bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular Weight Distribution in Starch Solutions when Hydrolised with alpha‐Amylase and when Oxidised with Sodium Hypochlorite
Authors: Henriksnäs H. , Bruun H.
Published: November 2006

The time course for hydrolysis of starch with α‐amylase and oxidation of starch with Na‐hypochlorite was studied with the aid of gel chromatography. It was found that the initial steps in the hydrolysis can be described as a consecutive reaction in which the fractions Mw > 5 · 105, 5 · 105 > Mw > 1 · 105 and Mw < 1 · 105 are contained. The reaction in the course of decomposition with α‐amylase is one of the first order, while decomposition by means of hypochlorite is a second order reaction. There are considerable differences in the changes in molecular weight distribution between the two methods. Hydrolysis with α‐amylase gives a solution with a symmetrical molecular weight distribution whereas hypochlorite oxidation obviously causes splitting of some of the starch molecules, which results in solutions with two molecular weight maxima.
Absorbent Polymers from Starch and Flour Through Graft Polymerization of Acrylonitrile and Comonomer Mixtures
Authors: Fanta G. F. , Burr R. C. , Doane W. M. , Russell C. R.
Published: November 2006

Polyacrylonitrile (PAN)‐containing graft copolymers of corn starch were prepared from monomer mixtures and then saponified, and dried. Incorporation of selected comonomers lead to shorter saponification times and higher yields of adsorbent products. Substitution of flour for starch gave products which had a higher absorbency than saponified starch‐g‐PAN.
Zur biotechnischen Erforschung der Herstellung von Glucose‐Fructosesirupen. Teil 2. Reaktionskinetische Untersuchung des Mechanismus der Glucoseisomerisierung
Authors: Läszló E. , Hoschke Á. , Holló J.
Published: November 2006

Der Mechanismus der enzymatischen Isomerisierung von Glucose wurde durch reaktionskinetische Methoden untersucht. Die kinetischen Konstanten wurden unter Verwendung von Glucose, 6‐Desoxyglucose, bzw. Sorbitol und 2‐Desoxysorbitol bestimmt. Es wurde festgestellt, daß der die Geschwindigkeit bestimmende Schritt der enzymatischen Reaktion die Bindung der Glucose in acyclischer Struktur ist. Die Aldehydgruppe weist die größte Bindungsenergie auf, so daß die Ringöffnung von der Enzymwirkung unabhängig abläuft. Dies ist der Grund für die relativ langsame enzymatische Glucoseisomerisierung. Die Geschwindigkeit der Isomerisierung kann nur durch Induzierung der Aufspaltung des Pyranoseringes erhöht werden. An eine industrielle Verwirklichung dieser Induzierung ist zur Zeit noch nicht zu denken.
Alkalizahlen thermisch dispergierter Stärken
Authors: Čeh M. , Stropnik Č. , Leskovar S.
Published: November 2006

Von sechs nativen Stärken und ihren Kleistern wurden die Alkalizahlen potentiometrisch bestimmt. Analoge Versuche wurden auch mit thermisch dispergierten Stärken ausgeführt. Alle nativen Stärken besaßen höhere Alkalizahlen als ihre Kleister. Bei weiterem thermischem Dispergieren steigen die Alkalizahlen unterschiedlich stark an, was als Folge verschiedener thermischer Degradationsgeschwindigkeiten in den Stärkemolekülen anzusehen ist. Eine gute Korrelation konnte zwischen den reziproken Alkalizahlen thermisch dispergierter Stärken und ihren Molekulargewichten beobachtet werden.
Trägergebundene xylanolytische Enzyme. I. Wirkungsweise xylanolytischer Enzyme
Authors: Puls J. , Sinner M. , Dietrichs H. H.
Published: November 2006

Es wird die Wirkungsweise der bei der Hydrolyse natürlich vorkommender Xylane beteiligten Enzyme beschrieben. Xylane, die ausschließlich aus Xylose aufgebaut sind, werden durch das Zusammenwirken von ß‐1,4‐Xylanasen und ß‐1,4‐Xylosidasen zu Xylose hydrolysiert. Endo‐ß‐1,4‐Xylanasen hydrolysieren die Bin‐dungen innerhalb der Xylankette mit Ausnahme der Bindungen am Kettenende und setzen dabei Xylooligomere frei. Exo‐ß‐1,4‐Xylanasen wirken am Kettenende der Xylane und spalten jeweils Xylose ab. Die durch die Wirkungsweise der Endo‐ß‐1,4‐Xylanasen freigesetzten Xylooligomeren werden von ß‐1,4‐Xylosidasen zu Xylose hydrolysiert. Bei Laubholzxylanen besitzt im Durchschnitt jeder 10. Xyloserest eine 1,2‐gebundene 4‐O‐Methyl‐ä‐D‐Glucuronosylseitengruppe. Seitengruppen wirken sich auf die enzymatische Hydrolyse blockierend aus. Endo‐1,4‐Xylanasen setzen in diesem Fall neben neutralen Xylooligomeren auch saure Xylooligosaccharide frei, die von ß‐Xylosidasen nicht weiter hydrolysiert werden können, ehe nicht die Seitengruppe von ä‐1,2‐Glucosiduronasen abgespalten worden ist.
Comparison of Starch Extraction from Tapioca Chips, Pellets and Roots
Authors: Meuser F. , Smolnik H.‐D. , Rajani Ch. , Giesemann H. G.
Published: November 2006

The extraction of starch from tapioca chips and‐pellets was studied in comparison to the extraction from tapioca roots especially with regard to the starch yield and ‐quality as well as to the use of by products on a laboratory scale. It was observed that the extraction of starch from the dried raw materials was more complicated than from fresh roots. Impurities were difficult to remove from chips and pellets, so that mostly mineral substances were found in the starch which reduce its quality. A wet cleaning is possible only with chips, because they have a sufficient mechanical stability.
Comparative Studies on Glucoamylases Isolated from a Strain of Aspergillus
Authors: Finch P. , Leonard P. A.
Published: November 2006

Two glucoamylase fractions have been isolated from an Aspergillus culture preparation by anion‐exchange chromatography and characterised by physico‐chemical and biochemical methods. The fractions were homogeneous on electrophoresis, molecular sieve chromatography and ultracentrifugation with molecular weights of 81,000. Both fractons were shown to be devoid of endo‐amylase activity and to possess similar activities towards wheat amylopectin (15–17 IU mg−1) and maltose (3–4 IU mg−1) at the optimum pH of 4.6. The fractions catalysed extensive, but not complete, conversion of wheat amylopectin to D‐glucose which was liberated with β‐anomeric configuration.
D‐Fructose – Struktur und Eigenschaften
Authors: Heyns K.
Published: November 2006

Es wird eine Übersicht über die Struktur und die wichtigsten Eigenschaften der D‐Fructose gegeben. Insbesondere werden erörtert: Konfiguration und Konformation, der Kristallaufbau, das chemische Reaktionsverhalten in Lösung, beim Erhitzen, bei verschiedenem pH, bei der Karamelisierung, in Gegenwart von Aminosäuren (Ketosylamin‐Umlagerung, Pyrazinbildung). Erwähnt werden ferner einige Vorstellungen über die Beurteilung des Süßgeschmacks im Vergleich mit anderen Zuckern. Von Interesse ist fernerhin ein Vergleich der Eigenschaften der D‐Fructose mit denen der D‐Glucose, vor allem im Hinblick auf die Mutarotation, grundlegende Unterschiede im chemischen Verhalten, z. B. bei der Reversion. Über das Verhalten im Stoffwechsel werden einige grundlegende Zusammenhänge kurz dargestellt und im Hinblick auf die physiologischen Auswirkungen zusammenfassend diskutiert.
Rohstoffe für Fermentationen
Authors: Dimmling W.
Published: November 2006

Die Biotechnologie hat heute vor allem Bedeutung für Lebensmittel und alkoholische Getränke, für die chemische Industrie und Pharmazie, die Biomasseproduktion sowie für Abwasserreinigung und Biogasgewinnung. Die in den 80er Jahren zu erwartenden Veränderungen auf dem Rohstoff‐ und Energiesektor sowie bei Ernährung und Umweltschutz werden hier neue Aufgabenstellungen bringen. Dazu gehören z. B. die Erzeugung proteinhaltiger Futtermittel und die stärkere Verwendung von Neben‐ und Abfallprodukten z. B. für Fermentationsäthanol als Benzinzusatz und für die Biogasgewinnung. Die möglichen Rohstoffe für Fermentationsreaktionen werden hinsichtlich Verfügbarkeit und Wirtschaftlichkeit diskutiert.
Neue Untersuchungsmethoden in der Cyclodextrinchemie
Authors: Szejtli J.
Published: November 2006

Zur Optimierung der Herstellungstechnologie von Cyclodextrinen und ihren Einschlußverbindungen ist die Kenntnis des Kristallisationsprozesses unerläßlich. Durch Registrierung der Trübung während der Komplexbildung können entsprechende Informationen gewonnen werden. Die Komplexbildung selbst läßt sich durch Dünnschicht‐Chromatographie nachweisen. Zur Untersuchung der Stabilität von Einschlußverbindungen eignet sich die TAS‐Technik (Thermomikro‐, Abtrenn‐, Transfer‐ und Auftragsverfahren von Substanzen).
Properties of Lintnerized Starch Granules from Rices Differing in Amylose Content and Gelatinization Temperature
Authors: Maniñgat C. C. , Juliano B. O.
Published: November 2006

A study was made on the properties of starch granules of eight rices differing in amylose content and gelatinization temperature subjected to hydrolysis in 2.2‐N HC1 at 35°C for 15 days. The recovery of lintnerized starch was greater for samples with high gelatinization temperature and, to a lesser extent, high amylose content. Lintnerized starch had sharper X‐ray diffraction peaks than native starch. Their DP ranged from 18.8 to 30.3 glucose units, and the β‐amylolysis limit ranged from 74.5 to 92.1%. Gel chromatography showed two peaks corresponding to DP 29–34 and 14–7. Varietal differences were noted in the ratio of the two amylodextrin peaks.
Temperature Dependence of Stability and Activity of an Immobilized Glucose Isomerase in a Packed Bed
Authors: Roels J. A. , van Tilburg R.
Published: November 2006

A mathematical model describing the kinetics of the conversion of glucose to fructose by an immobilized glucose isomerase has been developed. The model is a straight‐forward one and based on known kinetic behaviour of glucose isomerase and on limitations posed by diffusional resistance when a spherical particle containing the enzyme is considered.

The model has been used to derive a relationship between initial enzyme activity and temperature. It can be demonstrated that the relationship between activity and temperature shows deviations from the familiar Arrhenius plot. The same holds for the activity half life time in a packed bed column.

Experimental material confirming the theoretical considerations is presented. The experimental results have been applied to estimate some important parameters of the material used. An Arrhenius‐type relationship is shown to hold for the estimated enzyme activity as well as for the kinetics of the deactivation process. The parameters obtained can be used in temperature optimization studies for the packed bed conversion process. The influences of initial activity, particle size and temperature on the production of fructose are discussed.
Der Energieaufwand in der Reibenstation bei der Kartoffelstärkefabrikation
Authors: Gladkowski J. , Sroczyśki A. , Bielarz H.
Published: November 2006

Drei Typen von Kartoffelreiben, die zur Zeit in der polnischen Kartoffelstärkeindustrie verwendet werden, wurden überprüft: ZT‐300 “Spomasz” (Polen), Holthius (Holland) und RU 80‐500 Nivoba (Holland). Es wurde die optimale Kartoffelverarbeitungsfähigkeit in Abhängigkeit vom Energieaufwand und vom Zerkleinerungsgrad der Reibsel für das Verreiben einer Tonne Kartoffeln festgestellt. Die Untersuchungsergebnisse haben die Annahme bestätigt, daß eine Vergrößerung der Reibenbelastung eine Energieaufwandverminderung zur Folge hat. Diese Belastung wird aber durch den Zerkleinerungsgrad der Reibsel (min. 90%) begrenzt. Der Reibselzerkleinerungsgrad hat einen entscheidenden Einfluß auf den Gehalt gebundener Stärke in der Kartoffelpülpe und demzufolge auf die Höhe der Stärkeausbeute. Für die drei Reiben wurde die optimale Reibenbelastung ermittelt.
Influence of Media Composition on the Production of alpha‐Amylase and Amyloglucosidase by a Strain of Aspergillus niger
Authors: Ramachandran N. , Sreekantiah K. R. , Sreenivasa Murthy V.
Published: November 2006

The nature of thermophilic amylolytic enzymes produced by a strain of Aspergillus niger Van Tieghem was influenced by media composition. While glucose, maltose, dextrin and soluble starch induced the production of amyloglucosidase, pectin and sodium polypectate almost exclusively induced the formation of α‐amylase. Alkali ions suppressed the formation of amyloglucosidase. NH4NO3, (NH4)2HPO4 and (NH4)2C4H4O6 served as good inorganic nitrogen sources, while casein, groundnut protein and corn steep liquor served to a similar capacity as nitrogen sources from organic material. Deletion of the growth factors pyridoxine‐hydrochloride and inositol suppressed enzyme production, while the absence of riboflavin had the opposite effect.
Preparation and Physicochemical Properties of Starches and Their Fractions from Finger Millet (Eleusine coracana) and Foxtail Millet (Setaria italica)
Authors: Wankhede D. B. , Shehnaz A. , Raghavendra Rao M. R.
Published: November 2006

The isolation and physicochemical properties of starches and their fractions from different varieties of finger millets and foxtail millets have been studied. Starches from all the millets exhibited single stage swelling and low solubility. The Brabender viscosities decreased considerably during cooking. Purna starch had the tendency to retrograde considerably during cooling. Native millet starches were susceptible to glucoamylase attack. Amylose content of the millet starches ranged from 15,5 to 17,5%. Successive leeching of starches with water and alkali yielded different amylose components having different molecular weights and β‐amylolysis limit, suggesting the heterogeneity of total amyloses.
Simplified Determination of Amylose in Milled Rice
Authors: Sowbhagya C. M. , Bhattacharya K. R.
Published: November 2006

Previous defatting is essential for correct determination of amylose content in rice by colorimetric iodine method. Since no simplified method of defatting of flour is satisfactory, a simple method involving defatting in liquid phase has been developed. The flour is dispersed in diluted alkali, and the dispersion is shaken successively with petroleum ether and carbon tetrachloride. The aqueous solution is pipetted from top for colour development. The method gives results essentially identical to that given by defatted flour. The colour is developed and read at about pH 7.5 and at 630 nm.
Cold Gelatinization of Starch
Authors: Lindqvist I.
Published: November 2006

The cold gelatinization of starch and the subsequent leaching with water has been studied by a spectrophotometric difference method. It has been proved that the gel formation can only take place if amylose has first leached out of the starch granules and that amylopectin is the predominant gel forming component of starch.
Degradation of Starch Granules by Alpha‐Amylase of Streptomyces precox NA‐273
Authors: Takaya T. , Sugimoto Y. , Fuwa H. , Wako K.
Published: November 2006

The action of purified α‐amylase of Streptomyces precox NA‐273 on starch granules of normal maize and potato was studied. The hydrolysis was followed by measuring total soluble carbohydrates and glucose released. Patterns of degradation were observed by scanning electron microscopy (SEM). The main soluble product was maltose, small amounts of glucose and higher oligosaccharides were always observed. By SEM, attack started small pits on the surfaces of maize starch granules, pits increased in number and in size, and pores penetrated into the inner portions of the granules toward the center. The enzyme seemed to degrade the inner portion of starch granules better than the well‐known general α‐amylases.
Ethanol aus Biomasse als zukünftiger Kraftstoff für Automobile
Authors: Bernhardt W. , Menrad H. , König A.
Published: November 2006

Von den zur Zeit diskutierten Alternativkraftstoffen scheinen die Alkohole Methanol und Ethanol die günstigsten Voraussetzungen für einen zukünftigen Einsatz als Kraftstoff für Automobile zu bieten. In Ländern mit Kohle‐, Erdgas‐ oder Holzvorkommen und hochentwickelter industrieller Technologie wird Methanol die günstigste Lösung darstellen, während in Ländern mit intensivem Pflanzenwuchs und einer mehr landwirtschaftlich ausgerichteten Wirtschaft Ethanol der Kraftstoff der Zukunft sein wird. Über Möglichkeiten der Herstellung von Methanol aus Kohle, Erdgas und städtischen Abfällen ist schon oft berichtet worden. Man weiß jedoch verhältnismäßig wenig über die Herstellung von Ethanol aus Pflanzen, sog. Biomasse. Aus der Sicht der Automobilindustrie wird die zukünftige wirtschaftliche Bedeutung von Ethanol aus Biomasse als Kraftstoff für Automobile beleuchtet.
Application of Differential Scanning Calorimetry to Starch Gelatinization. II. Effect of Heating Rate and Moisture Level
Authors: Wootton M. , Bamunuarachchi A.
Published: November 2006

The influence of heating rate on the gelatinization of wheat starch and starch/water ratio on the gelatinization of wheat, maize, waxy maize and amylomaize starches was examined. More rapid heating resulted in a lowering of the onset temperature of gelatinization for wheat starch from 52 °C at 8°C/min to 46 °C at 32 °C/min. A linear relationship was observed between moisture content and gelatinization energy for starch/water ratios between 1 :2 and 2:1. This allowed calculation of the minimum level of water necessary to initiate gelatinization of each starch. These levels were in excess of the water binding capacity for each starch and were 0.45, 0.45, 0.47 and 0.52 g water/g of wheat, maize, waxy maize and amylomaize starches respectively.
Fluoro‐ and Chlorodeoxy Derivatives of Starches
Authors: Srivastava H. C. , Srivastava V. K.
Published: November 2006

Treatment of 6‐O‐p‐tolylsulfonyl starch with anhydrous potassium fluoride in boiling 1,2‐dihydroxyethane afforded deoxyfluorostarches (D. S. Fluorine 0.18). Reaction of starch with hydrofluoric acid in dimethyl sulfoxide at −30 °C gave deoxyfluorostarches of high fluorine content (D. S. Fluorine 0.91). Chlorodeoxystarches have been prepared by the reaction of corn starch with (chloromethylene) dimethylimminium chloride in N, N′‐dimethyl‐formamide.
On the Possibility of Dietary Fiber Formation by Interaction in the Intestine between Starch and Lipids
Authors: Larsson K. , Miezis Y.
Published: November 2006

Potato starch gels were exposed to monoolein solubilized in bile acid micelles and in the form of a cubic aqueous phase, in order to similate the situation occurring in the intestine. The gels were degraded by pancreatic amylase, and this process was followed by colorimetric determination of dextrose equivalents (DE). A reduction in DE‐values after 1 h of about 20% was observed in the starch gels first exposed to lipids compared to the situation when amylase was added directly to the same starch gel. This difference can be accounted for if it is assumed that the whole amylose fraction forms the helical amylose‐lipid complex, which is relatively stable against enzymatic degradation. The possibilities for such complexing reactions in vivo, corresponding to formation of dietary fiber from pure starch and fat in the food, are discussed.
Die Wirkung von Glucoseisomerase auf Oligosaccharide in Stärkehydrolysaten
Authors: Boruch M. , Nebesny E.
Published: November 2006

Bei der Untersuchung der Glucoseisomerisierung mittels Glucoseisomerase wurde beobachtet, daß die Glucoseisomerase unter besonderen Bedingungen nicht nur auf Glucose, sondern auch auf die in Starkehydrolysaten befindlichen Oligosaccharide wirkt. Es wurde festgestellt, daß Glucoseisomerase geringe Mengen von Matose in ein unbekanntes Ketodisaccharid umwandelt und Ketoseeinheiten in Molekülen von Maltooligosacchariden bildet. Eine besonders intensive Wirkung von Glucoseisomerase auf Maltose und Maltooligosaccharide läßt sich in glucosearmen und glucosefreien Lösungen beobachten.
An Automatic Viscometer for the Analysis of Speciality Starches
Authors: Poyser I. R. , Wright R. G.
Published: November 2006

An automatic viscometer is described, that will determine the viscosity of starches more rapidly, and with less labour than is possible by conventional techniques. An accurately prepared slurry of the sample is poured into the instrument, where it is pumped under pressure through an electrically heated tube, which gels the starch. Viscosity is measured by a commercially available viscometer. The temperatures of gellation and measurement are thermostatically controlled. The instrument can receive samples at the rate one every 10 min, and the viscosity value of each sample is available within 7 min. Measurements can be carried out at either constant shear rate, or constant shear stress, and the results are displayed on a pen recorder.
Rapid Determination of Dextrose Equivalent by Cryoscopy
Authors: Fitton M. G.
Published: November 2006

This paper describes the development of a novel method for determination of Dextrose Equivalent of Malto‐dextrins and glucose syrups. The new method uses depression of freezing point as a measure of the number of molecules in solution; Dextrose Equivalent is also a measure of the number of molecules in solution. The advantages of the cryoscopic method are its inherent rapidity (2 min per determination), its precision and the fact that previous expertise is not required.
Resorption, Metabolism and Toxicity Studies on the Peroral Application of beta‐Cyclodextrin
Authors: Szejtli J. , Sebestyén G.
Published: November 2006

It is probable that only an insignificant amount of β‐cyclodextrin is absorbed in unchanged form from the intestinal tract. The oral administration of the conversion mixture (38% β‐cyclodextrin, 2.8% α‐cyclodextrin, the rest partially decomposed starch) to rats and dogs, as well as the crystalline β‐cyclodextrin (97%) at doses of 200, 400 and 600 mg/kg of bodyweight daily, according to the clinico‐biochemical tests has not caused significant changes. The pathological and histopathological studies performed after a 6 months treatment have not proved any observable changes. β‐Cyclodextrin proved not to be embryotoxic and teratogenic. The chromosoma test performed on rats treated for 6 months has not increased the incidence of spontaneous aberration and no change relating to mutation could be observed, either.
Conversion of Glucose into Gluconic Acid by Means of Immobilized Glucose Oxidase
Authors: Richter G. , Heinecker H.
Published: November 2006

The properties of a glucose oxidase from Aspergillus niger var., immobilized by different methods were studied in a batch process. Dependencies between formation of gluconic acid and concentration of enzyme and glucose, supply with oxygen, pH‐value and temperature were determined and the optimal parameters of reaction fixed. In this connexion consideration of the oxygen demand of the system was of special importance. Different “oxygen carriers” (pure oxygen, air, hydrogen peroxide) were used and their influences investigated not only on glucose oxidase but also on catalase, which is a conclusive fact in the reaction process. This led to very informative experiences on stability, re‐usability and productivity of the carrier bound enzyme system. The results obtained should be applied to develop a continuous process for gluconic acid production and an enzyme preparation adapted to this process.
Technische Herstellung von Fructose
Authors: Lauer K.
Published: November 2006

Ein in ernährungsphysiologischer Hinsicht interessanter Zucker ist der Fruchtzucker (D‐Fructose, Laevulose). Die großtechnische Herstellung erfolgte über Jahrzehnte aus Saccharose nach dem sogenannten Calcium‐Fructosat‐Verfahren. Ein entscheidender Fortschritt wurde erzielt, als es gelang, mit Hilfe von lonenaustauschern auf chromatographischem Wege die Trennung von Fruchtzucker und Traubenzucker durchzuführen. Es wird über die Entwicklung und die zehnjährige Erfahrung mit einer Großanlage berichtet.
Beitrag zur mechanischen Entwässerung von Kartoffelpülpe
Authors: Kempf W.
Published: November 2006

In der Bundesrepublik Deutschland werden jährlich etwa 600000 t Kartoffeln zu Stärke verarbeitet. Dabei fallen große Mengen an Kartoffelpülpe an, die wirtschaftlich nur sehr begrenzt verwertet werden können. Ihr dominierender Verwendungszweck besteht darin, sie entweder sofort oder aber vorwiegend nach vorausgegangener Trocknung als Futtermittel einzusetzen. Zu diesem Zweck wird die Kartoffelpülpe zunächst mechanisch vorentwässert und anschließend bevorzugt in Stromtrocknern getrocknet. Bei der mechanischen Vorentwässerung von Kartoffelpülpe werden selbst in modernsten Pülpepressen und unter Anwendung extrem hoher Drucke lediglich Trockensubstanzgehalte von max. 25% erreicht. Um den mechanischen Entwässerungseffekt zu erhöhen und dadurch die Energiekosten bei der anschließenden thermischen Dehydratation zu senken, wurde versucht, wahlweise durch eine chemische oder enzymatische Vorbehandlung die Kartoffelpülpe weitestgehend aufzuschließen. Bei Verwendung von Kieselgur konnte der Entwässerungseffekt um rund 5% von durchschnittlich 26% auf durchschnittlich 31% gesteigert werden, während der Einsatz von Calciumchlorid eine Erhöhung des Gehaltes an Trockensubstanz (TS) um rund 11% von durchschnittlich 29% auf durchschnittlich 40% ergab. Unter den gewählten Bedingungen konnte auch durch Einsatz pektolytisch wirksamer Enzyme in flüssiger Form eine um 10% verbesserte TS‐Ausbeute erzielt werden.
Darstellung von Methyl‐beta‐D‐fructopyranosid, Methyl‐alpha‐D‐fructofuranosid und Methyl‐beta‐D‐fructofuranosid
Authors: Voß Peter
Published: November 2006

Ein Methyl‐D‐fructosid‐Gemisch, das bei der Behandlung von D‐Fructose mit H+‐haltigem wasserfreiem Methanol entsteht, läßt sich auf einfache Weise an einem stark basischen Ionenaustauscher auftrennen. So konnten Methyl‐β‐D‐fructopyranosid, Methyl‐α‐D‐fructofuranosid und Methyl‐β‐D‐fructofuranosid rein isoliert werden. Der Verlauf der Fischer‐Reaktion der D‐Fructose läßt sich bequem gaschromatographisch nach der Trimethylsilylierung von Reaktionsgemischen verfolgen. Es bilden sich zuerst in einer kinetisch kontrollierten Reaktion hauptsächlich die furanoiden Methyl‐D‐fructoside; nach der Äquilibrierung ist das Methyl‐β‐D‐fructopyranosid der thermodynamisch stabilere Hauptbestandteil.
Simplified Economical Cassava Starch Process
Authors: Caransa A.
Published: November 2006

In consultation with the Royal Tropical Institute in Amsterdam (The Netherlands) a simplified cassava starch flowsheet was developed. The equipment is suitable for skid‐mounting which would make it possible to move the plant to another harvesting site, when desired. After peeling, washing and desintegration of the tubers the fruit‐water is removed in solid bowl centrifuges. The fibers are removed on a small battery of DSM‐screens; pre‐dewatering of the fibers takes place only when local circumstances require this. The crude, screened starch milk is degritted, concentrated and purified in a counter‐current hydrocyclones washing system with a small amount of fresh water. The entire system is suitable for cleaning in place and has been designed for continuous operation.
Effect of Embraced Lipid on the Gelatinization of Rice Starch
Authors: Ohashi Kazuji , Goshima Gisho , Kusada Harufumi , Tsuge Haruhito
Published: November 2006

Quantitative evalution of starch‐lipid interaction was attempted by means of amylography, the degree of gelatinization, iodine affinity, iodine color intensity, solubility and swelling power using isolated non‐defatted, defatted, and re‐embraced or impregnated starch with fatty acids, whose starch was isolated from non‐glutinous rice. The data obtained support that characteristics of rice starch are greatly affected by a trace amount of embraced lipid. The saturated amount of lipid in the rice starch might be reasonably deduced to be about 1 % or less. This value estimated from set back and maximum viscosity in amylography is in good agreement with the data obtained already.
Effect of Chemicals on the Carbohydrate Contents of Lagenaria vulgaris Seeds During Germination
Authors: Oza J. A. , Kotecha C. C. , Vyas D. N.
Published: November 2006

The effect of soaking treatment of fertilizers and growth regulators on the carbohydrate contents of Lagenaria vulgaris seeds during germination was studied. The carbohydrate contents of the seeds after soaking treatment at the optimum pH of the medium were also determined. From the results it is concluded that the contents of carbohydrate are affected differently and the effect is much pronounced after second day of germination. Variations in the contents of carbohydrate are explained by the effect of chemicals and of metabolites on the related enzymes. Results are discussed in relation to nutritive value.
Raw Starch Digestion by Bacillus polymyxa beta‐Amylase
Authors: Ueda S. , Marshall J. J.
Published: November 2006

Unlike plant ß‐amylases, Bacillus polymyxa ß‐amylase digests raw starch at a significant rate. The action of this bacterial ß‐amylase on raw starch is stimulated greatly by the presence of the debranching enzyme pullulanase.
Application of Differential Scanning Calorimetry to Starch Gelatinization. III. Effect of Sucrose and Sodium Chloride
Authors: Wootton M. , Bamunuarachchi A.
Published: November 2006

The influence of sucrose and salt on the gelatinization endotherm of wheat starch was examined using differential scanning calorimetry. Sucrose was found to decrease gelatinization energy (– ΔHG) and to increase peak temperature (Tp) as its concentration was increased. Onset and conclusion temperatures (T0 and Tc) were not affected by sucrose level. The effect of salt on the endotherm was more complex. A decrease in – ΔHG occurred as the level of this solute in the aqueous phase was raised to 6% but further increases in salt caused it to rise again. Salt levels up to 9% caused increases in T0 and Tp. With further rises in solute level, T0 then decreased and Tp remained relatively constant. Tc rose slowly as salt concentration increased.
Composition of Starch and Protein of Milled Rice as Related to Cooking Process
Authors: El‐Saied Hani Mohamed , El‐Attar Wafaa Mohamed , Ahmed El‐Sayed Abdel‐Gawal , El‐Shirbeeny Ahmed E.
Published: November 2006

Rice is a principal source of carbohydrate and protein. An increase in protein content has been reported to be accompanied by a reduction in the amounts of all essential amino acids. However, a study for 16 varieties indicated that not all the essential amino acids were affected. Although some correlation has been reported on the relationship between the protein or amylose and certain cooking quality characteristics, there is lack of data concerning the changes on the protein and amylose contents. The study deals with the changes of starch and protein composition which accompany cooking process at several degrees of cooking the rice.
Automatic Determination of Reducing Carbohydrates
Authors: Böhringer H. R. , Mörmann‐Buchmann J. E. , Mühlemann H. R.
Published: November 2006

The present paper describes a quick, simple and reproducible automatic optical determination of microgram amounts of reducing carbohydrates, which react with acid hydrazides in alkaline solution to form yellow anions.
Changes in the Bifringent Characteristics of Cereal Starch Granules at Different Temperatures and Water Activities
Authors: Marchant J. L. , Blanshard J. M. V.
Published: November 2006

Small angle light scattering has been used to study the major and abrupt changes in birefringence that occur on gelatinization. The effects of annealing and added solutes can be readily followed. In addition, more subtle modifications which reflect changes in order in the granules can be examined. This has been exemplified by the gelatinization behaviour under conditions of reduced water activity. These results are compared with those of other authors using the equation developed by Flory to describe the effect of diluent upon the order/disorder transition in polymers.
Theoretical Study of the Depolymerization of Starch under the Combined Action of Protons and Gamma Radiation
Authors: Raffi J. , Michel J. P. , Saint‐Lèbe L.
Published: November 2006

A theoretical study of the depolymerization of starch under the combined action of protons and gamma radiation is proposed. It allows prediction of the variations of the average degree of polymerization and the mass of water‐soluble products of the sample as a function of the parameters of the treatment and the characteristics of the starch; the main interest of this combined treatment is to allow independent variations of these two values.
Effect of Water Content on the Gelatinization of Wheat Starch
Authors: Eliasson A.‐C.
Published: November 2006

The influence of water content on the gelatinization of wheat starch was examined by differential scanning calorimetry. Three endothermic transitions were observed when starch was heated to 140 °C with 35 to 80% (w/w) water. The temperature of the second and third endotherms and the enthalpies of the first and second endotherms vary with water content.
Use of the Brabender Amylograph to Determine the Gelatinization Temperature of Corn Starch
Authors: Oosten B. J.
Published: November 2006

Names and definitions in the field of starch analyses by gelatinization temperature are very confusing. A new name is introduced as an attempt to overcome this. It is shown that the Brabender Amylograph cannot reveal the initial gelatinization temperature of corn starch suspensions. However, the apparatus is very suitable to determine the effects of electrolytes on the gelatinization temperature of starch suspensions with compositions as encountered in making starch derivatives. The measured data can be fitted to mathematical equations.
Über die Phosphorsäure der Kartoffelstärke
Authors: Palasiński M.
Published: November 2006

Kartoffelstärke enthält chemisch gebundene Ortho‐Phosphorsäure (30 bis 175 mg% P). Von den physikalisch‐chemischen Eigenschaften der Kartoffelstärke, die von der Phosphorsäure bestimmt werden, sind Ionenaustausch und Selbsthydrolyse die wichtigsten. Die Fähigkeit der Kartoffelstärke zum Ionenaustausch ermöglicht die Darstellung der Salze von reinen Estern der Amylophosphorsäure (Kationenstärken). Natrium‐, Kalium‐, Ammonium‐, Calcium‐ und Magnesium‐Stärken unterscheiden sich in ihren rheologischen Eigenschaften. Die Wasserstoffionen der sogenannten Wasserstoffstärke können die hydrolytische Spaltung der Kartoffelsärke bewirken. Dabei laufen zwei Prozesse ab, und zwar die Spaltung der glucosidischen Bindungen und die Spaltung der Esterbindung zwischen der Phosphorsäure und der Glucoseeinheit. Die Geschwindigkeit der Selbsthydrolyse ist von der Wasserstoffionen‐Konzentration abhängig. Die Selbsthydrolyse von Wasserstoffstärke ermöglicht die Herstellung von Stärkeabbauprodukten mit unterschiedlichen anwendungstechnischen Eigenschaften ohne Verwendung von Chemikalien und/oder Enzympräparaten.
Simplified Determination of Water‐Insoluble Amylose Content of Rice
Authors: Shanthy A. P. , Sowbhagya C. M. , Bhattacharya K. R.
Published: November 2006

The traditional “starch‐iodine blue value” of rice gives the hot‐water‐soluble amylose content of rice, but previous defatting is essential for its correct determination as amylose by iodine colorimetry. Since defatting of flour is laborious and time‐consuming, the hot‐water extract of rice flour is defatted by shaking with petroleum ether. Colour is then developed with iodine and read at 630 nm against an amylose standard. Subtracting the above value from the total amylose content gives the insoluble amylose content.
Isolation and Physicochemical Properties of Starch from Winged Bean (Psophocarpus tetragonolobus)
Authors: Umadevi S. , Wankhede D. B.
Published: November 2006

Preparation and physicochemical properties of winged bean starch have been studied. Gelatinization temperature range was 60–70°C and it exhibited single stage swelling and low solubility. The extensive solubility in dimethylsulfoxide may be due to heterogeneous bonding forces within the granule. The amylolytic susceptibility of native and gelatinized starch with human salivary α‐amylase and glucoamylase was studied. The starch was found to be non‐ionic. The amylose content was 38.5%.
Gamma‐Irradiated Cationic Starches: Paper Surface‐Sizing Agents
Authors: Hofreiter B. T. , Heath H. D. , Schulte M. I. , Phillips B. S.
Published: November 2006

Cationic starches, precisely depolymerized by gamma‐irradiation (60Co), were dispersed in mild alkali and evaluated as surface sizes for bond paper on a pilot paper machine. The irradiated products had excellent dispersion properties, were well retained on fibers when sized wastepaper (broke) was repulped and had an ability to enhance paper properties that was comparable to that of starch‐based materials used commercially. A yellow corn flour, cationized by an essentially dry reaction process recently developed at this Center, was also radiolyzed and evaluated as a size. This latter product was unique in that all drying steps were eliminated in the preparation of a cationic ceral product of reduced viscosity.
The Starch of Wild Rice (Zizania aquatica)
Authors: Lorenz K.
Published: November 2006

Starch was isolated from wild rice (Zizania aquatica) for a study of physico‐chemical properties, functional characteristics and a comparison with wheat starch. The starch is very small in granular size (2 – 7μ) and angular and polygonal in shape. The granules exhibit an A‐type pattern on X‐ray diffraction. Amylose content of wild rice starch is only about 2%. The gelatinization temperature range is higher than that of wheat starch. Waterbinding capacity, swelling power and enzyme susceptibility of wild rice starch were higher and solubilities lower than those of wheat starch. Viscosities were higher than those of wheat starch at equal concentrations. Wild rice starch performed better than wheat starch in fillings stored for several days at room temperature and under refrigeration.
Photochemical Grafting of Vinyl Monomers onto Starch
Authors: Hérold R. , Fouassier J.‐P.
Published: November 2006

A general study of the UV light‐induced grafting of vinyl monomers upon potato starch is reported. A large variety of monomers with hydrophilic and hydrophobic properties and of initiators of free radicals was used. The best conditions of the grafting reaction were determined and several parameters were investigated: temperature, oxygen, initiator concentration, additives. Percentage of grafting‐time conversion curves, percentage of homopolymer, rate of grafting were obtained. For a given monomer, the most efficient photoinitiator can be selected.
Some Properties of Normal‐ and Waxy‐Type Starches of Amaranthus hypochondriacus L
Authors: Sugimoto Y. , Yamada K. , Sakamoto S. , Fuwa H.
Published: November 2006

Starch granules were prepared from seeds of two types of Amaranthus hypochondriacus L., which are native to Nepal. The perisperm of one type of seeds stained reddish‐brown with iodine solution and that of the other blue. Starch granules had round shape of about 1 μm diameter. X‐ray diffraction diagrams were very similar each other and identical with the corresponding ones of rice and maize starches (A‐type). Amylose contents and distribution of average chain‐lengths of amylopectin were determined by gel filtration for isoamylase‐debranched starches. Amylose content was about 14% and 0%, resp. Both types of Amaranthus starches had typical amylopectin nearly identical with those of rice and maize starches. Starch‐granule digestibility by amylases and pasting characteristics of the Amaranthus starches were similar to those of fine starch granules.
Preparation of Starch Esters of Herbicides and Their Evaluation as Slow‐Release Agents
Authors: McGuire T. A. , Wing R. E. , Doane W. M.
Published: November 2006

A number of starch esters of various herbicides were prepared from an activated pregelatinized starch and the acid chlorides of the respective herbicides. Picloram was released from aqueous suspensions of the ester, to which nonsterile soil was added, in sufficient amount to inhibit lettuce growth. Application of the suspensions to a sterile soil at a rate equivalent to 5 kg picloram/ha was phytotoxic to lettuce for at least three seedings over 48 days. Similar results were obtained by incorporating the solid herbicide ester directly into nonsterile soil. In nonsterile soil, pregelatinized starch picloram esters hydrolyze more readily than unmodified starch picloram esters.
Isolation and Physico‐chemical Properties of Starch Extracted from Yam, Elephant (Amorphophallus campanulatus)
Authors: Wankhede D. B. , Sajjan S. Umadevi
Published: November 2006

The Isolation and physico‐chemical properties of the yam, elephant starch have been investigated. The yield of extracted starch was about 80%. The starch exhibited single stage swelling and moderate solubility in water and low resistance to solubilization by DMSO. The amylose content of the starch was found to be 24.5%. The viscosity decreased considerably during cooking at 90°C. The amylolytic susceptibility of the native and gelatinized starch with human salivary α‐amylase und glucoamylase have also been investigated.
International Cooperative Testing on the Amylose Content of Milled Rice
Authors: Juliano B. O. , Perez C. M. , Blakeney A. B. , Castillo T. , Kongseree N. , Laignelet B. , Lapis E. T. , Murty V. V. S. , Paule C. M. , Webb B. D.
Published: November 2006

An international cooperative test was undertaken to determine the reproducibility of the revised simplified amylose assay in nine laboratories.
Effect of Gamma Rays on Corn Grains. Part III. Effect of Post‐Irradiation Storage on Some Technological Properties of Corn Grains and Fatty Acids
Authors: Roushdi M. , Fahmi A. A. , Sarhan M. A.
Published: November 2006

The effect of storage after irradiation of corn grains on steeping process, starch isolation, quality of by‐products and fatty acids composition of germ oil was investigated. It was found that post‐irradiation storage led to a decrease in water absorption and protein solubilization during steeping process. The starch yield was lower, contained a high percentage of protein and was darker from above 500 Krads. Post‐irradiation caused a change in the proportions and disappearance or induced new fatty acids in the corn germ oil.
Utilization of Aqueous By‐Products of Starch Industry for Improving Bread Quality
Authors: El‐Saied H. M. , El‐Farra A.‐H. A.
Published: November 2006

Corn gluten water, rice gluten water and rice steep water resulting from wet milling were added to bread doughs. They improved the physical properties of the unyeasted dough such as resistance to extention, extensibility, water absorption and mixing requirement as well as resistance to stirring. Moreover, the palatability for Balady and European breads as well as the protein content, water soluble protein, and free amino acids were increased. The nutritional value of Balady bread protein was almost the same and showed that it is deficient only in threonine, methionine, isoleucine and lysine.
In vitro Digestion of Hydroxypropyl Derivatives of Wheat Starch. III. Analysis of Oligosaccharide Fractions Using High Pressure Liquid Chromatography
Authors: Wootton M. , Chaudhry M. A.
Published: November 2006

The oligosaccharide fractions of a number of hydroxypropyl wheat starches formed during partial digestion by porcine pancreatic α‐amylase were analysed using high pressure liquid chromatography. The procedure enabled separation of oligosaccharides up to G 11. It was found that increasing degree of substitution caused higher proportions of G 3 and G 4 oligomers, but a decrease in G 5, in the digests.
Isolation and Purification of alpha‐Cyclodextrin by Synthetic Adsorption Polymer
Authors: Yamamoto M. , Horikoshi K.
Published: November 2006

Several synthetic polymers were examined to isolate α‐cyclodextrin from an enzymatic hydrolyzate of starch. Amberlite XAD‐2 and XAD‐4 were suitable for this purpose. These polymers did not adsorb any type of sugars except cyclodextrins. The adsorbed cyclodextrin could be eluted by heating. By these procedures, α‐cyclodextrin from a crude cyclodextrin mixture was isolated and crystallized without using any organic solvent.
Gamma Radiolysis of Starches Derived from Different Foodstuffs. Part IV. Study of Radiodepolymerization
Authors: Raffi J. , Dauberte B. , d'Urbal M. , Pollin C. , Saint‐Lèbe L.
Published: November 2006

The foodstuffs from which the investigated starches (maize, waxymaize, amylomaize, manioc, bread‐wheat, potatoe, rice and haricot bean) derive has only little influence upon their radiodepolymerization, as previously stated by theory.
Modification of Rice Starch through Thermal Treatment with Urea
Authors: Abd El‐Thalouth I. , El‐Kashouti M. A. , Hebeish A.
Published: November 2006

Modification of starch with urea was carried out at 165 °C according to solid state, paste and film techniques. With the solid state and paste techniques the extent of the reaction, expressed as % N, increased by increasing the time of treatment. Samples prepared by the film technique showed, during the first 15 min reaction time, significantly higher nitrogen content which, however, decreased by prolongation of the treatment. Infra‐red spectrum of the reaction products indicated involvement of both starch and urea in a chemical reaction. Examination of the swelling properties of the products revealed that these properties are dependent upon the technique used for preparation rather than the extent of the reaction. Samples prepared by the paste and film techniques acquired higher apparent viscosity than those prepared by the solid state technique irrespective of the rate of shear. For a given rate of shear, the apparent viscosity increases by increasing the temperature.
Preparation of Cationic Starch Ether: A Reaction Efficiency Study
Authors: Carr M. E. , Bagby M. O.
Published: November 2006

Cationic starch ether, important as a papermaking additive, was prepared from native corn starch and 2‐chloro‐3‐hydroxypropyltrimethylammonium chloride in aqueous media in a study to ascertain conditions yielding maximum reaction efficiency (RE). Based on the amount of monomer retained after exhaustive washing procedures, RE values of 84–88% were achieved with 0.025–0.05 mole of monomer/mole of starch. Degrees of substitution of up to 0.075 were investigated. A number of variables were studied that allow high RE under a variety of reaction conditions, including those involving low energy input. The excellent stability of the monomer during etherification suggests that the water‐soluble active monomer and salts could be recycled in subsequent reactions.
Fortschritte bei der Separation und Stabilisierung von Kartoffelprotein
Authors: Wilhelm E. , Kempf W.
Published: November 2006

Thermisch koaguliertes Kartoffelprotein war ohne erhebliche Qualitätsminderung bislang nicht lagerbar, was seinen Einsatz in Lebensmitteln wesentlich erschwerte. Die dafür verantwortlichen, im Fruchtwasser gelösten Stoffe gelangen durch Adsorption in das Koagulat. Bestandteile wie Lipide und Lipoproteine werden bei der Lagerung in Licht und Sauerstoff autoxidiert und verändern die organoleptischen Eigenschaften des Proteins negativ. Lipoproteine wurden durch Zentrifugieren vom Fruchtwasser abgetrennt, Lipide aus dem Proteinkoagulat mit organischen Solvenzien extrahiert. Eine Proteinstabilisierung durch Stickstoffatmosphäre war nur zu erreichen, wenn Sauerstoffausschluß während des gesamten Prozesses sichergestellt war.
Enzymatic Hydrolysis of Inulin — An Alternative Way to Fructose Production
Authors: Zittan L.
Published: November 2006

In the seventies large amounts of fructose have been produced from starch by isomerization of glucose. An alternative source of fructose is inulin, present as energy reserve in plants, e. g. from the composite family such as chicory and Jerusalem artichoke. To produce fructose from inulin a hydrolysis step is necessary. This can be performed by acids, but enzyme hydrolysis is preferable because of lower byproduct formation. An enzyme specially suited for industrial application is described. Full hydrolysis of inulin more than 98% (fructose and glucose) can be achieved at 60–65°C using economical dosages of enzyme. The reasons for the special efficiency of the enzyme are touched upon.