bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and Characterization of Starch‐N‐methylol Acrylamide‐Methacrylic Acid Cation Exchange Composites
Authors: Abo‐Shosha M. H. , Ibrahim N. A.
Published: November 2006

Starch‐N‐methylol acrylamide methacrylic acid cation exchange composites were synthesized by polymerizing of highly concentrated aqueous mixtures of methacrylic acid and N‐methylol acrylamide with starch using ammonium peroxydisulphate, as an initiator, alone and with different reductants, viz. sodium thiosulphate, sodium pyrosulphite and glucose. Sodium thiosulphate proved to be the best reductant that can produce the composite at the lowest solidification time with the highest insoluble yield and carboxyl content. Factors affecting the process such as temperature, redox system concentration and concentrations of monomers were reported. Four kinds of cation exchange composites, of different nitrogen and carboxyl contents, were prepared. These composites were characterized by potentio‐metric titrations, water solubility and swellability, as well as durability to use.
Properties of Sweet Potato Starches from Different Tissue Zones
Authors: Noda T. , Takahata Y. , Nagata T.
Published: November 2006

Sweet potato starches prepared from the peel (P), cambium (C), and inner‐tissue (IT) were tested for physicochemical properties. The average granule sizes of the IT starches were tended to be larger than those of the P and C starches. Amylose contents of starches from the different tissue zones did not differ significantly. The onset and peak temperatures (To, Tp) of the P starches determined by differential scanning calorimetry (DSC) were somewhat high. The C starches were readily digested by the four glucoamylases.
Determination of the Carbonyl Groups in Oxidized Polysaccharides by Hydroxylammonium Formate
Authors: Tihlérik K. , Pašteka M.
Published: November 2006

Oximation method for determination of carbonyl groups in starch and pectic acid oxidized with nitrogen dioxide was modified. As oximation agent hydroxylammonium formiate in 2‐methoxyethanol was used. The unconsumed amount of the agent applied in known excess was determined by titration with perchloric acid solution in 2‐methoxyethanol. Thymol blue indicator was used. Blank determination is unavoidable. The standard deviation 0.180 and variation coefficient 7,950 were found from 10 determinations of carbonyl groups in sample of starch treated with nitrogen dioxide to high degree of oxidation and standard deviation 0,122 and variation coefficient 6.210 of pectic acid, oxidized to lower degree of oxidation with nitrogen dioxide were found.
Starch‐Derived Products for Detergents
Authors: Koch Helmut , Beck Roland , Röper Harald
Published: November 2006

Recent developments in the formulation of detergents have been driven by a strong consumer demand for natural and biodegradable products. Detergent manufacturers responded to this demand with corresponding products and advertising slogans such as “fully biodegradable”, “natural” or even “double natural” to oust their competitors. In a detergent formulation, starch‐ derived products can in principle be used for the following purposes: as the hydrophilic head group in surfactants, as the starting material for (poly)carboxylate co‐builders and as the backbone of bleaching activators. Non‐ionic classical surfactants can be replaced by alkylpolyglucosides (APGs), a class of products completely based on renewable resources such as glucose and fatty alcohols derived from natural fatty acids. Sodium tripolyphosphate (STPP), the product responsible for the eutrophication of surface waters, can be substituted by a combination of an inorganic zeolite and highly oxidised starch (dicarboxylic starch) or by citrate. Acetylated polyols derived from hydrogenated carbohydrates such as sorbitol can take over the function of the petrochemically‐based tetraacetyl ethylene diamine (TAED) used as activator to allow perborate bleaching at lower washing temperatures.
Studies on Sweet Potatoes. Part II: Isolation and Characterization of Starch
Authors: Madhusudhan B. , Susheelamma N. S. , Tharanathan R. N.
Published: November 2006

By differential sedimentation and centrifugation steps four starch isolates were recovered from sun dried sweet potato flour. The granules in these isolates were of different size, shape and population characteristics, and were anionic in nature. They showed a single stage swelling with 30 to 35% solubility in water and only ∼30% solubility in DMSO even after 72h. Their starch content varied from ∼48 to 88%. The presence of thermostable amylases in sweet potato resulted in considerable decrease in Brabender viscosity values as amylographic studies in the presence of HgCl2 showed significant increase in peak (PV) and setback (SBV) viscosities. The starch isolate I had 25% higher PV as compared to the isolate II but retrogradation was much low in this. Susceptibility to glucoamylase digestion showed a decreasing trend from the isolate I to the IV on solid basis, but comparable on starch basis.
Effect of Heat Damage on the Baking Quality of Starch Extracted from Wheat
Authors: Lorenz K. , Collins Fort , Kulp K. , Every D. , Larsen N.
Published: November 2006

Eight wheat samples of four cultivars, grown in different regions of New Zealand, were heated at 75‐110°C in order to heat‐damage them. Untreated wheat samples were used as controls. The wheats were then milled to give white flours. Starches were isolated from the treated and untreated flour samples. The baking potentials of the starches were estimated from remix baking tests using a starch gluten system. Heat‐damage to wheats had a significant adverse effect on the baking performance of starches isolated from these wheats. This effect was not as large as the effect on gluten quality. Heat‐damage caused no apparent alterations in starch physicochemical parameters as measured by scanning electron microscopy, Amylograph pasting, gelatinization ranges, X‐ray diffraction, swelling power and solubility, and water hydration capacity.
Enthalpy ‐ Entropy and Frequency Factor ‐ Activation Energy Compensation Relations for Diffusion in Starch and Potato Tissue
Authors: Özilgen M.
Published: November 2006

Diffusion of water in hydrated starch, hydrated starch plus sucrose, and diffusion of glucose, potassium, magnesium and ascorbic acid in potato tissue, i.e. a major natural source of starch, were analyzed with Eyring's diffusion theory and the compensation relations. The results implied that there may be an isokinetic temperature for the diffusion of water in amioca (amylopectin, one of the major macromolecular components of starch) and hylon 7 (native corn starch). Having an isokinetic temperature may imply that diffusional jump occurs via formation of similar activated complexes. Although the compensation relations were satisfied, there was no isokinetic temperature with diffusion of water in hylon 7 plus sucrose and diffusion of glucose, potassium, magnesium and ascorbic acid in potato tissue, therefore the compensation relations with these two system were considered only as empirical correlations for estimating the diffusivities.
Chemical Modification, Cross‐Linking and Characterization of Some Starch Hydrogels
Authors: Aggour Y. A.
Published: November 2006

Modified starch hydrogels were prepared via the reaction of starch with acrylamide (AAm), under certain conditions and cross‐linking with N,N'‐methylenebisacrylamide (MBA Am). Rheological measurements of different ratios gels shows that both increasing of cross‐linker or substrate concentration, lead to increase the elasticity of the gels. The molecular weight between two entangelement points (Me), was calculated from plateau modulus (Gp) values. The effectiveness of the cross‐linker was calculated by comparison between the number of elastically effective points rheologically [ne(r)] and that obtained from theoretical values [ne(t)]. The effectiveness has a maximum value 5.76% at the higher substrate concentration of 25% (w/w) gels. Swelling of different gels were studied in pure water and in different salt solution. The curves show shrinking of the gels, however no collapsing occurs with increasing the concentration of salts. The maximum water absorption capacity were 140 g/g for 15/3 gels. the structure of the gels were interpreted with the guide of 13 C NMR spectrometry.
13C CP/MAS NMR Spectroscopy of Native and Acid Modified Starches
Authors: Singh Vasudeva , Ali S. Zakiuddin , Divakar S.
Published: November 2006

13CP/MAS NMR spectroscopic studies of some starches from cereals (wheat, maize and finger millet), pulses (green gram, chick pea), tuber (potato) and root (tapioca), and their respective acid (HCI, HNO3) modified starches were carried out. While cereal starches exhibited a triplet signal for their anomeric carbons, pulse, tuber and root starches showed doublets. Line width changes in signals indicated that debranching in the above modified starches led to narrowing of C6 signals (more pronounced in the case of potato and tapioca starches) and were consistent with the release of branching strains. Potato starch, both native and modified, was found to be different from other starches as inferred from the chemical shift values for their anomeric carbons and line shape. The dihedral angle (ϕ′2) calculated from chemical shift values for C1 and conformation of dihedral angel (x) as predicted from chemical shift of C6 are discussed with respect to structural organization.
Effects of Reaction Medium on Grafting of Acrylonitrile Onto Sodium Salt of Partially Carboxymethylated Amylose
Authors: Patel Bipin K. , Patel Chandrakant P. , Trivedi Harikrishna C.
Published: November 2006

The grafting of acrylonitrile (AN) onto sodium salt of partially carboxymethylated amylose (Na‐PCMA) using ceric ammonium nitrate (CAN) as an initiator has been studied in water/solvent mixtures. The solvents used include methanol, ethanol, propanol, butanol, acetone and carbon tetrachloride. The results have been discussed. The effect of reaction medium on the molecular weight of grafted PAN has also been studied. The chain transfer constants (Cs) for solvents like methanol, ethanol, propanol, butanol, acetone and carbon tetrachloride have been evaluated at 30°C by the help of Mayo's equation.
Semitechnical Methods for the Isolation of Wrinkled Pea Protein
Authors: Wiege B. , Lindhauer M. G. , Bergthaller W.
Published: November 2006

Isoelectric precipitation and ultrafiltration were tested as semitechnical methods for the isolation of wrinkled pea protein. By aqueous extraction of wrinkled pea flour followed by centrifugation approximately 90% of the total protein could be isolated. Using isoelectric precipitation at pH 4,4 and centrifugation by means of a separator, followed by washing and defatting steps, 65% of the protein contained in the flour were isolated from the extracted protein solution. The crude protein content of this fraction proved to be 83% in dry matter (D.M.). Ultra‐and diafiltration with a plate and frame process unit were used as alternative methods of protein separation. By diafiltration at optimized process conditions, i.e. temperature, pressure and degree of concentration, a crude protein content of 82% D.M. was achieved in the concentrate. The yield of the native final product was 83%.
Isolation and Partial Properties of Cyclomaltodextrin Glucanotransferase‐producing Alkaliphilic Bacillus spp. from a Deep‐sea Mud Sample
Authors: Georganta G. , Kaneko T. , Nakamura N. , Kudo T. , Horikoshi K.
Published: November 2006

Cyclomaltodextrin glucanotranferase (CGTase) producing alkaliphilic bacteria were isolated from deep‐sea bottom mud samples. Isolates no. 3–22 and no. 1–7 were identified as an alkaliphilic Bacillus sp. and an alkaliphilic Bacillus subtilis strain from their taxonomic characteristics, respectively. Isolate no. 3–22 grew at 4°C whereas isolate no. 1–7 did not. The crude enzymes of both strains showed activity in both broad temperature and broad pH (5–9) ranges, Isolate no. 3–22 produced the main product. β‐cyclodextrin (β‐CD), and minor products, α‐ and γ‐CDs from starch. On the other hand, isolate no. 1–7 produced the main product, β‐CD, and the minor product, γ‐CD from starch; no α‐CD was detected.
Preparation and Characterization of Starch/Methylelnebisacrylamide/Dimethylaminoethyl Methacrylate Anion Exchange Composite
Authors: Ibrahim N. A. , Abo‐Shosha M. H.
Published: November 2006

Starch/methylenebisacrylamide/dimethylaminoethyl methacrylate anion exchange composite was prepared by polymerizing aqueous mixture of dimethylaminoethyl methacrylate (DMAEMA) / methylenebisacrylamide (MBA) in presence of starch using ammonium peroxydisulphate/sodium thiosulphate redox system. The effects of the concentrations of each of ammonium peroxydisulphate, sodium thiosulphate, MBA and DMAEMA as well as the polymerization temperature on the synthesis were investigated. Polymerization conditions were chosen to prepare an anion exchange composite having amino and MBA‐nitrogen contents of 145 and 72 meq/100g, respectively. Potentiometric titration showed that this composite is a weak base anion exchanger of a pKb of 7. Water solubility and swellability as well as durability of this composite were investigated.
Comparative Starch Synthase Activity of Indica and Japonica Developing Rice Grain
Authors: Villareal C. P. , Juliano Los Baños B. O.
Published: November 2006

Developing grain of japonica rice had higher specific activity of granule‐bound starch synthase than indica rice at the same growth stage, with indica‐japonica hybrid having intermediate synthase activity. All were of similar amylose content in the mature grain. It supports an earlier speculation that for japonica rice to synthesize the same amount of amylose in its starch granule with a lower level of bound starch synthase, it must have a more efficient enzyme than indica.
Subcloning and Nucleotide Sequencing of the pul Gene of Thermus sp. AMD‐33
Authors: Sashihara Nobuhiro , Nakamura Nobuyuki , Horikoshi Koki
Published: November 2006

The entire sequence of a thermostable pullulanase gene pul of Thermus sp. AMD‐33 was determined. A single open reading frame of 2.154 bp was found which encodes a protein with a molecular mass of 80.327. Pullulanse purified from an E. coli transformant harbouring the plasmid encoded pul gene had a molecular mass of 81.000 as determined by SDS‐PAGE. The plasmid‐encoded enzyme was inhibited by pCMB, however, the activity was recovered after treatment with 2‐mercaptoethanol. The N‐terminal region was almost identical to that deduced from the DNA sequence. No signal peptide‐like sequence could be detected. Amino acid sequence analysis revealed that 4 regions out of the 6 regions which are characteristically found in amylases were conserved in the plasmid‐borne pullulanase. but no amylase activity could be detected.
Untersuchungen an Kartoffelpulpe als Ballaststoffquelle. Zum Einfluß Von pektolytischen und cellulolytischen Enzymen
Authors: Dongowski Gerhard
Published: November 2006

Es wird der Einfluß einer Behandlung mit verschiedenen pektolytischen und cellulolytischen Enzympräparaten auf die Wasserabtrennbarkeit und die Zusammensetzung von Kartoffelpulpe untersucht. Im Gegensatz zu Pektinesterase, Pektatlyase oder Cellulase zeigen Pectinex Ultra SP‐L und Pektinase/Cellulase‐Kombinationen eine starke Wirkung auf die Kartoffelpulpe. Je nach eingesetztem Enzymprä;parat sind der Gehalt an Pektin, Stärke und Protein sowie die Wasserbindungskapazität verändert. Die eintretenden Änderungen in der übermolekularen Struktur des Gewebes von Kartoffelpulpe wurden rasterelektronenmikroskopisch untersucht. Besonders durch eine kombinierte Wirkung von Pektinasen und Cellulasen wird die biologisch gewachsene Überstruktur teilweise oder weitgehend zerstört. Der Stärkegehalt der Püpepräparate bleibt auch nach intensiver Behandlung mit zellwandabbauenden Enzymen verhältnismäßig hoch.
Graft Copolymerization of Acrylonitrile Onto Sodium Salt of Partially Carboxymethylated Starch Using Ce4+ Amine System as Redox Initiator
Authors: Patel B. K. , Sinha V. K. , Patel C. P. , Trivedi H. C.
Published: November 2006

Graft copolymerization of acrylonitrile onto Sodium salt of partially carboxymethylated starch using ceric ammonium nitrate(CAN) has been carried out in the presence of triethylamine, diethylamine, ammonia and pyridine. The percentage of grafting varied with the nature and concentration of the amines. All the amines with exception of diethylamine have been found to suppress grafting. The relative reactivity of different amines towards grafting has been determined and found to follow the order: DEA > TEA > ammonia > pyridine.
Endosperm α 1,4—α 1,6 Glucopolysaccharides Utilization During Germination of Sweet Corn and Other Maize Genotypes
Authors: Pagano Eduardo A. , Krisman Clara R.
Published: November 2006

The quantity variations and the structural changes of the α 1,4 —α 1,6 glucopolysaccharides contained in the endosperm of sweet corn, waxy and amylose extender maize genotypes, were studied during early germination. The α 1,4 —α 1,6 glucopolysaccharides were fractionated according to their branching degree.

The results obtained showed that: the degradation pattern of the α 1,4 —α 1,6 glucopolysaccharides was similar for the different corn genotypes studied. In addition, soluble dextrins or partial degradation products were not detected, but reducing sugars were accumulated. Furthermore, the structure of the remaining polysaccharides was similar to those present in the non germinating seed.

These results led us to propose that once a polysaccharide molecule was used as the substrate by degradative enzymes during germination, that molecule was totally degraded.
α 1,4 — α 1,6 Glucopolysaccharides Contained in Developing Maize Kernels
Authors: Curá J. Alfredo , Tolmasky Diana S. , Reid Alejandro , Salerno Juan C. , Krisman Clara R.
Published: November 2006

Corn grains with different filling times were fractionated in order to obtain their α 1,4 — α 1,6 glucopolysaccharide composition and structure. Sugary, waxy, flint and several hybrids were the varieties analyzed.

There is an increase in the total content of polysaccharides, as the grain is completed. But, no differences in composition and structure were detected between the first sample analyzed (15th day after pollination) and the last one, which corresponds to the complete grain filling period.

The methodology developed by us, allowed us to observe that the introduction of su character on the hybrids (F x S and S x F) has influence on the final polysaccharide structure. Also, in the F x W hybridα 1,4 — α 1,6 glucans, their structural characteristics were different from those of F or W pure.
Characterization and Chemical Modification of Amylose Complexes
Authors: Kubik Stefan , Wulff Günter
Published: November 2006

Complexes of amylose with various organic guest molecules have been studied by means of c. d. spectroscopy and microcalorimetry in aqueous solution. From the results the structure of the complexes and the mechanism of their formation are deduced. It is concluded that amylose can adjust its helix conformation to the shape and structure of the guest molecule included. Investigations about intramolecular and intermolecular crosslinking of amylose indicate that the complexing behaviour of amylose can be manipulated specifically.
Alcohol Fermentation from Sago Starch Granules Using Raw Sago Starch Digesting Amylase from Penicillium brunneum No. 24 and Saccharomyces cerevisiae No. 33
Authors: Haska Nadirman , Ohta Yoshiyuki
Published: November 2006

Treatment of the sago starch granules before incubation with the enzyme by heating to below gelatinization temperature at low pH condition was effective in improving the hydrolysis. Glucose could be produced from treated (at 60C. pH 2.0) sago starch granules using the raw sago starch digesting amylase from our strain. Alcohol fermentation from the treated sago starch granules using the raw sago starch digesting amylase from Penicillium brunneum and a strain of yeast, Saccharomyces cerevisiae No. 33 could produce ethanol under incubation conditions of 35C, pH 4.8. Addition of yeast and an extra half dose of enzyme after 24 h enzyme reaction was sufficient to continue starch hydrolysis during fermentation. This condition resulted in a conversion of sago starch to ethanol at a rate of about 44% in 72 h culture time.
Studies on the Structure of Pea Starches. Part 2: α‐Amylolysis of Granular Wrinkled Pea Starch
Authors: Bertoft Eric , Manelius Robin , Qin Zhu
Published: November 2006

Wrinkled pea starch, separated into fractions containing intact granules and fragmented granules together with small intact granules, respectively, was hydrolysed by the α‐amylase of Bacillus amyloliquefaciens in a column. The solubilisation rate was similar for both fractions and occurred in three stages: initially increasing, then slowly decreasing, and finally it was very slow. The mixtures of solubilised dextrins had DP (degree of polymerization) 2–100 and their compositions changed as the solubilisation proceeded through the different stages. The products were mostly linear and the composition of the granular residues indicated that amylose preferentially solubilised. Scanning electron microscopy could hardly reveal the site of the attack even though 20% of the granules had been solubilised. It is suggested that the enzyme attacked amylose chains in an amorphous state, whereas chain residues with DP 50–300 remained in the crystalline parts within the granules.
Alkylpolyglucoside ‐ Technologie und Eigenschaften
Authors: Biermann Manfred , Schmid Karl , Schulz Paul
Published: November 2006

Obwohl oberflächenaktive Kohlenhydratverbindungen seit langer Zeit bekannt sind, ist ihre großtechnische Herstellung erst seit wenigen Jahren aktuell geworden. Aus der Gruppe der bekannten Kohlenhydrattenside werden sich die langkettigen Alkylpolyglucoside in naher Zukunft als großvolumige Leittenside durchsetzen.

Die Entwicklung der Zuckertensidchemie generell, und speziell die der Herstellverfahren für Alkylpolyglucoside, werden skizziert und die entscheidenden Produkt‐ und Verfahrensverbesserungen beschrieben, die eine unter ökonomischen und qualitativen Gesichtspunkten marktgerechte, großtechnische Alkylpolyglucosidherstellung ermöglichen.

Eine Zusammenfassung der relevanten anwendungstechnischen Leistungsmerkmale der Alkylpolyglucoside vervollständigt das Bild dieser hautmilden, ökologisch und toxikologisch sehr günstig bewerteten Tensidklasse.
Studies on the Properties of Starch of Diploid Ipomoea trifida (H. B. K.) Don. Strains
Authors: Asante S. A. , Yamada T. , Hisamatsu M. , Shiotani I.
Published: November 2006

Starches of six diploid Ipomoea trifida (H. B. K.) DON. clonal strains were examined. Granule size, granule traits obtained by scanning electron microscopy (SEM), X‐ray diffraction patterns and differential scanning calorimetry (DSC) parameters of starches of the diploid strains were compared with those of two sweet potato cultivars. The granule sizes of the diploids were definitely smaller than those of cultivars. SEM showed that starches of the diploid strains were composed of predominantly angular granules having crater‐like impressions. Starches of both the diploids and the cultivars showed typical X‐ray diffraction patterns (C type) with diffuse maximum peak around 18.5° 26, but in the case of diploid strain “H3–28”, distinctive sharp peaks suggesting some differences in crystal structure were observed. DSC parameters, namely, onset temperature (To), peak temperature (Tp), conclusion temperature (Tc) and enthalpy of gelatinization (Δ) obtained from starch‐water mixtures (ratio 1:3) were higher in the diploid starches compared to those of the two cultivars. Significant correlation coefficients were found between the gelatinization parameters and mean granule diameter of the starches studied.
Der Einsatz von Stärke bei der Modifizierung synthetischer Kunststoffe
Authors: Fritz H.‐G. , Widmann B.
Published: November 2006

Synthetische Kunststoffe wurden unter Verwendung von Stärken modifiziert und neue Verbundwerkstoffe entwickelt, deren resultierende Eigenschaftsprofile Anwendungen zulassen, die dem Ausgangspolymeren verschlossen bleiben. Drei unterschiedliche Kategorien von Verbundwerkstoffen wurden auf einem gleichsinnig drehenden, dicht kämmenden Doppelschneckenextruder hergestellt und hinsichtlich ihrer physikalischen und mechanischen Eigenschaften charakterisiert. Die erste Kategorie umfaßt Werkstoffe, bei denen die Stärke in ihrer natürlichen granulären Erscheinungsform als funktioneller Füllstoff genutzt wird. Das Eigenschaftsprofil hängt dabei ent‐scheidend von den Wechselwirkungen zwischen Stärkekornoberfläche und Matrixpolymer ab, und kann durch ein Organosilancoating der Stärke signifikant verbessert werden. Die anderen beiden Kategorien basieren auf der Verwendung von destrukturierter Stärke, die durch mechanisch/thermische Desintegration der makroskopischen Stärkekörner unter Zugabe von Plastifikatoren und Weichmachern im Extruder erzeugt wird. Die so erzeugte entstandene, thermoplastisch verarbeitbare Formmasse kann im Einzelfall direkt als Werkstoff Verwendung finden. Der bedeutendere Anwendungsbereich für thermoplastische Stärken (TPS) ergibt sich jedoch im Verbund mit Polymeren in Form von Legierungen und Blends. In Kombination mit Ethylencopolymeren entstehen Verbundwerkstoffe, bei denen die TPS trotz ihres höheren Anteils in Form kleinster, diskret verteilter Partikeln in der, die kontinuierliche Phase bildenden Polymermatrix eingelagert ist. Die resultierenden Eigenschaften solcher Blends hängen dabei entscheidend von der sich ausbildenden Mikrostruktur und Morphologie ab.
Biosensor for Determination of Starch
Authors: Vrbová E. , Pecková J. , Marek M.
Published: November 2006

Biosensor for determination of starch was prepared by fixing a carrier with immobilized enzyme system on the tip of a Clark‐type oxygen sensor. Enzymes amyloglucosidase, mutarotase, glucose oxidase and catalase were co‐immobilized either on the partially hydrolyzed nylon net or on the activated collagen membrane. In both cases the covalent bond was made in the presence of glutaraldehyde and cyclohexyl isocyanide. The prepared biosensors were compared from the viewpoint of a specific activity of the immobilized amyloglucosidase, of a linear response area of the biosensor to the substrate concentration, of the pH and temperature of the reaction mixture and of the biosensor stability. Biosensors prepared were used for the determination of starch in the samples of cultivaiting media for the monensin production.
A Simplified Method for Measurement of Lactic Acid and Sulfur Dioxide in Corn Wet Milling Steep Water
Authors: Shandera Donald L. , Jackson David S.
Published: November 2006

A rapid HPLC method for measurement of lactic acid in corn wet milling steep water was developed. This technique is also suitable for simultaneous analysis of sulfur dioxide (sulfurous acid). Lactic acid and sulfur dioxide were analyzed using a Shodex Ionpak KC‐811 HPLC column with a Waters 410 refractive index detector within 11 min. In preparing steep water for laboratory batch steeps, lactic acid from 85% syrup must be diluted to 10% (w/w) and heated at 95°C for 24 h to obtain free lactic acid. Steep water solubles, developed as steep time increases, did not interfere with the analysis. Duplicated injections (64) of steep water gave an average coefficient of variation of less than 4% between duplicates for both lactic acid and sulfur dioxide. Coefficients of variation for pure sulfur dioxide and lactic acid solutions were less (2.2% and 0.2%, respectively). This HPLC method is rapid, precise, and suitable for automation.
Isolation and Partial Characterization of a Polysaccharide Gum from Cryptocarya wightiana Bark
Authors: Tharanathan R. N. , Susheelamma N. S. , Reddy G. Changala , Joseph Cibia
Published: November 2006

The present investigation describes the isolation and partial characterization of a gummy polysaccharide derived from the bark powder of Cryptocarya wightiana tree. The isolated polysaccharide is highly viscous, exhibits ‘pituity’ characteristics, and is composed of arabinose and xylose in 6:1 ratio, respectively. Preliminary fractionation by precipitation with alcohol gave four fractions of varying compositional and viscosity characteristics. The major fraction (58%) was composed of arabinose and xylose in 5:1 ratio, respectively, together with an unidentified peak (∼21%) coeluting at the ascending part of the arabinose peak. The gum has potential applications both in food and non‐food industries.
Molecular Depolymerization of Moist Sweet Potato Starch Melt by Shearing Force under an Elevated Temperature
Authors: Fujio Y. , Igura N. , Hayashi N. , Haykawa I.
Published: November 2006

Sweet potato starch (SPS) with 20 or 25% moisture was heated and then fused at 150°C for 15 min under pressurization at 30–500 Kg/cm2. At the same time, the heated SPS melt was extruded through a capillary tube under specified pressure in order to give shearing force. Thus, intact SPS, heated SPS and heated sheared SPS specimen were prepared and examined. The heated and heated sheared SPS did not contain any pyrolysis products because their spectrum profiles were the same as that of intact SPS. By heating and shearing, the intact SPS molecule was depolymerized into small molecules including a few amount of glucose. This finding was revealed by means of molecular weight estimation by viscometry and by gel filtration. The shearing toward SPS melt markedly stimulated the depolymerization while the effect of only heating on depolymerization of SPS was modulate in comparison with heated shearing. Water solubilities of intact SPS, heated SPS and heated sheared SPS with 20% moisture were 0.07, 3.5 and 51.5% respectively, and also the degrees of gelatinization of 1.8% for intact starch increased markedly to 29% for heated SPS and 80–95% (depending on the pressure at extrusion) for heated sheared SPS.
The Study of Melting Temperature and Enthalpy of Starch from Rice, Barley, Wheat, Foxtail‐ and Proso‐millets
Authors: Fujita S. , Fujiyama G.
Published: November 2006

Endosperm starch granules prepared from rice, barley, wheat, foxtail‐and proso‐millets were analyzed by Differential Scanning Calorimetry (DSC) and the relationship between melting temperature and enthalpy for starch gelatinization was discussed. Peak temperature for gelatinization (Tp) ranged from 57 to 80°C and enthalpy from 6.4 to 15.6 J/g. Starch from rice, barley, foxtail‐ and proso‐millets which has a waxy phenotype, has shown a correlation between Tp and enthalpy, while that of wheat has not.
Chemical Factors Affecting Acetylation of Cassava Starch
Authors: Aiyeleye F. B. , Akingbala J. O. , Oguntimein G. B.
Published: November 2006

The effects of liquid‐starch ratio, concentration of sulphuric acid, and glacial acetic acid on the degree of substitution of acetylated cassava starch were investigated. The optimum liquid starch ratio was 2.5. The degree of substitution increased rapidly with sulphuric acid concentration up to 0.36m at a liquor‐starch ratio of 2.5. The optimum concentration of glacial acetic acid at liquor‐starch ratio of 2.5 and 0.64m sulphuric acid was 13.9m with a reaction efficiency of 88%. The acetylated cassava starch was more soluble than the native cassava starch.
Herstellung und thermische Eigenschaften hochsubstituierter Benzylstärken
Authors: Braun Dietrich , Stipp Gabriele
Published: November 2006

Stärke kann in alkalischem Medium mit Benzylchlorid zu Benzylstärken mit unterschiedlichen Substitutionsgraden umgesetzt werden. In wäßrig‐alkalischem Medium werden Benzylstärken mit einem maximalen Substitutionsgrad von 0,9 erhalten. Im wasserfreien Medium erzielt man höhere Substitutionsgrade. Die höchsten Substitutionsgrade (2,9–3,0) werden bei Umsetzungen von in Dimethylsulfoxid (DMSO) gelöster Stärke mit festem Natriumhydroxid und mit Benzylchlorid erhalten. Niedrigere Substitutionsgrade (max. 2,7–2,8) ergeben sich in homogenem Medium, wenn eine Lösung aus Natriumhydrid/DMSO mit in DMSO gelöster Stärke mit Benzylchlorid umgesetzt wird. Durch Herabsetzen der Benzylchloridkonzentration können hierbei gezielt Benzylstärken mit niedrigeren Substitutionsgraden erhalten werden.

Die Glastemperaturen von Benzylstärken mit Substitutionsgraden über 2,5 liegen bei ca. 45–55°C. Mit abnehmendem Substitutionsgrad wird ein Anstieg der Glastemperatur bis über 70°C beobachtet. Der Schmelzbereich der Benzylstärken liegt zwischen 150‐180°C; dabei beginnt allerdings auch bereits die Zersetzung.
Enzymatic Degradation of Polydextrose® and of a High‐Molecular Polydextrose Fraction
Authors: Richter Manfred , Grossklaus Rolf , Boczek Peter
Published: November 2006

The enzymatic degradation of the alternative carbohydrate, Polydextrose® (PD) and of a high‐molecular fraction of PD (PD‐D) obtained by dialysis was studied. The reaction products were measured by thin‐layer chromatography (TLC) and high‐pressure liquid chromatography (HPLC). Taking into account the experimentally determined extraneous activity of enzymes, a digestibility of 22.5% was measured under in vitro conditions. This digestibility was brought about primarily by glucoamylase activity. The results also served to demonstrate contemporary concepts of the structure of PD which, instead of an arbitrary one, proposes a defined arrangement of α‐glucosidic 1,4 and 1,6 bonds within structurally different segments of the PD molecule. It has been documented by in vivo studies that the digestibility of PD in the small intestine is obviously based on the interaction of a number of substrates and enzymes and can be influenced by the composition of the diet.
Automatisierte enzymatische Bestimmung von Glucose, Maltose und Stärke auf Mikrotiterplatten
Authors: Richter M. , Tietz U. J.
Published: November 2006

Es wird eine automatisierte Methode zur Zucker‐ und Stärkebestimmung beschrieben. Die Eliminierung methodisch bedingter Fehler bei der optischen Vermessung der Mikrotiterplatte sowie die Auswertung der 96 Rohdaten erfolgt mit dem Softwareprogramm „LBR1993”︁. Die Analytik basiert auf einer 10minütigen Substrathydrolyse durch Glucoamylase bei Zimmertemperatur und Bestimmung der Glucose mit der GOD‐PAP‐Methode. Eine Wiederfindungsrate größer 99% sowohl für Mais‐ als auch für Kartoffelstärke wird erreicht, wenn die Stärke bei 100°C durch α‐Amylase in α‐Dextrine umgewandelt und diese nachfolgend mit 8,88 g Glucoamylase/g Substrat verzuckert werden. Bei Kartoffelstärke führt das Dispergieren in 1 N Natronlauge bei Zimmertemperatur zu einer Wiederfindungsrate von 93%. Das Erhitzen (60°C) in 0.5 N Natronlauge (AFNOR‐Methode) ist zur Analyse von Zuckern sowie bestimmter Stärkearten ungeeignet.
Viscosity Behaviour of the Mucilage Extracted from Ruredzo (Dicerocaryum zanguebarium)
Authors: Benhura Mudadi A. N. , Marume Maud
Published: November 2006

The concentration of metal ions in the mucilage that is extracted from Ruredzo (Dicerocaryum zanguebarium) was determined by atomic absorption spectroscopy. Calcium, magnesium, potassium, iron, copper, lead and zinc were found to occur in concentrations ranging from 0.01 ppm for lead to 15 ppm for calcium. Cations were removed from solutions of the mucilage using Dowex 50W‐X12 resin and the viscosity of the decationized mucilage studied. Addition of CaCl2, NaCl and sucrose decreased the viscosity of the decationized mucilage but addition of sucrose resulted in an increase in viscosity. The effect of incubating the mucilage at various temperatures for up to 30 min before measuring the viscosity at 25°C was investigated. No change in viscosity was observed for samples incubated at 40°C and 60°C. 80°C incubation resulted in reduced viscosity. Solutions of the decationized mucilage exhibited maximum viscosity at pH 5.
Solubility Pattern and Recrystallization Behavior of Oat Starch
Authors: Shamekh S. , Forssell P. , Poutanen K.
Published: November 2006

The oat starch studied had a lipid content of 1,3% and amylose content of 29%. Based on the colorimetric assay, only 15% of the starch leached out from the native granules at 95°C was amylose, whereas 85% of the starch leached from the defatted granules was amylose. The solubilized amylopectin‐type material of native oat starch was of clearly lower molecular weight than most of the amylopectin in the original starch. The amylopectin recrystallization enthalpy of 50% native oat starch dispersion Id after gelatinization was 2J/g and that of defatted oat starch was 4J/g.
Comparative Study about Commercially Available Starches for High Shear and High Temperature Applications in Foods
Authors: Kuhn Klaus , Schlauch Sandra
Published: November 2006

The shear stability and heat resistence of hot starch pastes of more than 30 different commercially available starches has been evaluated. The shear experiments were carried out by a high shear system in the BOHLIN CS rheometer and in comparison outside the rheometer by treatment with a high shear mixer. Native starches are very sensitive against shear stress. The viscosity of non cross‐linked chemically modified starches was also decreased. It was not possible to find a correlation between the dependence of shear influence on the viscosity and the type of chemical modification. The high temperature measurements (up to 140°C) in principle showed 3 categories of viscosity development. Firstly, a category, where the viscosity breaks down, secondly, a category where the viscosity remains constant and a last category where the viscosity will be built up during the heating period. No direct dependence on the chemical modification could be observed with respect to the viscosity development.
Physicochemical Properties of Jacatupé (Pachyrhizus erosus L. Urban) Starch
Authors: De A. Mélo Enayde , Krieger Nádia , Stamford Tâania Lúcia Montenegro
Published: November 2006

The physicochemical properties of the starch extracted from Jacatupé (Pachyrhizus erosus L. Urban) were studied. The small‐sized granules (approximately <10μm long) present varying geometric forms: round, cupoliform and convex‐biconcave shaped granules predominate. The amylose content is 23% and crystallinity pattern is type A. Values for intrinsic viscosity and absolute density are similar to those for cassava (Manihot utilissima) starch. Extraction and purification procedures are easy to perform. Root productivity is high (50t/hectare). According to these results, Jacatupé roots can be considered a new alternative source for starch production.
Gelation of Amylopectin without Long Range Order
Authors: Cameron Ruth E. , Durrani C. Matin , Donald Athene M.
Published: November 2006

Weak amylopectin gels have been formed directly following dissolution of waxy maize granules. Rheological characterisation of these gels has been carried out as a function of stress and frequency. The gels are visually clear and homogeneous, and environmental scanning electron microscopy shows no trace of the original granules remaining. It is postulated that the origin of the gel network lies in pairwise aggregation of outer chains of the amylopectin molecules, presumably via double helix formation. However, these pairs of chain segments do not aggregate to develop crystallinity.
A Study on Reaction Influencing Factors in Carboxymethylation of Leucaena glauca Seed Gum
Authors: Raval D. K. , Patel S. P. , Patel R. G. , Patel V. S.
Published: November 2006

Sodiummonochloroacetate and sodiumhydroxide were employed under different conditions to prepare and optimize the carboxymethyl derivative of Leucaena glauca seed gum. The effects of concentration of reactants, reaction temperature and time have been interpreted in terms of degree of carboxymethylation as well as efficiency and rate of carboxymethylation reaction. The formation of the proposed derivative has also been supported by providing infra‐red spectral characterization.
Improved Reaction Conditions for Preparation of β‐Cyclodextrin (β‐CD) from Cassava (Manihot esculenta Crantz) Starch
Authors: Raja K. C. M. , Ramakrishna S. V.
Published: November 2006

Experimental conditions for bioconversion of starch to get higher yield of ß‐cyclodextrin using cyclodextrin glycosyl transferase (CGT‐ase) (EC 2.4.1.19) were worked out. A 5% initial starch concentration gave ß‐CD yield of 20‐28% that could be separated as ß‐CD bromobenzene complex from the reaction mixture. Addition of bromobenzene during the second phase of the reaction, i.e. CD formation phase, was found beneficial.
Starch and Amylopectin — Rheological Behavior of Gels
Authors: Bello‐Pérez L. A. , Paredes‐López O.
Published: November 2006

Rheological behavior of starch and amylopectin gels was evaluated by small amplitude oscillatory testing using the storage modulus (G′), loss modulus (G″) and the complex viscosity (n*). It was found for the three starches (normal and waxy corns, and amaranth) that at low frequency the viscous component G″ had a major contribution on the gel structure than the elastic G′ and that the complex viscosity (n*) diminished when the frequency was increased. Amaranth amylopectin showed G″ values higher than those of G′. Corn commercial and waxy corn amylopectins presented a similar behavior in the G′ values. Normal corn amylopectin gave the highest complex viscosity values.
Structure and Chemical Properties of Partially Heated Corn Starch Granules
Authors: Sahai Deepak , Jackson David S.
Published: November 2006

Partially heated (65°C) normal dent corn starch granules (5% aqueous suspensions) were fractionated according to granule size and apparent density. The fractions obtained were individually characterized by high performance size exclusion chromatography (HPSEC), differential scanning calorimetry (DSC), X‐ray diffraction, scanning electron microscopy and enzymatic susceptibility. Heat damaged granules were concentrated in a single fraction. The heat damaged fraction was highly susceptible to degradation by amyloglucosidase. HPSEC profiles of fractions showed differences in apparent solubility of amylose and amylopectin. The heat damaged fraction showed a high temperature (85°C) gelatinization endotherm in a DSC, indicating melting of double helices, but showed a V type X‐ray diffraction pattern. Starch granules exhibited different responses to heat because of inherent heterogeneity in their native state.
Reaction of Starch and Cellulose with Products of Thermal Decomposition of Mono‐ and Disaccharides
Authors: Tomasik Piotr , Jane Jay‐Lin
Published: November 2006

D(—)‐Fructose, dextrose and sucrose were thermally decomposed in the presence of native and pregelatinized corn starch, cellulose as well as its mixtures with native corn starch. Several products were obtained in which reactive intermediates thermally generated from lowmolecular saccharides were involved. When starch either was not gelatinized or it could not gelatinize on reaction, the preference for the formation of a physical mixture of caramel with starch and starchsugar complexes was observed. Otherwise products of substitution of starch with reactive intermediates and inclusion complexes were formed. Cellulose appeared to be more reactive. It was grafted to starch by reactive intermediates thermally generated from dextrose.
Extraction of High Amylose Starch from Wrinkled Peas
Authors: Meuser Friedrich , Pahne Norbert , Möller Matthias
Published: November 2006

In Europe, the extraction of starch from wrinkled peas is interesting in economic terms as it would enable a high amylose starch to be isolated from a native raw material. Extraction of starch from wrinkled peas with a high yield and purity does, however, make high demands on the mechanical processing of the raw material. For this reason, studies were carried out with the aim of developing processing parameters with which a suitable disintegration of the raw material could be achieved. This included an investigation into the influence of the way the raw material was prepared and its disintegration. Based on the results of these investigations, a process was developed in which wrinkled peas were steeped in warm water, then hulled using rubber rollers in order to separate the husks from the cotyledons. This was followed by gentle particle size reduction of the cotelydons and high‐pressure disintegration of the screened out protein/starch fraction suspended in the process water. This process enabled up to 89% of the starch present in the wrinkled peas to be extracted, with a residual protein content of around 1%, and by‐product fractions containing a high concentration of the constituent characterising them to be obtained.
Effects of Solutes on Retrogradation of Stored Starches and Amylopectins: A Calorimetric Study
Authors: Bello‐Pérez L. A. , Paredes‐López O.
Published: November 2006

Starch and amylopectins from different sources were studied to know their calorimetric behavior when mixed with sucrose, glucose and sodium chloride to different concentrations, and stored to different times. It was found that for control samples of amaranth, waxy and normal corn starches slight changes in enthalpy values were observed. The three starches presented retrogradation endotherms, in the presence of sugars, after 2 storage weeks with low enthalpy values; these values tended to be higher by decreasing sugar concentration. The effect of sodium chloride on starch retrogadation was different to that of sugars; waxy corn starch did not show enthalpy values at all experimental conditions. theories on retarding effect of sugars have been proposed but the effect of salt on retrogradation until now is difficult to explain. Amylopectin in the presence of sucrose showed retrogradation endotherms after 3 storage weeks and with glucose after 4 weeks, except potato amylopectin which did not exhibit this trend at any tested condition. With sodium chloride all amylopectins presented retrogradation endotherms after 4 weeks. The different behavior of amylopectins with solutes could be explained by the different chain distribution in such macromolecules.
Physicochemical Changes in Cassava Starch and Flour Associated With Fermentation: Effect on Textural Properties
Authors: Numfor Festus A. , Walter William M. , Schwartz Steven J.
Published: November 2006

Physicochochemical changes in cassava starch and flour associated with fermentation were investigated and related to textural properties of its flour pastes. Cyanide and pH decreased, while crude protein, acidity, and apparent amylose content increased in the fermented products. Average starch granule diameter, solubility, and swelling power were depressed, while gelatinization enthalpy increased. Amylograph of starch showed increased peak visocity temperature, reduced peak, breakdown, and setback viscosities, while Texture Profile Analysis showed a decreased in hardness, cohesiveness, elasticity, and gumminess of the fermented flour paste. The altered textural properties were attributed to greater starch granule stability due to short amylose‐like fragments formed by enzymatic hydrolysis of amylopectin.