidized by 1 g/l active chlorine.
Synthesis and Processing of Graft Copolymers from Cornstarch and Methyl Acrylate: Physical and Mechanical Properties
Authors: Patil Damodar R. , Fanta George F.
Published: November 2006

Starch‐g‐poly(methyl acrylate) (S‐g‐PMA), containing 40‐65% PMA, was prepared with ceric ammonium nitrate (CAN) initiation in a 2‐gallon reactor. CAN initiator was added either in one portion or portionwise. Graft copolymers were characterized with respect to % acetone‐extractable polymer (largely PMA homopolymer), PMA content of the graft copolymer, and Mw of PMA grafts. Normal cornstarch as well as waxy and high amylose cornstarches were used in the grafting reaction. Conversions of monomer to polymer were nearly quantitative. Continuous plastic ribbons for tensile testing were prepared by extrusion processing. Tensile properties varied with the method used for CAN addition (i. e., single portion vs. portion‐wise) and depended upon the particular starch variety used in the graft polymerization reaction. Since water acts as a plasticizer for starch, samples extruded at high moisture content exhibit higher % elongation (%E) values than the same polymers extruded at low moisture. Values for %E also increase with higher percentages of PMA in the graft copolymer.
Biogenic Amino Acids and their Metal Salts as Catalysts of Caramelization
Authors: Sikora M. , Kraków P. Tomasik
Published: November 2006

Basic amino acids and one neutral aminohydroxy acid ‐ serine ‐, all at the concentration of 5%(w/w), are the most suitable as catalysts of caramelization. Among basic amino acids asparagine is the superior catalyst. Although caramels obtained with serine as the catalyst showed higher tinctorial strength they do not fully dissolve in alcohol, beer, hydrochloric acid and aq. citric acid. The application of lithium, sodium, and potassium salts of amino acids under study sometimes give an increase of tinctorial strength of caramels which, however, form precipitate in the citric acid test. The choice between particular salts as catalysts can be dependent on requested aroma of the caramel.
Gelatinization Characteristics of a Cassava/Corn Starch Based Blend during Extrusion Cooking Employing Response Surface Methodology
Authors: Seibel Wilfried , Hu Ruguo
Published: November 2006

The gelatinization characteristics of a cassava/corn starch based blend with relatively high moisture content during cooking extrusion were studied. The study was carried out by using Response Surface Methodology. The results showed that the die temperature Td (°C) was the main influencing factor for the starch gelatinization, and the feed rate of the materials Vf (g/min) was another minor one. Because of the high material moisture content during extrusion the moisture content Mc (%) influenced the gelatinization degree not so obviously. The residence time distribution of the mass during extrusion were studied as well as discussed as a influencing factor on the gelatinization results.
Kinetics of the Formations of Gelatinized and Melted Starch at Extrusion Cooking Conditions
Authors: Qu Di , Wang S. S.
Published: November 2006

Typical DSC thermograms of starch phase transition in the low moisture content range (15‐40%) showed two thermal transition peaks. This suggests the existence of two different cooking mechanisms. We call them gelatinization and melting. “Gelatinization” describes thermal transition of starch with water and “melting” without water. Kinetics of the formation of gelatinized starch (GEL) and melted starch (MELT) were studied. Conversions caused by gelatinization and melting were separately analyzed by using information from DSC (Differential Scanning Calorimetry) isothermal studies. The rate of formation of gelatinized fraction followed first order kinetics and that of melted fraction zeroth order. The overall reaction rate followed zeroth order because melting is the dominant mechanism of the two under limited water contents of extrusion cooking conditions.
Investigations on High Amylose Corn Starch Films. Part 1: Wide Angle X‐Ray Scattering (WAXS)
Authors: Bader Herbert G. , Göritz Dietmar
Published: November 2006

By autoclaving aqueous high amylose corn starch suspensions, homogenous and isotrope films were obtained with different processing parameters. The films were used for structural investigations by wide angle x‐ray scattering. The experimental results prove a systematical dependence on different parameters: on one hand the starch crystallinity shows a continous transformation from the ‘B’‐type to the ‘A’‐type with increasing drying temperature, on the other hand the drying temperature also influences the kind of interaction between the starch chains and the native lipids. Fatty acids were added to clearly outline the corresponding effects.
Chemical Composition of Cell Wall Material from Sweet Potato Starch Residue
Authors: Noda Takahiro , Takahata Yasuhiro , Nagata Tadahiro , Shibuya Naoto
Published: November 2006

Cell wall material was isolated from the residue obtained after the extraction of sweet potato starch by treatment with the α‐amylase. The wall material was fractionated by successive extraction with various reagents. The pectic substance was mainly composed of uronic acid (47.1%) residues and contained galactose as the predominant neutral sugar residues. The hemicellulosic fraction was further fractionated by precipitation with iodine in the presence of calcium chloride to give two fractions, a iodine precipitatable‐iodine complex (HC‐IP) and a supernatant solution (HC‐IS). The HC‐IS fraction had a higher glucose content (53.4%), whereas the HC‐IP fraction had a high content of xylose residues (35.1%). The HC‐IP fraction consisted mainly of xylan, as judged by the degradation with purified xylanase.
Investigations on High Amylose Corn Starch Films. Part 2: Water Vapor Sorption
Authors: Bader Herbert G. , Göritz Dietmar
Published: November 2006

By autoclaving a watery high amylose corn starch suspension, homogenous and isotrope films were obtained with different processing parameters. The films were used for extensive investigations on the water vapor sorption behavior.It was observed that both the internal structure and the native lipid content of the investigated starch effect the sorption behavior. A good theoretical description of the sorption behavior was obtained with a modified B.E.T.‐equation only for films prepared from a previously defatted starch fraction. In addition it was shown by using this modified B.E.T.‐equation that a temperature dependent prediction is possible for the sorption behavior of defatted starch films.
Effects of Suspension Crosslinking Reacting Conditions on the Sizes of Starch Microspheres
Authors: Jiugao Yu , Jie Liu
Published: November 2006

Using the method of suspension crosslinking polymerization and epichlorohydrin as the crosslinking agent, starch microspheres have been synthesized. And the effects of reacting parameters, including the surfactant concentration, stirring speed, two phases viscosities and densities on the microspheres mean size (18–36μm) are also discussed. One equation is deduced to demonstrate these effects:
Corn Starch‐Xanthan Gum Interaction and Its Effect on the Stability During Storage of Frozen Gelatinized Suspension
Authors: Ferrero C. , Martino M. N. , Zaritzky N. E.
Published: November 2006

The knowledge of starch pastes behavior during frozen storage becomes necessary to understand more complex systems (e.g. sauces, dressings and desserts) The effect of sub‐zero storage on the quality attributes of corn starch pastes (10% w/w) with and without xanthan gum (0.3% w/w) was analyzed. Pastes were frozen at different rates (0.3 to 270cm/h) and stored at −5, −10 and −20°C.

Exudate production (syneresis) and rheological behavior were studied by means of capillary suction and rotational viscometry respectively. Ice recrystallization was analyzed by indirect microscopic observations using isothermal freeze fixation and amylopectin retrogradation by differential scanning calorimetry (DSC). Samples stored at −5°C (glass transition temperature) or higher temperatures were under the rubbery state evidenced by starch recrystallization. This state favored molecular mobility leading to deteriorative changes (like spongy structure formation related to amylose retrogradation). At lower storage temperatures (−10 and −20°C) under the glassy state, starch retrogradation was not detected and deteriorative changes can be related to ice recrystallization.

The addition of xanthan gum minimized amylose retrogradation, syneresis and rheological changes, however, its presence did not prevent ice recrystallization nor amylopectin retrogradation.
Holes in Starch Granules: Confocal, SEM and Light Microscopy Studies of Starch Granule Structure
Authors: Baldwin Paul M. , Adler Jeremy , Davies Martyn C. , Melia Colin D.
Published: November 2006

Following an initial observation of putative holes within potato starch granules during observation in a medium with the same refractive index, the internal architecture of starch granules has been investigated using confocal, scanning electron and light microscopy. These complimentary microscopy techniques confirmed the existence of holes at the hilum of potato, rice and wheat starch granules. Observations were made with minimal sample preparation to avoid the generation of artifactual holes. Using image analysis we have quantitatively measured the occurrence and the size distribution of holes and linked their appearance to the drying of the granule.
Hydrothermische Behandlung von Stärke in Gegenwart von α‐Amylase Teil 2: Einfluß einer hydrothermischenzymatischen Modifizierung auf die Quellungstemperatur von Weizenstärken
Authors: Stoof Gisela , Kruse Hans‐Peter , Anger Horst
Published: November 2006

Bei der hydrothermischen Behandlung von Weizenstärke in Gegenwart von Bakterien‐α‐Amylase wird auf die Gewinnung der modifizierten Reststärke bei maximaler Verschiebung der durch DSC‐Messung bestimmten Quellungstemperatur Tmax und einer hohen Ausbeute orientiert. Die Temperung der kornförmigen Stärke in Gegenwart von Enzym ergibt bei Temperaturen unterhalb der Quellungstemperatur (50°C) dieselbe Tmax‐Verschiebung wie die Temperung in Wasser. Auf Grund des laufenden enzymatischen Abbaus von angequollenem Material können jedoch höhere Reaktionstemperaturen angewandt werden, wodurch die Temperung effektiver wird. Der gebildete Maltosesirup verlangsamt die Tmax‐Verschiebung und schützt gleichzeitig das Stärkekorn. Weizenstärke kann mit einer Ausbeute von 70% und einer Tmax‐Verschiebung von 8K innerhalb von 24h getempert werden.