bluuebunny/crossref_metadata_2025 huggingface dataset:
Starch Synthesis in Potato Tubers: Identification of the in vitro and the in vivo Acceptor Molecules of Soluble Starch Synthase Activity
Authors: Ponstein Anne S. , Oosterhaven Koos , Feenstra Will J. , Witholt Bernard
Published: November 2006

A soluble starch synthase preparation obtained from potato tubers (Solanum tuberosum L.) was used to identify the acceptor molecules of the enzyme in vitro. Maltose was the shortest effective primer molecule, and several straight and branched glucose polymers were also able to serve as primer. Osmotically permeabilized potato tissue slices were used to identify the acceptor molecules of granule‐bound and soluble starch synthases under semi in vivo conditions. Specific assay conditions were employed to differentiate between the different starch synthesizing enzyme activities. Both the granule‐bound and the primed soluble starch synthases elongated amylose and amylopectin molecules which were already deposited into starch granules. Soluble malto‐oligosaccharides also functioned as acceptor molecules. In the presence of 0.5 M sodium citrate, starch synthase activity was enhanced. Both amylose and amylopectin accepted more glucose units than in the absence of sodium citrate, indicating that the citrate stimulated soluble starch synthase elongated both starch components as well. The acceptor molecules of the citrate stimulated reaction are probably partly soluble. The elongation patterns of the different starch synthases are dealt with in view of some of the models explaining the side‐by‐side synthesis of amylose and amylopectin in higher plants.
Effects of Heating Rate and Sample Size on Differential Scanning Calorimetry Traces of Starch Gelatinized at Intermediate Water Levels
Authors: Liu Hua , Lelièvre John
Published: November 2006

A study was made of the effects of heating rate and sample size on differential scanning calorimetry traces of aqueous suspensions containing 50% (w/w) rice starch. The variation in the thermal profiles so obtained was due to changes in the resolution of the instrument. Thus, the biphasic traces that characterise the gelatinization of starch at intermediate water levels are not due to polymer recrystallization as has been suggested elsewhere.
Synthesis of Diethylaminoethyl‐Starch (DEAE‐Starch). Part I
Authors: El‐Alfy E. A. , Samaha S. H. , Tera F. M.
Published: November 2006

This work dealt with the synthesis of soluble aminated starch having a tertiary amino group. Factors affecting the degree of substitution of the tertiary amino group mainly: reaction temperature, time, amine and sodium hydroxide concentration besides the liquor ratios were studied and discussed briefly. It was concluded that higher nitrogen content of aminated starch is obtained at 80°C and in 30 min while the concentration of 2‐chloro‐ethy‐diethyl amine hydrochloride (amine) and sodium hydroxide were 30% and 40%, respectively. Increasing the liquor ratio was accompanied by an increase in nitrogen content.
Factors Affecting the Technological Properties of Starch Carbamate
Authors: Hebeish A. , Refai R. , Ragheb A. , Abd‐El‐Thalouth I.
Published: November 2006

Starches having different molecular sizes were obtained by subjecting rice starch and maize starch, independently, to oxidation with aqueous sodium hypochlorite solutions of different concentrations. These starches were then reacted with urea in a dry state to yield mainly starch carbamate. The latter was isolated from the reaction products by treatment of the latter with either water or 4% aqueous NaOH solution. It was observed that regardless of the kind and molecular size of starch, treatment with water brings about starch carbamate which swells but does not dissolve completely in water. Against this was water soluble starch carbamate isolated by ethyl alcohol precipitation from NaOH solution (after neutralization). Studies of the rheological properties of the water soluble starch carbamates revealed that starch carbamates derived from rice starches are characterized by either thixotropic or pseudoplastic character depending on the molecular structure of starch. On the other hand, starch carbamates derived from maize starch exhibit pseudoplastic behaviour by virtue of their relatively lower molecular weight and higher carboxyl content. It was also found that the apparent viscosity of starch carbamates is determined by the kind of starch, the degree of oxidation and the storing time.
Purification and Characterization of the Commercialized, Cloned Bacillus megaterium α‐Amylase. Part I: Purification and Hydrolytic Properties
Authors: Brumm P. J. , Hebeda R. E. , Teague W. M.
Published: November 2006

An amylolytic enzyme, originally isolated from Bacillus megaterium. was shown to increase the maximum amount of dextrose produced during saccharification by decreasing the amount of residual oligosaccharides. The enzyme, now commercially produced in a genetically engineered strain of Bacillus subtilis, was purified to homogeneity from the commercial product. A combination of gel permeation chromatography in the presence of 1.0 M NaCl and chromatofocusing between pH 9.0 and 7.0 were used to obtain the pure enzyme. The molecular weight of the Bacillus megaterium α‐amylase was 59,000 by SDS gel electrophoresis, and the isoelectric point was 8.9 to 9.0. The enzyme was shown to possess both hydrolytic and transferase activity. The enzyme hydrolyzed a wide variety of soluble substrates. The rate of hydrolysis was greatest on soluble starch; α(1,6)‐branched substrates and cyclodextrins were hydrolyzed more slowly.
Agronomic Factors Related to the Quality of Wheat for the Starch Industry. Part I: Sprout Damage
Authors: Kelfkens M. , Hamer R. J.
Published: November 2006

The wheat starch industry in the Netherlands processes about 300.000 t of wheat annually. However, only a small percentage of this wheat is grown in the Netherlands although it has been demonstrated that Dutch wheat varieties can also be successfully processed. Climatological and cultural aspects can however negatively affect Dutch wheat quality. Due to climatological conditions the Dutch wheat regularly suffers from sprout damage. It is for this reason that the effects of sprout damage on processing quality and quality of gluten and starch have been investigated using a pilot scale gluten starch separating system. Low levels of sprout damage appeared to have no effect on gluten yield and even improved the gluten coagulation. In baking tests also no effect of sprout damage on gluten quality could be detected. On the other hand, low levels of sprout damage may lead to a lower starch yield and starch has low viscosity characteristics, limiting its scope of application. Also the amount of solubles in the waste water was increased. These findings lead to a further definition of requirements of wheat for the starch industry, enabling future selection of wheat on the basis of more accurate criteria.
Agronomic Factors Related to the Quality of Wheat for the Starch Industry. Part II: Nitrogen Fertilisation and Overall Conclusions
Authors: Kelfkens M. , Hamer R. J.
Published: November 2006

In the N.W.‐European wheat growing system high levels of nitrogen fertiliser are applied. Especially late nitrogen applications are thought to increase the amount of soluble proteins, leading to extra losses and wastage. On the other hand, protein content is the most important factor determining gluten yield. The effects of fertilisation on processing quality have been investigated using a pilot separator. Samples from fertilisation trials show a high correlation between gluten yield and protein content of the flour. This relation is variety dependent, due to differences in water‐soluble proteins. For both varieties the percentage of water‐soluble proteins appeared to decrease with increasing N‐fertilisation levels. At low protein contents of the flour the coagulation of the gluten is adversely influenced. Using soft bread wheats, this may cause severe difficulties during separation. At high fertilisation levels the amount of solubles in the waste water increased slightly. ‐ A review on research results is made, showing the criteria for wheat for the starch industry.
Preparation and Characterization of Anion‐Exchange Starches
Authors: Khalil M. I. , Waly A. , Farag S. , Hebeish A.
Published: November 2006

Treatment of poly (glycidyl methacrylate (GMA))‐starch graft copolymer containing 270 m.eq.epoxy groups/100 g sample with ethylenediamine was carried out under different conditions. Results indicated that three reactions are likely to occur during this treatment, namely amination, crosslinking and hydrolysis. The highest amine content could be achieved upon using amine/epoxy molar ration of 2.5 and material to liquor ratio 1:3, at 90°C for 180 min. The dependence of the amination percent on the type and nature of the amine was also studied. The values of amination percent for the different types of amine follows the order: O‐phenylene‐diamine > m‐phenylenediamine > p‐phenylenediamine > ethylenediamine; whereas studying the nature of the amine brings about the order: diethylamine derivative > ethylamine derivative > ethanolamine derivative > triethylamine derivative. Evaluation of the different reaction products (aminated copolymers) for their anion exchange properties was made. The capacity of the anion exchangers relied on the inital epoxy content of the copolymer and type and nature of the amine used. On the other hand, heavy metal anions and dye removal efficiency followed the order: diethylamine derivative > ethylenediamine derivative > triethylamine derivative > p‐phenylenediamine > derivative > ethylamine derivative. The pH‐metric titration curves revealed that triethylamine derivative behaves as a strong base while the other exchangers as weak bases. Other properties such as pKb value, durability, solubility, etc. indicated that the synthesized products can be regarded as anion exchangers with acceptable properties.
A New Bacillus licheniformis Alpha‐Amylase Capable of Low pH Liquefaction
Authors: Antrim Richard L. , Solheim Barbara A. , Solheim Leif , Auterinen Anna‐L. , Cunefare Jerry , Karppelin Sinikka
Published: November 2006

A new alpha‐amylase has been developed capable of catalyzing industrial scale liquefaction of starch at lower than conventional pH levels. Low pH liquefaction results in significant cost savings and less complex operations for a starch processor. Liquefaction studies in a pilot scale jet cooker demonstrated that, surprisingly, commercial starch slurries taken from different sources vary greatly as to ease of liquefaction at lower than conventional pH values. Apparently low levels of stabilizing or destabilizing factors exist in commercial starch slurries which affect the stability of alpha‐amylase during high temperature (103–107°C) liquefaction.
Expression of the CGTase Gene of Alkalophilic Bacillus No. 38‐2 in Various Hosts
Authors: Georganta Georgia , Kaneko Takahiro , Kudo Toshiaki , Horikoshi Koki
Published: November 2006

We compared the expression level of cyclomaltodextrin glucanotransferase (CGTase) gene of alkalophilic Bacillus species No. 38‐2 in various hosts. Plasmid pEAP85, a new excretion vector, containing tac promoter for expression was constructed. CGTase gene was introduced into a new excretion vector pEAP85 and a shuttle vector pHY300PLK and plasmids pCS8, pEAP85‐CGT and pKG‐1 were constructed. Escherichia coli carrying pEAP85‐CGT excretes 70% (350 U/ml culture) of total CGTase (500 U/ml) into the culture broth. This amount was higher than that produced by the original Bacillus species. Bacillus subtilis carrying pGK‐1 produced very low level of CGTase(< 0.1 U/ml).
Recent Advances in Knowledge of Starch Structure
Authors: Imberty Anne , Buléon Alain , Tran Vinh , Péerez Serge
Published: November 2006

Three dimensional models of crystalline zones and amorphous branching zones of starch granules are reviewed. In crystallites of both A and B starch, double helices are found in pairs, and all chains are packed in parallel arrays. The pairing of double helices is identical in both polymorphs and corresponds to the interaction between double helices that has the lowest energy. The differences between A and B starch arise from water content and the manner in which these pairs are packed in the respective crystals. A transition from B starch to the A form can be accomplished by rearrangement of the pairs of double helices. The 1–6 linked amylopectin branch points occur in amorphous regions, but actually promote the formation of ordered double helices.
Purification of Barley Starch by Protein Extraction
Authors: Schulman Alan H. , Kammiovirta Kari
Published: November 2006

Preparation of pure starch samples requires gentle extraction from the endosperm matrix, followed by removal of contaminating endosperm proteins. Published techniques for removal of these proteins include protease treatment or centrifugation through CsCI. We present a simple method to remove proteins from starch, exploiting the solubility of the major groups of endosperm proteins in aqueous, saline, and alcoholic solvents. The data show that the purity of the starch and retention of B‐granules is similar to conventional techniques. Denaturing polyacry‐lamide gel electrophoresis reveals very few proteins retained with the starch. One major protein has an apparent MW of 54000 and probably corresponds to the “waxy” protein, granule‐bound starch synthase.
Extrusion‐Grafting Starch Onto Vinylic Polymers
Authors: Chinnaswamy R. , Hanna M. A.
Published: November 2006

The review outlines the rationale behind starch polymer based thermoplastic resin production using reactive extrusion processing techniques, as well as characterization of these polymers.
Amylase, β‐Glucanase and Protease Activities from a Mutant of Bacillus subtilis
Authors: Yin X. S. , Li Y. X. , Stark J. R.
Published: November 2006

Enzymes in the shake culture of a mutant of Bacillus subtilis developed mainly during the stationary phase of growth. Extracellular α‐amylase and protease activities increased and then declined to relatively low levels after 48 h of incubation while the β‐glucanase activity remained high. The production of extracellular proteolytic activity commenced only when the low molecular weight nitrogen source in the medium was completely consumed. Enzymes were fractionated by ionexchange chromatography and the molecular weights of β‐glucanase, α‐amylase, protease I and protease II were estimated by gel filtration to be 1.3 × 104, 3.2 × 104, 6.3 × 103 and 2.0 × 104, respectively. The β‐glucanase and α‐amylase showed maximum activities at around pH 7, but the two proteases had different pH optima (pH 6–7 and 8.5, respectively). The presence of proteolytic activity in the enzyme preparation had a significant effect on the stability of the β‐glucanase and the α‐amylase at 65°C.
Examination of Starch‐Water and Cellulose‐Water Interactions With Near Infrared (NIR) Diffuse Reflectance Spectroscopy
Authors: Delwiche Stephen R. , Pitt Ronald E. , Norris Karl H.
Published: November 2006

Starch‐water and cellulose‐water interactions were examined with NIR diffuse reflectance spectroscopy. Samples of native potato, wheat, and corn starches and microcrystalline cellulose (MCC) were equilibrated to water activities (aw) ranging from 0.11 to 0.94 aw. A modified B.E.T. model was applied to the water vapor sorption isotherm (T=25°C) data. NIR spectra (1000 to 2640 nm) revealed no abrupt changes in molecular structure. However, as has been suggested in the literature, there appear to be two species of non‐freezable water whose relative quantities change as aw varies. It is hypothesized that the first species represents water within the monolayer, and the second species represents multilayer water. NIR spectra of starch suggests that some multilayer water is present before the monolayer is completed. Spectra of MCC corroborate the existence of two species of highly associated water. The isotherm model was highly successful in describing sorption behavior over the aw range examined.
The Efficiency of Hydrocyclones for the Separation of Different Starches
Authors: van Esch Frans
Published: November 2006

Since many years the starch industry uses hydrocyclones to purify starch. The starch is washed countercurrently with water in a number of washing stages. For a good washing effect, in each stage a separation of starch and impurities must be obtained. Different methods can be used to describe the efficiency of separation. As most suitable, the reduced grade efficiency is chosen. This efficiency is quantified for different starches: maize, potato, rice, wheat. From the measured efficiencies, relative sizes for washing batteries are calculated. The results correlate well with existing plant practices. The influence of starch damage on the separation efficiency was also investigated. Damaged starch appears more difficult to separate.
Zum thermischen Verhalten von Glucanen. Teil 1: Thermoanalytische Untersuchungen an Stärken und stärkehaltigen Systemen
Authors: Gloyna Dieter , Schreck Swetlana , Schierbaum Fritz , Westphal Günther
Published: November 2006

Das thermische Verhalten nativer, z.T. entfetteter Stärken und Quellstärken sowie ihrer Hauptbestandteile Amylose und Amylopektin wird bis 300°C mittels Derivatographie unter Ausschluß von Wechselwirkungen mit Nichtkohlenhydratkomponenten sowie in aminosäure‐ bzw, proteinhaltigen Modellgemischen und Getreidemehlen untersucht. Charakteristisch für die Thermolyse der reinen Polysaccharide ab 200°C sowohl unter anaeroben als auch aeroben Bedingungen ist der dominierende endotherme Charakter, wobei native Stärke, Amylose und Amylopektin sich untereinander im Derivatogramm bezüglich Thermolysebeginn. Massenverlust und Reaktionswärme unterscheiden. Die botanische Herkunft ist dagegen ohne spezifischen Einfluß. Die Quellstärken zeigen gegenüber den entsprechenden nativen, entfetteten Stärken ein verändertes thermisches Verhalten, das auf Unterschiede in den übermolekularen Strukturen zurückgeführt werden kann. Bei Stärke‐Aminosäure‐ und Stärke‐Proteingemischen sowie bei Getreidemehlen wird ein deutlich ausgeprägter exothermer Charakter der Hauptabbaustufe nachgewiesen. Dies wird durch aktive Mitwirkung des Proteins bei der Thermolyse des Mehlbestandteils Stärke erklärt. Sauerstoff beeinflußt während der Thermolyse die Reaktionsgeschwindigkeit des Hauptabbauprozesses. Bei der Mehlthermolyse bewirkt er eine Erhöhung, bei der Thermolyse von Nativstärke eine Verminderung der Geschwindigkeit. Bei Sauerstoffanwesenheit wird der exotherme bzw. endotherme Charakter des Hauptabbaus in jedem Fall um ein Vielfaches erhöht.
Effect of the Degree of Phosphorylation on the Crystallinity of Native Potato Starch
Authors: Muhrbeck Per , Svensson Erik , Eliasson Ann‐Charlotte
Published: November 2006

X‐ray diffraction technique, combined with digital image processing was used to compare the crystallinity of native starch from a number of potato varieties, differing in the degree of phosphorylation. The crystallinity was found to decrease linearily with an increased degree of phosphorylation. Based on earlier observations of the gelatinization enthalpies, it was assumed that the C‐6 phosphates, which have an orientation out of the α‐helices disturb the crystallization of the amylopectin during the starch synthesis. The C‐3 phosphates, which are located in the interior parts of the α‐helices, are not believed to interfere with the crystal structure.
DSC Characteristics of Gelatinization of Starches of Single‐, Double‐, and Triple‐Mutants and Their Normal Counterpart in the Inbred Oh43 Maize (Zea mays L.) Background
Authors: Inouchi N. , Glover D. V. , Sugimoto Y. , Fuwa H.
Published: November 2006

Starch granules were isolated from mature kernels of single‐, double‐, and triple‐mutants of endosperm starch modifying genes [waxy(wx), dull(du), amylose extender(ae), sugary‐2(su2)] and their normal counterpart in the inbred Oh43 maize (Zea mays L.) background. Gelatinization characteristics of the starch granules were investigated by means of differential scanning calorimetry (DSC). The onset, peak, and conclusion temperatures of gelatinization (To, Tp, and Tc, respectively) and the heat of gelatinization (ΔH) of starch were determined from the DSC thermograms.

The Tc of wx was higher than normal starch, and the ΔH of wx was larger than normal starch. The Tp and Tc values of ae starch were the highest. The To, Tp, and Tc values of su2 starch were low. The noticeable effects of each of the wx, ae, and su2 genes on To, Tp, Tc and ΔH were observed in starches of their respective mutant combinations. Apparent epistatic effects of the genes for gelatinization temperature were observed. Pronounced effect of the heating rate on gelatinization temperature of su2 mutant were lower than other mutant starches and were affected by the heating rate.
DSC Characteristics of Retrograded Starches of Single‐, Double‐, and Triple‐Mutants and Their Normal Counterpart in the Inbred Oh43 Maize (Zea mays L.) Background
Authors: Inouchi N. , Glover D. V. , Sugimoto Y. , Fuwa H.
Published: November 2006

Starch granules were isolated from mature kernels of single‐, double‐, and triple‐mutants of starch modifying genes [waxy(wx), dull(du), amylose extender(ae), sugary‐2(su2)] and their normal counterpart in the inbred Oh43 maize (Zea mays L.) background. Gelatinization characteristics of retrograded starches were investigated by means of differential scanning calorimetry (DSC). The thermograms of the retrograded starch shifted to lower temperature ranges and were broader compared with the native starch.

The heat of gelatinization (ΔH) of the retrograded starch increased with increasing storage duration. The maximum value of the ΔH reached for each mutant and mutant combination was somewhat characteristic of the genotype and associated with duration of storage.
Purification and Characterization of Bacillus acidopullulyticus Pullulanase for Enzymatic Starch Modification
Authors: Lappalainen Arja , Niku‐Paavola Marja‐Leena , Suortti Tapani , Poutanen Kaisa
Published: November 2006

The pullulanase (EC 3.2.1.41) of Bacillus acidopullulyticus was purified using anion exchange chromatography and preparative isoelectric focusing. The purified preparation migrated as a single protein band upon SDS gel electrophoresis and its molecular weight was estimated to be 102,000. Two main activity bands having pl‐values 5.0 and 5.2 were detected by analytical isoelectric focusing. The enzyme was purified 4‐fold with the yield 38% by this two‐step purification procedure. The purified pullulanase showed maximal activity at 50°C and pH 5 and was slightly activated by Ca2+. It was stable at 50°C but totally lost its activity at 60ºC in one hour. This purified pullulanase efficiently hydrolyzed the α‐1,6‐glucosidic bonds of pullulan and gelatinized starch.
Overall Performance Evaluation and Functional Analysis of Egyptian Starch Manufacturing Plants
Authors: El‐Halwagi M. M. , Hefny M. A. El , Aziz H. A. Talaat , Sorour M. H. , Abulnour A. G. , El‐Defrawy N. M. H.
Published: November 2006

The present paper outlines the approach and principal results of a full‐fledged performance evaluation and functional analysis program conducted at the Egyptian Starch and Glucose Company that has been wholly documented elsewhere [12]. The ultimate goal of the program is to come up with well‐defined and appropriate courses of action to improve products quality, plant productivity and overall economy. The paper also reports the results of additional computer work that has been undertaken to enhance the applicability of the results. The adopted methodology for applying the developed computer material balance (MASSBAL) in the evaluation program and in analysing the impacts of stepwise improvements in the individual plant sectors of concern is also presented.
Prediction of Degradability of Starch by Gelatinization Enthalpy as Measured by Differential Scanning Calorimetry
Authors: Wolters Mechteldis G. E. , Cone John W.
Published: November 2006

It was investigated whether the degradability of starch could be predicted by differential scanning calorimetry (DSC). Degradation of potato starch with a varying degree of gelatinization. of isolated starch of different origins, and of raw materials differing in origin and technological treatment was determined with α‐amylase and bovine ruminal fluid. Gelatinization enthalpy and the gelatinization temperature of starch were determined by DSC.

There was a good correlation between gelatinization enthalpy measured by DSC and degradation with α‐amylase and ruminal fluid for potato starches with varying degrees of gelatinization and for isolated starch granules of different origins. For raw materials of different origins there was a good correlation between gelatinization enthalpy and degradation with α‐amylase, whereas the correlation between gelatinization enthalpy and degradation with ruminal fluid was poor. There was a good correlation between gelatinization enthalpy and degradation with both α‐amylase and ruminal fluid for (technologically treated) raw materials of one and the same origin. There was no relation between starch degradation and gelatinization temperature.
A Spectrophotometric Method for the Determination of Iodine Binding Capacity for Starch and Its Components
Authors: Karve M. S. , Kale N. R.
Published: November 2006

A spectrophotometric method for the determination of iodine binding capacity (IBC) for amylose, amylopectin and starch on a microscale is developed. It is based on the observation that free iodine (I3) can be determined fairly accurately by recording the absorbance at 286 nm. By using a constant volume titration method, bound iodine is calculated by subtracting the free iodine from the total iodine. A plot of free iodine vs bound iodine shows an inflection, which on extrapolation gives the bound iodine. The IBC values obtained by this method are in good agreement with those obtained by conventional potentiometric and amperometric methods.
Screening of α‐Amylase Suitable for Evaluating the Degree of Starch Retrogradation
Authors: Tsuge Haruhito , Tatsumi Eizo , Ohtani Naoko , Nakazima Akiko
Published: November 2006

To estimate the degrees of starch retrogradation in the complex foods, an enzymatic method using α‐amylase from Bacillus subtilis was proposed in the previous report (Tsuge, H. et al.: Starch/Stärke 42 (1990), 213–216). However, actual digestibility of the enzyme for the native starch granules was not checked at that time. A comparative study to see the digestibility of native starch granules was carried out using four different α‐amylase preparations and digestion of retrograded wheat starch was tested by two α‐amylase preparations. Pancreas α‐amylase preparation digested some native starch granules to a great extent, while Aspergillus oryzae enzyme did not digest native starch granules virtually. In conclusion, α‐amylase preparation from A. oryzae was an ideal enzyme as the tool to distinguish between raw and gelatinized starches. It was justified for the use of A. oryzae enzyme as well as B. subtilis α‐amylase to evaluate the retrograded starch contents in the complex foods.
Enzymes as a Processing Aid in the Separation of Wheat Flour into Starch and Gluten
Authors: Weegels P. L. , Marseille J. P. , Hamer R. J.
Published: November 2006

A pilot system for the separation of wheat flour into starch and gluten was used to study the effect of four enzyme preparations as processing aids. Technical enzyme preparations with hemicellulase, cellulase or protease activities appear to improve gluten yield, protein recovery in gluten and gluten coagulation in a flour with intermediate processing properties. With these enzymes similar results were obtained compared to a flour with good processing properties without the use of enzymes. The use of enzymes did not adversely affect protein content, baking quality and rheological properties of the gluten. The proportion of soluble proteins, however, increased when the protease was used.

The yield of starch was slightly increased by the action of the cellulase and hemicellulase, but was significantly decreased with the protease. Starch purity as determined by its protein content was not affected. Based on these results it is concluded that some cellulases and hemicellulases can act as important processing aids for gluten/ starch separation.
Pyrolysis Mass Spectrometry (PyMS) and Degradability of Starch Granules
Authors: Cone John W. , Tas Albert C. , Wolters Mechteldis G. E.
Published: November 2006

The degradation of isolated starch granules of different origin and of different mixtures of potato starch was determined with α‐amylase and rumen fluid from a cow. There was a rather constant order in degree of degradability of the different starches. Degradation of mixtures of native potato starch and unsealed potato starch showed that there was a linear correlation between degradation and degree of unsealing. Principal component regression on pyrolysis data from starches of different origin enabled a ranking according to the enzymic degradability. For potato starches with different degrees of unsealing this ranking was not possible. The results on the different potato starches show that differences in degradability between different starch samples are not necessarily caused by chemical properties but likely also by physical properties.
Production and Application of a Maltogenic Amylase by a Strain of Thermomonospora viridis TF‐35
Authors: Takahashi K. , Totsuka A. , Nakakuki T. , Nakamura N.
Published: November 2006

An extracellular and thermostable maltogenic amylase‐producing moderate thermophile (Thermomonospora viridis TF‐35), which grew well at 28–60°C, with optima at 45°C and pH 7, was isolated from soil. Maximal enzyme production was attained after aerobical cultivation for 32 h at 42°C with a medium (pH 7.3) composed of 2% (w/v) soluble starch, 2% gelatin hydrolyzate, 0.1% K2HPO4 and 0.02% MgSO4 · 7H2O. The partially purified enzyme, which was most active at 60°C and pH 6.0 and stabilized with Ca2+, converted about 65, 80, 75, 75, 65 and 60% of maltotriose, maltotetraose, maltopentaose, amylose, amylopectin and glycogen into maltose as a major product under the conditions used, respectively. Glucose and small amounts of maltooligosaccharides were also formed concomitantly as by‐products. The molar ratio of maltose to glucose from maltotriose were larger than 1 during all stages of the hydrolysis. About 70 and 76% of 25% (w/v) potato starch liquefites having a 3.5 DE value were converted into maltose by the enzyme in the absence and presence of pullulanase during the saccharification, respectively. About 90 and 94% of the starch liquefites were also converted into maltose with relatively low contents of maltooligosaccharides by the cooperative 2 step reaction with the enzyme after obtaining starch hydrolyzates containing about 85 and 90% maltose by the simultaneous actions of soybean ß‐amylase and debranching enzymes.
Saponification of Graft Copolymers of Sodium Salt of Partially Carboxymethylated Amylose and Its Water Absorbency
Authors: Shah S. B. , Patel B. K. , Patel C. P. , Trivedi H. C.
Published: November 2006

The grafting of acrylonitrile (AN) onto amylose and sodium salt of partially carboxymethylated amylose samples having different degrees of substitution has been carried out using ceric ammonium nitrate (CAN) as redox initiator. The saponification of all the PAN‐containing graft copolymers has been carried out by methanol precipitate method. The water retention values of all the graft copolymers have been measured and compared. The results have been discussed.
Studies on Alkali‐Modified Cassava Starch ‐ Changes of Structural and Enzyme (α‐Amylase) Susceptibility Properties
Authors: Raja K. C. M.
Published: November 2006

Properties of cassava starch could be modified by subjecting to alkalitreatment under controlled experimental conditions. Modified starch samples showed lower amylose content and higher alkali number. Compared to untreated starch samples, alkali modified starches had higher α‐amylase (Bacillus sp.) susceptibility. The properties could be advantageously made use of for preparing maltodextrins having DE 20–23.
Microscopic Evaluation of Hydroxypropyl Potato Starch Granules During Treatment with Urea
Authors: Kim Hak‐Ryang , Hermansson A.‐M. , Eriksson E.
Published: November 2006

A microscopic methodology was devised for the quantitative measurement of the changes in light intensitiy during the loss of birefringence of starch granules in aqueous urea under polarized light. This has been adapted to a native potato starch, hydroxypropyl potato starches of varying molar substitution (M.S.) and a hydroxypropyl and cross‐linked potato starch. Several of the factors influencing the measurement results such as urea concentrations, sodium sulphate content and temperature were examined. The hydroxypropyl potato starches rapidly lost their birefringence with increasing M. S., and the relationship between the M. S. and the rate of changes in light intensity was found. There were marked differences in the morphology of the swollen shapes of granules between hydroxypropyl potato starch, and hydroxypropyl cross‐linked potato‐starch.
Glucose Assay with Extended Concentration Range by Flow‐Through Enzyme Enthalpymeter
Authors: Sugier H. , Kurczewski J.
Published: November 2006

The possibility of extending measurable concentration range of glucose in a flow‐through enthalpymeter with immobilized glucose oxidase by supplying the column with additional oxygen was examined.
Feinstruktur und Hyperfeinstruktur von klinisch verwendeter Hydroxyethylstärke
Authors: Sommermeyer Klaus , Hildebrand Ulrich , Cech Franz , Pfitzer Edith , Henning Klaus , Weidler Burghard
Published: November 2006

An einer Reihe unterschiedlicher Proben Hydroxyethylstärke wurden durch Multidetektions‐HPGPC die Mark‐Houwink‐Parameter, sowie über die gaschromatographische Methylierungsanalyse neben der Verzweigung die molekularregionsspezifischen Substitutionsgrade MS und DS und die Substitutionsmuster gemessen. Innerhalb der Molekularregionen nichtreduzierender Kettenenden, Verzweigungseinheiten sowie linearer Kettenglieder ergeben sich charakteristische Unterschiede in bezug auf die Substitution, die diskutiert werden. Hydroxyethylstärken, welche aus enzymatisch durch Amylase vorbehandelter Wachsmaisstärke hergestellt wurden, weisen einen signifikant höheren Anteil an Verzweigung auf, verglichen mit säurehydrolytisch vorbehandelter Stärke. Die klinische Relevanz der Ergebnisse wird diskutiert.
Purification and Characterization of a β‐Amylase of Hendersonula toruloidea
Authors: Odibo F. J. C. , Okafor N. , Tom M. U. , Oyeka C. A.
Published: November 2006

β‐Amylase produced by Hendersonula toruloidea was purified to homogeneity by salting out with ammonium sulphate, ion‐exchange chromatography on DEAE‐cellulose and gel‐filtration on Sephadex G‐75. The relative molecular mass of the enzyme was estimated to be 60,000 by gel filtration. The enzyme was optimally active at pH 6.0 and 60°C, stable between pH 6 and 8 (24 h) and retained 74% activity at 70°C (30 min). It was strongly activated by Na+ but inhibited by Hg2+, Zn2+ and Cu2+. The enzyme hydrolyzed amylopectin (Km 0.42 mg/ml) forming maltose, maltotetraose and unidentified maltooligosaccharide, and hydrolyzed soluble starch (Km 0.3 mg/ml) and glycogen (Km 0.5 mg/ml) forming maltose and unidentified maltooligosaccharide.
Characterization of High‐amylose Type Endosperm Starches of Rice Plants Cultivated in Asia
Authors: Fuwa H. , Okuno K. , Asashiba R. , Kikuzaki H. , Asaoka M. , Inouchi N. , Sugimoto Y.
Published: November 2006

Starch granules were prepared from 14 indica rice grains which were collected from various places of Asia and had the amylose content of 28% and over by a blue value method. The starches were high‐ and medium‐amylose types by the enzymatic and chromatographic method. However, none of them belonged to the type of high amylose mutants which were induced by the chemical mutagen treatment of a japonica rice cultivar: Kinmaze and possessed similar characteristics of endosperm starch to that of the amylose‐extender (ae) mutant of maize (Zea mays L.).
Chromatographische Untersuchungen zur Polydispersität von Hydroxyethylstärke
Authors: Sommermeyer Klaus , Cech Franz , Hildebrand Ulrich , Pfitzer Edith , Baumbach Cornelia
Published: November 2006

Eine repräsentative Probe von einer klinisch verwendeten Hydroxyethylstärke wurde mittels semipräparativer HPGPC in enge Molekulargewichtsfraktionen im Bereich von ca. 3 000 bis 800 000 D aufgetrennt. Ausgangsprobe und ausgewählte Einzelfraktionen wurden durch gaschromatographische Methylierungsanalyse in bezug auf die Substitutionsgrade MS und DS charakterisiert, wobei diese nach Substitutionsposition C2, C3 und C6 der Anhydroglucosen und deren glycosidische Bindungsart α‐1, α‐1,4 bzw. α‐1,4,6 unterschieden wer‐den. Ebenfalls ermittelt wurde die Polydispersität in bezug auf die Verzweigung.

Weiterhin werden die durch Multidetektions‐HPSEC ermittelten Kenngrößen zur Molekulargewichtsverteilung und die Mark‐Houwink‐Parameter angegeben. Die Daten zeigen insgesamt eine weitgehende Homogenität der Ausgangsprobe in bezug auf die gemessenen Parameter. Ihre klinische Relevanz wird diskutiert.
Chain Length Specifity of Cyclodextrin Glycosyltransferase
Authors: Vetter Dirk , Thorn Werner
Published: November 2006

Bacillus macerans CGTase recognizes the terminal 6 glucose units of the non‐reducing end of α‐(1→4)‐glucans. Analysis of the chain‐length distributions produced by the action of CGTase on well‐defined maltodextrins gave information on the enzyme's specifity in regard of the size of the transferred glucanosyl‐moiety.

It was found that in the presence of α‐cyclodextrin, maltohexaosyl‐groups could be highly specifically coupled to an acceptor like maltose. The product, maltooctaose, appeared in a yield of 45 % molar amount. The affinity for hexaosylresidues was explored by using homodisperse substrates from glucose to maltotriadecaose. HPTLC‐analysis of the product patterns in early states of CGTase catalyzed reactions revealed that the yield of the primary coupling product decreased with increasing DP. This was due to the effect, that disproportion was more rapid on higher oligomers. The intermolecular transfer of glucanosylgroups was also found to be size‐dependent, inasmuch as the relative CGTase transfer activity decreased gradually from maltohpxaosyl‐ to glucosylresidues. In an investigation of the enzymic degradation of maltodextrins maltononaose gave the highest yield of α‐CD.
Coupling of 1‐Aminododecan to Starch by Bromine Oxidation and Reductive Amination
Authors: Salomonsson B. Ann‐Christine , Theander Olof
Published: November 2006

Conjugates of potato starch have been prepared by coupling of bromine oxidized starch to 1‐aminododecan by reductive amination. The starch was oxidized at two different levels of molar ratios bromine/starch (1/20 and 1/5) and at two different temperatures (22deg;C and 94deg;C). The content to introduced keto functions was highest for the 1/5 sample oxidized at 22deg;C. The GPC (gel permeation chromatography) analyses of the molecular weight showed that oxidation 1/5 at 94deg;C provided an oxidized starch with molecular weight below 50,000 whereas the other oxidation conditions gave products with higher molecular weights. The keto functions of the oxidized starch was aminated with 1‐aminododecan by reductive amination at different temperatures (22deg;C and 80deg;C) and reaction times. The proportion of coupled amine was highest at 80deg;C after 3 h.
Modification of Starch‐Based Hydrogels Through Grafting by a New Chelating Monomer
Authors: Mikhael Michael G. , Kulicke Werner‐M.
Published: November 2006

Native maize starch was grafted by N‐acryloyl‐N′‐cyanoaceto‐hydrazide (ACAH) using potassium persulfate as a free radical initiator in aqueous medium. Spectral (FT‐IR) and elemental analyses were used in combination to elucidate both the structure and composition of the thoroughly washed grafted samples. Gelation of the produced grafted samples has been carried out in alkaline medium using sodium trimetaphosphate (Na3P3O9) as a cross linker. The effects of temperature and sodium hydroxide, substrate and crosslinker concentrations were found to be significant in determination of the rheological properties of the prepared modified gels. The influence of grafting ratio and cross‐linker concentration on the gel swelling ability was investigated in deionized water as well as in sodium and potassium chloride 10−2 molar solutions. The produced gels showed a great tendency towards complexation with many metal cations. Chelation with Cu(II), Ni(II) and Cr(III) chloride solutions has been spectrophotometrically investigated. Stability constants of the formed complexes were found to be of the order of 107.
Preparation and Characterization of Copolymers of Modified Starches and Polyacrylonitrile
Authors: Honig David H. , Carr Merle E.
Published: November 2006

Starch graft polyacrylonitrile (S‐g‐PAN) copolymers were prepared from a commercial unmodified cornstarch and from three chemically modified commercial cornstarch products including Amaizo 395 (highly acid modified, HAM), Amaizo 590 (highly hypochlorite oxidized, HHO) and Amaizo 791D (hydroxyethyl, highly acid modified, HEHAM). Using similar reaction conditions and ratio of monomer to starch (1:1), the percentages of PAN in the copolymers ranged from 39% for the unmodified starch to 48% for the modified starches. Only 5% of the PAN of the copolymer prepared from unmodified starch could be extracted by dimethylformamide (DMF) treatments compared to 22–28% for copolymers prepared from the modified starches. However, copolymers from the modified starches apparently contained relatively high proportions of low‐molecular‐weight copolymer along with homopolymer. Acid hydrolysis treatment of the DMF insoluble and DMF soluble fractions to remove starch from the various copolymers gave essentially quantitative yields of PAN. However, these PAN samples exhibited large differences in DMF solubility. The copolymer from the HHO starch was by far more soluble in DMF, had the lowest number average molecular weight, and had a grafting frequency of 2.5–3 times greater than those of the other copolymers. This study indicated that hypochlorite modified starch substrates may be particularly suitable for obtaining copolymers with widely different properties than copolymers having the acid modified starch substrates.
13C‐NMR Spectroscopic Detection of Malto‐oligosaccharide Complexes
Authors: Vetter Dirk , Thorn Werner
Published: November 2006

Fragments of amylose were enzymatically synthesized and purified to α‐(a→4)‐glucans of well defined degress of polymerization by preparative size exclusion chromatography. Maltooligosaccharides from DP 3 to 12 were subjected to 13C‐NMR‐spectroscopy.

The addition of iodine as a complexing agent selectively affected the carbon atoms involved in the glycosidic bond. Resonances of C‐1 and C‐4 experienced a dramatic downfield shift. This is interpreted as a change of conformation of the amylose helix. The shift differences can be measured conveniently and be used for calculations of complex stability constants. Maltohexaose and higher saccharides gave strong effects upon complexation, indicating that one helical turn brings about a gain in helical stability. No lower chain‐length limit for the complex‐forming capacity was observed. Even the smallest fragments of amylose showed complexing behaviour.
Determination of the Potato Starch Content in a Slurry by an Areometer
Authors: Potze Jan
Published: November 2006

The determination of the quantity of starch per volume (kg/m3) in a slurry of potato starch in water by measuring the density of the slurry with a standard areometer and the temperature is reviewed. A formula is developed in which occur two physical constants of potato starch (soaked in water): the density at 20°C and the temperature correction factor. The constants are calculated from measurements in starch slurries. In this report the method is given. A limited number of recent measurements resulted in the given preliminary constants. It showed that the density of the starch (soaked in water) differs between never dried starch and dried and reslurried starch. Starch tables can be made with the help of the developed formulas.
Starch Derivatives for Flocculation of Ferric Soaps
Authors: Cherian Xavier M. , Satymoorthy Poornakala , Kumar Velayyudhan N. G.
Published: November 2006

Although water soluble synthetic polymers find wide applications as flocculating agents, the potential problem associated with their use is lack of biodegradability and high cost. Development of substitutes based on natural polymers can be more attractive from biodegradability point of view and the important factor here will be matching the performance.

We have studied the flocculating effects of starch derivatives (cationic and anionic) for ferric soap flocculation at different pHs and compared their efficiency with synthetic flocculants like Zeetag‐63 and Floc‐acid‐25. Charge interaction between colloidal particles and polymeric flocculating agents is one of the factors that contribute to the changes in rae and extent of flocculation. :Under certain pH conditions starch based flocculants are shown to perform better than the synthetic flocculants (Zeetag‐63) and the effects are explained on the basis of variation of surface charge (measured by collid titration) of ferric soaps precipitated at different pHs.
Swelling and Reactivity of Maize Starch Granules
Authors: Hauber Richard J. , Bemiller James N. , Fannon John E.
Published: November 2006

It is concluded that granule swelling is required for any chemical derivatization of common yellow dent maize starch with fatty acyl chlorides in organic solvents, even for reaction at granule surfaces. It was also concluded that progressively less of hot pyridine‐swollen granules is available for reaction with fatty acyl chlorides as the carbon chain length increases from C6 to C14, with those two lengths being the approximate outside limits for partial exclusion.
Continuous Saccharification of Corn Starch in a Membrane Reactor. Part I: Conversion, Capacity and Productivity
Authors: Sims Kevin A. , Cheryan Munir
Published: November 2006

Effects of enzyme concentration, substrate concentration and residence time on substrate conversion, reactor capacity and productivity were evaluated. As enzyme concentration increased from 1 to 6 g/L, substrate conversion also increased. Substrate conversion was essentially unchanged at enzyme concentrations greater than 6 g/L. Reactor capacity was significantly affected by both substrate and enzyme concentration. As residence time increased, substrate conversion increased 15–22%. Productivities of the continuous reactor were 10 to 20 times greater than those obtained in a batch reactor. The continuous membrane reactor was capable of producing a highly pure glucose syrup at low residence times. Due to the high levels of substrate conversion, minimal operational problems were experienced.