bluuebunny/crossref_metadata_2025_split huggingface dataset:
Some Disaccharide‐derived Building Blocks of Potential Industrial Utility
Authors: Lichtenthaler Frieder W. , Immel Stefan , Martin Dierk , Müller Volkhard 
Published: November 2006

AbstractThe 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

AbstractX‐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

AbstractThe 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

AbstractHigh‐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

AbstractIndependent 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

AbstractThe 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

AbstractDSC 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

AbstractViscosities 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

AbstractRecombinant 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

AbstractMolecules 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

AbstractDNA 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

AbstractDie 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

AbstractA 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

AbstractA 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

Abstractα‐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

AbstractRaw 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

AbstractA 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

AbstractWe 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

AbstractThe 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

AbstractIn 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

AbstractStarch 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

Abstractβ‐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.