bluuebunny/crossref_metadata_2025 huggingface dataset:
Production and Characterization of Cyclodextrin Glycosyltransferase from Bacillus lentus
Authors: Sabioni Jose G. , Park Yong K.
Published: November 2006

A new alkalophilic Bacillus. which produced exceptionally high activity of cyclodextrin glycosyltransferase, was isolated from soil. This strain of Bacillus was identified as Bacillus lentus. The enzyme was purified and characterized. It was found that optimum pH and temperature for cyclodextrin forming activity were 6.5–8.5 and 45–55°C. Thermal stability of the enzyme was remarkably increased by the addition of calcium ions. The maximum conversion of starch to cyclodextrin by the enzyme was 65%. The cyclodextrins formed after 24 h of enzymatic reaction consisted of α‐. β‐ and ‐y‐cyclodextrins in proportion of 1:67 : 1.6.
On the Mechanical Properties of Native Starch Granules
Authors: Schroeter Johannes , Hobelsberger Marco
Published: November 2006

As a fundamental prerequisite for starch based material development, we set up a method to determine mechanical properties of native starch granules. Instead of measuring tiny single granules, we developed an indirect procedure. It relies on a verified composite material theory and simple tensile tests with starch filled plastics. Resulting data for native potato starch granules: elastic modulus 2.7 GPa, tensile strength 60 MPa, indentation hardness 113 N/mm2. These data are similar to those of rigid thermoplastics.
The Modification of Starch by High Pressure. Part II: Compression of Starch with Additives
Authors: Kudla Ewa , Tomasik Piotr
Published: November 2006

Dry and wet starch containing 2, 5, 10, 15, 18, 20 and 22% of humidity was compressed under 0.8, 1.0 and 1.2 × 109 Pa. Also starch containing chlorides of sodium, calcium barium, tin (II), zinc, copper (II), cobalt(II) and iron (III) as well as molecular iodine and all sodium fluoride, bromide, iodide, phosphate, sulfate and rhodanide was similarly compressed. It was found that humidity accelerates the destruction of starch matrix. Among mineral additives only cobaltous and ferric chlorides as well as iodine corraborate with high pressure in the deterioration of starch matrix.
A Pulsed NMR Method for the Study of Starch Retrogradation
Authors: Teo C. H. , Seow C. C.
Published: November 2006

A rapid and non‐destructive pulsed NMR method of monitoring starch retrogradation was developed based on the principle that the signals from protons in the “solid‐like” and liquid components in a system decay at significantly different rates following a 90° radio‐frequency pulse. As molecular association or recrystallization proceeds during aging of a starch gel, the proportion of the “solid‐like” component in the system increases. The resulting decrease in segmental mobility of the starch chains causes a decrease in the signal from the liquid component, but a concomitant increase in the signal attributed to protons in the “solid‐like” fraction. The method was applied to study the retrogradation tendency of starches from different botanical sources.
Cyclodextrin Degrading Enzymes
Authors: Saha Badal C. , Zeikus J. Gregory
Published: November 2006

Cyclodextrinase is an enzyme that hydrolyzes cyclodextrins. Some amylolytic enzymes can also hydrolyze cyclodextrins. A comprehensive review of these cyclodextrin degrading enzymes and their action pattern is presented.
Effect of Molar Substitution (MS) on Calcium Binding by Hydroxypropyl Rice Starches
Authors: Islam M. Nurul , Azemi B. M. N. Mohd.
Published: November 2006

Unisolated rice starch was obtained by wet milling of broken milled rice grains. Hydroxypropyl rice starches of different level of molar substitution (MS) were prepared and characterized. Both native and modified starches were treated with calcium carbonate at various calcium: starch ratios. Binding was markedly influenced by the calcium concentration in the reaction mixtures. Native starch binds less calcium than modified starch. Ability to bind calcium decreased with increasing calcium concentration in both native and modified starches. A parallel increased in calcium binding was observed as MS increased to the value of 0.09 and thereafter reversed. Increased level of substitution depressed the optical rotation and electrical conductivity of starch‐calcium complex.
Microstructural and Physicochemical Properties of Oxidized Potato Starch for Paper Coating
Authors: Autio Karin , Suortti Tapani , Hamunen Antti , Poutanen Kaisa
Published: November 2006

Heat‐induced structural changes were examined for a series of potato starches differing in degree of oxidation and prepared as 25 and 35% dispersions. The molecular weight of amylopectin decreased markedly with the degree of oxidation. Microstructural studies revealed that all oxidized potato starch dispersions heated to 90deg;C contained whole granules. The least oxidized potato starch (Raisamyl 316) paste contained large numbers of swollen granules filled with dissolved amylose. In the more oxidized potato starch dispersions, both amylopectin and amylose were solubilized within the granule. Mixing of the amylose and amylopectin occurred and amylose‐ and amylopectin‐rich domains could be seen inside the granule. At 35% concentration all starches studied formed a gel during cooling (from 90 to 30deg;C). The lower the degree of oxidation, the higher the gelling temperature. Raisamyl 310 formed the firmest gel. The gel formation of most oxidized potato starches was weak. Raising the heating temperature from 90 to 120deg;C, in combination with shearing, delayed the gelation.
Effect of Processing on the Physico‐Chemical Characteristics of Quinoa Flour (Chenopodium quinoa, Willd)
Authors: Ruales Jenny , Valencia Silvia , Nair Baboo
Published: November 2006

The nature and extent of the modification of starch in quinoa, caused by various processes like cooking and autoclaving of the seeds, drum drying of the flour and extrusion of the grits was investigated by measuring the physico‐chemical properties ‐ the water absorption, water solubility, swelling power, viscosity and degree of gelatinisation ‐ of the processed samples. Autoclaved samples showed the lowest degree of gelatinisation (32.5% by DSC) of the starch, while the degree of gelatinisation of the precooked/drum dried samples was found to be 97.4% by DSC method. Higher polymer degradation was observed in cooked samples than in autoclaved samples as seen in the gel chromatographic separation. The water solubility in cooked samples (5.44 to 15.58) and in autoclaved samples (7.02 to 9.64) increased with the process time. In the extrusion process, the moisture content as well as the compression ratio was found to affect the degree of starch modification significantly (p <0.01).
Studies on Modification of Enzymatic Saccharification Process
Authors: Slomińska Lucyna
Published: November 2006

In general the production of high DE starch hydrolysates in a sequence of continous process steps (liquefacion) and discontinuous steps (bath saccharification). The batchwise saccharification process requires long conversion time (48–72 h) what is connected with the necessity to operate large saccharification tank volumes. Attemps to change saccharification conditions for reduction in significant degree of enzymatic time degradation of liquefied starch combined with increasing substrate conversion have been made.
A Simple Laboratory Scale Method for Isolation of Amaranth Starch
Authors: Perez E. , Bahnassey Y. A. , Breene W. M.
Published: November 2006

Starch was isolated from the seeds of Amaranthus hypochondriacus and Amaranthus cruentus by two established methods and a new simpler method involving steeping in dilute alkali, neutralization, and ambient air drying without using expensive or highly hazardous chemicals. The latter is recommended for isolating amaranth starch for human food uses on a laboratory scale.
Some Chemical, Physical, and Functional Properties of Native and Modified Starches of Amaranthus hypochondriacus and Amaranthus cruentus
Authors: Perez E. , Bahnassey Y. A. , Breene W. M.
Published: November 2006

Starch isolated from A. hypochondriacus and A. cruentus was chemically modified by cross‐linking with phosphate. Native and modified starches from both species did not differ in crude protein or fat content and overall purity and contained about 90% amylopectin and 10% amylose. Phosphorus and ash contents were highly correlated (r = 0.98). Modification eliminated swelling power at 85°C and increased gelatinization temperature range, gel consistency, and peak and overall consistencies while decreasing resistence to mechanical breakdown, blue value and initial pasting temperature. Modification effects were greater for A. hypochondriacus than for A. cruentus starch. Acidification to pH 4.5 decreased overall viscosity more in modified than in native forms.
Synergistic Action of α‐Amylase and Glucoamylase on Raw Corn
Authors: Arasaratnam Vasanthi , Balasubramaniam Kandiah
Published: November 2006

Optimum ratio of glucoamylase to α‐amylase for synergistic hydrolysis of starch in corn flour was 1.8 AGU/1.0 KNU. The rate of hydrolysis of starch in dry milled corn was faster than that of waxy maize starch and wet processed corn. Hydrolysis of the starch in dry milled corn was the most efficient compared with that of wet milled, corn steeped in water or NaOH.
Annealing of Granular Rice Starches — Interpretation of the Effect on Phase Transitions Associated with Gelatinization
Authors: Seow C. C. , Teo C. H.
Published: November 2006

The effects of annealing on phase transitions associated with gelatinization at different moisture contents of an atypical non‐waxy rice starch exhibiting a clearer‐than‐usual glass transition were studied by differential scanning calorimetry. Consistent with observations on synthetic glassy polymers, annealing at temperatures below the glass transition for limited periods caused an elevation of Tg which is attributed to the slow relaxation of the amorphous regions of the starch granules to their equilibrium glassy states. The crystalline regions were significantly affected only after annealing at temperatures above the glass transition, the resulting increase in crystallite melting temperatures and narrowing of the gelatinization range being ascribed to crystal growth and/or perfection. Passage through the glass transition (which precedes crystallite melting) appears to give rise to an apparent endotherm which becomes even more prominent on sub‐Tg annealing of samples at low moisture contents. Annealing of an ordinary rice starch (with no clearly discernible glass transition) at a temperature below its onset gelatinization temperature (T0) produced effects which paralleled those observed after sub‐Tg annealing of the atypical rice starch. The conclusion drawn is that a glass transition is superposed on the crystalline melt at the leading edge of the single endothermic peak observed at high moisture contents. Where biphasic endotherms at intermediate moisture levels are concerned, however, the present results suggest that the first or G endotherm very likely arises from a glassy‐to‐rubbery state transformation while the second or M1 endotherm is associated with crystallite melting.
Physicochemical Properties of Defatted Oat Starch
Authors: Gibiński M. , Palasiński M. , Tomasik P.
Published: November 2006

Three Polish varieties of oat starch were subjected to defatting by a cold extraction with the chloroform‐methanol‐water (3:2:1) mixture followed by a hot extraction with 1‐propanol. A comparison of results allowed discussion of the effectiveness of the extraction procedures, their effect on the structure of original starch as well as the structure of oat starch‐lipid inclusion complexes.
Effects of Shrunken and Other Mutations on the Properties of Rice Endosperm Starch
Authors: Asaoka Masako , Okuno Kazutoshi , Yano Masahiro , Fuwa Hidetsugu
Published: November 2006

Starch granules were isolated from rice endosperms of twenty mutants, included two kinds of shrunken (shr) mutant, and two cultivars of their normal counterparts. The shr mutants, EM‐20 and Kenkei 2088, showed opposite effects on the amylose content, that is, EM‐20 had 5% higher than its normal counterpart and Kenkei 2088 had 3% lower than its one. The amylopectin of EM‐20 was composed of slightly shorter chains on the average than its normal one. The gelatinization temperature and heat of gelatinization were affected by the mutation of shr, EM‐20. The amylose extender (ae) mutant, Kenkei 2064, had a comparable amylose content with its normal counterpart but its amylopectin had higher content of long chain than the normal one. Twelve kinds of dull (du) mutant reduced the amylose content which varied from 2% to 16%.
Molecular Properties of Cereal Based Breakfast Foods
Authors: Tan Yen , Chinnaswamy Rangan
Published: November 2006

Molecular status of starch in ready‐to‐eat breakfast cereal foods and its relationship with cereal produkt functional properties such as water solubility index and water absorption index were studied. Gel chromatographic separation of cereal product polymers dispersed in DMSO gave three major fractions. Factions I and II reflected starch content, whereas Fraction III reflected the sugar content in the product formulation. Contents of Fraction I, II and III varied from 0.31 to 3.53 mg, 0.06 to 2.82 mg, and O to 4.63 mg, respectively. Water absorption index increased while water solubility index decreased with increasing Fraction I or Fraction II contents. Conversely, water absorption index decreased whereas water solubility index increased with increasing Fraction III content. Iodine blue values showed that Fraction I and Fraction II mainly composed of amylopectin and amylose, respectively. λmax values of Fraction I and II varied from 511 to 584 nm, 490 to 661 nm, respectively. Iodine binding capacity which was indicative of the amount of amylose present, varied from 0.37% (Kellogg's Corn Flakes) to 2.84% (Kellogg's Honey Smacks).
Structural Studies of Pullulan by Nuclear Magnetic Resonance Spectroscopy
Authors: McLntyre Deane D. , Calgary Hans J. Vogel
Published: November 2006

Nuclear Magnetic Resonance (NMR) spectroscopy was used to probe the primary structure of the glucan pullulan. Carbon‐13, proton and phosphorus‐31 NMR spectra in aqueous solution of the intact poly‐saccharide obtained from three different sources indicate that significant structural differences can occur among these samples. In particular, two samples consist solely of α(1 → 6) linked maltotriose units, in accord with the generally accepted structure. However a third sample has fewer α(1 → 6) linkages and appears to consist of higher α(1 → 6) linked maltooligosaccharides in addition to maltotriose. Unlike the other samples, this sample was also phosphorylated. Enzymatic digestion of pullulan followed by NMR spectroscopy using pullulanase confirmed these results, as did HPLC analysis of the resulting digest, which showed the presence of maltooligosaccharides consisting of ten and more glucose units. However, HPLC analysis of acid hydrolysed pullulan indicated that no sugars other than glucose were present in any of the samples examined.
Changes of Carbohydrate Compositions During Enzymatic Hydrolysis of Starches of Various Origin
Authors: Nebesny E.
Published: November 2006

Hydrolysis of starch of various origin, liquefied with bacterial α‐amylase to DE 13.5 and then saccharified only with glucoamylase and simultaneously with pullulanase to DE 97–98, was investigated. It was found that the hydrolysis of wheat starch was delayed in relation to the hydrolysis of potato and maize starch, particularly in the first period of saccharification. The delay decreased with time but at the end of the saccharification it was still 24 h. The carbohydrate composition of wheat starch hydrolyzates differed from the hydrolyzates of potato‐ and maize starch in a smaller content of glucose and lower oligosaccharides (G1‐G4) and a greater content of higher oligosaccharides and dextrins (G5‐Gn). This, among other things, could have an influence on higher viscosity of solutions of wheat starch hydrolyzates in relation to respective hydrolyzates of potato and maize starch.
Thermal Hysteresis of Infrared Spectra of Corn Starch/Water Systems
Authors: Mizoguchi Masaru
Published: November 2006

Infrared spectra of O.10mm thick corn starch‐water systems were measured with a FTIR spectrometer. With increasing temperature from 25 to 95°C, the absorbance at 2700cm−1 decreased abruptly around 80°C due to sol‐gel process. The absorbance of the gel increased by freezing and returned to the unfrozen value after thawing. The present method of using the absorbance at 2700cm−1 is promising to investigate the interaction between water and starch including sol‐gel process.
Influence of Surfactants on the Rheological Behavior of Starch/Gelatin Gels and Gel‐Emulsions
Authors: Daković Ljubomir , Milošević Svetlana , Sovilj Verica
Published: November 2006

Thixotropic behavior of mixed 8% starch/gelatin gels and gel‐emulsions (8% of the sunflower oil dispersed in the starch/gelatin gel), prepared with the addition of different emulsifiers, by means of the rotational viscometer with coaxial cylinders, has been investigated. Different emulsifiers (Na‐dodecyl sulfate, cetyl alcohol, mono‐ and diglycerides of fatty acids and alkyl polyglycolethers) were applied before (at 40°C) and after (at 96°C) gelatinization of the starch. Thixotropic properties, i.e. the coefficients of thixotropy of gels and emulsions were determined by the thixotropic loop method. Samples were taken in different time intervals (up to 72 h), in order to investigate the ageing effects. Very stable gels and gel emulsions (containing carbohydrate, protein and fatty component), with high aging stability can be obtained.
Enzymatic Starch Hydrolysis of Extruded Potato Peels
Authors: Camire Mary Ellen , Camire Alex L.
Published: November 2006

Potato peels discarded by potato processors are a potential source of dietary fiber and starch. This starch may be hydrolyzed for fermentation to value‐added products. Dried steam peels were extruded at 135°C and 22% feed moisture and digested with α‐amylase and/or amyloglucosidase. Two barrel temperatures and feed moistures were also studied. Glucose was measured colorimetrically at O,1,2,4,8 and 24h of incubation. All peels treated with either no enzymes or α‐amylase alone produced minimal glucose. Nonextruded peels digested with both enzymes produced more glucose than did those treated with amyloglucosidase alone. Complete digestion of starch occurred in extruded peels digested with amyloglucosidase, but not when α‐amylase was used.
Some Studies on Starch Carbamate
Authors: Khalil M. I. , Farag S. , Mostafa Kh. M. , Hebeish A.
Published: November 2006

Starch carbamate was prepared by reacting maize starch with urea using solid state technique. The different factors affecting this reaction were studied. These factors include urea concentration, type of starch, reaction and duration. The carbamate extent and carbamation reaction efficiency (%) were traced by estimating the nitrogen content of the reaction product. Solubility, viscosity and total ester content of starch carbamate samples were estimated. The carbamate extent increases by increasing urea concentration as well as reaction temperature and duration. Increasing the reaction temperature and duration has the same effect on carbamation reaction efficiency (%), while increasing urea concentration do the reverse. The solubility (%) of starch carbamate samples depends on urea concentration, reaction temperature and duration as well as the type of starch used. The maximum solubility obtained was 63% and 43% for starch carbamate derived from pregelled and native starch, respectively. Tentative mechanism for the reaction between starch and urea has been proposed.
Conformational Contributions of Amylose and Amylopectin to the Structural Properties of Starches from Various Sources
Authors: Aberle Th. , Burchard W. , Vorwerg W. , Radosta S.
Published: November 2006

Six starches of different amylose content were studied by static light scattering from very dilute aqueous solutions at 20°C. Reproducible results were obtained after submitting the solutions to a controlled autoclaving step where the solutions were heated up to 135‐155°C. Amylose rich starches exhibited significantly different angular dependences from those with low amylose content. The high experimental accuracy of the angular dependences allowed separate determination of the molar masses Mw and radii of gyration Rg for both components in the mixture. Molar masses of 60‐106 to 110‐ 106 and radii around 220nm were found for the amylopectins from the various starches. Unexpectedly high molar masses between 450‐103 and 2.5‐106 were found for the amylose components but only low radii of gyration. Comparison with synthetic amyloses indicate strong intra and intermolecular aggregation in the form of laterally (side‐by‐side) aligned chains which could contain up to 35 amylose chains. The possibility of a quantitative determination of the degree of branching via the shrinking factor g (=Rg2Ap/Rg2Am I at the same molar mass) is discussed at some length.
A Study of Starch Granular Aggregation
Authors: Wang Shaw S. , Qu Di , Chiew Yee C.
Published: November 2006

The aggregation behavior of starch granules during cooking was investigated. Granular aggregation was found to depend mainly on water content and degree of conversion (cooking) of starch. There were threshold values of water content and degree of conversion for powdery starch to undergo a phase transition from a nonaggregated to an aggregated state. A method for determining such threshold values of the transition was developed. A mathematical model was also developed to describe the aggregation behavior of cooked starch. Its potential application to food systems, especially to the simulation of starch extrusion process, was discussed.
Thermal Behaviour of Calcium‐Hydroxypropyl Rice Starch Complexes
Authors: Islam M. Nurul , Azemi B. M. N. Mohd.
Published: November 2006

Thermal behaviour of hydroxypropyl rice starches and their calcium complexes was determined by using Differential Scanning Calorimetry (DSC) with starch: water in the ratio of 1:1. Glass transition and gelatinization temperatures were reduced by hydroxypropyl groups and enhanced by calcium treatment. Gelatinization enthalpies were reduced by both hydroxypropyl groups and calcium treatment. The interaction of hydroxypropyl groups and calcium with starch altered the two endothermic peaks observed in native starch into a single melting peak.
Spectrophotometric Titration of Starch Polysaccharides with Iodine
Authors: Richter Manfred
Published: November 2006

Two methods of Spectrophotometric titration (SPT) are described. Method A describes the determination of the extinction (E) at 4 wavelengths (WL) 714, 625, 555, and 500 nm and of 16 concentrations of iodine in the range of [I] = 2.5 and 166.7 · 10−5 N I2 or pI = 4.60 and 2.28 (pI = ‐log [I]) as well as the calculation of the extinction‐relationship R of two WL for 6 possible pair combinations. The dependence of E respectively of log [I] in form of E‐ or R‐curves of amyloses, amylopectins, Nägeli‐amylodextrin and starches of several botanical sources are discussed under the aspect of the reaction of helical segments of molecules with iodine. Method B of the SPT defines E of the 4 wavelengths at pI 3.6 and 3.0 and calculation of the extinction relation ships R(M) and R(H) of middle (M) and high (H) concentrations of iodine. The position of the parameters R(M) and D=R(M) — R(H) of the 6 wavelength combinations in each X‐Y‐diagram depends on the botanical origin of potato, tapioca, wheat and regular maize starch.
Chemical Modification of Guaran Gum. Part 3: Carboxymethylation in non‐Aqueous Medium
Authors: Ragheb A. A. , Kamel M. , El‐Thalouth I. Abd , Nassar S. H.
Published: November 2006

Guar gum was isolated from the seeds and subjected to modification via non‐aqueous carboxymethylation. Highly substituted carboxymethyl guaran derivatives could be obtained via repeating the reaction four times, where a product of degree of substitution (D.S.) 2.07 was obtained indicating that the free hydroxyl groups of both glucose and mannose (which form the main constituents of guaran) can react with monochloro acetic acid. The modification increases the solubility of the gum in cold water, and increases the stability of its pastes to microorganisms. Pastes of these derivatives are characterized by non‐Newtonian pseudoplastic behaviour regardless of their D.S. or the measuring temperature, while their apparent viscosity decreases by increasing the D.S. and/or the measuring temperature.
Microscopic Observation and X‐Ray Diffractometry of Heat/Moisture‐Treated Starch Granules
Authors: Kawabata Akiko , Takase Naoaki , Miyoshi Emako , Sawayama Shigeru , Kimura Toshiaki , Kudo Kenichi
Published: November 2006

Heat/moisture‐treated potato and corn starch granules were observed by microscopy and X‐ray diffraction patterns were obtained. A scanning electron microscope (SEM) photograph of the cross section of the heat/moisture‐treated potato and corn starch granules showed a large hollow area about 1/3 of the diameter at the center of the starch granules and a layered structure resembling growth rings. From the X‐ray diagrams it was confirmed that heat/moisture‐treatment caused an alteration from the B‐type in the direction an A‐type structure in potato, whereas corn starch did not change and maintained an A‐type structure. The enzymatic digestibility of heat/moisture‐treated starch was found to be less resistant than that of native starch.
The Significance of Starch Polymorphism in Commercially Produced Parboiled Rice
Authors: Ong Mei H. , Blanshard John M. V.
Published: November 2006

A study of eight commercial parboiled samples derived from two varieties of rice produced by four different processes has shown that depending on the parboiling process, the starch component itself can be present as native and/or retrograded starch in addition to the amylose‐lipid complex. Further, it was demonstrated that the polymorphic states of starch can influence the texture and behaviour of cooked rice. The parboiled rice samples which had all three states of starch (i.e. ungelatinized and recrystallized amylopectin plus the amylose‐lipid complex) possessed the hardest eating property but the lowest solubility. A negative linear relationship was demonstrated between the hardness and the solubility of cooked, parboiled rice. Overall, the observations suggest the existence of different forms of starch in parboiled rice which vary with the different parboiling protocols. The conditions governing their formation need to be established before investigating the specific functionality of individual forms within the rice. This study further confirmed that retrograded starch (amylopectin) in parboiled rice did not exhibit a B‐tye X‐ray pattern but mixed A+V patterns.
Utilization of Potato Pulp for Baking of Bread
Authors: Nebesny E.
Published: November 2006

Aqueous potato pulp suspension of 5% d.s. was subjected to streaming under pressure of 1 atmosphere for 1h and, subsequently, bounded starch was enzymatically liquefied and saccharified, insoluble suspension was filtered and rest of sugars was washed out with hot water and dried to obtain a fiber preparation containing 79% d.s. of dietary fiber. The fiber preparation produced from raw pulp contained only 71.7% d.s. of dietary fiber. For baking of bread wheat meal containing 0,5% and 10% of the fiber preparation obtained from potato pulp was used. Organoleptic tests and physico‐chemical properties of wheat bread containing 5% fiber preparation in relation to wheat meal, appeared to be as good as in bread without this preparation. However, bread containing the fiber preparation was healthier for consumers.
Verwendung von Kartoffelpülpe und Kartoffelfruchtwasser als Nährmedium zur Anzucht von Laccase produzierenden Pilzen
Authors: Trojanowski Jerzy , Kharazipour Alireza , Mayer Frank , Hüttermann Aloys
Published: November 2006

Abfallprodukte aus der Stärkeindustrie (Kartoffelpülpe und Kartoffelfruchtwasser) werden als Nährlösung zur Anzucht von ausgewählten Polyporaceae‐Stämmen verwendet, aus denen phenoloxidierende Enzyme (Laccase) gewonnen werden können. In den von uns isolierten Stämmen von Trametes villosa, Trametes versicolor und Polyporus brumalis wurde neben einer hohen Laccase‐Aktivität zum ersten Mal auch eine hohe amylolytische Aktivität nachgewiesen. Die ausgewählten Stämme sind in der Lage, die stärkehaltige Pülpe als einzige C‐Quelle zu verwerten. In dem Kartoffelfruchtwasser wurden hohe Aminosäuren‐Gehalte, insbesondere Asparagin und Asparaginsäure gefunden, die eine optimale N‐Quelle für die verwendeten Weißfäulepilze darstellen. Technischer Einsatz der bei der Stärkegewinnung anfallenden Abfallprodukte zur Produktion von pilzlichen Enzymen bietet eine wirtschaftlich interessante Alternative zum kostspieligen synthetischen Standardmedium.
Viscosity Measurements of Potato Starch Paste with the Rapid Visco Analyzer
Authors: Haase Norbert U. , Mintus Thomas , Weipert Dorian
Published: November 2006

Viscosity behaviour of potato starch paste was measured with the Rapid Visco Analyzer (RVA, Newport Scientific, Warriewood, Australia). By reason of high viscosity properties of potato starch suspensions, starch concentration was reduced from 3.0 to 2.0 g starch weight (14% moisture) in 25 ml distilled water.

In view of Brabender viscograms a short temperature profile (13 min including heating, stable hot phase, and cooling) achieved the best results. Reproducibility of RVA‐measurements was high as well with new canisters as with re‐used ones. Coefficient of variation (s%) was below 2%.

A comparison of RVA and Brabender viscograms pointed out a close correlation of r=0.94 for both, the peak viscosity and the viscosity difference between peak and trough.
Two‐Steps Procedure for the Purification of Corn Flour Hydrolysate
Authors: Arasaratnam Vasanthy , Sritharan Kiburahary , Balasubramaniam K.
Published: November 2006

When corn flour hydrolysate filtrate (CFHF) was treated with 100% (w/v) (NH4)2SO4 for purification, 80.5% of the protein was removed. Among the pH values studied, at pH 1.5, 90.2% of the total protein was precipitated from CFHF and supernatant was removed by decantation. The corn flour hydrolysate was purified with Amberlite and DEAE‐cellulose after precipitating the protein at pH 1.5. Charcoal was better than cation‐ and anion‐ exchange resins for the removal of proteins, amino acids and pigments from the hydrolysate.
Maize Mutants. Part 1: Studies on their Starch Components
Authors: Curá José A. , Krisman Clara R.
Published: November 2006

The present study was conducted in order to evaluate the starch components contained in several maize mutants. The α1,4‐α1,6 glucopolysaccharides were fractionated according to their branching degree. The determination of the wavelenght of maximum absorption (γ max) in the presence of Krisman's reagent [12] as well as the glucose α1,6 linkages involved in the branching point were determined. The mutants analyzed possess characteristics that allow us to identify them according to the composition and structural properties of their polysaccharides (phytoglycogen, amylopectin, amylose).
Kritische Situationen bei der Bestimmung des Substitutionsgrades von Amyloseverbindungen über ihren Kohlenstoffgehalt
Authors: Otto Andrè Henry
Published: November 2006

Der Substitutionsgrad (DS) von Amyloseverbindungen ist nicht immer über ihren Kohlenstoffgehalt bestimmbar. Kritische Situationen treten für Derivate mit einem Substituenten auf, wenn die Kohlenstoffwerte des letzteren und von reiner Amylose (4/9 = 0.444) gleich sind. In der Praxis trifft man dies kaum an.

Disubstituierte Amyloseverbindungen weisen eine Vielzahl kritischer Situationen auf. Das hängt vom DS des bestimmten Subsitutenten ab und ist nur möglich, wenn der zu bestimmende Substituent der kleinere ist. Der kritische DS(1)(=DSkr kann jeden Wert von 0 bis 3 annehmen. Bei trisubstituierten Verbindungen treten kritische Situationen selten auf. Dafür ist es notwendig, daß der zu bestimmende Substituent [DS(3)] seiner Größe nach zwischen den beiden bekannten Substituenten liegt. Die Summe DS = DS(1)+DS(2) der letzten ist offensichtlich immer größer als 2. Alle Paare DS(1) und DS(2) sind über lineare Gleichungen verbunden.

Es wurden spezielle und allgemeine Formeln für die Voraussage von kritischen Situationen für alle Amyloseverbindugen hergeleitet.
Ethanol Production From Raw Sago Starch Under Unsterile Condition
Authors: Pranamuda Hardaning , Lee Sang‐Won , Ozawa Tetsuo , Tanaka Hideo
Published: November 2006

In order to utilize raw sago starch as fermentation material, mold strain (Aspergillus niger N‐10) which produces raw sago starch hydrolyzing enzyme, was isolated. Maximum raw sago starch consumption rate by the strain was obtained when the initial pH of the medium was 3.5 and the enzyme showed high stability and activity at lower pH values. Direct ethanol production from raw sago starch was investigated using a mixture of the strain and ethanol producing yeast, Saccharomyces cerevisiae IFO 0309. Neither the growth of the strains nor ethanol production was inhibited in the mixed culture of the two strains. Moreover, when fed‐batch mixed culture was conducted under unsterile condition (both the medium and the apparatus were not sterilized), about 30g/1 of ethanol was produced with ethanol yield from raw sago starch Yp/s of 0.40g ethanol/g starch.
Components of the Porous Maize Starch Granule Prepared by Amylase Treatment
Authors: Yamada Tetsuya , Hisamatsu Makoto , Teranishi Katsunori , Katsuro Kimiaki , Hasegawa Nobuyu , Hayashi Mitsugu
Published: November 2006

Porous starch granules were prepared from normal and waxy maize starch with amylase (from Aspergillus sp.) treatment, but we failed to make it from amylostarch under the same condition. The porous normal starch samples of some digestive stage were analyzed to X‐ray diffraction, DSC and GPC after debranching process. The X‐ray diffraction patterns were changed following with proceed of digestion, but the values obtained from DSC and GPC were not changed. These observations suggest that crystal region may be more sensitive to the amylase than amorphous one, and amylose may be homogeneously distributed in the both regions.
A Rapid Method for the Determination of Amylose Content by Using Differential‐Scanning Calorimetry
Authors: Mestres Christian , Matencio Françoise , Pons Brigitte , Yajid Myriam , Fliedel Geneviève
Published: November 2006

A calorimetric procedure to measure amylose content of various starchy raw materials has been developed. It is based on the measurement by Differential Scanning Calorimetry (DSC) of the enthalpy change of the formation of complexes between amylose and add phospholipid (L‐α‐lysophosphatidylcholine from egg yolk) observed during cooling. Contrasting to the colorimetric determination of amylose, the DSC procedure is not influenced by the presence of amylopectin or indigenous lipids. For rice and maize flours, the amylose content determinations are very similar for both colorimetric and DSC methodologies whether the starchy material was raw or pre‐cooked. But the DSC methodology is more repeatable and time saving; in particular, the defatting and starch determination steps can be omitted.
Synthesis, Characterization and Properties of Polyacrylamide‐Starch Composites
Authors: Hebeish A. , El‐Rafie M. H. , Higazy A. , Ramadan M.
Published: November 2006

Polyacrylamide‐starch composite was prepared by polymerization of maize or rice starch with acrylamide (Aam) using potassium permangante/citric acid initiation system. Major factors affecting the polymerization reaction were studied with a view to discover appropriate conditions for preparation of the composite. Results obtained imply that the total conversion (monomer converted to homopolymer and graft) increases by increasing concentrations of potassium permanganate from 0.5‐0.20%, citric acid from 0.1‐0.15 and acrylamide from 10‐30% ows. Polymerization can easily be carried out at 40°C for 6 min at pH 4 using a material to liquor ratio 1:25 under a stirring rate of 350 rpm. The results further imply (a) that the apparent viscosity of the composite increases by increasing Aam concentration irrespective of the rate of shear, (b) that for 30% Aam concentration the composite consists of 77.7% starch and 22.3% polyacrylamide of which 10.4% are grafted, (c) that the sizeability of polyacrylamide‐starch composites is much better than that of native starches, and (d) that the kind of starch not only determines the total conversion but also the composition of the composite.
The Use of Freezing‐Point Depression for the Theoretical Dextrose Equivalent Measurement
Authors: Marchal Leon M. , Jonkers Jan , Tramper Johannes
Published: November 2006

The determination of the theoretical dextrose equivalent was investigated, by measuring the osmolality (mol dissolved particles/kg H2O) by freezing‐point depression. Relations for dextrose equivalent and increase in dry weight during a hydrolysis were derived as a function of molality and amount of dry weight at the start of the hydrolysis. With freezing‐point depression it was possible to determine the theoretical dextrose equivalent of oligosaccharides (dextrose to maltoheptaose), whereas a traditional titration method (Luff‐Schoorl) overestimates 20‐50%. The relation for the increase of dry weight during the hydrolysis of starch with an α‐amylase was experimentally validated. The overestimation of dextrose equivalent by Luff‐Schoorl titration was also evident in the hydrolysis of amylopectin potato starch. With freezing‐point depression it was possible to determine the theoretical dextrose equivalent fast and accurate.
Per‐O‐methylated α‐ and β‐CD: Cyclodextrins with Inverse Hydrophobicity
Authors: Immel Stefan , Lichtenthaler Frieder W.
Published: November 2006

The investigation focuses on the computer‐aided generation of the molecular geometries, contact surfaces, and lipophilicity patterns of per‐O‐methylated α‐CD (1) and its β‐CD homolog2, and compares them with their parent non‐substituted cyclodextrins. The molecular geometries, compared via statistical analysis of crystal structure data available, reveal1and2to be considerably more flexible than α‐and β‐CD, allowing wide variations in the tilting of the glucose units relative to the macrocyclic ring axes. The comparative evaluation of their contact surfaces not only discloses a substantial increase of the torus heights upon per‐O‐methylation (from ∼8.0Å in α‐ and β‐CD, to → 11.1Å in1and2), but also an enlargement of their cavity areas by 40% (+35Å2for α‐CD →1) and 70% (+75Å2for β‐CD →2), respectively. The hydrophobic characteristics of1and2, emerging from the molecularlipophilicitypatterns (MLPs) generated and projected onto the contact surfaces in color‐coded from, are inverse to those for α‐ and β‐CD: the most hydrophobic surface regions of1and2are located at the torus rims made up by the 2‐OMe and 3‐OMe groups at one side, and the 6‐CH2OMe moieties at the other, with a hydrophobic „band”︁ wrapping around the outside of the macrocycles; these „exo‐lipophilic”︁ topographies are opposed by pronouncedly hydrophilic central cavities. A variety of experimental findings can be rationalized on the basis of the opposite lipophilicity profiles of the CDs and their permethylated analogs, such as for example the opposite orientation of benzaldehyde,p‐nitrophenol, and 3‐iodopropionic acid in the cavities of α‐CD and of1. Thus, the notion is substantiated that the operation of dispersive interactions between guest and CD‐host cavities play a more dominant role in inclusion complex formation than hitherto appreciated.
The Starch Component of the Wood Parasite Cistanche deserticola Y. C. Ma
Authors: Naran Radna , Ebringerová Anna , Hormádková Zdena , Babor Karol
Published: November 2006

Starch fractions have been isolated from the underground part of the parasite using hot water and alkali treatments, respectively. Chemical, enzymic and spectroscopic analyses as well as gel chromatography were used to characterize the starch fractions. Both hot water‐(HWS) and alkali‐extracted (AP) starch fractions contain amylose and amylopectin components in different proportions. The water soluble part of alkali‐extracted starch (APS) was well sparated by precipitation with cetyltrimethylammonium bromide into amylose and amylopectin compontents differing in the molecular weight. APS shows a larger contamination with cell wall constituents (protein, lignin, glucuronoxylan and pectin) in comparison with that of the other starch fractions.
Mechanische Modifizierung nativer und poröser Stärken durch Vermahlung zur Verwendung als Fettimitate. Teil 1: Eigenschaften nativer Stärken nach der Vermahlung im trockenen Zustand
Authors: Niemann Claudia , Meuser Friedrich
Published: November 2006

Zur Herstellung von modifizierten Stärken, die als Fettimitate fungieren können, wurden handelsübliche Stärken aus Mais, Weizen, Gerste, Wachsmais, Wachsgerste, Hafer, Sago und Palerbsen einer Prallmahlung oder Kugelschwingmahlung ausgesetzt. Die dadurch hervorgerufenen änderungen physiko‐chemischer Eigenschaften der Produkte, z.B. des Kaltwasserbindevermögens, der Kaltwasserlöslichkeit, des Grads der mechanischen Stärkeschädigung, des scheinbaren Amylosegehalts sowie der Partikelgrößen‐Verteilung wurden bestimmt. Die Prallmahlung hatte wenig Einfluß auf die physiko‐chemischen Eigenschaften. Die Kugelschwingmahlung bewirkte hingegen eine erhebliche Fragmentierung und Verformung der Stärkekörner. Entsprechend dem Grad der Fragmentierung und Verformung wurden die Kaltwasserbindeeigenschaften gezielt so verändert, daß die Vermahlungsprodukte Gele in kaltem Wasser bildeten, die stabil gegenüber Zentrifugalkräften und einer Gefrier‐Tau‐Behandlung, vergleichbar mit handelsüblichen Fettersatzstoffen, waren. Die Kriterien für die Verwendung mechanisch modifizierter Stärken als Fettimitate wurden ermittelt.
Kinetics of Starch Hydrolysis with Bacillus amyloliquefaciens‐α‐Amylase Under High Hydrostatic Pressure
Authors: Raabe Eduard , Knorr Dietrich
Published: November 2006

Kinetic studies on the isothermal pressure inactivation of Bacillus amyloliquefaciens α‐amylase (BAA) in Tris/HCl buffer and in 15.% (w/v) starch solution were performed at 25°C. The reaction rate of hydrolysis was studied at 25°C under high pressure conditions.

The inactivation kinetics and the pressure dependence of the hydrolysis reaction could be described with a first‐order kinetic model. The activation volume of the enzyme inactivation reaction in 0.05M Tris/HCl buffer pH 7.2 was calculated as ‐28.4→2.2cm3/mole and in 1.5% (w/v) starch solution pH 7.2 the activation volume was ‐13.8→2.1cm3/mole. The difference of the activation volumes obtained confirm the protective effect of the substrate against pressure inactivation. The hydrolysis of starch was found to be retarded with increasing pressure and the resulting activation volume of the hydrolysis was +22.7→1.9cm3/mole. In preliminary studies the inactivation kinetics in buffer solution was found to strongly depend on the initial enzyme concentration.

A high pressure pretreatment of the substrate resulted in no changes in the digestibility of the substrate.
Dynamic Simulation of a Simulated‐Moving‐Bed Chromatographic Reactor for the Inversion of Sucrose
Authors: Meurer Markus , Altenhöner Ulf , Strube Jochen , Untiedt Armand , Schmidt‐Traub Henner
Published: November 2006

The combination of a chemical or biochemical reaction and a chromatographic separation process in a single unit‐operation allows higher yields and a better separation performance not only for reversible decomposition reactions but also for irreversible reactions. A continuous Simulated‐Moving‐Bed (SMB) chromatographic reactor for the irreversible enzymatic inversion of sucrose is presented. In addition, a simulation based strategy for the design and optimization of chromatographic reactors is explained. Dynamic simulation studies using a rigorous model of the SMB process, illustrate the advantages of the continuous chromatographic reactor in comparison to conventional chromatographic processes for the inversion of sucrose. Reaching at least the same product purity as comparable conventional processes, the new reactor allows not only the reduction of capital costs but also a reduced desorbent rate and a higher productivity in terms of the converted amount of sucrose.
Modification of Microstructure of Starch Extruded With Selected Lipids
Authors: Bhatnagar Sandeep , Hanna Milford A.
Published: November 2006

Normal corn starch was extruded with palm, peanut and coconut oils; myristic, stearic and behenic acids and three monoglycerides in a C. W. Brabender single screw laboratory extruder at 140°C barrel temperature, 140rpm screw speed and 22% moisture content. Microstructure of extrudates was studied using a scanning electron mircocope. The pore size distribution, pore volumes and shear strengths of the extrudates were also studied. Addition of lipids resulted in modification of pore size distribution and pore volumes depending on the type of lipid. Complexing lipids gave lower pore volumes, smaller size pores, lower porosities and higher shear strengths of the extrudates. Porosity correlated well with the shear strength values.
Production of Trehalose from Starch by Thermostable Enzymes from Sulfolobus acidocaldarius
Authors: Mukai Kazuhisa , Tabuchi Akihiko , Nakada Tetsuya , Shibuya Takashi , Chaen Hiroto , Fukuda Shigeharu , Kurimoto Masashi , Tsujisaka Yoshio
Published: November 2006

The optimum conditions for the production of trehalose from starch were investigated using two thermostable enzymes, maltooligosyl trehalose synthase (MTSase) and maltooligosyl trehalose trehalohydrolase (MTHase), from Sulfolobus acidocaldarius ATCC 33909. The optimum pH was 5.5 and the optimum temperature was 55—57°C using isoamylase from Pseudomonas amyloderamosa as a debranching enzyme. The addition of CGTase to the reaction mixture during the saccharification process caused an increase in trehalose and a decrease in maltose and maltotriose. Isoamylase was better than pullulanase as a debranching enzyme. The yield of trehalose was independent of the type of starch used. Under optimum conditions, the yield of trehalose from corn starch at 30% concentration was more than 82%.
A Comparative Study on Retrogradation of Rice Starch Gels by DSC, X‐Ray and α‐Amylase Methods
Authors: Kim Jeong‐Ok , Kim Wan‐Soo , Shin Mal‐Shick
Published: November 2006

The degree of retrogradation (DR) of 10 and 50% rice starch gels, which were stored at refrigerator, room temperature and freezer for 1, 3 and 6 days, were investigated by DSC, X‐ray diffractometry and α‐amylase‐iodine methods. Besides being affected by moisture content and storage conditions applied, the nonwaxy rice starch gels were retrograded faster and higher than the waxy ones. DR of 50% starch gels was higher than that of 10% starch gels. In case of 50% starch gels DR increased in the following order: refrigerated < room temperature < frozen. For 10% starch gels, no typical X‐ray pattern of the retrograded starch was shown, while DSC and α‐amylase‐iodine method gave information on DR of starch gels. Due to interpretative sensitivity of the data obtained, α‐amylase‐iodine method was suggested as an adequate mens for the DR of starch gels.
Preparation of Starch Succinates by Reactive Extrusion
Authors: Wang Linfu , Shogren Randal L. , Willett Julious L.
Published: November 2006

The succinylation of cornstarch by extrusion processing has been studied. Several different factors affecting the succinylation of starch were investigated including water content, succinic anhydride quantity, catalyst type and quantity, and reaction temperature. The degree of substitution (DS) increases with decreasing water content and increasing succinic anhydride quantity. Higher temperature favors higher DS using sodium bicarbonate as catalyst while the opposite is true using magnesium hydroxide as catalyst. Of the three catalysts used, sodium bicarbonate is best. Aqueous solubility and viscosity of the starch succinates tend to increase with increasing DS. Based on the results of aqueous solution viscosity, some samples appear to be promising as commercial thickening agent.