bluuebunny/crossref_metadata_2025 huggingface dataset:
Enzymatic Evaluation for the Degree of Starch Retrogradation in Foods and Foodstuffs
Authors: Tsuge Haruhito , Hishida Mayumi , Iwasaki Hiroaki , Watanabe Satoshi , Goshima Gisho
Published: November 2006

The simple, enzymatic evaluation procedure for the degree of starch retrogradation, which is applicable to the complex foods in the food industry, was proposed. This procedure includes the digestion of gelatinized starch by Bacillus subtilis α‐amylase, which can only attack the gelatinized starch, and then the residual non‐digestible starch was determined colorimetrically with iodine. The presence of considerable amounts of ingredients, i.e. 30% sucrose, 20% NaCl or 30% casein did not interfere with the determination. However, the values were positively biased by the presence of more than 0.5% of lecithin. Preliminary digestion by 0.2% actinase E® for 16 h at 37°C and subsequent dialysis against large volume of distilled water were adopted to avoid the erroneous results due to the interference with ingredients.
One‐Dimensional Nuclear Magnetic Resonance Studies of Starch and Starch Products
Authors: McIntyre Deane D. , Ho Clinton , Vogel Hans J.
Published: November 2006

The use of one‐dimensional Nuclear Magnetic Resonance (NMR) spectroscopy as applied to structural studies of starch, starch products and glycogen is reviewed. Proton, carbon‐13 and phosphorus‐31 NMR spectra of a range of starches and starch products are described. These spectra, particularly carbon‐13 NMR spectra, permit one to obtain structural information regarding these molecules. From the proton NMR spectra, which can be obtained with greater sensitivity, it is possible to determine the DP (degree of polymerization, the average number of glucose units per molecule) and the degree of branching (the proportion of glucose units which are (1→6) linked) without recourse to chemical or enzymatic methods. Moreover, the anomer distribution of the reducing sugars can be determined by 1H or 13C NMR. Finally, some examples of the application of NMR to follow the time course of enzymatic digestion and sugar anomerization are discussed, as is the solid‐state NMR of starch and glycogen. The phosphorus‐31 NMR spectra provide information about the nature of the phosphate groups in potato starch.
Alkanosulfonylated Starches
Authors: Barabasz Wieslaw , Chociej Jecek , Tomasik Piotr
Published: November 2006

Syntheses of alkanosulfonylated starches are presented with alkane moiety being 1‐propyl‐, 1‐butyl‐, 1‐octyl, 1‐decyl‐ and 1‐octadecyl. Some properties of these compounds are described and results of their biological screening against Escherichia coli, Bacillus subtilis, Aspergillus niger and Aspergillus flavus are given.
Characterization on the Conformation of Glucoamylase from Rhizopus niveus and Rhizopus delemar
Authors: Ohnishi Masatake , Higuchi Atsuko , Todoriki Setsuko , Hiromi Keitaro , Ohgushi Wmikio , Wada Akiyoshi
Published: November 2006

Using the pH‐jump (neutral to above 11) for Tyr‐OH ionization as a probe, two glucoamylases from Rhizopus niveus and Rhizopus delemar were found to be caused the change in conformation, which is in a kinetically single step. The pH titration at pHs below 12 was carried out on a multidimensional correlation spectrophotometer. Correlations among the spectrophotometric properties: fluorescence, absorption and circular dichroism are almost identical for the two enzymes. These results suggest that conformational characteristics of the niveus enzyme is almost the same as that of the delemar one.
Estimation of Amylose Content of Starches after Precipitation of Amylopectin by Concanavalin‐A
Authors: Yun Suk‐Hun , Matheson Norman K.
Published: November 2006

The estimation of the amylose content of starches has been studied by precipitating the amylopectin with concanavalin‐A and then, after denaturing the remaining concanvalin‐A by heat, determining the unprecipitated glucan in the supernatant by (a) hydrolysis with amyloglucosidase: α‐amylase followed by glucose oxidase‐peroxidase reagent, (b) colorimetrically with phenol‐sulphuric acid or (c) by colour with iodine.
Interactions Between Starch and Electrolytes
Authors: Oosten B. J.
Published: November 2006

The view that starch exhibits ionic features is applied to the process used to make ungelatinized starch derivatives. This leads to some simple experiments, which reveal the validity of that theory. The statement that the anions are the actual gelatinizing agents is substantiated by experimental evidence.
Changes in Carbohydrate Fractions in Enzyme‐Supplemented Bread and the Potential Relationship to Staling
Authors: Lin Wei , Lineback O. R.
Published: November 2006

White breads were prepared with and without bacterial α‐amylase. Breads containing α‐amylase became firm (staled) more slowly than did those without the added enzyme. Larger quantities of carbohydrate were extracted from enzyme‐supplemented breads. The additional carbohydrate was mainly branched‐chain material with an average chain length (CL) of 19–24. Thus, the α‐amylase acts on starch during baking to form predominantly branched‐chain polymers of lower molecular weight. These polymers apparently have a decreased ability to retrograde, interfere with the ability of amylopectin to retrograde after the bread is baked, or interfere with other interactions involved in firming, thus reducing the extent of firming (staling).
Study on Interactions of Corn Starch and γ‐Cyclodextrin with Lipid Peroxide
Authors: Komiya T. , Yamada T. , Imai K. , Hisamatsu M. , Masui H. , Kawakishi S.
Published: November 2006

The deterioration of corn starch and γ‐cyclodextrin (γ‐CD) as a model compound by coexisting of methyl linolate (ML) has been studied in the solid system. With the elapse of oxidation time of ML, the reducing values of above the sugars increased and the value of γ‐CD with Silica Gel done more largely than without the one. The molecular weight of corn starch may decrease slightly, the glycosidic linkages of amylopectin and amylose molecules in the starch may be cleaved partially and the crystalline structure of the starch will be deteriorted a little by some active radicals formed by the autoxidation of ML. The propagative autoxidation of ML induced the deterioration of γ‐CD giving the two processes of the hydrolysis and the depolymerization in the similar way as observed in the reaction of γ‐CD with OH radicals.
Physical Characterization of Bromine Oxidised Potato Starch
Authors: Muhrbeck P. , Eliasson A.‐C. , Salomonsson A.‐C.
Published: November 2006

Native potato starch and potato starch oxidised with bromine at different concentrations were studied. A successive decrease of the gelatinisation enthalpy and a downward shift in the gelatinisation temperature were observed by the use of differential scanning calorimetry. When the oxidation was followed by a reduction step, those effects were accentuated. The mean molecular weight of the starch diminshed as the concentration of bromine oxidant was increased. In accordance with this, the viscosity of water solutions of corresponding samples successively decreased. However, when samples were reduced after the oxidation step, an increase in the viscosity was observed. A microscopic investigation showed that the granule structure was lost already at the lowest level of oxidation.
Changes of Carbohydrates and Molecular Structure of Dextrins During Enzymatic Hydrolysis of Starch with Maltogenase Participation
Authors: Nebesny E.
Published: November 2006

Investigations of the potato starch hydrolysis during bacterial α‐amylase “BAN 240 L” liquefaction to 19.5 DE and then saccharification with exo‐acting α‐amylase “Maltogenase 1000 L” alone and together with pullulanase “Promozyme 200 L”, were carried out. Under adequate conditions at different enzyme dosages hydrolyzates of the maltose, content of 60 to about 80% in DS at significantly lower glucose and minimal maltotriose content were obtained. Investigations comprised both carbohydrate contents in hydrolyzates, changing with hydrolyse course and dextrin molecular structure in hydrolyzates. It was found that decreasing dextrin molecular weight and the number of branchings in dextrin molecules was accompanied by characteristic changes of the viscosity of hydrolyzate solutions.
Halogen Azide Displacement to Prepare Some Symmetrically Substituted β‐Cyclodextrin Derivatives
Authors: Szurmai Zoltán , Lipták András , Debrecen  , Szejtli József
Published: November 2006

The heptakis (2,3‐di‐O‐acetyl‐6‐bromo‐6‐deoxy)‐β‐cyclodextrin has been converted to the 6‐azido derivate with 82% yield, then deacetylated by the Zemplén's method (yield 75%) and methylated by methyl‐iodide (yield 66%), to heptakis (2,3‐di‐O‐methyl‐6‐azido‐6‐deoxy)‐β‐cyclodextrin, which is an appropriate intermediary toward methylated amino‐CD‐derivatives. The structure of all compounds were unambiguously proven by NMR spectroscopy.
α‐D‐Polyglucane‐Iodine Complexes
Authors: Thorn W. , Mohazzeb S.
Published: November 2006

The temperature‐dependent dyeability of oligoglucanes and polyglucanes with I2/KI solution is based on the interaction between iodine and the C‐atoms of glucosidic bonds (Vetter and Thorn [1, 2]). Only when the helix is compressed, the expansion of the lumen that is necessary for the attachment of iodine bands is achieved as suggested by Freudenberg et al. in 1939 [3].

The development of colour starts with the maltododecaosis (just over two spirals) within a temperature range of 20 to 25°C adsorbing one pentaiodide and bringing about a pale shade of pink. The rich blue tone is achieved with pure amyloses forming a maximum of about 610 to 620 nm. Unramified polysaccharides which had been synthesised by our team from 30 glucoside residues, still showed a purple colour with a maximum of 510 nm at temperatures from 20 to 25°C. Defined polysaccharides from 40 residues are bluish‐purple (just 7 spirals of a tension‐free helix) with a maximum absorption of about 550 nm. According to our knowledge, the rich blue tone requires at least 50 glucoside residues linked in an unramified chain [1, 2].

Amylopectin from potatoes has a maximum of 575 to 580 nm which shifts to 555 to 560 nm after partial break‐down into β‐dextrin by β‐amylase (EC 3.2.1.2) and does a long‐wave re‐shift to 570 nm after splitting off of the side‐chain stumps in the basic structure by pullulanase (EC 3.2.1.41). In the case of maize, the maximum is 535 nm for amylopectin, 520 nm for β‐dextrin, and 555 nm for the basic structure. This means that in amylopectin from potatoes the helical sections available for the adsorption of iodine bands are longer than those in amylopectin from maize [4]. In glycogen iodine accumulates in a diffuse manner without forming any long bands. For this reason, an absorption shoulder of merely 400 to 500 nm is found by photometry [4].

A treatment with β‐amylase makes the situation even worse; only when the side‐chain stumps are separated by pullulanase does the formation of iodine bands in the basic structure of the glycogen improve to a maximum of 500 nm. This maximum corresponds to unramified sections of less than 30 glucoside residues [4, 2, 6].
Enzymic Determination of Starch in Samples with High Sugar Content
Authors: Henry Robert J. , Blakeney Anthony B. , Lance Reginald C. M.
Published: November 2006

Starch may be determined by hydrolysis with α‐amylase and amyloglucosidase followed by specific measurement of glucose using glucose oxidase. However biological samples to be analysed for starch often also contain glucose, maltose and higher oligosaccharides derived from the hydrolysis of starch. These sugars may be difficult to remove quantitatively by solvent extraction. We have found that reduction with sodium borohydride followed by evaporation with 2,2 dimethoxypropane removed interference from glucose, maltose and the two reducing terminal residues from higher oligosaccharides. The specific glucose test was not sensitive to glucitol produced by reduction of free glucose. Maltitol was not hydrolysed significantly by the amyloglucosidase, removing interference from maltose and the two reducing terminal residues from higher polymers. The method has potential for monitoring the hydrolysis of starch especially in the mobilisation of starch reserves in plant tissues such as in the endosperm of germinating cereal grains. A reduction ratio based upon the method is proposed for use in characterising starch hydrolysates.
The Effects of Water Soluble Arabinoxylan on Gelatinization and Retrogradation of Starch
Authors: Gudmundsson M. , Eliasson A.‐C. , Bengtsson S. , Aman P.
Published: November 2006

The effects of soluble pentosans, in the form of the main water‐soluble arabinoxylan from rye grain, on the gelatinization and retrogradation of starch were studied. Five different starches, waxy, amylomaize, wheat, maize and potato starches and wheat flour were used. The water contents of the samples varied from 46.5 to 50%. Differential scanning calorimetry (DSC) showed that the arabinoxylan had a negligible effect on the gelatinization. However, the arabinoxylan did affect the retrogradation. The recrystallization process is particularly sensitive to the water content in the sample. The maximum extent of recrystallization occurs when the starch concentration is between 50 and 60%. The effects of the arabinoxylan are probably caused by the water absorption ability of the arabinoxylan. i.e. control of the water availability of the starch which thereby, increases the retrogradation. The effects of arabinoxylan addition are. however, dependent on the initial starch concentration. The results of the rheological measurements agreed with the DSC measurements because potato starch gels (42.–42.8% on dry matter basis (d.b.)), with added (2% d.b.) arabinoxylan, were more rigid after seven days of storage than pure potato starch gels.
Determination of the Posphorylation of Starch from Native Potato Varieties by 31P NMR
Authors: Muhrbeck P. , Tellier C.
Published: November 2006

31P NMR technique was used to determine variations between potato varieties in the degree of phosphorylalion on the C‐3 and C‐6 sites of the glucosidyl units of the amylopectin molecules. The C‐3 phosphorylation was independent of the potato variety, while a substantial variation in the C‐6 phosphorylation was observed.
Anreicherung pflanzlicher Inhaltsstoffe durch selektives Trockenzerkleinern und anschließendes Klassieren
Authors: Heideker Hans‐Thomas , Schubert Helmar
Published: November 2006

Seit mehreren Jahrzehnten wird über die Anreicherung meist von Protein aus Getreide und Hülsenfrüchten durch trockenes Feinzerkleinern und anschließendes Windsichten berichtet. Im Gegensatz zum bisher rein empirischen Vorgehen behandelt die vorliegende Arbeit die beiden Verfahrensschritte Zerkleinern und Klassieren getrennt voneinander. Dieser Ansatz führt zu einer Gleichung. mit der man eine mechanische Inhaltsstoffverschiebung aus wenigen Versuchsdaten berechnen kann. Experimentelle Untersuchungen zum Verfahrensschritt Zerkleinern ergeben. daß sich bei biologischen Stoffen mit einer Matrix‐Zellstruktur die Art der Beanspruchung durch Druck oder Prall nicht auf die Selektivität der Zerkleinerung auswirkt. Anhand des Arbeitsstoffs Palerbsen wird für die Prallzerkleinerung gezeigt, wie sich Selektivität und Proteinverschiebung mit der Partikelgrößenverteilung des Mehls verändern. Simulationsrechnungen behandeln den Einfluß des Vertfahrensschritts Klassieren auf die Protein‐ und Stärke‐verschiebung. Aus den Ergebnissen der Arbeit folgen Empfehlungen für eine einfachere und zuverlässigere Anvendung des Verfahrens.
Nuclear Magnetic Resonance Studies of Homopolysaccharides Related to Starch
Authors: McIntyre Deane D. , Vogel Hans J.
Published: November 2006

One‐ and two‐dimensional 1H and 13C NMR spectra were obtained for a variety of homopolysaccharides, including the glucans dextran and pullulan, and the fructans levan and inulin. The NMR results provided information about the primary structure of these polysaccharides. Our results are in agreement with those determined previously by methylation analysis and other classical methods. The number of α(1 → 44) and α(1 → 6) linkages could be quantitated for pullulan. The presence of a single nonreducing glucose residue in the polyfructose inulin could also be demonstrated. In the case of the branched polysaccharides dextran and levan, it was possible to determine the degree of branching. In addition for lower molecular weight polysaccharides such as inulin and partially hydrolyzed dextran, it was possible to detect signals arising from reducing and non‐reducing end groups. Their approximate molecular weight could be determined by quantitation of these signals.
The Cationic Distribution in a Cationised Potato Starch
Authors: Salomonsson B. Ann‐Christine , Fransson Gunnel M. B. , Theander Olof
Published: November 2006

In the present study the distribution of cationic groups among the starch fractions, amylose and amylopectin, was investigated to illustrate the reactivity of the two starch components and also to better understand the behaviour of the cationised starch. A quaternary ammonium potato starch was separated in amylose and amylopectin by GPC. The content of nitrogen‐containing substituents in the fractions obtained was analysed by proton NMR and by nitrogen analysis. The sample studied here contained 0.27% nitrogen, made up of 0.21% nitrogen from the amylopectin and 0.06% from the amylose fraction. Thus in the cationic starch studied, with a DS of 0.03, the amylopection was more reactive than the amylose.
Continuous Synthesis of Glucoamylase by Immobilized Fungal Mycelium ofAspergillus niger
Authors: Abraham T. Emilia , Jamuna R. , Bansilal C. Vijay , Ramakrishna S. V.
Published: November 2006

The extracellular glucoamylase enzyme (EC 3.2.1.3) was synthesized continuously by the immobilized mycelial fragments of A. niger. Of the several polymeric matrices attempted for immobilization k‐carrageenan and alginate were found to be the most effective. However, the enzyme activity exhibited by the immobilized mycelia (I.M.) was 15‐20% lower than that of free cells under batch conditions. The immobilized cells have retained nearly the same enzymatic activity (120IU/g of I.M.) for 6 repeated batches and thereafter decline in activity was noticed. An aerated packed bed reactor with I.M. was operated continuously for 360 h. The volumetric productivity of the reactor was 1600IU/L/h for 192 h and reduced to 25% in 360 h.
Evolution of the Structural Representation of Sucrose [1]
Authors: Lichtenthaler Frieder W. , Immel Stefan , Kreis Uwe
Published: November 2006

Following a historical account on the establishment of the constitutional formula of sucrose and of its conformational features, the present possibilities for interactive graphics display of its molecular geometry, based on X‐ray structural data, are given. In addition, the MOLCAD program‐computed contact surface is presented as well as ‐ in a 16 color code ranging from violet ro red ‐ the electrostatic potential and, most relevant for structure‐sweetness relationship considerations, ist hydrophobicity potential profile on the contact surface. Finally, an attempt is made towards a tentative assessment of the computer‐generated distribution of hydrophilic and hydrophobic regions over the surface of the sucrose molecule in terms of the “sweetness triangle” AH‐B‐X concept. Also given are the graphic displays for the contact surfaces and hydrophobicity profiles of leucrose, isomaltulose and its reduction products α‐glucosyl‐mannitol and ‐sorbitol.
Encapsulation of EPTC in Starch by Twin‐screw Extrusion
Authors: Trimnell D. , Carr M. E. , Doane W. M.
Published: November 2006

A twin‐screw extruder was used for encapsulation of the herbicide EPTC (S‐ethyl dipropylcarbamothioate) in starch. Three starch/water ratios, 35/65, 50/50, and 65/35, were evaluated for efficiency to encapsulate 13.9% EPTC on a dry starch basis. Analysis of extrudates, after drying and grinding to the desired particle size, showed recovery of active ingredient (a.i.) and effectiveness of encapsulation to be best at 35% starch solids (35/65 starch/water ratio). Scanning electron micrographs showed smaller and a more even distribution of a.i. at 35% starch. Suspending particles in water caused a release of EPTC which increased with agitation and smaller mesh size. Air‐dried particles released EPTC more slowly than oven‐dried particles of the same mesh range. Particles from extrusion at 35% solids released a.i. more slowly than those from extrusion at 65% solids. The slowest releasing particles showed the least swellibility. EPTC was also encapsulated at 10.2% a.i. using 20% and 35% starch solids with steam‐injection cooking followed by Sigma blade mixing for comparison with an extrusion. Herbicide retention and encapsulation were superior, release of a.i. into water was slower, and swelling of particles was less in twin‐screw extrusion prepared products.
Rheological Studies on Potato Starch Pastes at Low Concentrations. Part IV: Absolute Measurements of the Rheological Properties of Starch During Gelatinization
Authors: Janas Piotr
Published: November 2006

The method of absolute measurement of the rheological properties of starch suspensions during gelatinization is presented. It enables to determine the flow curves already in the early stage of the process. The studies were carried out on 1.5% aqueous suspension of potato starch. They have shown that just at the temperature of approximately 15°C above the beginning of gelatinization the formed paste starts to behave as a shear‐thinning liquid with the yield stress, τy. The non‐ Newtonian effects increase as the temperature increases. Experimental data are satisfactorily described by the modified four‐parameter power law: τ = τy + τ0(γ˙/γ˙0)n. The temperature dependences of n‐ and τy‐parameters univocally determine the evolution of rheological properties which are observed on experiment. This evolution is understood as the transformation of Newtonian liquid through a pseudoplastic liquid into a nonlinear viscoplastic one.
Determination of Glucoamylase Activity with Glucose Electrode
Authors: Przybyt Malgorzata
Published: November 2006

The method of glucoamylase activity assay by oxygen electrode with immobilized glucose oxidase is described. The optimal conditions of assay were established and are following: 1% starch, pH 4.5, and 25°C. The method could be applied to kinetic measurements of glucoamylase action on starch. The results of such investigations are similar to obtained earlier by chemical method. The method could be used for assay of glucoamylase activity in the presence of α‐amylase by changing the pH of solution to 7.
A Characterization of Faba Bean Starch (Vicia faba L.)
Authors: Haase Norbert U. , Shi Hai Lin
Published: November 2006

In Far East faba bean starch is always present in several food applications. But often the starch quality is low and knowledge of characteristic attributes do not exist. Therefore, we tried to isolate a faba bean starch with few impurities, and to analyse the starch quality with different types of techniques. Furthermore, a comparison between three cultivars (two Chinese and one German) should point to possible differences.

The crude protein content of all isolated starches was lower than 0.3% dry matter. Particle size distribution of the starch granules was mainly between 20 and 40 μm diameter. Gelatinization range was between 56 and 81°C. Brabender viscograms showed very stable hot gels with no viscosity reduction during the hot phase. A gel filtration analysis of the starch molecules gave relevance to molecular weights of amylose between 100 and 200 × 103 MW. In spite of quite different genetic backgrounds and agricultural conditions the quality of the starches was not very different between the two Chinese and one German cultivars.
Spectrophotometry on the Change in Conformation of Bacterial Alpha‐amylase, Characterized with 6m Urea
Authors: Iwata Ken , Hiromi Keitaro , Ohnishi Masatake
Published: November 2006

Change in conformation of bacterial alpha‐amylase (Bacillus subtilis, liquefying, BLA), induced with 6m urea, was observed on difference absorption‐ and optical rotation spectrophotometries as probes. Time courses of the latter were coincident with those of the former for the whole time range examined (‐110min). BLA‐catalyzed activity in 6m urea, the third probe, was found to show a biphasic time‐course. Phase I and Phase II, and to be lost at Phase II: Phase I is tolerant against the urea‐induced change in conformation. Hence, the active site may be conservative in an enzyme engineering on the BLA molecule.
Glucoamylase Covalently Bound to Acrylic Carriers
Authors: Wawrzyniak B. , Krauze J.
Published: November 2006

Glucoamylase from Aspergillus niger was covalantly bound to three acrylic carriers differing in the content of amino groups, particle size, porosity, etc. Yield of immobilization ranged from 58.7% to 87.0%. Enzyme immobilized on Vinylaff 818 was the most stable. That carrier was a copolymer of butyl acrylate and ethylene dimethacrylate, containing 0.44 mmol/g of amino groups.

The immobilized catalyst used for hydrolysis of 40% maltodextrin solution (DE 18.3) retained its initial activity at 50°C for about 33 d. The pretreatment of soluble glucoamylase with low concentrated glutaraldehyde solution (0.13%, 1.4 mg/100 mg of protein) increased the operational stability of immobilized enzyme to about 50 d and its half‐life to 60 d.

The immobilization of enzyme on Vinylaff 818 resulted in the slight shift of pH optimum to acid side, though it did not influence the temperature optimum. Thermostability of immobilized glucoamylase in the range of temperature between 50 and 75°C was higher than that of soluble enzyme. Maximum concentrations of glucose in hydrolyzates were obtained in relatively short time. The prolonged hydrolysis of concentrated starch substrate by enzyme immobilized on the porous carrier caused, however, the accumulation of disaccharides with simultaneous reduction of glucose content.
Progress in the Enzymatic Saccharification of Wheat Starch
Authors: Konieczny‐Janda G. , Richter G.
Published: November 2006

Problems were noticed when trying to include wheat starch to the normal liquefaction and saccharification lines because of the formation of precipitations which are difficult to filter. The effects of different side activities of Aspergillus niger glucoamylases on the filterability of wheat syrups are demonstrated. In order to speed up filtration, viscosity has to be decreased by degradation of arabinoxylanes with present pentosanes. A new enzyme has been discovered which is able to split partially the lysophospholipids contained in wheat starch and let the insoluble components flocculate to big particles. This enzyme splits the phospholipids into free fatty acids and glycerophophorylcholines. The properties of this enzyme present in a novel glucoamylase preparation for the wheat starch processing are demonstrated by using an HPLC method, showing the degradation of wheat lipids as well as synthetic lysophopholipids.
Studies on Rye Starch Properties and Modification. Part I: Composition and Properties of Rye Starch Granules
Authors: Schierbaum Friedrich , Radosta Sylvia , Richter Manfred , Kettlitz Bernd , Gernat Christine
Published: November 2006

Rye is considered as a potential raw material for starch industry. Starting from a survey of technical procedures of isolating starches from rye‐flour and ‐grits investigations will be reported, which were performed on pilot plant‐ and laboratory‐isolated rye starches. The present paper deals with its granule appearance and composition.

A distribution of granule size between small granules (⩽ 10 μ − 15%) and large granules (⩾ 11 … ⩽ 40 μ − 85%) is typical for the totality of the starches. Differing distributions depend on the conditions of isolation: the entity of starch containing samples resulted from the laboratory procedures under investigation. Large‐granule starch preparations were isolated in the pilot plant: the centrifuge‐overflow contains the small‐granule fraction which is high in impurities. Granule crystallinity amounts to 16%. The crystalline component ‐ like in wheat and triticale starches ‐ consists predominatly of A‐polymorph ‐ with up to 9% of the B‐type. The isotherms of water exchange are of the cereal type.

The contents of minor constituents largely relate to the small granule fraction which assembles the majority of crude protein, pentosans and lipids, which are difficult to remove

Large granule samples may be produced in high purity (⩽ 0,2% crude protein)

. Lipid components in all fractions influence the results of linear chain‐iodine interactions and they must be removed to proceed from apparent to absolute polysac‐charide indices. The absolute amylose contents amount to ∼ 25% for large granule samples and to 20–21% for small granule samples. The average chain‐length of iodine binding helical regions was determined with 220–240 AGU.
On Crystallinity in Cereal and Tuber Starches
Authors: Muhrbeck Per
Published: November 2006

The size and shape of the crystalline regions of wheat and potato starch were analyzed by X‐ray line broadening. It was found that wheat A‐ and B‐granules contained almost identical roughly spherical crystallites, about 100Å in size. Potato starch crystallites showed about the same dimensions in the different directions, but were somewhat smaller than wheat starch. The crystallite size agreed well with literature values of the radial length of the amylopectin cluster.
Measurements of the Refractive Index Increment on Hydroxyethyl Starch as a Basis for Absolute Molecular Weight Determinations
Authors: Kulicke Werner‐Michael , Kaiser Uwe , Schwengers Dieter , Lemmes Rolf
Published: November 2006

Solutions of hydroxyethyl starch are used as a blood plasma substitute. If their physiological efficiency is to be optimized, they need to be accurately characterized in terms of their molecular weight and its distribution. The absolute determination of molecular weight and molecular weight distribution by means of light scattering require a knowledge of the refractive index increment. Although numerous investigations of the refractive index increment of hydroxyethyl starch have already been published, the results vary significantly due to the use of different samples and the choice of different measuring parameters. There was therefore an urgent need to examine the extent to which the refractive index increment depends on molecular parameters, the experimental method used and the type of processing. Here it was found that different sample preparations result in different contents of solid matter, so that an exact determination of the quantity is required. Hydroxyethyl starches in the molecular weight range of about Mw = 200.000 g/mol and varying degrees of substitution between DS 0.38 and 0.50 which are regarded as optimal for clinical use give a refractive index increment of dn/dc633nm = 0.146 = 0.005 cm3/g (solvent: H2O/0.02% NaN3; T = 25°C).
Thin‐Boiling and Nongelling Adhesive Prepared from Maize and Wheat Starches
Authors: Chung Koo Min , Seib Paul A.
Published: November 2006

To prepare thin‐boiling and nongelling adhesives, granular wheat and corn starches were thinned by treatment with aqueous hydrochloric acid or sodium hypochlorite and then hydroxypropylated with propylene oxide. Chlorine oxidation gave more rapid chain cleavage and whiter products with better freeze‐storage stability than acid‐treatment. Under the same depolymerization conditions, wheat starch was converted to a low viscosity granular starch more rapidly than corn starch. The best adhesive, judged by bonding strength, viscosity stability, and freeze‐thaw stability, resulted from wheat or corn starch oxidized with 0.82% Cl at pH 8.0 for 1 h followed by hydroxypropylation to molar substitution (M.S.) ∼ 0.07.
Seasonal Effects on the Physico‐chemical Properties of Starch from Four Cultivars of Cassava
Authors: Asaoka M. , Blanshard J. M. V. , Rickard J. E.
Published: November 2006

Four varieties of cassava plants were cultivated at CIAT in Colombia and harvested on four different occasions with a view to evaluating whether there was any relationship between the texture of the cooked roots and the constituent starch. The organoleptic qualities of the cooked roots showed considerable differences in ‘glassiness’ and hardness of texture, both between varieties and times of harvest. The starch granules were isolated and examined by a variety of techniques. The size of the granules did vary with the seasons but there were only minor differences in the x‐ray crystallinity, the elution patterns of iso‐amylase‐debranched material (including the amylose content), the proximate composition of the starch and the time course of digestion by glucoamylase. None of these provided a basis for explaining the differences in cooked texture.
Studies on Sago Starch. Part I: Characterization and Comparison of Sago Starches Obtained from Metroxylon sagu Processed at Different Times
Authors: Sim S. L. , Oates C. G. , Wong H. A.
Published: November 2006

This paper reports on a study undertaken to determine some of the factors responsible for the variability shown by sago starch, which at present severely limits the commercial value of this material. Two batches of sago starch extracted from Metroxylon sagu species were characterized physicochemically and structurally. One batch was white in colour while the other was reddish‐brown. The latter contained significantly more protein (0.06%) than the former (0.015%). Non‐proteinaceous material constituted 40% of the total nitrogen in the former. The ionic contents of the two batches of starch exhibited a similar ion profile except for the following striking differences. The white batch contained 20‐fold more phosphorus and 15‐fold more aluminium whilst the reddish‐brown batch contained double the quantity of iron and calcium. The solubility and swelling capacity of both batches were also different. Amylographic representation was used to reveal the strength of starch granules during pasting. Scanning electron microscopy disclosed different degrees of pitting between the two batches, the morphology of which were also shown to be disparate. Flow curves also displayed significant differences in the rheological behaviour.
Perspective Study of Vinyl Grafting onto Leucaena glauca Seed Gum and Guar Gum by Hydrogen Peroxide Initiation
Authors: Raval O. K. , Patel M. V. , Patel R. G. , Patel V. S.
Published: November 2006

Graft copolymerization of various vinyl monomers onto Leucaena glauca seed gum has been performed using hydrogen peroxide as the initiator in aqueous slurry. Guar gum grafts also have been prepared to compare graftability of both the gums as they are structurally related to each other. To study the grafting behaviour of vinylic monomers towards the polygalactomannans the reaction conditions were kept constant for all the sets. The choosen monomers were acrylonitrile, methylmethacrylate, acrylamide, styrene, methacrylic acid and acrylic acid. The reaction products were characterized by grafting parameters like percent grafting, grafting frequency, grafting efficiency along with thermogravimetric and infra‐red spectroscopic analysis.
Studies on Rye Starch Properties and Modification. Part II: Swelling and Solubility Behaviour of Rye Starch Granules
Authors: Radosta Sylvia , Kettlitz Bernd , Schierbaum Friedrich , Gernat Christine
Published: November 2006

Rye starch shows the typical inhibited swelling behaviour of triticeae starches with an onset of swelling at rather low temperature (50–55°C). Swollen rye starch granules exist as individuals even after swelling at 100°C. The total dispersion of rye starch needs temperatures above 120°C with pressure cooking. On heating of the rye starch suspension preferentially amylose is leached. Defatting of rye starch exhibits no influence on swelling power but results in higher solubility and in increased amylose leaching. The drying procedures applied here resulted in stronger assoziation of the polymer molecules in the starch granule leading to higher swelling temperatures and a reduced solubility. Shiftings of the crystalline/ amorphous‐ratio of the starch granules as caused by different drying procedures, had no influence on the results of swelling power investigation but the highest swelling enthalpy as well as Brabender viscosity were exhibited by a sample dried at room temperature. It is proved to be possible to change the swelling behaviour of rye starch to “potato starch type” by slight chemical modification like succination.
Mechanism of Hydrolysis of the Treated Sago Starch Granules by Raw Starch Digesting Amylase from Penicillium brunneum
Authors: Haska Nadirman , Ohta Yoshiyuki
Published: November 2006

We have prepared raw starch digesting amylase from Penicillium brunneum, which is similar to other raw starch digesting enzymes, and is effective in hydrolyzing raw cereal starches, but not effective for raw sago starch and raw root starches. Treatment of sago starch granules before incubation with the enzyme by heating to below gelatinization temperature at low pH condition was effective in improving the hydrolysis. Observation by scanning electron microscope showed that structure of treated sago starch granules at 60°C pH 2.0 for 2h was not changed. Observation under polarized light showed the birefringence clearly was preserved. However, viscosity of treated sago starch granules decreased. After incubation with the enzyme, untreated starch granules corroded and several holes were seen on the surface of granule. Enzyme action on the treated starch granules resulted in much higher intensity of degradation and the holes deepened into the interior of granules. Analysis of the product of this process showed that mainly glucose was produced from the hydrolysis of treated or untreated sago starch granules by crude enzyme. But on gelatinized sago starch other types of sugars were formed during enzyme reaction.
Digestibility of Sweet Potato Raw Starches by Glucoamylase
Authors: Noda Takahiro , Takahata Yasuhiro , Nagata Tadahiro , Monma Mitsuru
Published: November 2006

Three crude glucoamylase preparations from Rhizopus sp., Chalara paradoxa and Aspergillus sp. K‐27 were used to determine the digestibility of raw starches from eight sweet potato varieties. Granule sizes and amylose contents were also measured. The average granule sizes ranged between 10.5 and 14.2 μm. The amylose contents varied between 18.2 and 21.8%. The hydrolysis rates for the raw starches by any of the three glucoamylases were similar. However, starch of the variety Hi‐starch had a slightly lower hydrolysis rate than other starches when Rhizopus sp, enzyme was used.
Flow Behaviour of Mung Bean Starch Pastes
Authors: Oates C. G. , Lee W. P.
Published: November 2006

The rheological properties of mung bean starch pastes were characterised using a co‐axial rotational viscometer. The flow curves of pastes were typical of a viscoplastic shear thinning behaviour, no yield value was evident and the pastes showed unusual resistance to high shear forces. The rheological properties of these pastes were thought to result from the combined influence of intact swollen granules and an extensive extragranular network of exuded amylose.
Fractionation of Starch Amylopectin and Amylose by High Performance Gel Filtration Chromatography
Authors: Kennedy J. F. , Rivera Z. S. , Lloyd L. L. , Warner F. P.
Published: November 2006

A gel filtration chromatographic method has been developed which is capable of fractionating amylose and amylopectin in starch. Three GFC columns (2 × 4000 A and 1 × 300A PL Separation Sciences, Polymer Laboratories Ltd,) are used in series using sodium chloride solution as eluent. Minimal sample preparation is involved which includes a preliminary wetting of powder starch with ethanol followed by dissolution with sodium hydroxide. Since the solvent system is aqueous, cooked starch samples are analysed by direct dissolution with sodium hydroxide. The method shows promise as a rapid technique in elucidating starch structure.
Studies on Starch Granules Digestion by α‐Amylase
Authors: Sreenath Hassan K.
Published: November 2006

Raw corn starch was partially digested with commercial α‐amylase for a short period of 7–8 h at 25°C to obtain granular pitting. The patterns of granular digestion was observed by light and scanning electron microscopy (SEM). The main soluble products of starch digestion were glucose, maltose and higher oligosaccharides. In vitro digestion of starch was discontinued on the basis of nature of granular pitting and relative release of glucose in the reaction mixture. The pitted starch was obtained with high yields and found to be warm water soluble.
The Dehydration of Fructose Towards 5‐Hydroxymethylfurfural Using Activated Carbon as Adsorbent
Authors: Vinke P. , van Bekkum H.
Published: November 2006

5‐Hydroxymethylfurfural (HMF) can be selectively adsorbed onto activated carbon with loadings up to 30% (w/w), depending on the type of carbon used. Adsorption isotherms of HMF on several types of carbon and in different solvents are presented. Activated carbon is used in in the dehydration of fructose towards HMF in order to suppress the formation of side‐products (e. g. levulinic acid). A dehydration set‐up in which the formation and adsorption of HMF take place at different temperatures is presented. The HMF is recovered by extraction of the loaded activated carbon with organic solvent.
Physicochemical Studies on Starches Isolated from Plantain Cultivars, Plantain Hybrids and Cooking Bananas
Authors: Eggleston Gillian , Swennen Rony , Akoni Stephen
Published: November 2006

Starches from mature, unripe fruit pulp of plantain cultivars (Musa supp., AAB group) representing the wide variability in Africa, tetraploid and diploid plantain hybrids and starchy cooking bananas (Musa spp., ABB group) were isolated and characterised. In general, studies revealed very compact irregularly shaped and sized granules, with low amylose content (9.11–17.16%), highly resistant to bacterial α‐amylase attack; Brabender amylograms showed very restricted swelling type patterns with great stability and negligible retrogradation. Results indicate that differences in physico‐chemical properties exist amongst the three Musa fruit group starches. Plantains represent a chemical/molecular homogeneous group, but heterogeneous for granule structure. Ploidy level affected hybrid properties. ABB cooking bananas starches exhibited highly pronounced restricted swelling and high gelatinisation and pasting temperatures, indicating a more ordered, very strongly bonded granule structure; chemical and physical properties varied considerably within the ABB genotype.
Modifications of Urethane‐Foam Formulations Using Zea mays Carbohydrates
Authors: Cunningham R. L. , Carr M. E. , Bagley E. B. , Nelsen T. C.
Published: November 2006

Four carbohydrates derived from Zea mays (corn), ordinary cornstarch, two high‐amylose starches (one instant starch), and canary dextrin, were substituted partially (8–30%) for polyether polyol in rigid polyurethane foams. Because of different carbohydrate water contents the level of substitution was chosen for each carbohydrate to maintain uniform water contents in the foams. In addition, a lower level of canary dextrin was added to one formulation to evaluate the effect of water addition. With the exception of the dextrin‐filled foams, which were similar in density to the controls, the carbohydrate‐filled foams were more dense (0.0280–0.0296 versus 0.0272 g/cm3). Substitution of 8% of the polyether polyol with Amalean I (high‐amylose starch) increased the density by 9%. With 15–16% substitution of the polyether with instant starch or dextrin, the compressive strength values of the foams were 10–16% lower than for the control foams. Exchanges of 8–16% polyether with any of the four carbohydrates resulted in 3–4% and 4–5% increases in volumes after 14 days of accelerated aging under thermal (70°C, ambient RH) and humid (38°C. 97% RH) conditions, respectively. The lowest priced carbohydrate, cornstarch, substituted at the 10% level for the polyether provided foams exhibiting 4% less compressive strength and similar insulating value than the control foams without carbohydrate. Since the polyether polyol is ten times more expensive than cornstarch, further study of utilizing corn‐derived carbohydrates as polyols in foam formulation is merited.
Composition of Polydextrose® Before and After Intestinal Degradation in Rats
Authors: Radosta Sylvia , Boczek Peter , Grossklaus Rolf
Published: November 2006

The alternative carbohydrate Polydextrose® was separated by gel permeation chromatography (GPC) with an aminomodified silicagel and by high performance liquid chromatography (HPLC) on a silvercharged cation exchanger. It has been proved that Polydextrose® contains about 32% oligomers with a degree of polymerization of up to four. Because of the great variability of binding types between the glucose monomers, a satisfactory chromatographic separation is not yet possible. The degradation of Polydextrose® in the small intestine of rats is an accidental event; there are no especially resistent molecules in this process. Within 3 h after oral administration, the spectrogram of high‐and low‐molecular fractions of Polydextrose® was not changed by digestion in the small intestine irrespective the visible decrease of glucose. Thus, this study gives new insights into the molecular composition of Polydextrose®.
Studies on Sweet Potatoes. Part I: Changes in the Carbohydrates During Processing
Authors: Susheelamma N. S. , Reddy G. Changala , Rukmani C. S. , Tharanathan R. N.
Published: November 2006

The qualitative and quantitative changes in the nature of different carbohydrate fractions of sweet potatoes (hard and soft cooking types), after dry (baking and toasting) and wet (steaming) processing have been studied. Maltose, glucose and fructose were the predominant sugars in the ethanol soluble fraction. The total sugar and amylose contents significantly decreased in the ethanol insoluble residues. This was supported by the decrease in blue value and the absorption maxima of the iodine complex.
Hydrothermal Modification of Starches: The Difference between Annealing and Heat/Moisture ‐Treatment
Authors: Stute Rolf
Published: November 2006

Annealing and heat/moisture‐treatment both cause a physical modification of starches without any gelatinization, or any other damage of the starch granules with respect to size, shape or birefringence only via a controlled application of heat/moisture. Since with respect to the application properties (gelatinization. viscosity etc.) almost idential modifications can be obtained with both treatments, there was no exact differentiation between the two treatments types.

By application of both treatments as well as a combination of both to potato starch it could be demonstrated that both treatments cause completely different alterations of the internal granule structure. From the interpretation of the Brabender viscosity, the sorption isotherm, the DSC‐curves and the X‐ray diagrams it could be confirmed that a heat/moisture‐treatment always means a structure alteration from a B‐type in the direction of an A‐type structure, whereas within annealing processes the property alteration have to be explained by a modification of the binding forces between the crystallites and the amorphous matrix.