bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies on Purification and Kinetics of Glucose Isomerase on Hydrolysates of Starch
Authors: El‐Sahy K. M. , Siliha H. A. , Fahmy A. H. 
Published: November 2006

AbstractGlucose isomerase was produced from Streptomyces phaeochromogenes by aerobic fermentation at 28°C for 24 h. The crude enzyme was obtained by disintegrating the harvested cells. Ammonium sulphate at a saturation of 0.65 gave the maximum enzyme recovery 89.4%) from the crude extract, while acetone gave 66.4% at a concentration of 3/1 (v/v). The crude enzyme extract was purified by concentration, dialysis, precipitation with ammonium sulphate, passing through a column of Amberlite, and then the eluate was treated with acetone to precipitate the enzyme. The kinetic behavior was studied and it was found that optimum D‐glucose concentration was 0.8‐M. No change in Km value was observed, while Vmax was affected.
Maltulose Formation During Saccharification of Starch
Authors: Dias F. F. , Panchal D. C. 
Published: November 2006

AbstractMaltulose precursors are produced due to chemical isomerization of the reducing end glucose units during enzyme liquefaction and autoclaving of starch in the enzyme‐enzyme process of glucose manufacture. The precursors are hydrolyzed during subsequent saccharification with amyloglucosidase to form maltulose as one of the products. Temperature, pH and DE of the liquefied starch during autoclaving and α‐amylase treatment are important factors in controlling precursor formation, low temperature, low pH and low DE resulting in less maltulose formation. Acid liquefaction prior to saccharification does not result in maltulose precursor formation. Blocking of the reducing end glucose unit by hydrogenation to sorbitol prevents the formation of maltulose; maltitol is produced instead.
Change in Digestibility of Raw Starch by Gamma‐Irradiation
Authors: Kume T. , Tamura N. 
Published: November 2006

AbstractIrradiation effect on digestion of raw starch by glucoamylase has been investigated as a basic research for application of radiosterilization on uncooked starch fermentation. The digestibility of raw tapioca starch decreased with an increase in dose while that of other starches such as wheat, corn, sweet potato and potato were little changed by irradiation. Tapioca starch granules coagulated by irradiation and were sedimented rapidly in suspension. The coagulation of irradiated tapioca starch granules can be dispersed completely by ultrasonic treatment. These results show that the decrease in digestion of raw tapioca starch depends on the coagulation of starch granules but other factors also contribute because the recovery of digestibility by ultrasonic treatment was not complete.
Functional Characteristics of the Mucilaginous Polysaccharides Derived from Cowpea (Vigna sinensis), Black Gram (Phaseolus mungo) and Linseed (Linum usitatissimum)
Authors: Muralikrishna G. , Bhat U. Ramadas , Tharanathan R. N. 
Published: November 2006

AbstractThe cowpea polysaccharides had the maximum viscosity at around pH 6 and it decreased with increase in temperature but increased with increase in concentration. Both black gram and cowpea polysaccharides stabilized against thermal disruption the foam formed by the surface active proteins. Black gram starch and the mucilage together showed greater foam stability, probably due to enhanced viscosity caused by synergistic interactions between these polysaccharides. Gelatinization temperature as well as the peak and set back viscosities of wheat starch were considerably decreased by adding either the black gram or the linseed polysaccharide. In farinograph experiments the black gram polysaccharide exhibited a strengthening effect on wheat flour dough, whereas the linseed polysaccharide resulted only in an increased water absorption. Extensographic data indicated increased resistance and decreased extensibility of wheat flour dough by the addition of black gram and linseed polysaccharides.
Properties of Starch Obtained from Frozen and Thawed Potato Tubers
Authors: Golachowski A. 
Published: November 2006

AbstractStarch separated from frozen potato tubers differed from that separated from unfrozen material in the initial pasting temperature and viscosity of 7% pastes. The starch separated from frozen and thawed potato tubers was characterized by higher temperatures of pasting than starch obtained from unfrozen potato tubers. Moreover, it showed some differences in granularity, phosphorus, calcium, sodium and potassium content as well as viscosity of 7% pastes in comparison with starch obtained from unfrozen potato tubers.
Application of a Multi‐enzyme Complex in the Utilization of Potato Pulp
Authors: Slomińska L. , Starogardzka G. 
Published: November 2006

AbstractAttempts of desintegration of potato pulp by use of a multi‐enzyme complex a new enzyme preparation of Novo Industri A/S have been made. The research was to help in the utilization process of potato pulp by means of dehydration and hydrolysis of containing starch. The results of experiments show the influence of the multi‐enzyme complex on the decrease of viscosity and the increase of dry substance content of the enzyme‐treated potato pulp. The action of liquefying and saccharifying enzymes on multi‐enzyme complex pretreated potato pulp yields a higher degree of liquefaction and saccharification.
Functional Properties of Okra (Hibiscus esculentus) Mucilage
Authors: Bhat U. Ramadas , Tharanathan R. N. 
Published: November 2006

AbstractFrom immature okra pods a mucilage was isolated. The native mucilage, although not soluble in water and various salt solutions, was easily solubilized (∼ 80%) in aqueous sodium borohydride solution (1%). The viscosity of the borohydride‐soluble fraction was maximum at a pH range of 4–6, it exhibited a pseudoplastic behaviour and its viscosity decreased on adding water‐soluble additives. However, with maltodextrin an increase in viscosity was noticed, which may be the result of hydrogen bonding interactions. The fraction exhibited foam stabilizing and gelling properties, and a “strengthening effect” on soft wheat dough, as shown by farinography and extensograph experiments.
Differential Scanning Calorimetry Properties and Paper‐Strength Improvement of Cationic Wheat Starch
Authors: Craig S. A. S. , Seib P. A. , Jane Jay‐Lin 
Published: November 2006

AbstractCationic derivatives of normal corn and wheat starch were produced and investigated. Differential scanning calorimetry showed that substitution lowered the starch gelatinization temperature, the gelatinization endotherm, and the temperature of amylose‐lipid V‐complex dissociation. Substitution lowered the starch‐iodine color and inhibited precipitation of the amylose‐alcohol complex by standard fractionation techniques. Cationic derivatives of normal corn and wheat starch gave similar improvements in dry strength of paper when added at the wet‐end.
Composition of the Low Temperature Precipitate from Commercial High Dextrose Equivalent Maltodextrins and the Kinetics of its Formation
Authors: Kennedy J. F. , White C. A. , Noy R. J. , Steadb J. A. 
Published: November 2006

AbstractAnalysis of the precipitate formed from 50% w/w solutions of maltodextrins with high dextrose equivalents shows that oligosaccharides with degrees of polymerization of 11 and above are the major components with no evidence for the presence of small oligosaccharides with degrees of polymerization up to 7. Fast precipitating batches of commercial high dextrose equivalent maltodextrins give precipitates which contain almost constant amounts of oligosaccharides with degrees of polymerization 8 to 10, irrespective of the time of storage. For slower precipitating batches the contribution of these oligosaccharides increases with the time of storage. Analysis of the water content of the precipitate resulted in values within the range 40 to 48% w/w. This indicates that a constant gel/solvated precipitate structure exists for both fast and slow precipitating samples. Photomicroscopy of the precipitate, stained with iodine/potassium iodide, indicates that it consists of essentially spherical particles ranging from 1.0 to 8.5 μm diameter. The particle distribution is non Gaussian with approximately 90% of the particles having diameters less than 3.5 μm. The mean diameter was found to be 2.4 μm.A study of the kinetics of the precipitation reaction showed that it cannot be considered as a single chemical reaction with zero or first order kinetics. By considering the reaction as the formation and growth of crystals in mother liquor an Avrami exponent of between 2 and 3 was obtained indicating that the reaction represents three dimensional crystal growth with instantaneous nucleation. The effect of the mean molecular weight and molecular weight distribution on the kinetics is discussed and compared to the better documented systems of bread staling and amylose retrogradation.
Thermostabile Bindung von Aromastoffen an Stärke. Teil 2: Bindung von Menthol durch Autoklavieren
Authors: Schmidt E. , Maier H. G. 
Published: November 2006

AbstractDie Herstellung thermostabiler Sorbate aus Menthol und Stärken, modifizierten Stärken sowie β‐Cyclodextrin durch Autoklavieren wird beschrieben. Die gebundene Menge steigt im allgemeinen mit dem Gehalt an Amylose und beträgt maximal 80 g/kg. Mit Amylomaisstärke (49% Amylose) wurde ein 34‐Faktorenversuchsplan durchgeführt und statistisch ausgewertet. Das berechnete Maximum der Mentholsorption betrug 64,5 g/kg bei 163°C, 10 bar, 5 min und 55% Wassergehalt. Gründe für die schlechtere Bindung bei höherer Temperatur und niedrigem Wassergehalt werden diskutiert.
The Effect of Phosphoric Acid Bound with Potato Starch on Its Starch Gelatinization
Authors: Yamada T. , Morimoto Y. , Hisamatsu M. , Komiya T. 
Published: November 2006

AbstractA series of potato starch substituted with proton, potassium and calcium ion were prepared with washing method by hydrogen chloride solution, and their properties were compared with that of native starch on viscograph. After viscograph test, these samples were subjected to gel chromatography and compared with that of non‐test samples. It was proved by GPC pattern analysis that with the starch substituted with proton some extent of hydrolysis took place during viscographic measurement process. The role of phosphoric acid bound with starch in this hydrolysis was discussed in relation to its content, locus and distribution in the amylopectin molecule.
Purification and Characterization of a Maltotriogenic α‐Amylase I and a Maltogenic α‐Amylase II Capable of Cleaving α‐1,6‐Bonds in Amylopectin
Authors: Suzuki Y. , Nagayama T. , Nakano H. , Oishi K. 
Published: November 2006

AbstractExtracellular α‐amylases I and II, produced by a facultative thermophile Bacillus thermoamyloliquefaciens KP 1071 capable of growing at 30–66°C, were purified to homogeneity. α‐Amylase I consisted of a single polypeptide with methionine residue at the NH2‐terminus. α‐Amylase II consisted of two equivalent polypeptides each comprising a methionine at the NH2‐terminus. α‐Amylase I hydrolyzed endotypically α‐1,4‐bonds in glycogen, amylopectin and β‐limit dextrin, but not their α‐1,6‐bonds. α‐Amylase II degraded amylopectin and β‐limit dextrin in exo‐fashion by cleaving preferentially α‐maltose units from the non‐reducing ends and hydrolyzing their α‐1,6‐branch points. α‐Amylase II hydrolyzed maltotriose, phenyl‐α‐maltoside, α‐ and β‐cyclodextrins and pullulan, whereas α‐amylase I had no activity for all these sugars. α‐Amylases I and II hydrolyzed maltotetraose, maltopentaose, α‐limit dextrin and amylose, but they were inactive for maltose, isomaltose and panose. It was suggested that α‐amylase I is the most thermostable type of hitherto known maltotriogenic endo‐acting α‐amylases, and α‐amylase II is the first maltogenic exo‐acting α‐amylase able to split α‐1,6‐bonds in amylopectin.
Characterization of Starch from Bread Aged at Different Temperatures
Authors: Zeleznak K. J. , Hoseney R. C. 
Published: November 2006

AbstractA series of bread samples stored at various temperatures (4°, 25°, and 40°C) were analyzed by differential scanning calorimetry (DSC) to determine if retrogradation (quantified by DSC enthalpy values) and storage temperature were correlated. The increase in enthalpy values during storage time was dependent on storage temperature. However, the rate of recrystallization was not linear at any of the temperatures studied. The net result was that the enthalpy values tended to converge with time, irrespective of storage temperature. Another effect of the increased storage temperature was an increase in the peak temperature (Tp) of the amylopectin endotherm. This indicates either that storage temperature affects the type of crystal being formed as the starch recrystallizes, or that annealing of crystals occurs at the higher storage temperatures. X‐ray diffractometry of starch isolated from the crumb gave similar diffraction patterns indicating no difference in crystal type among the treatments. In addition, the DSC endotherm became sharper at the higher temperatures. Thus, the increase in Tp was apparently the result of annealing of the crystals at the higher storage temperatures.
Effect of Hydrolysis Conditions of Cassava on the Oligosaccharide Profile and Alcohol Fermentation
Authors: Abraham T. Emilia , Krishnaswamy C. , Ramakrishna S. V. 
Published: November 2006

AbstractVarious hydrolysis procedures for saccharification of cassava starch were tried to maximise glucose content in the hydrolysate. The malto‐oligosaccharide profiles from HPLC analysis of hydrolysates prepared by acid, acid‐enzyme and enzyme‐enzyme showed that the hydrolysate prepared by acid contains malto‐oligosaccharides up to DP10, whereas with acid‐enzyme and enzyme‐enzyme process their presence is negligible. A commercial hydrolysate showed less amount of glucose and various sugars up to DP10. The fermentability of hydrolysates were compared and enzyme‐enzyme hydrolysate is found to be best.
Chain Length Distribution of Amylopectins of Several Single Mutants and the Normal Counterpart, and Sugary‐1 Phytoglycogen in Maize (Zea mays L.)
Authors: Inouchi N. , Glover D. V. , Fuwa H. 
Published: November 2006

Abstractβ‐Limit dextrins of starches of normal (nonmutant), amylose‐extender (ae), dull (du), sugary‐2 (su2) and waxy (wx) maize, and phytoglycogen of sugar‐1 (su1) maize were prepared. The β‐limit dextrins were successively debranched by isoamylase and pullulanase, and followed by quantitative gel‐filtration.The ratio of A to B chains for the ae starch appeared to be high and that for su1 phytoglycogen was low. The ratio of short B to long B chains for the du starch was high and that for the ae starch appeared to be low. The phytoglycogen did not contain long B chains. The unit chain‐length distribution of amylopectins of the normal, wx, and su2 starches were similar. Fine structures of maize amylopectins and su1 phytoglycogen were modeled and described.
Mobility of Water in Starch‐Sucrose Systems Determined by Deuterium and Oxygen‐17 NMR
Authors: Richardson S. J. , Baianu I. C. , Steinberg M. P. 
Published: November 2006

AbstractThe molecular mobility of water in a starch‐sucrose system was determined by deuterium (2H) and oxygen‐17 (17O) high‐field Nuclear Magnetic Resonance (NMR) spectroscopy. The starch‐sucrose system was composed of freeze‐dried starch:sucrose (FSS) (90:10) in deuterium oxide or enriched oxygen‐17 water over the solids concentration range of 10 to 93% solids. The NMR transverse relaxation rate (R2) and peak behavior were analyzed in terms of solids concentration and water activity. R2 of the FSS system is compared to the R2 of starch and sucrose systems alone. The relaxation behavior of the 2H and 17O were compared for FSS, starch and sucrose. The results led to the conclusion that the best NMR methodology for the investigation of water mobility is provided by 17O NMR.
Eigenschaften der Triticalestärke am Beispiel polnischer Triticalesorten
Authors: Palasiński M. , Fortuna T. , Gambuś H. , Nowotna A. 
Published: November 2006

AbstractDer hohe Stärkegehalt der Triticalekörner gibt Anlaß zu der Vermutung, daß dieses Getreide auch als guter Rohstoff für die Stärkegewinnung dienen kann. Daher wurden zahlreiche polnische Triticale‐Stämme und ‐Sorten auf die wichtigsten physikalisch‐chemischen Eigenschaften ihrer Stärke, wie Korngrößenverteilung, Wasserbindungsvermögen, Wasserlöslichkeit und Verkleisterungscharakteristik untersucht. Die Stärken vieler untersuchter Triticale‐Stämme und ‐Sorten verfügen über für die Stärkeindustrie interessante Eigenschaften. Im Vergleich zu Weizen scheint Triticale gut als Rohstoff für die Lebensmittelindustrie und besonders zur Stärkegewinnung geeignet zu sein. Dafür sprechen ein hoher Korn‐ und Stärkeertrag, günstige Korngrößenverteilung sowie die Viskositäten und hohen Reinheitsgrade der isolierten Stärken.
Effects of Starch Particle Size and Protein Concentration on Breadmaking Performance
Authors: Lelievre J. , Lorenz K. , Meredith P. , Baruch D. W. 
Published: November 2006

AbstractStarch granules of three size classes were prepared from a New Zealand wheat by sedimentation fractionation. Each was recombined with gluten from the same wheat at protein concentrations of 8%, 12% and 16%, and test baked. The pup loaves were judged for volume, crust and crumb characteristics. Sliced crumb was physically tested in compression and shear. There appeared to be a differing optimum starch size fraction for each protein concentration; that is, there was interaction between protein and starch in forming loaf texture and volume. The most notable result is that the starch fraction greatly and directly affected the toughness or bite of the breadcrumb, but only affected the softness of chew in a complex manner dependent on the protein level. The percentage of protein had large effects on both bite and chew properties as expected.
Application of Cyclodextrins in the Chromatography
Authors: Szejtli J. 
Published: November 2006

AbstractThe central cavity of the cylinder‐shaped cyclodextrin molecules behaves as an empty molecular capsule: it can accomodate so called ‘guest molecules’ of appropriate size, shape and polarity. The stability of the formed inclusion complexes is however very different. This is the basis of the separation of various substances by cyclodextrins. The separation can be realized by non‐chromatographic methods or by chromatographic methods. The present review summarizes the utilization of cyclodextrins and their derivatives in gas‐liquid and gas‐solid‐, gel‐, inclusion‐, thin‐layer‐, affinity‐, and high performance liquid chromatography.
Preparation of Long‐Chain Alkyl D‐Glucosides by Alcoholysis of 1,2:5,6‐Di‐O‐Isopropylidene‐α‐D‐Glucofuranose
Authors: Straathof A. J. J. , Romein J. , van Rantwijk F. , Kieboom A. P. G. , van Bekkum H. 
Published: November 2006

AbstractThe acid‐catalysed conversion of 1,2:5,6‐di‐O‐isopropylidene‐α‐D‐glucofuranose (1) in 1‐butanol was studied using HPLC, 1HNMR, and 13C NMR. The course of the reaction, which involved six compounds containing isopropylidene groups, was elucidated. Eventually an anomeric mixture of butyl D‐glucosides was formed. Sulfuric, methanesulfonic, and tetrafluoroboric acid, an ion‐exchange resin (–SO3H), and a silica‐alumina catalyst showed different selectivities and catalytic activities. The ion‐exchange resin was the catalyst of choice, yielding up to 90% butyl D‐glucoside. Conversion of 1 in 1‐octanol gave a reaction mixture from which octyl α‐D‐glucopyranoside could be crystallised in 30% yield. An almost quantitative yield of the latter compound, however, was obtained by recycling the mother liquor. This procedure also avoids wasting of the ionexchange resin catalyst and the excess of octanol. 1‐Decanol and 1‐dodecanol gave crystalline α‐D‐glucopyranosides by the same method.
New Methods for Determination of Starch Gelatinisation Temperatures
Authors: Leszczyński W. 
Published: November 2006

AbstractTwo objective methods for determination of starch gelatinisation temperatures have been worked out. The microscopic method includes the recording of the loss of birefringence in starch granules under the conditions of progressively increasing temperatures. The conducting method enables the recording of changes in the intensity of electric current passed through gelatinising starch suspension. The temperatures are read from the curves plotted by a recorder. The new methods have proved to be fast and simple in operation. Moreover, they guarantee adequate precision of the results. The equipment necessary to carry out the tests is small in size and easy to adjust to ordinary laboratory devices.
Amylograph Pasting Behaviour of Cereal and Tuber Starches
Authors: Leelavathi K. , Indrani D. , Sidhu J. S. 
Published: November 2006

AbstractThe pasting characteristics in terms of peak viscosity (P), hot paste viscosity (H), cold paste viscosity (C) and at the selected fixed peak viscosities, the various ratios i.e., breakdown (H/P), setback (C/P), total setback (C/H) and relative breakdown, BDr, (P‐H)/(C‐H) to distinguish the starches from different species, are reported. Important differences in these characteristics among various starches have been observed. The amount of soluble amylose present in a starch, significantly affected its tendency for retrogradation. The breakdown (H/P), setback (C/P), total setback (C/H) ratios and especially the relative breakdown (BDr) can be made use of in distinguishing the starches from different species of wheat.
Varietal Differences in Properties Among High Amylose Rice Starches
Authors: Juliano B. O. , Villareal R. M. , Perez C. M. , Villareal C. P. , Baños Los , Takeda V. , Hizukuri S. 
Published: November 2006

AbstractAmong three high‐amylose starches differing in gel consistency, the hard gel starch (IR42), corresponding to harder cooked rice, had higher amylograph consistency and setback, higher gel viscosity in 0.2 N KOH and higher alkali viscograph peak than starch with soft (IR32) or medium (IR36) gel consistency. IR42 starch had less extractable starch and amylose in boiling water than IR32 and IR36 starches. The three starches had similar amyloses; the differences in gel consistency were due to the amylopectin fraction. IR42 amylopectin had higher iodine affinity, more long‐chain linear fractions on isoamylase debranching and gel filtration or 1‐butanol precipitation, and less DPn 16–17 fraction than IR32 and IR36 amylopectins.
Vergleichende Untersuchungen zur Erbsenstärkeisolierung auf naßtechnischem Wege
Authors: Haase N. U. , Kempf W. , Tegge G. , D'heur U. 
Published: November 2006

AbstractKörnererbsen enthalten Stärken, die abhängig von der Sorte über sehr hohe Amyloseanteile verfügen. Für die bisher weitgehend fehlenden analytischen Untersuchungen derartiger Stärken müssen vorab möglichst gute Isolierungen durchgeführt werden. Deshalb wurden in der vorliegenden Untersuchung die drei Verfahren der Flutung, der Zentrifugation und der Extraktion einander gegenübergestellt, wobei die Proteinabtrennung besonderes Gewicht einnahm. Ein kurzzeitiger Kontakt der vermahlenen Erbsen mit Natronlauge führte sowohl bei der Flutung als auch bei der Zentrifugation zu einer vergleichbar hohen Stärkequalität, doch lag der Wirkungsgrad der Stärkeabtrennung bei der Flutung um 30% höher. Die Extraktion fiel gegenüber den beiden anderen Methoden bezüglich der verwendeten Meßkriterien deutlich ab. Ein zusätzlich vorgenommener Sortenvergleich wies darauf hin, daß die Stärke aus Palerbsen besser abtrennbar ist als die aus Markerbsen.