bluuebunny/crossref_metadata_2025 huggingface dataset:
Nitratability of Dextrans
Authors: Mustafa Ahmed , Dawoud Abdel Fattah , Marawan Ashraf
Published: November 2006

Nitratability of three different polymeric dextrans with predominantly α‐1,6‐linked anhydro‐D‐glucopyranose units was studied in different nitrating agents. The degree of substitution (D. S.) increases with increase of the absolute nitric acid/dextran ratio. Due to gelatinization of dextrans in this medium, this nitrating agent is comparatively less effective for dextran nitration than for starch with predominantly α‐1,4‐D‐glycosidic linkages; the latter has great affinity to dissolution in this medium. Nearly complete nitrations (D. S., 2.96) were readily obtained from dextrans by nitration in presence of 25% each of acetic acid and acetic anhydride.

In nitric‐sulphuric acids mixtures the nitratability of dextran is mainly a function of acids composition. Gelatinization occurred in mixed acids containing up to 20% H2SO4. Successful nitrations (D. S., ca. 2.6) were always obtained, however, from mixed acids containing 38% or more sulphuric acid, but the use of 62% sulphuric acid is more economic for industry. The sulphate content is greatly dependent on the acids composition and it is, as well, affected by the chemical nature of the corresponding dextran.
Scanning Electron Microscopy of Wheat Starch II. Structure of Granules Modified by Alpha‐Amylolysis – Preliminary report
Authors: Evers A. O. , McDermott E. E.
Published: November 2006

Wheat starch granules were subjected to alpha‐amylolysis after which they were examined in the Scanning electron microscope.

Much variation exists among starch granules; thus conclusions based on the observation of the precise mode of α‐amylase attack on a few individual granules may not be generally applicable. It has been found, however, that where a groove is present in a granule, α‐amylase attack generally occurs here, complete penetration either occurring exclusively at this feature or accompanying penetration at apparently randomly located sites on the major surfaces.

This preliminary investigation of starch granules attacked by amylase has provided new information which augments the results of studies by other microscopical methods. Observation of the detailed structure of the equatorial groove in modified granules is particularly relevant to a better understanding of this feature in starch granules.
Neue Erfahrungen mit Dorr‐Oliver Multizyklonen und D‐O DSM‐Bogensieben in der Kartoffelstärke‐Industrie
Authors: Caransa A.
Published: November 2006

Recent Experiences with Dorr‐Oliver Multicyclones and D‐O DSM Screens in the Potato Starch Industry. Potato starch flowsheets are described i. e. one from 1958, one from 1962 and the most up‐to‐date one (1968) showing a combined D‐O DSM‐Screening system for coarseand fine pulp together and separate Dorr Clone washing systems for optimal refining of coarseand fine granule starch.

Tables are given, showing results obtained during recent campaigns. Finally data are disclosed regarding power consumption and water saving.
Studies on Dextrinization. Part I. Pyrodextrinization of Corn Starch in the Absence of Any Added Catalyst
Authors: Srivastava H. C. , Parmar R. S. , Dave G. B.
Published: November 2006

Corn starch has been dextrinized at a bath temperature of 125°–213°C. In certain cases, the moisture content of the starch was reduced to 2% before it was subjected to dextrinization. Under the various conditions of dextrinization, the changes that take place in the properties of starch such as solubility, reducing power, alkali lability, intrinsic viscosity and β‐amylolysis have been recorded. These results show that at lower temperatures of 125° and 150°C hardly any reaction is perceptible, the dextrinization reaction taking place at 200°C or thereabouts. Decreasing the moisture content of starch increases the rate of dextrinization reaction. Various theories of pyrodextrinization of starch are discussed.
Zum Stand der Kenntnisse über die Vorgänge bei der Alterung der Stärke in Backwaren
Authors: Augustat S. , Schierbaum F. , Richter M.
Published: November 2006

On the State of Knowledges Concerning the Processes During Staling of Starch in Baked Goods. 1. The present level of knowledge on staling of baked goods is discussed shortly on the example of most essential theories. 2. Research into the problem of staling of gels of wheat starch or wheat flour was performed viscographically and ridgelimetrically. 3. The photometric titration with iodine and the paper elution analysis with perchloric acid are recommended as new methods for a separated characterization of the starch constituents during staling. 4. In the staling of baked goods, the changes of starch play a predominate role, the swelling condition of the starch granule and the chemo‐physical and chemo‐colloidal behavior of the two starch constituents being decisive factors. 5. The natural fat content of flour or the addition of saccharose monostearate counteract the hardening of the corresponding gels, caused by staling, by inhibiting the swelling process of the starch granules and the effect of amylose on the formation of structure.
New Varieties of Sorghum Grain Suitable for Starch Production
Authors: Mustafa A. I. , Macmasters M. M.
Published: November 2006

Thirty‐one samples of sorghum grain produced experimentally were processed by a laboratory wet‐milling procedure. Twelve gave acceptable white starches because there was no nucellar tissue remaining in the mature grain. Paste viscosity and gel strength of all starches were determined and organoleptic evaluation was made of each starch in the form of asidah, a Sudanese food. Some differences in paste viscosity and gel strength were found. Some of the samples were waxy and some nonwaxy. All the white nonwaxy starches were rated highly acceptable as asidah. The experimental lines provide germ plasm from which commercial varieties suitable for wet milling can readily be developed.
Studies on New Starches. Part 2. A Study of the Properties of Four Varieties of Mucuna Bean (Stizolobium)
Authors: Tolmasquim E. , Corrêa A. M. N. , Nakamura T.
Published: November 2006

The starches of the four varieties of Mucuna that have been studied are formed by granules of different sizes and rounded shapes. The average affinity for iodine is 5.60% and the amylose content is not very high. The values of the restricted swelling power and solubility and the slow and progressive solubilization in DMSO suggest a very homogeneous structure, with strong linking forces and a high degree of association inside the granules. The Brabender viscosity curves are very similar to those of the starches with artificially crossed linkages. These properties give the Mucuna bean starches very useful technological applications.
Die spezifische Drehung des Sorbits und des Sorbit‐Molybdat‐Komplexes
Authors: Lippke G. , Thaler H.
Published: November 2006

The Specific Rotation of Sorbitol and of the Sorbitol Molybdate Complex.

The specific rotation of the hexite at 365, 405, 436, 546 and 578 nm has been determined in solutions of different concentration with a commercial sorbitol preparation as well as with a self‐produced sorbitol. Contents of both preparations had been determined enzymatically and by means of periodate. The specific rotation [α]D was obtained mathematically from these data as well as by graphic extrapolation.

Conditions, under which the sorbitol molybdate complex shows its maximum of specific rotation were defined by systematic experiments at varying sorbitol, molybdate and hydrogen‐ion concentration.

From these results a diagram was set up, which shows the molybdate and acid doses in order to determine sorbitol polarimetrically in the widest possible range.

The specific rotation of the sorbitol molybdate complex was determined at the same wavelengths as that of the sorbitol. It was also mathematically and graphically extrapolated for [α]D.
Die Auswirkungen der Verordnung über die Verwendung von Schwefeldioxid vom 13.8.1969 auf Stärkeverzuckerungserzeugnisse
Authors: Schroeter K. A.
Published: November 2006

Influence of the Ordinance (13. 8. 1968) on the Use of Sulfur Dioxide on Starch Derived Sweeteners.

An information is given on the ordinance concerning the use of sulfur dioxide in foodstuff and on its legal effects on starch derived sweeteners:

1. In general starch and starch derived sweeteners may contain a maximum residue of 50 ppm SO2 being a residue of a so‐called technical aid. Dextrose may contain only a residue of 10 ppm SO2. Label declaration of these residues is not necessary.

2. Starch derived sweeteners which are destined to be used in the manufacturing of foodstuff mentioned in Annex 2 of the ordinance, may have a higher SO2‐content. A maximum content has not been fixed, a SO2‐content, however, being higher than 50 ppm is to be labelled as „sulfured.

3. As far as, according to para 2 above, a declaration of the SO2‐content is necessary the declaration has to be indicated on the package itself. In case of products being sold in bulk, the declaration has to be mentioned on the accompanying papers.
A Simplified Colorimetric Method for Determination of Amylose Content in Rice
Authors: Sowbhagya C. M. , Bhattacharya K. R.
Published: November 2006

The colorimetric iodine method of amylose estimation in rice has been simplified. The flour is dispersed in alkali by heating in water bath or by overnight soaking at room temperature. The extract is neutralized before colour development by direct addition of phenolphthalein and decolourizing with dilute acid.

No simplified method of defatting (including extraction by methanol at room temperature) was found satisfactory. But apparent amylose content as determined in undefatted milled rice flour was close to 86% of the true value in 46 milled rice samples tested; hence determination without defatting and multiplication of the results with 1.16 was satisfactory for routine and approximate work. The apparent amylose value was, however, dependent on the degree of polish of the rice.

Particle size of the flour within reasonable limits had no appreciable effect on the results. The extract was quite stable even when stored in the room temperature.
The Characterisation of Starch and Its Components Part 4. The Specific Estimation of Glucose Using Glucose Oxidase
Authors: Banks W. , Greenwood C. T.
Published: November 2006

The glucose oxidase/peroxidase technique for determining microgram quantities of glucose in aqueous solution has been critically examined. The function of each of the constituents in the solution has been studied, and the relation between time and temperature of incubation determined. Potential errors due to the temperature‐dependent pH‐behaviour of tris buffers, and the presence in the solution to be analyzed of high concentrations of buffer salts, glycerol, and reducing substances, are discussed. The relation between the absorbance, and the type and normality of acid used to stabilize the colour is examined.
Beiträge zur Geschichte der Stärke‐Mikroskopie. 2. Mitt.
Authors: Seidemann Johannes
Published: November 2006

Contributions to the History of Starch Microscopy. Part 2.

An answer to the question, how the different dates for the first detailed microscopie evidence of starch came about is followed by a closer look at the microscopie description and the graphic reproduction of wheat, bean and pea starch by A. van Leeuwenhoek.
Zusammenhang zwischen Konformation der Glucopyranoseeinheiten und Molekülkonfiguration der Amylose
Authors: Szejtli J.
Published: November 2006

Relationship between the Conformation of the Glucopyranoside Units and the Molecular Configuration of Amylose.

As a consequence of the tetrahedral valence angle as well as of the interactions between the H and OH groups attached to the C atoms the most probable form of D‐glucopyranose is the Cl conformation. The rotation around the oxygen‐bridge between the two glucopyranose units in maltose is hindered to such an extent that the existence only of that form seems to be probable, in which all similar substituents are placed on the same side of the molecule. The non‐bonded interaction between H–1 and H–4′ is diminished by a slight twisting of the plane of the two rings about the glucosidic bond in opposite directions. This arrangement renders possible the forming of O–2… O–3′ hydrogen bonds which contributes to the stabilization of the helical structure. Therefore under such conditions when this H bond is stable, the homologues of maltose – amylose too – achieve a helical molecular configuration.
Neuere Untersuchungen über die Lipide der Getreidestärken. I. Einleitung Methodik
Authors: Becker G. , Acker L.
Published: November 2006

Recent Studies on Lipids of Cereal Starches. Part 1. Introduction and Methodology.

A survey on the more recent works in the field of lipids of cereal starches is given. Subsequently, there is a report on the isolation of lipids of cereal starches and their analysis.
Some Observations on the Stability of Amylose and Amylopectin in Aqueous Solution
Authors: Greenwood C. T. , Hourston D. J.
Published: November 2006

Results are presented for a series of light‐scattering experiments on the stability of the starch components, amylose and amylopectin, in 0.33 M KCl. Potato, regular maize amylose, and the amylose from two amylomaize starches have been studied. The findings are generally in agreement with previous studies in this area, but in the case of amylopectin, contrary to the findings of Čeh and Vene, no retrogradation has been observed.
Weizenstärkekörner. polarisationsoptisch und elektronenmikroskopisch
Authors: Czaja A. Th.
Published: November 2006

In earlier studies since 1961 [1] the author has observed that the A type starch granules of Wheat and other Hordeae show between crossed Nicols in most cases differentiated polarization crosses. In the center of these there is a little high double refracting disk with a small dark polarization cross. In the broader outer zone, which is not so bright, the armes of the small cross are persued much broader and indistinct.

A. D. Evers (1971) has shown with the scanning electron microscope that the development of A type starch granules begins with an initial minute spherical granule, which becomes a „nucleus”︁, and which is progressively surrounded in the equatorial plane by a continually enlarging structure which resembles two lips with a furrow between them. When the lips have surrounded the „nucleus”︁ the thickness and diameter of the granule continue to increase in such a way that the furrow becomes shallower and is present in the mature biconvex structure only as a shallow score.
Studies on the Structure of Leguminosae Starches. 1. Solubility in Dimethyl Sulfoxide and by Enzymatic Action
Authors: Rosenthal Feiga R. T. , Nakamura Takeko
Published: November 2006

In order to elucidate the granular structure of the leguminous starches the speed of solubilization of several starches was determined by digestion with dimethyl sulfoxide and with α‐amylase. By microscopic investigations with normal and polarized light different forms of erosion were observed in the different starches, all of them less intense than those observed in cereal starches.

It was concluded that the starch granules of mucunã seeds are the most homogeneous and have the least porous structure, followed by chick pea, jack, lablab and guanda beans. It is supposed that maturation, climate and soil influence the cristallinity of the granules, resulting in different digestibility.
Der fermentative Abbau der Kartoffelstärkekörner
Authors: Czaja A. Th.
Published: November 2006

The Fermentative Degradation of Potato Starch Granules. The difference between the fermentation of the starch granules as a whole in the living cells during germination of the potato tuber and the enzymatic destruction of the isolated starch granules by microorganisms (bacteria or fungi) is once more demonstrated. The last named process results by setting pores or little channels into the substance of the starch granules or following the weaker zones of the sheaths.
A Reassessment of the Chemical Structure of Barley and Wheat Starch Granules
Authors: Bathgate G. N. , Palmer G. H.
Published: November 2006

Barley starch exists in two clearly defined populations of large (ca. 25 μ diameter) and small (ca. 5, μ diameter) granules, whilst in wheat there is a range of granule sizes with no similar bimodal distribution. The small granules of barley represent about 90% of the total starch granules by number, but account for only about 10% of the total starch in weight. Fractions containing only large or only small granules have been isolated from both barley and wheat. The small granules from barley have a higher amylose content than the large granules, a higher gelatinisation temperature, and are usually associated with more protein. In contrast, large and small granules from wheat differ only slightly in their respective amylose contents but, like barley differ in gelatinisation temperatures and amounts of associated protein. It is proposed that starch synthesis in the small starch granules of barley is under different genetic control from that in the large granules.
Critical Features of the Morgan Assay of Hydroxyethyl and Hydroxypropyl Substituents in Polysaccharides
Authors: De Belder A. N. , Persson Å. , Markström S.
Published: November 2006

The conditions for obtaining an accurate and reproducible assay of hydroxyethyl and hydroxypropyl substituents in the corresponding polysaccharide derivatives are described. Suitable compounds for standardising the procedure are described.
Einfluß der Klärmittel und ihrer Menge auf die polarimetrische Bestimmung von Kartoffelstärke nach Ewers
Authors: Dudáš F.
Published: November 2006

Influence of Clearing Agents and their Amount on Polarimetric Determination of Potato Starch According to Ewers. According to the results of chemical analysis and its statistical evaluation the Carrez clearing agent at an amount of 1 ml appears to be the most suitable for determination of starch in potatos. Use of sodium molybdate or ammonium molybdate led to lower values in average. Among these two sodium molybdate, as during examination of starch samples, appeared more suitable than ammonium molybdate. Phosphortungstic acid proved the least suitable. Normal as well as basic lead acetate after Horn did not show fully clear results upon revision. This is why they were not used.
5th Plenary Meeting of ISO/TC 93 in Paris
Authors: Kempf W. , Graefe G.
Published: November 2006

This article will report on the course and the result of the 5th Plenary Meeting of Technical Committee 93 of the International Organization for Standardization (ISO) which deals with standardization of analytical methods and test processes in the field of starch and its derivatives and by‐products. By invitation of the French Standardization Committee ”︁Association Française de Normalisation„ (AFNOR) it was held on Thursday 16, March and Friday 17, March, 1972, in Paris. There will be a report on the resolutions which were passed as recommendations in the course of the 2‐days Plenary Meeting as well as on resolutions passed – also as recommendations – by the two Sub‐Committees SC 1 ”︁General Problems„ and SC 3 ”︁Starch Hydrolysates„. The latter committees had been newly constituted by the Central Secretary's office during reorganization of the entire ISO/TC 93 in 1970 without questioning or consent of the technological experts. These committees gathered also in Paris fo the first meeting after their constitution on the 14th and 15th of March.
Influence of Food Emulsifiers on Pasting Temperature and Viscosity of Various Starches
Authors: Krog N.
Published: November 2006

The influence of monoglycerides (DGMS), stearoyl‐2‐lactylates (CSL, SSL), and diacetylated tartaric acid esters of monoglycerides (DATE) on amylograph curves of various starches has been investigated. DGMS gave the greatest increase in pasting temperature of wheat and tapioca starch, followed by SSL, CSL and DATE. The pasting temperature of corn and potato starch was less affected by these emulsifiers. Peak viscosity of wheat starch in distilled water was increased by all emulsifiers, and was decreased in tapioca and potato starch.

Both pasting temperature and peak viscosity were strongly influenced by variations in pH, and were to some extent also dependent on ion concentration. In hard tap water the peak viscosity was slightly decreased by the anionic emulsifiers (SSL > CSL > DATE), due to the presence of Ca++ and Mg++ ions, while DGMS gave a higher peak viscosity than in distilled water. DATE seems to be more sensitive to variations in pH or ion concentration than the other emulsifiers.
Degree of Gelatinisation of Cooked Rice
Authors: Birch G. G. , Priestley R. J.
Published: November 2006

A method for determining degree of gelatinisation of rice starch or rice flour, based on the amylose/iodine blue value after dispersion in alkali, has been developed. The method can be used to follow the course of cooking of rice under different conditions, and has been checked against a novel infrared technique for relating degree of gelatinisation to the phenomenon of hydrogen bonding.
Studies on the Biosynthesis of Starch Granules. Part 5. Properties of the Starch Components of Normal Barley, and Barley with Sturch of High Amylose‐Content, During Growth
Authors: Banks W. , Greenwood C. T. , Muir D. D.
Published: November 2006

Changes in the molecular components of barley starch, from related genotypes of barley differing in amylose‐content, have been investigated over the period of reserve‐starch deposition in the plants. Striking similarities in the changes in amylose‐contents, and in the fine structure of component amylose and amylopectin fractions, were observed over this period, despite the large differences in the types of starch.
Investigations into and an Enzymic Assay Method of Transglucosidase Activity of Commercial Glucoamylase Preparations
Authors: Vámos L. , Rose P.
Published: November 2006

An enzymatic assay method was developed for the quantitative determination of transglucosidase activity in commercial glucoamylase preparations. The method is based on the determination of residual glucose after incubation of the glucoamylase preparation with this substrate under welldefined conditions (pH 4,2 and 30°C). Glucose determination was carried out by the glucose oxidase‐peroxidase method and transglucosidase activity expressed in international enzyme activity units. The over‐all time requirement of the analysis is 3 h with liquid and 26 h with powdered preparations. The variation coefficient was less than 3% in the former and 4% in the latter case. Optimum substrate concentration was found to be 8,3% w/v, higher glucose concentrations markedly inhibited the reaction at 30°C. Temperature optima were observed at 40 and 50°C, respectively, more elevated temperatures up to 60°C caused a strong decrease in activity.
Potentiometric Titration of Chloride in Corn Syrup Using the Chloride Ion Electrode
Authors: Jacin H.
Published: November 2006

A potentiometric method for the determination of chloride ion in corn syrup was developed. Chloride is titrated with silver nitrate and the end point determined by a specific chloride‐ion electrode. The method is applicable to normal and deionized corn syrups. The recoveries of added chloride ranged from 97 to 101 percent. The relative standard deviation in a series of six determinations was 0.51%.
Determination of Silica in Corn Syrup
Authors: Jacin H.
Published: November 2006

A method for the determination of silica in corn syrup is presented. A silico‐molybdate complex is formed. The interfering phospho‐molybdate is neutralized by the addition of oxalic acid. The silico‐molybdate complex is reduced by 1‐amino‐2‐naphthol‐4‐sulfonic acid to give the heteropoly blue which absorbs at 810 nm. Repeated analysis of a corn syrup gave a value of 17.8 microgram silica per gram of solids and a standard deviation of 0.06 for nine determinations. The recovery of added silica was in the range of 99–103%.
Studies on the Biosynthesis of Starch Granules. Part 7. Compound Granules in Potato Starch
Authors: Banks W. , Greenwood C. T. , Muir D. D.
Published: November 2006

The nature of compound starch granules in potato starch is examined. The relevance of this investigation to the possible formation of potato starch is discussed, and a mechanism for synthesis of compound granules proposed.
Développement des connaissances sur l'ultrastructure du grain d'amidon. I. L'amidon de blé
Authors: Gallant Par D. , Guilbot A.
Published: November 2006

Developments in Starch Ultrastructure Knowledge. I. Wheat Starch Granules.

The observations made by Sandstedt, in 1946, have been precised and explained with considerable improvement of technics for observations, especially with transmission and scanning electron microscopy. In the outline of the present reviewing concerning new developments in the wheat starch ultrastructure knowledge are studied: 1) The development of larger and smaller starch granules, extracted from the endosperm cells or examined in situ; 2) The lintnerization or enzymatic hydrolysis of lenticular shaped wheat starch granules; 3) The hydrolysis of smaller granules of which technological importance is recalled. A tridimensional diagram is given to complete the Buttrose's one, proposed in 1962.
Complexes of Starch and its Related Materials with Organic Compounds. Part. X. X‐Ray Diffraction of Amylose‐Fatty Acid Complexes
Authors: Takeo K. , Tokumura A. , Kuge T.
Published: November 2006

X‐ray diffraction analyses of the complexes of amylose with a wide variety of fatty acids were carried out. The unit cell dimensions of the complexes were calculated for both the wet and dry states. Both the 61‐ and 71‐helical conformations of amylose were found in these complexes, and the conformation seems to depend on the linear chain length of the acid molecules. The orthorhombic unit cell was proposed for the 71‐helical structure of the wet complexes. The dibasic acid gave the crystal modification of the complexes exhibiting the diffraction pattern of hexagonal or orthorhombic nature. It was also found that complexations with n‐propionic acid give rise to three kinds of the patterns, depending on the amount of n‐propionic acid added to aqueous solution of amylose.
Etude de l'acidité formée au cours de l'irradiation gamma de l'amidon de maïs
Authors: Athanassiadis Par H. , Berger G.
Published: November 2006

Study of γ Radioinduced Acidity in Corn Starch.

Amounts of radioinduced acids and esters in corn starch have been measured in terms of different conditions of irradiation (dosis, dosis rate, temperature, atmosphere) and of starch characteristics (% water, impurities, kind of glucosidic link) and results have been compared to those given by heat sterilization. Subsequent development of acidity have been checked during the storage at ambient temperature.
Presence d'acide formique dans l'amidon de maïs irradié
Authors: Dauphin J. F. , Athanassiadis H. , Berger G. , Saint‐Lèbe Et L.
Published: November 2006

Presence of Formic Acid in Irradiated Maize Starch. Formic acid occurs in relatively large amounts during gamma irradiation of maize starch (100 μg/g/Mrad, in oxygen). It represents the main part of radio‐induced free acidity. We determined the influence of several parameters: irradiation conditions (dose, dose rate, temperature, surrounding gas), storage temperature, starch characteristics (moisture, impurities), heat treatment. A formation process is prosposed.
Gamma‐Irradiated Corn Starches. Alkaline Dispersions for Surface‐Sizing Paper
Authors: Hofreiter B. T. , Russell C. R.
Published: November 2006

Corn starch was depolymerized by gamma irradiation (cobalt 60, approximately 1.25 Mrads/h) to prepare reduced viscosity products for surface‐sizing paper. The general effects of irradiation were determined on the extent of starch degradation, as well as dispersion variables. Low levels of irradiation, 0.02 to 0.5 Mrad, had a profound influence on granule swelling and disruption at a pasting temperature of about 90°C as determined in a recording viscometer. Product properties are affected considerably by carbonyl and carboxyl groups even when introduced at levels below 1 mmol/100 g. Carbonyl groups impart alkali sensitivity that produces significant degradation during dissolution in stoichiometric quantities of alkali. Carboxyl groups in starch paper sizes are detrimental because they act as dispersants for fines and fillers in repulped paper. Apparently dispersion in alkali is the most effective way to utilize irradiated starches as surface‐sizing agents. Corn starch irradiated to 2 Mrads and dispersed in alkali improved paper properties as well as a high quality commercial product.
The Characterization of Starch and Its Components. Part 6. A Critical Comparison of the Estimation of Amylose‐Content by Colorimetric Determination and Potentiometric Titration of the Iodine‐Complex
Authors: Banks W. , Greenwood C. T. , Muir D. D.
Published: November 2006

This paper is dedicated to Mr. Ernst Hees, Editor of „Die Stärke”︁ from 1958 until December, 1973, as a token of the esteem with which we regard his work in this capacity. We thank him for his efforts, which have so successfully helped to advance the subject of starch chemistry in all its diverse aspects.

The techniques of (i) semi‐micro, differential, potentiometric iodine titration of starch with iodine, and (ii) colorimetric assay of the starch‐iodine complex in solution have been compared as analytical tools for the measurement of the amylose‐content of starches. Although the colorimetric method may be calibrated to give comparable results to the potentiometric assay, the former technique is not applicable to maize starches of high amylose‐content.
Die dielektrischen Eigenschaften der Stärke im Mikrowellenbereich als Grundlage für die Feuchtigkeitsbestimmung
Authors: Mládek J. , Komárek K.
Published: November 2006

Dielectric Properties of Starch in the Range of Microwaves as a Basis for Determination of Humidity. The change of dielectric properties of starch with change of water content was utilized for continual determination of humidity. For that purpose, the balance method was applied, in order to measure attenuation and phase shift of the electromagnetic wave permeating the material. The 10 GHz‐microwave was generated by means of a reflex klystron. With increasing humidity there is an increase of electric loss. At the same time, the increase of attenuation of the electromagnetic wave in the starch makes possible to find the transitions between free and bound water of capillarity using a correction control circuit an accuracy in measurement of 0,3% absolute is reached.
Starch Xanthide Styrene‐Butadiene Rubbers. Effect of Prolonged Water Immersion
Authors: Buchanan R. A.
Published: November 2006

Both conventionally reinforced and starch xanthide reinforced styrene‐butadiene (SBR) rubbers swell continuously during water immersion without reaching equilibrium and eventually mechanical breakdown occurs. During 90 days of water immersion, starch xanthide‐reinforced SBR swells more than conventionally reinforced SBR, but much less than would be calculated from the volume fraction of starch xanthide and its swelling ratio as measured separate from rubber. Swelling rate of vulcanized starch xanthide‐SBR rubber specimens depends on their shape and is negligible for specimens with low enough surface to volume ratios. Standard tensile test specimens have low cross sections in the break area and provide a sensitive measure for the deleterious effect of prolonged water immersion. The effects after 90 days in water on both swelling and tensile properties of starch xanthide‐SBR are fully reversible by drying test specimens. Starch xanthide‐SBR masterbatch can be compounded either with reactive crosslinking and coupling agents or with low‐cost extenders and fillers to reduce greatly the effect of prolonged water immersion.
Derivatives of High‐Amylose Starch Xanthate in Rubber. Influence of Amylose Content of Starch Upon the Water Resistance of Starch‐Reinforced Styrene‐Butadiene Rubbers
Authors: Katz H. C. , Kwolek W. F. , Buchanan R. A. , Doane W. M. , Russell C. R.
Published: November 2006

Crosslinked low‐amylose (0 or 28%) starch xanthates used as reinforcing materials in styrenebutadiene elastomer imparted better dry tensile properties than their high‐amylose (55, 68 or 82%) analogues. After immersion in water for 70h the tensile strength of low‐amylose starch reinforced vulcanizates deteriorated considerably while high‐amylose starch reinforced vulcanizates changed little or not at all. Such variables as xanthate degree of substitution and starch loading influenced curing time and properties. Mode of crosslinking the xanthate significantly affected retention of starch in the coprecipitate, and produced significant variations in curing characteristics, and in such properties as compression set, set at break before immersion in water and tensile strength after water immersion. The method of drying affected compressions set and modulus.
Leistungssteigerung von Stärke‐Zentrifugen durch Siphon‐Trommel
Authors: Zeppenfeld K.
Published: November 2006

Capacity Increase of Starch Centrifuges by means of Siphon Drum. The operating method of a centrifuge drum with rotation siphons is described as the thus possible increase of filtration output. In addition, the use of the siphon drum when centrifuging maize starch are commented on. Due to the rotation siphon at the centrifuge drum and by means of a liquid sucking device to be swung into the siphon, the liquid level in the rotation siphon can be lowered to such an extent that below the filter cloth a considerable suction effect is caused. Thus the filtration speed may be increased by 50 to 300% according to the product and the capacity of the centrifuge is considerably increased due to the thus possible shorter cycle times. In the case of maize starch the filtration output can due to the rotation siphon be increased by the 1.7 to 2 fold.

The overflow process used at present reconvey a considerable part of the starch milk into the preceding process. In order to avoid this, the discharge process was taken up. For this process the drum is filled but once up to rim as quickly as possible. After a short sedimentation time the liquid descharge device is swung into the drum and the clarified liquid is discharged within a short time. Subsequently, the siphon drum causes a very quick dry sucking of the starch layer in the drum, so the centrifuge may after a short time be discharged.
Glucoseisomerase. Neue Möglichkeiten für die Stärke‐ und Lebensmittelindustrie
Authors: Geyer H. U.
Published: November 2006

Glucoseisomerase. A lecture is given about an enzyme, which convertsD‐glucose intoD‐fructose up to 50%. The glucoseisomerase is obtained from STREPTOMYCES, The enzyme is activ under plant conditions, i. e. at high substrate concentrations (> 30% ds), high temperature (> 60 °C) and at pH‐conditions which prevent formation ofD‐psicose. Correlations are presented between degree of isomerisation (I.D.), temperature, pH, substrate concentration, enzyme‐substrate ratio, Co‐factors and the effects of the processing conditions on the formation of colour as well as methods to avoid colour formation. The preceeding enzymatic steps with α‐amylase and gluco‐amylase are now linked by means of glucoseisomerase to the production of carbohydrates with 100% relative sweetness out of wheat, potatoes, corn etc.
Factors Affecting the Catalytic Hydrogenation of D‐Glucose. Part I. Effect of Type of Catalyst and Concentrations of both Glucose and Catalyst
Authors: Abdel Akher M. , Ghali J. , Raouf M. S. , Roushdi M.
Published: November 2006

The effect of five different types of catalyst and the concentration both of glucose and catalyst on the rate of the catalytic hydrogenation of glucose has been investigated.
European Maize Source Material for Wet‐Milling Industries. Activities of the Technical Committee of the E. C. Maize Starch Industries
Authors: Beaux Y. , Lasseran J. C. , Kempf W. , Guilbot A.
Published: November 2006

European maize wet‐milling industries process 3.2 million t of maize per year. For this supply the world market share decreases progressively to the E. C. market's advantage. Manufacturers have not always a long experience of such maize, the quality of which is variable.

The increasing number of cultivated varieties, the changes of maturity conditions according to years, and the evolution of the harvesting‐drying‐preserving sequence towards an industrialisation, emphasize the variations of E. C. maize wet‐milling quality.

The immediate care of manufacturers is therefore to have available simple and rapid methods for the appreciation of this quality. Then, these methods will have to be applied to the determination of good conditions of maize production for this industry.

Ensuing french studies, a concerted research program has been developed since the beginning of 1973 on the basis of the previous remarks. The coordination of these studies is undertaken by a Technical Committee of E. C. Maize Starch Industry grouping research institutes, i. e. I. T. C. F. (Technical Institute for Cereals and Forages, France), I.N.R.A. (National Institute of Agronomic Research, France), F.R.I.C.I. (Federal Research Institute of Cereal Industry, Germany), professional associations, i.e. A.G.P.M. (General Maize Growers Association, France), A.A.M. (Association of the Maize Starch Industries of the E.C., Belgium), and a representative of manufacturers for each member country.

The work done in 1973 represents the preliminary phase of these studies, and was carried out on samples from 1972 harvest, crop year abnormaly unfavourable for maize growing. The results obtained are therefore mostly on a methodology level, and the main purpose of the 1974 research program is to confirm and complete these informations.
Factors Affecting the Catalytic Hydrogenation of D‐Glucose. Part III. Effect of pH‐Value and Promotors
Authors: Abdel Akher M. , Raouf M. S. , Ghali J. , Roushdi M.
Published: November 2006

The rate of hygrogenation was highly increased by carrying out the reaction at pH 8. Addition of some metals and metal salts, especially calcium sulphate, highly increased the rate of hydrogenation at pH 6.8.
Kriterien zur Qualitätsbeurteilung von Trockenkartoffelerzeugnissen für die menschliche Ernährung
Authors: Bergthaller W. , Putz B. , Fehn K. H. , Schilling M.
Published: November 2006

Criterions to evaluate the quality of dried potato products for human consumption. The swelling properties of dried potatoes were tested. In the first part of this work the importance of starch and dry matter for the swelling behavior of dried potatoes is reported. To evaluate these experiments the correlation coefficient is used. 140 samples of dried potatoes were tested. Continuing the test series dried potatoes manufactured from one potato variety, what is devided into different classes of specific gravity were examined. The used physical conditions for estimating the swelling behaviour are the “swelling number” and the “rehydration value”.

The central point of the second part is a theory to explain the phenomena of swelling for itself. This theory tries to answer the basic question how to influence the swelling behaviour of dried potatoes. The results of these experiments are interpertated by the postulation that two reaction typs estimate the swelling of dried potatoes:

The first reaction depends on the surface and is exothermic.

The second reaction does not depend on the surface and is endothermic.
Characteristics and “Fodal”‐Factor of Mango Seed Kernel Starch
Authors: Abd‐Allah M. A. , Foda Y. H. , Hamed M. G. E.
Published: November 2006

Starch prepared from mango seed kernels is characterized by a low protein and fat content. Infrared studies proved the presence of amine and carboxyl groups of amino acids at wave numbers of 1485 and 1650 cm−1 respectively, whereas the phosphate group had been detected at 1150 cm−1.

The contents of amylose and amylopectin were 39.9 and 60.1 respectively, reducing value was 1.54 and the alkali number was 10.10. The percentage of soluble material associated with starch was 2.11, whereas the percentage of branching of the mango seed kernel starch was 4.23. The glucose residues per end group were 23.62 and those per a segment were 11.81. Corn starch showed approximately the same values, whereas rice starch showed different results.

The intrinsic viscosity was 1.72, 1.83 and 1.33 for mango seed kernel, corn and rice starches respectively, and the corresponding “Fodal” factors were 0.947, 0.983, and 0.992. X‐ray analysis indicates that mango seed kernel starch possesses an “A” type of X‐ray diffraction diagram.
Stufenweise Elutionsanalyse von Carboxymethylstärke
Authors: Čeh M. , Stropnik Č.
Published: November 2006

Gradual Elution Analysis of Carboxymethyl Starch. Paperchromatographic elution separation with perchloric acid solutions of different molarities were carried out with synthesized carboxymethylated starches (CMS) of the following degrees of substitution (DS): 0,30, 0,58, 1,09 and 2,17.

On the basis of occurring coloured sections in comparison with those of native starch it could be stated that the native starch is subjected during the CMS‐synthesis to a partial degradation. A comparison of the chromatograms of the starch ethers indicates for higher DS a change into violet colours, a fading of these colour intensities and an arising of new coloured sections which were separated by lower concentrations of perchloric acid. Already at a degree of substitution of 2,17 any coloured sections are lacking. Induced carboxymethyl‐groups in the course of the synthesis prevent the formation of the iodine complex of amylose and the amylopectin‐iodine reaction.

At defined conditions of the CMS‐synthesis the paperchromatographic elution separation makes it possible to evaluate the approximate degree of substitution of starch on the basis of the occurring coloured sections and colour shades.
Cationic and Nonionic Starch Graft Polymers for Filler Retention
Authors: Heath H. D. , Hofreiter B. T. , Ernst A. J. , Doane W. M. , Hamerstrand G. E. , Schulte M. I.
Published: November 2006

Graft co‐ and terpolymers were prepared by free radical polymerizations of vinyl monomers onto ω‐irradiated starch by a prototype commercial process. Products with graft contents of up to 46%, by weight, were obtained by grafting acrylamide and quaternary amine‐containing esters of methacrylic acid to starch. The graft polymers were evaluated on a pilot fourdrinier paper machine as filler retention aids and compared with several commercial flocculants. Drainage rate increased markedly with one of the starch graft terpolymers that was cationic. Since the number of starch graft polymers prepared was limited, the results reported, although excellent, are not necessarily optimal. Further studies are needed to establish the relationships of graft content and terpolymer compositions to retention and drainage.
Carbohydrates in the Brewing Industry
Authors: Maiden A. M.
Published: November 2006

The brewing of beer, which has been carried out in the United Kingdom for about 2,000 years, has been under some kind of legal restrictions for about the last 500 years. Initially this was because of the nutritional importance of beer in the daily diet, but for the last 300 years for revenue‐raising purposes. These restrictions have influenced the raw materials and techniques used in British breweries and also the strength of the beer. For the last 90 years U.K. brewers have been free to use the raw materials of their choice, subject only to restrictions guarding public health and the revenue from the Beer Tax. The techniques used in brewing are briefly surveyed and contrasted with those used by the maize wet‐milling industry. The nature of the carbohydrate raw materials other than malt used by brewers in the United Kingdom is discussed.
The Hydrogenolysis of Commercial Corn Glucose Syrup
Authors: Akher M. Abdel , Ghali J. , Raouf M. S. , Roushdi M.
Published: November 2006

Hydrogenolysis of corn syrup was carried out at 170°C and 60 at pressure. After 3 h 92.3% of the glucose content of the syrup was converted into sorbitol.
Zucker und Zuckeraustauschstoffe im neuen Lebensmittelrecht
Authors: Franck R.
Published: November 2006

Sugars and Sugar Substitutes in the New Food Legislation. In chemistry, sugar substitutes are sugar‐like substances of sweet taste having a caloric value which do not involve an effect upon carbohydrate metabolism or at least do so to a lesser degree than ordinary sugar (saccharose). Examples of such substances are above all fructose and the polyalcohols, sorbitol, xylitol and mannitol. The new Act on Foods and Articles of Daily Use of August 15, 1974, has placed sugar substitutes except fructose on the same level as the so‐called “additives” which means that from the legal aspect, they are considered as additives and require special approval if they are to be added to foods.

If sugar substitutes are not administered by the common enteral way of nutrition but parenterally, the question is raised whether in such a case they have to be considered as foods or drugs. It can be seen from the Foods Act of August 15, 1974, as well as from the Drugs Act in its current version that any type of enteral nutrition is subject to the provisions of food legislation. In contrast to this, parenteral nutrition is applied immediately to the circulatory system without involving the alimentary tract. For this reason it has to be considered as drug like solutions for infusion. The importance of sugar substitutes is explained by means of examples for various forms of the application.
Bewertung der Eigenschaften von Kartoffelstärken
Authors: Čeh M. , Stropnik Č.
Published: November 2006

Evaluation of Potato Starch Properties. Different potato starches were studied by determination of their consistency curves with a Brabender viscosigraph, their absolute viscosity values and the ranges of swelling temperatures of the starch grains. Gradual elution analyses for comparison were carried out, and a simple potentiometric method was introduced in order to determine the average number of molecular weights Mn. Between different potato starches essential differences of the physical and colloidalchemical properties could be revealed in spite of the fact that their quality corresponded to didacted standards. The physical and colloidal‐chemical changes of the starches may be ascribed to prolonged or inadequate storage. At the evaluation of the starch qualities the existing standards are no longer satisfactory. The starches should be classified especially by viscographic measurements and determinations of the average number of molecular weigths.
A Modified Analysis Method of Starch Determination by Iodine Spectrophotometry
Authors: Nedeltscheva M. , Stoilkov G. , Popova S.
Published: November 2006

Based on the Paloheimo‐Vainio method and making use of the contemporary iodine spectrophotometry, an improved method for quantitative starch determination is obtained. Certain optical iodine‐dextrine complex characteristics are examined. The principal factors are established, which influence the molar extinction coefficient, and the kinetics of complex formation is studied. The concentration interval is specified where Lambert‐Beer's law is valid. The high level of accuracy obtained and the short analysis time make the proposed modified method applicable both for industrial and for precise laboratory investigations.
Fractionation of Starch by Gel Filtration on Agarose Beads
Authors: Ebermann R. , Schwarz R.
Published: November 2006

A chromatographical system consisting of a Sephadex G 200 column and an agarose 2B or 4B column was used for fractionation of native starches. Fractionation of the amylose and amylopectin components was achieved, and the amylose part of starch was subfractionated according to its molecular weight. The molecular weight of amylopectin is beyond the fractionation limit of the agarose and seems to be higher than 20 × 106.