bluuebunny/crossref_metadata_2025 huggingface dataset:
Properties of Gel‐Entrapped Glucoamylase
Authors: Krauze J. , Wawrzyniak B.
Published: November 2006

Glucoamylase from Aspergillus niger was immobilized by entrapping in glutaraldehyde crosslinked gelatin. Preparations were prepared in the form of beads and thin layers on activated glass, polyester and aluminium foils. Immobilization did not cause changes of pH and temperature optimum. However, it increased thermal stability additionally stabilized by the presence of a substrate. The most stable preparations acted without change in activity for 34 days at a temperature of 50°C. Obtained preparations hydrolyzed α‐amylase liquefied starch to a DE value of about 97%.

The preparations of glucoamylase immobilized in a thin layer of gelatin on the polyester and aluminium foil were used in a thin layer flow reactor for hydrolysis of 10% starch solution.
Lipid Composition of Field Pea (Pisum sativum cv Trapper) Seed and Starch
Authors: Hoover R. , Cloutier L. , Dalton S. , Sosulski F. W.
Published: November 2006

The total lipids in field pea seeds and refined starch were extracted by five aqueous/organic solvent systems and the greatest yield of total. neutral and polar lipids was obtained with hot n‐propanol‐water (3:1 v/v). Lipids extracted from field pea seeds represented 2.9% of the seed weight and consisted of 43.2% neutral lipids, 3.2% glycolipids and 53.6% phospholipids. The major components of the three fractions were 70% triacylglycerol in neutral lipid, 28% esterified sterol glycoside in glycolipid and 55% phosphatidylcholine in phospholipid. The purified starch fraction contained 0.22% surface lipids and 0.09% internal lipids. The surface lipids were primarily sterol esters and free fatty acids while only free fatty acids were found in the internal lipids. The ability of lysophospholipids and fatty acids to complex with field pea starch was demonstrated by differential scanning calorimetry and X‐ray diffraction, respectively.
Effect of Storage on Starch Content and Modification of Cassava Starch
Authors: Osunsami A. T. , Akingbala J. O. , Oguntimein G. B.
Published: November 2006

The effect of storage on yield and modification of starch using hydrochloric acid and acetic anhydride were studied. Yield of starch from fresh roots (24.4%) was significantly greater than yield (16,2%) from roots stored at room temperature for six days. On a dry weight basis the amount of starch in the roots decreased over a six day storage period. The proximate composition of cassava starch on dry weight basis was 0.24% ash, 0.13% fat, 0.49% protein, 0.15% crude fibre and 98.4% starch. The isolated starch was treated with different concentration of hydrochloric acid to produce acid thinned and dextrinized starches and different concentration of acetic anhydride to produce acetyl substituted starches. The alkali number of acid thinned and dextrinized starches increased with acid treatment while the viscosity decreased.

The degree of substitution increased with the concentration of acetic anhydride used. The cold water solubility of the acid thinned and acetyl substituted starches were similar to that of native starches while the solubility of the dextrinized starches increased with the acid concentration. The viscosity of the acetyl substituted starches increased with the degree of substitution.
Thermal Degradation of Starch in Parboiled Rice
Authors: Mahanta Charu Lata , Bhattacharya K. R.
Published: November 2006

Raw and variously parboiled Intan rice (intermediate‐amylose variety) starch was fractionated in Sepharose CL‐2B column into a larger‐molecule (Fr I) and a smaller‐molecule (Fr II) fraction. The amount of Fr I decreased and that of Fr II increased in parboiled as compared to raw rice, the extent of change increasing with increasing severity of processing. The proportion of polysaccharide and “amylose” in Fr I decreased from 70% and 40% of total, respectively, in raw rice to 16% in parboiled rice prepared by 3 kg/cm2 gauge steam pressure. Simultaneously, the λmax of its iodine complex increased from 570 to 588 nm in Fr I and decreased from 635 to 620 nm in Fr II. The change was marginal or low after steaming at ambient pressure or after sand roasting. The data show that thermal degradation of starch must be considered as another contributor, in addition to starch gelatinization and reassociation, to the peculiar properties of parboiled rice.
Near Infra‐red Monitoring of Enzymatic Hydrolysis of Starch
Authors: Nishinari K. , Cho R. K. , Iwamoto M.
Published: November 2006

NIR measurement was carried out for a starch dispersion circulating from a reactor to an NIR flow‐through cell over a wavelength range of from 1000 to 2500 nm in 2 nm increments. Multiple regression analysis between NIR and HPLC shows a good correlation. It is shown that the NIR method can be used to determine glucose quantitatively in real time during enzymatic hydrolysis, and that NIR may be employed for controlling the reaction in a bioreactor.
Studies on Isolation and Characterization of Starch from Rajgeera Grains (Amaranthus paniculatus Lin.)
Authors: Wankhede D. B. , Gunjal B. B. , Sawate R. A. , Patil H. B. , Bhosale M. B. , Gahilod A. T. , Walde S. G.
Published: November 2006

Isolation and some of the important physicochemical properties of starch from rajgeera grains have been investigated. The yield of starch was about 61.2%, on whole grain basis. The results on physicochemical properties revealed that it exhibited moderate swelling and higher solubility (55.5%) in water, as compared to other millet starches. An extensive solubility in dimethylsulphoxid (72.5%) of the starch indicated easy penetration of solvent in a granular matrix, may be due to labile and heterogenous bonding forces within the granules. Brabender viscoamylographic data on pasting characteristics revealed that it yielded low viscosity (448 B. U.) at concentration of 10% (w/v) and showed very little tendency to retrograde during cooling of the starch paste. The amylopectin content was 88.5% indicating the starch of rajgeera is probably waxy in nature. Amylolytic digestibility of native and gelatinized starch of rajgeera by human salivary α‐amylase and glucoamylase was investigated.
A Critical Assessment of the Parameters Affecting the Official EC “Ewers” Method for the Determination of Starch
Authors: Kennedy J. F. , Stevenson D. L. , White C. A.
Published: November 2006

The Ewers method for the measurement of starch is currently the official EEC method for the measurement of starch purity. In this communication a critical assessment of variables affecting the Ewers method has been undertaken. It was found that the degree of hydrolytic degradation which occurs during the solubilisation of starch prior to polarimetric measurements is of crucial importance in the starch purity values obtained. Factors which influence the degree of hydrolytic degradation include hydrochloric acid concentration to a large extent, and heating and cooling times to a lesser extent. It has been shown also that the clarifing reagent of Carrez, which is used in Ewers method for the removal of other chiral molecules such as protein, etc, adsorbs lower molecular weight malto‐oligosaccharides leading to reduced starch purity values. For a series of starches with varying amylose: amylopectin ratios it was found that high amylopectin starches performed much better in Ewers method than high amylose starches. It is concluded that Ewers is not an acceptable satisfactory method for starch measurement on which to base quality control or eligibility for rebate and refund schemes.
Oxidation of Maltodextrins and Starch by the System Tungstate‐Hydrogen Peroxide
Authors: Floor M. , Schenk K. M. , Kieboom A. P. G. , van Bekkum H.
Published: November 2006

The potential of the aqueous system sodium tungstate‐hydrogen peroxide for glycol‐cleavage oxidation of maltodextrins, starch and trans‐1,2‐cyclohexanediol as a model compound has been evaluated. The peroxotungstate species formed in this medium effect oxidation of the glucose units via two major pathways: (i) glycol‐cleavage of the C2–C3 diol moieties in internal glucose units, followed by (undesired) hydrolysis of the ring‐opened intermediate and (ii) stepwise decarboxylation at the reducing terminal glucose unit until the glycosidic bond is reached. Both reaction types yield glucose oligomers terminated by erythronic acid at the former reducing end, which is an important fraction (up to 40%) of the oxidation product. Decomposition of hydrogen peroxide to oxygen and water is an inevitable side reaction.
Alternative Route to Non‐ammonia Caramels of High Tinctorial Strength
Authors: Sikora M. , Tomasik P.
Published: November 2006

The results of caramelization of highly saccharified starch syrup in the presence of α‐hydroxy and α‐amino acids and their sodium salts are presented, Sodium salt of glycine as the catalyst provides the caramel of the highest tinctorial strength.
Studies on Modified Tamarind Kernel Powder. Part I: Preparation and Physicochemical Properties of Sodium Salt of Carboxymethyl Derivatives
Authors: Prabhanjan H.
Published: November 2006

Sodium salt of 0‐carboxymethyl derivatives of tamarind kernel powder (TKP), at different levels of substitution, was prepared in iso‐propanol medium. The derivatives were characterised by degree of substitution (DS), intrinsic viscosity and elution profile (GPC). Alkaline solutions, purified by alcohol precipitation showed higher intrinsic viscosity due to an alkali soluble fraction. Solution properties of the derivatives as a function of DS were found to be affected both by the substituent groups as well as by the alkali used for derivatization. Swelling power, solubility and tolerance to organic solvents of the derivatives increased with increasing carboxymethylation. The interaction properties of TKP with calcium chloride and sodium tetraborate were found to be reversed upon carboxymethylation.
Acylierter Weizenkleber als Cobindemittel in Papierstreichfarben
Authors: Kersting H. J. , Kempf W.
Published: November 2006

Weizenkleber kann in nativer Form aufgrund seiner strukturbedingten Eigenschaften nicht für technische Applikationen genutzt werden. Aus diesem Grunde muß der Kleber durch chemische Methoden so aufgearbeitet werden, daß er den gewünschten technischen Anforderungen entspricht. Aufarbeitungsverfahren, Einflußgrößen sowie papiertechnische Anforderungen hinsichtlich eines Einsatzes von Weizenkleber in Papierstreichfarben sind Gegenstand dieses Artikels. So konnte durch unsere Untersuchungen gezeigt werden, daß chemisch modifizierter Weizenkleber als Cobindemittel in Papierstreichfarben eingesetzt werden kann, da er in einigen wichtigen technischen Eigenschaften, wie dem Fließverhalten, der Rupffestigkeit sowie des Wasserrückhaltevermögens, sich gegenüber einem industriellen Standard‐Cobindemittel gleichwertig oder sogar teil‐weise überlegen erweist.
Enzymatic Hydrolysis of Amaranth Flour — Differential Scanning Calorimetry and Scanning Electron Microscopy Studies
Authors: De La Rosa A. P. Barba , Paredes‐López O. , Cárabez‐Trejo A. , Ordorica‐Falomir C.
Published: November 2006

High‐protein amaranth flour (HPAF) and carbohydrate rich fraction (CRF) were produced from raw flour in a single‐step process using a heat‐stable α‐amylase preparation. Protein content of flour increased from 15 to about 30 or 39% at liquefaction temperatures of 70 or 90°C, respectively, and 30 min hydrolysis time. CRF exhibited 14–22 DE. Enzymatic action at 70°C increased endotherm temperatures and gelatinization enthalpy of HPAF, in relation to gelatinized flour, as assessed by differential scanning calorimetry (DSC). Hydrolysis at 90°C did not affect significantly (P > 0.05) DSC peak temperature. It is suggested that these changes in DSC performance might result from differences in amount and type of low‐molecular weight carbohydrates and residual starch. Scanning electron microscopy (SEM) demonstrated that hydrolysis temperature changed substantially the structural appearance of flour particles. HPAF and CRF might find applications as dry milk extender and sweetener, respectively.
Some Properties of Amaranthus paniculatas (Rajgeera) Starch Pastes
Authors: Singhal Rekha S. , Kulkarni Pushpa R.
Published: November 2006

The lysine rich high protein seeds of A. paniculatas (Rajgeera) are reported to contain 50–60% of waxy starch, concentrated in the endosperm. However its food related properties are comparatively unknown. In the present work, paste viscosity, paste clarity, freeze‐thaw stability and effect of shear on the viscosity of A. paniculatas starch paste have been studied and compared to corn starch. Also included are the stability of Rajgeera starch paste under pressure cooking (30 min, 15 lb pressure) and acidic conditions (pH 6.98—1.76). Rajgeera starch was found to have a higher paste viscosity, lower paste clarity and high freeze‐thaw stability than corn starch. Both Rajgeera and corn starch underwent thinning on being subjected to mechanical shear. Rajgeera starch withstood pressure cooking conditions admirably, but was found to be sensitive to acidic conditions.
Crystallinity of Raw Rice Starch Granules as Indexed by Corrosion with Hydrochloric Acid and Amylase
Authors: Juliano B. O. , Perez C. M.
Published: November 2006

After 15 d in 2.2N HCl at 35°C, residual starch of 34 granular rice starches differing in apparent amylose content (AC) and final gelatinization temperature (GT) ranged from 1.3 to 20.8% and was verified to correlate significantly with GT (r = 0.69**) and AC (r = 0.44**). Residual starch after 5 h corrosion with crude Chalara paradoxa amylase ranged from 0 to 29.4% and also correlated significantly with GT (r = 0.45**) and AC (r = 0.70**). The amounts of residual starch after Lintnerization and after C. paradoxa amylase digestion were significantly correlated (r = 0.72**).
Influence of Monoglycerides of Different Chain Lengths on Texture and Flavor of Breads Made with Waxy Cornstarch
Authors: Hartunian‐Sowa S. M. , White P. J. , Batres L. V.
Published: November 2006

The addition of monoglycerides (MGs) monolaurin (ML), monomyristin (MM), monopalmitin (MP), and monostearin (MS)) to a model system bread made from waxy cornstarch was studied for their effects on delaying staling. The model system breads containing 0.5% of a MG and a control bread containing no MG were prepared five different times and stored at room temperature for 1, 3, and 6 days. A sensory panel measured changes in firmness, stale flavor, and moistness, and an Instron universal testing machine (model 1122) was used to indicate firmness of the samples. The volumes of the loaves were measured on day 1 for the five replications. Results indicated that the addition of MGs to the model system breads decreased firmness and stale flavor and increased moistness compared with the control bread. Breads containing MM and MP were rated significantly (p<0.05) less firm and less stale on days 1 and 6 and more moist on day 1 than the breads containing MS and the control bread. In general, as the molecular weight (MW) of the MGs increased, the firmness (by Instron) of the breads also increased, and the volume of the loaves decreased. The control bread had the highest Instron firmness value and the lowest volume when compared with the breads containing MGs.
Studies on Mutagenicity of Caramel
Authors: Barabasz W. , Brzózka Ł. , Krzeczek J. , Tomasik P.
Published: November 2006

Caramels laboratory‐prepared by thermolysis of pure α‐D‐glucose, D‐fructose and sucrose as well as of these sugars with some nitrogen‐containing and nitrogen‐free catalysts were tested against Escherichia coli strains. These caramels exhibit free‐ radical character independently of the mode of their preparation. Biological functions of Escherichia coli in 10 subsequent generations grown without caramel and with caramel added to a nutrient broth were tested in a standard scope of 15 biological tests. Neither growth nor biological functions of all generations of this bacterium were influenced by caramels added.
Halbkornmethode zur Bestimmung des Amylosegehalts in Gerste
Authors: Schwank U. , Jacobi A. , Drawert F. , Fischbeck G.
Published: November 2006

Für die pflanzenzüchterische Nutzung von Amylosemutanten ist eine Methode, die den Amylosegehalt eines Einzelkorns messen kann, von Bedeutung. In der vorliegenden Arbeit wird eine potentiometrische Titration zur Amylosebestimmung an einem halben, reifen Gerstenkorn beschrieben und die Auswertung der Titrationskurven diskutiert. Mit Hilfe der dargestellten Methode gelingt eine Einteilung verschiedener Gerstensorten und ‐linien in Genotypen mit unterschiedlichem Amylosegehalt.
Studies on Applicability of Amaranthus paniculatas (Rajgeera) Starch for Custard Preparation
Authors: Singhal R. S. , Kulkarni P. R.
Published: November 2006

A. paniculatas or Rajgeera has been shown to contain 50–60% of waxy starch, having an extremely small granule size of 1–2 μm, and higher paste viscosity than corn starch. Studies on utilisation of Rajgeera starch for custard preparations showed it to be unsuitable for such purpose because of interactions among the various ingredients used in the formulation.
Production of Cyclodextrins by Simultaneous Actions of Two CGTases from Three Strains of Bacillus
Authors: Kaneko Takahiro , Yoshida Masahiro , Yamamoto Mikio , Nakamura Noboyuki
Published: November 2006

A moderate thermophile, which produces a large amount of extracellular and thermostable cyclomaltodextrin glucanotransferase, was isolated from soil samples at hot spring areas in Japan. The isolate (A‐147), that grew at 30–60°C with an optimum at 45–50°C, was identified as a strain of Bacillus coagulans. The enzyme, which was most active at pH 6.5 and 60°C, was stabilized by 2–3 mM Ca2+, and degraded about 40% (as dry basis) of 13% (w/w) potato starch solution into cyclodextrins composed of α‐ and β‐cyclodextrins dominantly at 74°C and pH 6.5 in the presence of 3 mM Ca2+. The ratio of α‐, β‐ and γ‐cyclodextrins was almost constant (2:2.6:1) during all stages of the reaction. By simultaneous actions of two enzymes from the bacterium and other 2 kinds of Bacillus, starch hydrolysates containing various amounts and rations of cyclodextrins were produced from starch.

Ein mäßiges Thermophiles, das eine große Menge an extracellulärer und thermostabiler Glucanotransferase produziert, wurde aus Bodenproben in Heißquellengebieten von Japan isoliert. Das Isolat (A‐147), das bei 30–60°C mit einem Optimum von 45–50°C wuchs, wurde als ein Stamm von Bacillus coagulans identifiziert. Das bei pH 6,5 und 60°C aktivste Enzym wurde durch 2–3 mM Ca2+ stabilisiert und baute etwa 40% (TS) einer 30%igen (w/w) Kartoffelstärkelösung zu Cyclodextrin ab, bestehend aus α‐ und β‐Cyclodextrin, vorwiegend bei 74°C und pH 6,5 in Gegenwart von 3 mM Ca2+. Das Verhältnis von α‐, β‐ und γ‐Cyclodextrinen war nahezu konstant (2:2,6:1) während sämtlicher Reaktionsschritte. Durch gleichzeitige Einwirkung von zwei Enzymen aus dem Bakterium und zwei anderen Arten von Bacteria wurden Stärkehydrolysate hergestellt, die verschiedene Mengen und Verhältnisse an Cyclodextrinen enthielten.
Two‐Dimensional Nuclear Magnetic Resonance Studies of Starch and Starch Products
Authors: McIntyre Deane D. , Vogel Hans J.
Published: November 2006

The use of two‐dimensional Nuclear Magnetic Resonance (NMR) spectroscopy as applied to studies of starch, starch products and glycogen is reported. The use of both homonuclear correlation (COSY, relay‐COSY and HOHAHA) and heteronuclear correlation (HMQC, HETCOR) experiments is discussed. This approach makes it possible to obtain complete assignments of the proton NMR spectra of these polysaccharides. This is not possible from 1‐D spectra due to excessive overlap of the non‐anomeric proton signals. The resulting assignments are useful in obtaining structural information regarding starch and related products. Moreover, the greater inherent resolution of the two‐dimensional spectra can reveal the presence of low molecular weight carbohydrates (glucose, maltose etc.) in dextrin samples, thus providing information about carbohydrate composition.
Subsite Structure of Rhizopus niveus Glucoamylase, Estimated with the Binding Parameters for Maltooligosaccharides
Authors: Ohnishi Masatake
Published: November 2006

Based on Kd and Ki for maltosaccarides Gn (n = 1 ± 7) and on a specified mode of their binding, the intrinsic affinities A1, A2, –, Ai at subsites i (i = 1 ± 5), were tried to estimate for glucoamylase from Rhizopus niveus. Previously, we have evaluated the apparent values Ai using Km and k0 on the enzyme‐catalyzed hydrolysis for Gn, where A1 is nearly 0 kcal/mol. Thus A1, which was found here 3.3 kcal/mol, may be cancelled out with the heat, which is consumed for the hydrolytic cleavage of a substrate glucosyl bond.
Kinetic Characterization of Chimeric Cyclomaltodextrin Glucanotransferase from Genes of Two Alkalophilic Bacillus
Authors: Kaneko Takahiro , Nakamura Nobuyuki , Horikoshi Koki
Published: November 2006

The chimeric CGTase, which was constructed genetically with two β‐CD forming type enzyme genes of different species of alkalophilic Bacillus, was characterized by comparing with the actions of parent enzymes. The final composition of CDs in the reaction digest from starch by the chimeric enzyme, especially in the yield of α‐CD, was different from those by parent enzymes, and total yields of CDs by these enzymes were almost the same. The chimeric enzyme catalyzed the formation of β‐CD as a major action from starch, the rapid synthesis of α‐CD from other CDs and maltooligosaccharides and the slow degradation and interconversion of α‐CD to others. From these results, the role of second and third segments in the enzyme molecules was discussed.
An Electron Diffraction Study on Whole Granules of Lintnerized Potato Starch
Authors: Chanzy Henri , Vuong Roger , Jésior Jean Claude
Published: November 2006

Potato starch granules which had been lintnerized for 10 d in 2.2 N HCL at 35°C, embedded in Nanoplast and cross sectioned with a low angle diamond knife having an angle of 33.7° have been studied by electron diffraction. The sections were apparently defect free. When they were surveyed under frozen hydrated conditions by transmission electron microscopy in diffraction mode, they gave electron diffractograms typical of B starch. Central sections gave fiber diagrams, whereas noncentral or tangential sections gave strongly arced or even continuous ring diagrams. This technique, if it can be extended to other starch systems, will enable more detailed studies to be made of the crystalline ultrastructure of starch and the organization of the amylose fragments within the starch granule.
The Combined Effect of Oxidation and Carbamoylethylation on the Rheological Properties of Maize and Rice Starches
Authors: Ragheb A. , Refai R. , El‐Thalouth I. Abd , Hebeish A.
Published: November 2006

The combined effect of oxidation and etherification on the molecular structure of starch was investigated. Maize and rice starches were used. Oxidation was effected using sodium hypochlorite while etherification was performed by reacting starch with acrylamide in presence of sodium hydroxide; this reaction is known as carbamoylethylation. The extent of the latter, expressed as % N, was found to increase by decreasing the molecular size of starch through oxidation. The carbamoylethyl starches so obtained could be precipitated by ethanol and they are soluble in water irrespective of the kind of starch. On the other hand, results of rheological properties indicated that they are governed mainly by the molecular size of starch. Oxidized starches with relatively high molecular size exhibit thixotropic behaviour. The degree of thixotropy decreases and changes into pseudoplasticity as the molecular size of starch decreases. The results also indicated that at constant rate of shear the apparent viscosity of carbamoylethyl starches decreases as the molecular size decreases. Furthermore, the rheological properties of carbamoylethyl starch pastes undergo considerable changes and so does the apparent viscosity when these pastes were stored for 3 days.
Lipids and Rheological Properties of Starch. Part II: The Effect of Granule Surface Material on Viscosity of Wheat Starch
Authors: Nierle W. , El Bayâ A. W. , Kersting H. J. , Meyer D.
Published: November 2006

The extraction of wheat starch with ethanol reduced the protein content from 0.4 to 0.3%. Wheat starch extracted with 1% SDS containing 1% 2‐ME or with 1% SDS gave no staining with amido black, indicating that most of starch surface protein has been separated. TLC of lipids extracted from starch without gelatinization showed that ethanol extracted considerable amounts of starch lipids such as lysophosphatidyl choline, lysophosphatidyl ethanolamine and free fatty acids. After extraction with SDS and especially with SDS + 1% 2‐ME only some starch granules were deformed. In this starch some changes have been observed also on the granules surface by REM. The extraction resulted also in considerable changes in rheological properties of extracted starches. The starch samples were characterized thermodynamically also.
Effects of Nixtamalization and Grinding Conditions on the Starch in Masa
Authors: Gomez Marta H. , Waniska Ralph D. , Rooney Lloyd W.
Published: November 2006

Starches from corn and sorghum masas were solubilized in water and their molecular characteristics were studied with high‐performance, size‐exclusion chromatography (HPSEC). Rheological properties of masa (smoothness, plasticity and cohesiveness) that are developed during lime‐cooking, steeping and grinding of cereals were correlated to the starch solubility. Corn and sorghum were processed at different cooking times and grinding conditions; and the starch in masa was extracted with water at 85°C and 120°C for HPSEC analysis.

Starches from corn and sorghum masas were affected in a similar way by the nixtamalization process; however, sorghum starch was more soluble than corn starch in flour and masa. Alkaline‐cooking, steeping and stone‐grinding did not depolymerize the cereal starch. All masas contained less than 10% soluble solids of which 30 to 50% was starch solubilized. Soluble solids increased with longer cooking time and finer grinding. About 50% of the insoluble starch, which remained in the particulate solids of masas was solubilized in water at 120°C. The remaining starch was indispersible because either the starch remained inside endosperm pieces or inside gelatinized and retrograded gels.

Several granular and molecular forms of starch were present in masa as a result of partial gelatinization, i.e. uncooked, swollen, and annealed starch granules, and soluble and retrograded amylose. Retrogradationo f starch polymers occurred during steeping of cooked corn and during cooling of masa after grinding. Masa, a unique dough system, resulted from a network of starch polymers, uncooked and partially gelatinized starch granules supporting the rest of the kernel components into a continuous phase of water.
Kinetic Properties of the Rhizopus Glucoamylase and Bacillus α‐Amylase, which are Immobilized on Cellulofine
Authors: Ohnishi Masatake , Iwata Ken , Tomita Takayo , Nishikawa Ukiko , Hiromi Keitaro
Published: November 2006

Glucoamylase from Rhizopus niveus was immobilized on Cellulofine, a kind of cellulose gel, to construct an enzyme‐Cellulofine structure, of which the molar activities k0 for maltose and for soluble starch were found almost equal to 4 and 1/9 times, respectively, of those found with the intact enzyme. Liquefying Bacillus α‐amylase was fixed to make another enzyme‐Cellulofine structure, of which ratio of the molar activities, k0 (modified)/k0 (intact) for an oligomer substrate maltohexaose is much larger than those for high‐polymer substrates, amylose and soluble starch. These findings suggest that the substrate specificity of the amylase‐Cellulofine structure is improved to be useful for the enzyme‐catalyzed hydrolysis of saccharides having small degree of polymerization.
Synthesis of Thermostable Alpha‐Amylase by Bacillus Isolate R–8
Authors: Jamuna R. , Ramakrishna S. V. , Bindu C.
Published: November 2006

An indigenous isolate Bacillus R–8 was found to produce thermostable β‐amylase. The enzyme yield was highest during the stationary phase of the culture. Maximum production of 100 units per ml was achieved in the maltose medium and also in the alkaline conditions of fermentation. It has been observed that the rate of enzyme formation was highest (2.8 units/g of cells/h) with glucose under neutral conditions. The variations in the fermentation parameters which have resulted in the significant difference in terms of total enzyme production and the rate of enzyme formation have been discussed.
Studies on Semi‐technical Separation of Mung Bean Starch
Authors: Haase Norbert U. , Tegge Günther , Thu Nguyen Manh
Published: November 2006

Starch of mung beans is the raw material for high grade glass noodles, but until now industrial starch separation is often less efficient. For testing new fields of commercial use it is of benefit to experiment with very pure starches. Regarding this, possibilities of starch isolation on a semi‐technical scale are described, which resulted in most pure starches. Crude protein content could be lowered down to 0.3% and crude fibre content down to 0.5% dry matter base.
Application of Differential Scanning Calorimetry to Amaranth Starch Gelatinization – Influence of Water, Solutes and Annealing
Authors: Paredes‐Lopez O. , Hernández‐Löpez D.
Published: November 2006

Gelatinization phenomena of amaranth starch were investigated using differential scanning calorimetry. Slight variations in onset (To) and peak (Tpl) temperatures were observed at moisture contents over 0.48 g water/g total. However, completion temperature (Tc) increased significantly. The intermediate transition temperature (Tp2) appeared at 0.61 g water/g total and below. The degree of gelatinization decreased by decreasing the moisture content. The three transition temperatures (To. Tpl and Tc) were increased and gelatinization delayed as the concentration of sucrose was enhanced. The three latter transition temperatures tended to increase as the sodium chloride was raised to 0.066 g/g total, but further increases in salt reduced significantly these temperatures. The gelatinization was delayed by increasing the salt concentration. After annealing for 12 h at 25 to 65°C, starch samples exhibited higher To and Tpl values, and narrowed gelatinization ranges. The degree of gelatinization augmented up to the annealing temperature of 55ºC and significantly decreased thereafter.
Compounding of Thermoplastic Starch with Twin‐screw Extruders
Authors: Wiedmann Werner , Strobel Edgar
Published: November 2006

The compounding of thermoplastic starch can be regarded as a combined process consisting of extrusion cooking and plastic compounding. The quality of the product is determined largely by the degree of mechanical shear, temperature and water content. These parameters can be influenced both by the machine system and the various components of a machine. These include infinitely adjustable throttle systems and continuous condensation and evaporation equipment. On account of the fact that the starch pellets are sometimes soluble in water, the type of pelletizing is also very important. A product quality which has been optimized can be reproduced every day by means of automatic systems. Some examples of on‐line quality control systems are shown.
Morphological Study of Products Containing β‐Cyclodextrin
Authors: Hódi K. , Tasić Lj. , Kata M. , Selmeczi B. , Jovanović M. , Djurić Z.
Published: November 2006

β‐Cyclodextrin (β‐CD) has been applied in various fields of drug formulation. Its presence in powder Paracetamol (PAR) products prepared with different methods (kneading and spray drying) changes the morphology of original drug. The product made by spray drying has nearly isodimensional spherical particles, and potentially better flowability than the kneaded product. Spray drying of PAR product without β‐CD shows similar morphology like a product with β‐CD, but the particles show a greater inclination to adhesion. The results were obtained by electron microscopic study.
Annealing of Starch at an Intermediate Water Content
Authors: Larsson Ingela , Eliasson Ann‐Charlotte
Published: November 2006

The effect of annealing on starch gelatinization behaviour has earlier been described in the literature. The starch: water ratio in these studies have been either very low or very high. In this work the gelatinization behaviour has been studied both with time and temperature at an intermediate starch/water ratio (1:1) by differential scanning calorimetry. Starches from maize, waxy‐maize, wheat and potato have been compared. This investigation shows that annealing causes an increase of To and Tm, a narrowing of the gelatinization temperature interval, and a change of the shape of the endotherm can also be observed. The annealing time has to be more than 6 h to induce these changes.
Verarbeitung von Kartoffelstärke auf Kunststoff‐Verarbeitungsmaschinen
Authors: Potente Helmut , Schöppner Volker , Rücker Andreas
Published: November 2006

Stärke als makromolekular aufgebauter organischer Werkstoff besitzt viele Eigenschaften, die mit herkömmlichen Kunststoffen vergleichbar sind. Dadurch ist es möglich. die Stärke auf konventionellen Kunst;stoffverarbeitungsmaschinen mit denselben Verfahren wie die synthetischen Polymere zu Produkten zu verarbeiten. Unter Zugabe von Weichmachern ist native Kartoffelstärke auf verschiedenen Extrudern zu Granulat und Folie weiterverarbeitet worden. Das Granulat diente als Ausgangsmaterial für Versuche zur Herstellung einfacher Formkörper aus Stärke auf einer Spritzgußmaschinen. Die mechanischen Kennwerte der erstellten Proben lagen auf einem zufriedenstellenden Niveau. Durch die Eignung der weit verbreiteten Schneckenmaschinen zur Stärkeverarbeitung ist es bei genauer Kenntnis der erforderlichen Verfahren ohne umfangreiche Anlageinvestitionen möglich, für Spezialanwendungen Kunststoffe durch Stärkeprodukte zu substituieren.
The Immobilization of Glucoamylase on Polyethylene Membrane Modified by Radiation Grafting of Acrolein
Authors: Miller Ewa , Sugier Henryk
Published: November 2006

The radiation grafting of acrolein to the polyethylene membrane and the immobilization of glucoamylase on such modyfied carrier were studied.
Use of a Twin‐Screw Extruder as a Chemical Reactor for Starch Cationization
Authors: Valle Guy Della , Colonna Paul , Tayeb Jean
Published: November 2006

The objective of this work was to study the obtaining of cationic starch by using a pilot scale twin‐screw extruder Clextral BC45 as a chemical reactor. The reagent was 3‐chloro 2‐hydroxypropyltrimethyl ammonium chloride (CHPTMA) and catalyst was sodium hydroxide (NaOH). In a first set of experiments extruded starch gave higher chemical efficiencies than native starch (+15%) both being fed at the same location of the barrel. Influence of extrusion conditions on reaction kinetics was studied starting from extruded starch in order to optimize the reaction without interfering with starch melting phenomenon. In a second set of experiments, a special screw design was implemented in order to obtain a homogeneous starch molten phase in a first stage, and to achieve starch modification in a second stage. Changes of reacting conditions were performed through the modification of reagent quantities and molar ratios related to starch and NaOH, location of reagent injection, temperature of reaction and Specific Mechanical Energy input. Samples were evaluated through their degree of substitution (final DS < 0,09); their homogeneity and rheological behavior were studied by ion exchange chromatography and Brabender viscoamylograph. resp., Reaction efficiency was computed to optimize the process, leading to values up to 82%. Extruded samples were then compared to commercial cationic starches.
Purification and Characterization of the Commercialized, Cloned Bacillus megaterium α‐Amylase. Part II: Transferase Properties
Authors: Brumm P. J. , Hebeda R. E. , Teague W. M.
Published: November 2006

Using an assay procedure based on reduction of iodine binding to starch. Bacillus megaterium, α‐amylase (BMA) demonstrated transferase activity using a wide range of acceptors. The enzyme had an absolute requirement for glucose or glucosides for acceptor molecules. Maltose acted as a transferase acceptor at low concentrations and as an inhibitor of starch hydrolysis at high concentrations. Kinetic analysis indicated that, in the presence of a suitable acceptor, the mechanism of starch hydrolysis is Ping Pong Bi Bi. The products of the transferase reaction have been determined using p‐nitro‐α‐D‐glucopyranoside as acceptor combined with a novel HPLC‐based system for product detection.
Qualitative and Quantitative Determination of Starch by a Colorimetric Method
Authors: Magel Elisabeth
Published: November 2006

A method for the qualitative and quantitative determination of low amounts of starch and its components, amylose and amylopectin, was worked out. It combines the extraction of starch with HCI, staining with KJ/J2 and measurement of the absorbancies at two wavelengths, 605 and 530 nm, the absorption maxima of amylose and amylopectin, respectively. The determination of the amylose fraction and the quantification of the starch were done according to two evaluated equations. Phenolic substances did not influence the method. The method proved to be useful for sensitive starch determination and characterisation in plant material.
Rapid Quantitative Measurement of Extrusion‐Induced Starch Fragmentation by Automated Gel Permeation Chromatography
Authors: Wasserman Bruce P. , Brunswick New , Timpa Judy D.
Published: November 2006

Gel permeation chromatography with application of the universal calibration concept was found to be a rapid and effective method for quantification of extrusion‐induced starch fragmentation. This method (Timpa. J.D., J. Agr. Food Chem. 39 (1991), 270–275) employs dimethyl acetamide (DMAC) with lithium chloride to solubilize samples and automated gel permeation chromatography for fractionation. Instrumentation was equipped with a viscometer and refractometer, data was interpreted by application of the universal calibration concept. These results confirm that the largest starch molecules in corn meal (107 to 108 Daltons) were slightly prone to fragmentation. Fragments produced were primarily in the weight range of 104–107 Daltons. In addition, some smaller fragments (ranging between 5,000 and 7.500) were also generated by extrusion.
Molecular Weight Patterns of Nägeli Amylodextrins
Authors: Jackson David S. , Waniska Ralph D. , Rooney Lloyd W.
Published: November 2006

This research was designed to assess the utility of a four‐column high performance size‐exclusion chromatography (HPSEC) system to characterize starch‐based carbohydrates of different sizes. Corn starches with varying amounts of amylose were treated with 16% sulfuric acid to create Nägeli amylodextrins. During treatment, sub‐samples were taken at various intervals from 0–100 days. The washed, dried sub‐samples were chromatographically analyzed using four Shodex lonpak columns linked in series. Chromatograms showed the progressive depolymerization of starch. Pullulan molecular weight standards were used to estimate amylodextrin molecular weights (MW). Number‐average MWs of amylodextrins decreased as the original starches' amylopectin content decreased. A single HPSEC system can be effectively used to characterize carbohydrates ranging in size from starch to amylodextrins; and to monitor the acid (or enzyme) depolymerization of starches.
Production of Cationic Starch Ethers Using an Improved Dry Process
Authors: Hellwig Georg , Bischoff Dietmar , Rubo Andreas
Published: November 2006

Cationic starch ethers have been established as additives in the paper industry for many years. A number of production processes are known and documented in numerous patents and articles. Whereas in the past starches were predominantly etherified in aqueous suspension, a trend has lately been observed towards a “dry” cationisation. Apart from the commercial aspects, the advantages of a “dry” reaction control lie in the ecological sphere as well. The advantages of the dry process for producing cationic starch ethers will be discussed here and compared with the “slurry” process. In so doing, particular attention will be paid to a dry process developed by our company since it is gaining nowadays more and more commercial relevance.
Production of Starch Saccharifying Enzyme (Glucoamylase) in Solid Cultures
Authors: Pandey Ashok
Published: November 2006

A laboratory process was established for the production of glucoamylase (amyloglucosidase) enzyme by Aspergillus niger (RRL isolate), using wheat bran of mixed particle size as main carbon source in solid cultures. The experimental studies were carried out in 500 ml conical flasks and subsequently in tray fermenters in static conditions. Experiments were conducted to monitor the impact of initial moisture content of the substrate as well as the steam cooking of the substrate on different atmospheric pressure on the productivity of the enzyme. An initial moisture level of 50–55% was found optimum for glucoamylase production when fermentation was carried out for 96h. Cooking of substrate at 1056 kg/cm2 under steam for 30 min gave most desirable qualities in substrate.
Herstellung von Stärkederivaten durch Heißextrusion
Authors: Narkrugsa W. , Berghofer E. , Camargo L. C. A.
Published: November 2006

Es wurde die Möglichkeiten untersucht, das Verfahren der Heißextrusion unter Verwendung eines konischen, gegenläufigen Doppelschneckenextruders zur Herstellung von Stärkederivaten einzusetzen. Als Rohstoffe wurden neben Mais‐ und Kartoffelstärke auch Maisgrieß verwendet. Als Derivatisierungsreagenzien wurden Citronensäure, Natriumtrimetaphosphat, 2,3‐Epoxypropyl‐trimethyl‐ammoniumchlorid und 3‐Clor‐2‐hydroxypropyl‐trimethyl‐ammoniumchlorid getestet.

Mit allen Reagenzien konnte eine Derivatisierung sämtlicher eingesetzter Rohstoffe erhalten werden.

Bei den Citratstärkederivaten wurden Reagenzienausbeuten zwischen 60 bis 70% erreicht, die durch eine nachträgliche Hitzebehandlung nach der Extrusion auf etwa 68 bis 77% gesteigert werden konnten. Durch diese nachträgliche Hitzebehandlung wurde weiters eine enorme Steigerung der Brabender‐Viskositätswerte erreicht und die Scherstabilität und Gefrier‐Tau‐Stabilität teilweise ebenfalls verbessert. Bei den Phospatstärkederivaten wurden Umsetzungsraten von etwa 30% gefunden. Diese Werte sind mit denen anderer Arbeiten vergleichbar. Durch eine nachträgliche Hitzebehandlung konnte auch bei diesen Derivaten eine weitere Steigerung bis 35% erzielt werden. Die Verbesserung der funktionellen Eigenschaften durch die Derivatisierung war hier ebenfalls zu beobachten, allerdings nicht in dem Ausmaß wie bei den Citratstärkederivaten. Die Herstellung von Kationenstärken durch Heißextrusion war ebenfalls ohne Probleme durchzuführen. Es wurden etwa 50 bis 60% der jeweils eingesetzten Reagenzien veräthert. Diese Werte steigen bei einer nachträglichen Hitzebehandlung auf etwa 65 bis 75% an. Damit sind die Ausbeuten durchaus mit der konventionellen Herstellungsweise vergleichbar.
Characterization of Internal and Surface Lipids of Oat Starches from Two Isolation Processes
Authors: Liukkonen Kirsi , Laakso Simon
Published: November 2006

Oat starches representing two different isolation methods were studied for lipid contents and compositions. One of the starch isolation methods utilized water and the other slightly alkaline solution. The internal lipids were practically identical in both starches. However, starch from the alkaline method contained 21% less non‐starch lipids as total fatty acids, 63% less Kjeldahl nitrogen, and the content of non‐starch free fatty acids was low. Instead, starch from the water method contained almost three fold higher amounts of free fatty acids which contributed up to 49% of non‐starch lipids. Therefore, it was concluded that isolation of starch under alkaline conditions both reduces the content of non‐starch lipids and maintains a better composition in the residual starch lipids.
Rigid Polyurethane Foam Prepared from Extruded Starch‐Derived Glycol Glucosides as Chemical Intermediates
Authors: Carr Merle E. , Cunningham Raymond L.
Published: November 2006

Starch‐derived glycol glucosides were prepared by a continuous, twin‐screw extrusion process; reacted with propylene oxide; and evaluated as the polyether polyol (PP) in rigid polyurethane (RPU) foam. Cornstarch with 10% moisture, ethylene glycol (EG), and sulfuric acid as the catalyst were reacted at 160°C in the extruder, using 4 moles EG/mole starch anhydroglucose unit (AGU). After removing unreacted EG from the extrudate by vacuum distillation, the crude mixture of products, which contained at least 85% anomeric glucosides, was reacted with propylene oxide to form the PP with a hydroxyl number of 470. The PP was then deionized and reacted with a polymeric diisocyanate, using a conventional type of formulation and pour‐in‐place procedure. The same formulation and procedure were used to prepare RPU foam from a commercial methyl glucoside PP (hydroxyl number 443) for comparison.

The insulating capacity, compressive strength, and dimensional stability properties of the foam with the experimental PP were at least as good as the foam with the commercial PP. This study demonstrates, for the first time, that the starch‐derived glycol glucosides prepared by reactive extrusion processing are suitable chemical intermediates for the preparation of RPU foams with good properties. Also the study suggests that other types of starch‐derived glucosides could be prepared by reactive extrusion processing for potential uses in foams, alkyd resins, surfactants and other products.
Study on Specific Modification of Glucosyl Cyclodextrins
Authors: Hisamatsu Makato , Yamada Tetsuya , Nakashima Kouchi , Tabata Kengo
Published: November 2006

The time courses of the periodate oxidation of glucosyl cyclodextrins complexed with organic solvents indicated the preferential oxidation of glucosyl residues on side chains, and the modified cyclodextrins could be purified by using a reversed phase column. HPLC and 13C‐NMR analyses ensured that the modified cyclodextrins were cyclodextrins having aldehyde residues on their side chains (aldehyde cyclodextrins).
Preparation and Application of Starch Graft Poly(vinyl) Copolymers as Paper Coating Adhesives
Authors: Carr M. E.
Published: November 2006

A series of starch graft copolymers were prepared from commercial cornstarch products and vinyl monomers and were evaluated as adhesives in pigmented paper coatings. Hypochlorite oxidized (HO), acid modified (AM), and hydroxyethlated acid modified (HEAM) starches were reacted separately with acrylamide (AAm), acrylic acid (AAc), and acrilonitrile (AN) using ceric ammonium nitrate as the polymerization initiator to yield copolymers containing 2–45% synthetic polymer. Pigmented coating mixtures with 6–14 parts co‐polymer/100 parts clay and 40–50% total solids were prepared and applied on one side of the paper stock using a hand‐drawn doctor blade. Viscosities, adhesive strength, and wet‐rub resistance of the coating adhesives and mixtures were determined. Adhesive strength of starch graft polyacrylamide (S‐g‐PAAm) copolymers containing as little as 12% PAAm was considerably superior to the commercial starches as paper coating adhesives. Adhesive strength of S‐g‐PAAc copolymers was similar to that of the HO and HEAM commercial starches, whereas adhesive strength of the S‐g‐PAN copolymers was poor. Copolymers that were prepared from the HO starch were slightly superior to those prepared from the AM and HEAM starches. Wet‐rub resistance of the pigmented copolymer coatings was not improved over that of the coatings containing the commercial starches.
Determination of Maltose and Starch by a Flow‐Through Enzyme Enthalpymeter
Authors: Kurczewski J. , Sugier H.
Published: November 2006

A column flow‐through enzyme enthalpymeter was used for the determination of maltose, starch and glucose.