bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular Composition of Starches from Growing Potato Tubers
Authors: Praznik W. , Burdicek G. , Beck R. H. F.
Published: November 2006

The changes in the molecular distribution of potato starch during the growth of tubers is determined by GPC (Sephacryl gel systems). After n‐butanol fractionation of amylose and amylopectin an efficient statement of the molecular weight alteration of the starch components is observed. Amylopectin of young immature tubers shows a narrow highmolecular weight distribution whereas the amylopectin of mature tubers have a broader distribution with low‐ and highmolecular weight portions. Also the branched structure is different regarding starch of small and big tubers. Amylose shows a continous increase of the molecular weight. The range up to 0.2 · 106 Dalton is diminished, the molecular weight range over 1.2 · 106 Dalton is increased. The range in between rests nearly constant. These changes in the molecular composition are observed by different potato varieties, Conny and Sieglinde. Clear differences between the amyloses and amylopectins of these two varieties are noticed. The starch components of Sieglinde have always lower molecular weights as Conny starches, just so the overlapping range is much broader.
An Evaluation of Cassava Starch as a Gelling Material for Electrochemical Salt Bridges
Authors: Iwunze M. O. , Nnodimele R. A.
Published: November 2006

Cassava starch was investigated for its potential use as a gelling material for electrochemical salt bridges. Different electrolytes, KCl, NH4 and NH4NO3, were mixed with the starch and the resulting voltage of a Zn–Cu Cell in which it is used as a salt bridge was measured. The observed voltage agreed with the theoretical voltage within 3.6% error. It was observed that the starch and ammonium nitrate electrolyte produced a better blend, gave more reproducible values and has the lowest resistance of all the other electrolyte‐starch mixtures.
Tepary Bean Starch. Part I. Physico‐chemical Properties
Authors: Abbas I. R. , Berry J. W.
Published: November 2006

Starch of high purity was isolated by a simple procedure from tepary beans (Phaseolus acutifolius var. latifolius). Granules were spherical to oval with a birefringence pattern similar to that of other legume starches. Under SEM they appeared smooth with no evidence of fissures. They showed a normal distribution of diameters with a range of 15.5–59.8 μ and a mean of 33.5 μ. Tepary starch had an amylose content of 30.7% and a gelatinization temperature range of 70.5–84.0°C. Other properties were also determined. Fractionation provided an amylose fraction with a β‐amyloysis limit of 76.3% and an average DPη of 618. The amylopectin fraction had an average magnified image values of 33, 22 and 10 glucose units respectively.
Studies on the Application of Maltogenic Amylase in the Production of Maltose Containing Syrup
Authors: Słomińska L. , Starogardzka G.
Published: November 2006

The thermostable and relatively acid stable maltogenic amylase produced by Bacillus stearethermophilus was investigated. (The investigations have been carried out with the aim of producing high maltose syrup from liquefied potato starch. The results of the investigations showed that the application of the maltogenic enzyme made possible to produce potato syrup containing 70–80% maltose from DE 12 enzyme liquefied starch in concentration of 30–35%.
Graft Polymerization of Acrylamide onto Starch Using Ferrous‐Starch Thiocarbonate‐Persulphate Redox System
Authors: Bayazeed A. , Farag S. , Hebeish A.
Published: November 2006

Graft copolymerization of acrylamide (Aam) onto starch using ferrous‐starch thiocarbonate‐persulphate redox system was investigated under different conditions including alkali concentration in the precarbon disulphide treatment, potassium persulphate concentration, ferrous ion concentration, monomer concentration, pH of the polymerization medium, polymerization temperature, use of solvent/water mixture instead of aqueous medium, and liquor ratio. The role of thiocarbonation on the magnitude of grafting of acrylamide onto starch has been studied with respect to K2S2O8 and ferrous ion concentrations. The graft yield was significantly favoured in acidic medium as well as by increasing the persulphate concentration, acrylamide concentration, and polymerization temperature. Carbon tetrachloride constitutes the optimal medium for polymerization. Grafting was also favoured in either higher or lower liquor ratios.
GPC‐Analyse von Stärkepolysacchariden
Authors: Praznik W.
Published: November 2006

Eine kurze Darstellung der bisher in der Literatur beschriebenen Trennsysteme für die Analytik und molekulare Charakterisierung von Stärkepolysacchariden wird gegeben. Die von uns verwendeten bzw. weiterentwickelten Trennsysteme, die sich durch hohe mechanische Stabilität auszeichnen und auch im hochmolekularen Trennbereich reproduzierbare Ergebnisse liefern, werden vorgestellt. Für die Bestimmung der molekularen Verteilung mittels GPC muß eine Kalibrierung der Säulensysteme durchgeführt werden. Synthetische Amylosen und Dextrane, die sich jedoch strukturell unterscheiden, können zur Eichung herangezogen werden. Ihr unterschiedliches Trennverhalten und ihre Anwendbarkeit als Eichsubstanzen werden diskutiert. Es werden Zusammenhänge zwischen strukturellem Aufbau und molekularer Größe in Bezug zum Trennverhalten der Polysaccharide festgestellt. Statistische, rechnerische Verfahren erlauben sowohl eine Bestimmung der quantitativen Zusammensetzung der Stärken als auch die Bestimmung der mittleren Molekulargewichte (Zahlen und Gewichtsmittel) sowie der molekularen Uneinheitlichkeit von Stärkepolysacchariden. In Folge werden Anwendungsbeispiele aufgezeigt, die von der Grundlagenforschung (z. B. strukturelle Untersuchungen) über die Verwendung bei der Pflanzenzüchtung (Sortenwahl), bis hin zur Beurteilung von nativen und modifizierten Stärken im technologischen und pharmazeutischen Bereich reichen.
Some Studies on Modified Starch for Low Humidity Application
Authors: Hari P. K. , Bhalla S.
Published: November 2006

Starch was chemically modified by substitution with hydroxyethyl groups to three levels (0.05, 0.1, 0.15 molar substitution) to reduce the brittleness of starch film for low humidity application. Substitution with hydroxyethyl groups reduced the density and sonic modulus and increased the moisture regain of the film. The brittleness of hydroxyethyl starch film at low humidity is reduced as the flexural rigidity, intermolecular friction, tensile modulus and breaking strength is decreased and breaking extension is increased.
The Effect of Physical Damage on Large and Small Barley Starch Granules
Authors: Stark J. R. , Yin X. S.
Published: November 2006

Barley starch from a Scottish brewing barley (Golden Promise) has been isolated, purified and fractionated into two populations according to the granule sizes. The effects of physical damage on the two types of granules have been examined by iodine staining, debranching, gel chromatography, viscosity measurements and scanning electron microscopy. The amylose content of large starch granules was slightly greater than that of the small granules and the effect of physical damage did not differ significantly between the two types of granules. Physical damage to both types of granules in the dry state followed by extraction with cold water resulted in the preferential solubilization of low molecular weight amylopectin.
A New Method to Short the Steeping Period of Corn Grains
Authors: Hassanean A. , Abdel‐Wahed A.
Published: November 2006

It was found that steeping of corn grains by circulating the corn grains with the steeping liquor is more efficient for removing the water‐soluble components and decreasing the steeping period compared to the usual counter‐current method.
Purification and Characterization of Extremely Thermostable Exo‐oligo‐1,6‐glucosidase from a Caldoactive Bacillus sp. KP 1228
Authors: Suzuki Y. , Fujii H. , Uemura H. , Suzuki M.
Published: November 2006

A p‐nitrophenyl‐α‐D‐glycopyranoside‐hydrolyzing oligo‐1,6‐glucosidase (dextrin 6‐α‐glucanohydrolase, EC 3.2.1.10) of a caldoactive Bacillus sp. KP 1228 capable of growing at 51–82°C was purified to homogeneity. The molecular weight was estimated as 140,000. The enzyme consisted of two identical subunits each comprising a threonine residue at the NH2‐terminus. The enzyme was most active at 85°C and pH 5.1, and stable for 10 min up to 85°C at pH 6.8. The enzyme had no antigenic determinant common to oligo‐1,6‐glucosidases from Bacillus cereus ATCC 7064 (mesophile), Bacillus coagulans ATCC 7050 (facultative thermophile) and Bacillus thermoglucosidasius KP 1006 (DSM 2542) (obligate thermophile). A strong correlation between the increase in proline content and the rise in thermostability of these 4 proteins was observed.
Alkaline Degradation of Monosaccharides Part VIII. A13C NMR Spectroscopic Study
Authors: De Bruijn J. M. , Touwslager F. , Kieboom A. P. G. , van Bekkum H.
Published: November 2006

The analysis of alkaline degradation products of monosaccharides has been performed by 13C NMR spectroscopy. The 13C chemical shifts of several carboxylic acids produced by alkaline degradation of monosaccharides have been determined. The application of these data to the identification and quantification of products in an alkaline degradation mixture of D‐glucose is presented. Carboxylic acid products up to 6 carbon atoms have easily been identified in such complex reaction mixtures. Furthermore, information on the different functional groups present in the oligomeric reaction products has been obtained from the alkaline degradation of 1‐13C‐D‐glucose.
Mobility of Water in Corn Starch Suspensions Determined by Nuclear Magnetic Resonance
Authors: Richardson S. J. , Baianu I. C. , Steinberg M. P.
Published: November 2006

The mobility of water in corn starch suspensions and high‐moisture powders (10 to 70% corn starch) was investigated by Nuclear Magnetic Resonance (NMR) spectroscopy, in water and deuterium oxide. Both oxygen‐17 (17O) and deuterium (2H) nuclei were probed with a single pulse. The standard isotropic two‐state model with fast exchange was used to interpret these data by means of a physical model (I) and a chemical activity model (II). According to I plots of relaxation rate against concentration indicated three regions of decreasing water mobility. According to II, the relaxation rate was linear with chemical activity over the entire concentration range. The correlation time calculated for the bound water showed high mobility.
Effects of Water Stress on Starch and Sucrose Metabolism in Cotton Leaves
Authors: Chang Ch. W. , Ryan R. D.
Published: November 2006

Studies of starch and sucrose metabolism as influenced by water stress in cotton plants (Gossypium hirsutum L.) have been meager. Therefore, metabolic enzyme activities and metabolites from well hydrated control and partially dehydrated plants were analyzed. Water stress decreases cotton leaf starch content directly by enhancing α‐amylase activity and indirectly by altering sucrose metabolism. In inhibition of sucrose synthetase causes an sucrose in the cytoplasm and also contributes to excess orthophosphate amassment in the chloroplasts. Orthophosphate inhibits ADP‐glucose pyrophosphorylase activity which is responsible for starch synthesis in the chloroplasts. The generally accepted metabolic relationship that leaf starch content is indirectly controlled by sucrose phosphate synthase activity was not observed.
Production of Ethanol from Tapioca (Manihot esculenta Crantz)
Authors: Srikanta S. , Jaleel S. A. , Sreekantiah K. R.
Published: November 2006

Ethanol production from fresh tubers, flour and starch of tapioca was studied by simultaneous saccharification and fermentation procedure. A 20% enzyme‐liquefied slurry showed about 2–3% reducing sugars, which increased to 10% on enzymic saccharification for 4h. Alcoholic fermentation of this hydrolysate with Saccharomyces cerevisiae, Var. ellipsoideus, yielded 8–9% alcohol showing about 95% fermentation efficiency. Large scale fermentation of tapioca flour by this process also showed fermentation efficiency of 90% thereby indicating the economic viability of the process.
Hafer, Gerste und Triticale — Eigenschaften und Chancen für die technische Stärkegewinnung
Authors: Wilhelm E. , Kempf W.
Published: November 2006

Die Entwicklung von Verfahren zur Gewinnung neuer Rohstoffe aus Agrarerzeugnissen für chemische und technische Anwendungsgebiete ist ein Schwerpunkt im Forschungsprogramm „Nachwachsende Rohstoffe”︁ des Bundesministeriums für Ernährung, Landwirtschaft und Forsten. Hafer, Gerste und Triticale wurden in vergleichenden Untersuchungen auf die Möglichkeiten der technischen Stärkegewinnung geprüft. Dabei standen der Vermahlungsprozeß und Verfahren zur Trennung von Stärke, Protein und Faser im Vordergrund, mit Auswasch‐, Sieb‐ und Zentrifugier‐Techniken, die im technischen Maßstab realisiert werden können. Durch Absenken des pH‐Wertes der Prozeßwässer bis zum isoelektrischen Punkt und Abtrennen der Proteine wurden die CSB‐Werte um 50% reduziert. Stärken mit hohen Feinkorn‐Anteilen werden für neue technische und chemische Derivate Bedeutung erlangen. Methoden zur Anreicherung und Isolierung von Feinkornfraktionen wurden erprobt und durch Rasterelektronenmiktroskopie kontrolliert. Die Stärken zeigten Unterschiede im Verhalten gegenüber Alkalibehandlung und in den Viskositätscharakteristika.
Novel Technique for Saccharification of Cassava Fibrous Waste for Alcohol Production
Authors: Srikanta S. , Jaleel S. A. , Ghildyal N. P. , Lonsane B. K. , Karanth N. G.
Published: November 2006

A novel technique, involving the hydrolysis of starch present in cassava fibrous waste in shallow layers in stainless steel trays, is developed to facilitate the use of higher slurry concentrations. The use of slurry containing 30% solids, 4% sulphuric acid, 30 min saccharification time at 121°C resulted in the complete conversion of the starch into reducing sugars. The spent residue, after separation of the hydrolysate, contained about 24% of the total sugars formed and these were recovered to the extent of 90–94% by using a counter‐current extraction technique. A large scale saccarification of a 75 kg batch gave 75 1 pooled hydrolysate containing 15% reducing sugars. An overall process efficiency of 76.4% was observed with the fermentation of hydrolysate pooled with the counter‐current extract for alcohol production. However, fermentation of the whole saccharified pulp without the separation of the hydrolysate and acid‐enzyme hydrolysis of the waste gave lower efficiencies.
Physico‐chemical Properties of Sorghum Starch Thermally Treated by Different Methods
Authors: Glennie C. W.
Published: November 2006

Separate samples of sorghum were pressure cooked, extruded and popped and the physico‐chemical properties of the starches compared. Pressure cooking and extrusion increased the water solubility of the samples more than did popping. Popping lead to a significant increase in beta‐amylase susceptibility. Gel permeation chromatography revealed a decrease in starch molecular weight after both extrusion and popping.
Estimation of Phosphorus in Native and Modified Starches. Improvement in the Molybdovanadophosphoric Acid Method
Authors: Singh Vasudeva , Zakiuddin Ali S.
Published: November 2006

The spectrophotometric method for estimation of phosphorus based on molybdovanadophosphoric acid complex has been improved for its sensitivity (8–10 fold) by reducing the reagents concentrations to one‐third and measuring the absorbance at its λ max (355 nm). The range of the method is brought down to 0.5 μg to 7 μg/ml for 1 cm light path. Phosphorus content of potato starch remained unchanged upon acid modification or oxidation with hypochlorite. Maize and tapioca starch, on the other hand, lost about 30–40% of their phosphorus upon acid modification. The difference probably lays in the state of phosphorus in the respective starch granules.
Properties of Residual Maize Starches Following Acid Hydrolysis
Authors: Inouchi N. , Glover D. V. , Fuwa H.
Published: November 2006

The properties of residual starches following initial acid hydrolysis were investigated. Starch granules of several endosperm mutants of maize, namely opaque‐2 (o2), amylose‐extender; opaque‐2 (ae o2), waxy; opaque‐2 (wx o2), dull; opaque‐2 (du o2), and sugary‐2; opaque‐2 (su2 o2) were used. Initial rate of hydrolysis for su2o2 was fastest and that for aeo2 was slowest. Following the acid hydrolysis by the enzymatic and chromatographic method, in the initial phase of hydrolysis amylose was preferentially hydrolyzed in the starches, except in the case of wx o2. In the case of wx o2 the long B chains of amylopectin were preferentially hydrolyzed. The rate of decrease in chain length of ae o2 was relatively fast and that of su2o2 was slow. Fine structures of amorphous regions in these starch granules are discussed.
Synthesis and Applications of Reactive Carbohydrates Part I: Behaviour of Carboxymethyl Starch Before and After Acid Hydrolysis Toward Grafting with Acrylamide
Authors: Bayazeed A. , Higazy A. , Hebeish A.
Published: November 2006

Carboxymethyl starch (CMS) was subjected to acid hydrolysis at 50°C for different periods of time. The CMS sample and the hydrolyzed CMS samples were then subjected to two independent reactions, namely grafting with acrylamide using K2S2O8 as initiator and oxidation using K2S2O8 under the grafting condition but in absence of the monomer. The samples were analyzed for copper number and carboxylic content before and after these two reactions. Acid hydrolysis resulted in creation – in CMS structure – of aldehydic groups which underwent partial conversion to carboxylic groups during drying. Grafting reduced significantly the copper number and so did the oxidation. The latter increased the carboxylic groups but grafting exerted opposite effect. Hydrolysis of CMS for shorter or longer periods of time enhanced the susceptibility of CMS during the initial stages of grafting. The opposite held true for the later grafting stages. Methylolation and application of grafted prehydrolyzed CMS to cotton fabrics were reported.
Chain Length Distribution of Amylopectins of Double‐ and Triple‐Mutants Containing the Waxy Gene in the Inbred Oh43 Maize Background
Authors: Fuwa H. , Glover D. V. , Miyaura K. , Inouchi N. , Konishi Y. , Sugimoto V.
Published: November 2006

Starch granules were isolated from mature kernels of double‐ and triple‐mutant combinations of the waxy (wx) gene with other starchmodifying genes in the inbred Oh43 maize background. The amylose content and the distribution of unit chain‐length of amylopectin were determined by enzymatic‐chromatographic methods. Starches of the mutants containing the wx gene comprised 100% amylopectin. Amylopectin of the amylose‐extender;waxy (ae wx) mutant had an increased proportion of long B chains and decreased proportion of short B chains, compared with wx amylopectin, whereas amylopectin of the dull;waxy (du wx) mutant had a decreased proportion of long B chains and an increased proportion of short B chains. Therefore, the ae wx and du wx mutants amylopectins were novel. The A:B chain ratios for amylopectins examined, namely for ae wx, amylose‐extender;waxy;floury‐2 (ae wx fl2), amylose‐extender;waxy;sugary‐1 (ae wx su1), amylose‐extender;waxy;sugary‐2 (ae wx su2), brittle‐1;waxy (bt1wx). dull;waxy (du wx), and sugary‐2;waxy (su2wx) amylopectins, were in a range of 1.1 to 1.4 and similar to the wx amylopectin. Thus, starches of double‐mutant combinations of the wx gene with other starch‐modifying genes are good sources for elucidating the fine structure of amylopectin, in regards to long‐ and short‐B chains, which is affected by a single recessive gene coupled with the wx gene.
Chemical Modification of Starch via Reaction with Acrylamide
Authors: Khalil M. I. , Bayazeed A. , Farag S. , Hebeish A.
Published: November 2006

Reaction of starch with acrylamide was carried out under different conditions including reaction medium, catalyst, acrylamide concentration, reaction time and temperature as well as liquor ratio. Organic solvents, namely, isopropyl alcohol, dimethylformamide and cyclohexane alone and in admixture with water at different ratios were used as reaction medium. Catalysts used include sodium hydroxide, trisodium phosphate, sodium carbonate, sodium benzoate, sodium acetate and sodium formate. Acrylamide concentration ranged from 25% to 200%, based on weight of starch. The reaction was studied over a wide range of temperature and duration. Results obtained showed that the extent of reaction of starch with acrylamide is governed by each of these factors. Furthermore, this reaction yields mixed starch ethers, namely carbamoylethyl starch and carboxyethyl starch. Solubility, viscosity and moisture content of these starch ethers are determined by the sum of the amide and carboxyl contents.
Synthesis and Applications of Reactive Carbohydrates Part II: Graft Polymerization of Starch and Hydrolyzed Starches with Acrylamide
Authors: Higazy A. , Bayazeed A. , Hebeish A.
Published: November 2006

Starch and different hydrolyzed starch samples were subjected to two independent reactions, namely, grafting with acrylamide using K2S2O8 as initiator and oxidation with K2S2O8 under the grafting condition but in absence of the monomer. Copper number and carboxylic group measurements showed that both grafting and oxidation decrease outstandingly the copper number of the hydrolyzed samples and diminish completely the copper number of the original starch sample. On the contrary, grafting and oxidation cause significant enhancement in the carboxylic content, indicating partial conversion of the aldehydic to carboxylic groups under the oxidative action of K2S2O8; but it is certain that higher amounts of carboxylic groups are created in absence than in presence of acrylamide. Polymerization studies showed that the hydrolyzed starch samples are much more susceptible than the original starch sample toward grafting with acrylamide only during the initial stages of the reaction. Preliminary experiments describing introduction of methylol groups into the molecular structure of grafted sample and application of the methylolated product to cotton fabric were also reported.
Absorbents from Saponified Starch‐g‐poly (acrylonitrile‐co‐2‐acrylamido‐2‐methyl‐propanesulfonic acid). Some Practical Considerations
Authors: Fanta G. F. , Burr R. C. , Doane W. M.
Published: November 2006

Ceric‐initiated graft polymerizations of monomer systems containing 90–99 mole % acrylonitrile and 1–10 mole % 2‐acrylamido‐2‐methyl‐propanesulfonic acid onto gelatinized starch, followed by alkaline saponification of the polyacrylonitrile (PAN) moiety, were carried out under more practical conditions. Highest absorbencies of both water and 0.9% NaCl were obtained when starch was gelatinized either by stirring in water at 95°C or by jet cooking and when the temperature of the exothermic graft polymerization was not allowed to exceed 30°C. Saponifications should be run at the lowest practical polymer concentration and for a period of time somewhat longer than that required for loss of the red color characteristic of alkali‐treated PAN. Moreover, the alkaline saponificate should not be neutralized prior to methanol precipitation. Increased conversions of monomers to polymer were obtained by adding a second equal portion of ceric ammonium nitrate initiator.
Extrusion Cooking of Starches for Semi‐Products
Authors: Wiedmann W.
Published: November 2006

Extrusion cooking is introduced as a modern high‐temperature‐short‐time process. The cooking time at high temperatures is a matter of seconds, which has a favourable effect in maintaining the properties of the ingredients and active substances, while giving high rates for the destruction of micro‐organisms. The end‐products have a long shelf‐life on account of their low process moisture content. The quality of extruder‐cooked products depends on the extrusion system. The self‐cleaning co‐rotating twin‐screw extruder with its narrow residence time spectrum is the optimum system. However, the counter‐rotating intermeshing machine has certain advantages for products of low viscosity. Continuous extrusion cooking has economic advantages mainly because it replaces many batch processes and because extrusion is carried out entirely or almost entirely with the final moisture content, thus avoiding the necessity to evaporate huge quantities of water.
Biomolecular Modelling: An Interactive Program for the Visualization and Modelling of Carbohydrate (Starch and Oligosaccharide) Complexes in Solution
Authors: Neszmélyi A. , László E. , Holló J.
Published: November 2006

Computer aided molecular modelling has been used to study the solution‐conformation of various complexes of amylose. The preferred conformation of the complexes is determined by the HSEA Hard‐Spheres Exo‐Anomeric effect) method using the interactive computer program CAOS (Conformational Analysis of Oligosaccharides). NMR spectroscopy (nOe experiments, relaxation time measurements and the observation of local shielding) can follow and prove the conformation changes in solution.
Comparative Acid Modification of Various Starches
Authors: Singh Vasudeva , Ali S. Zakiuddin
Published: November 2006

Eight starches (maize, sorghum, finger millet, waxy and nonwaxy rice, chick pea, tapioca and potato) were acid modified with 0.5N HCl at 50°C. Alkali fluidity number (AFN) increased progressively with time of modification, and was highest in cereal followed by root, legume, and tuber starches. However, reduction in the number average molecular weight (M̄n) was in the reverse order. Potato starch had the highest M̄n, among the nonwaxy native starches and showed the greatest fall upon modification, whereas cereal starches had the least M̄n in native form and showed the least fall. In fact, there was a clear proportionality between the M̄n, of native starch and the extent of its hydrolysis under any given set of conditions. This relationship could be expressed by two intersecting lines, one for grains and one for root and tuber starches. When acid modified starches were recovered and dried without neutralization, hydrolysis still continued strongly in potato starch and slightly in tapioca, finger millet and sorghum starches. Other starches showed no change.
Measurement of the Starch Content of Commercial Starches
Authors: Moreels E. , Amylum N. V.
Published: November 2006

For the EC starch regulation 2169/1986 a minimum purity of 97% starch on dry substance is required to obtain the new end‐use refunds. Three different methods for the determination of starch were tested. Two polarimetric methods (EC L123/72, AOAC 14031‐032) and an enzymatic method (EC L158/86) were used to determine the high starch content of commercial unmodified starches. The results of a ring test between six laboratories shows that the AOAC method, solubilizing the starch in the presence of calcium chloride, has the smallest standard deviation. An explanation for the differences observed between the three methods is given, based on the sugar spectrum of the hydrolyzed starch. An independent ring test in France shows a modified enzymatic method, developed by AFNOR (the French standards organization) produces satisfactory results.
Studies on the Susceptibility of Granular Cassava and Com Starches to Enzymatic Attack Part I: Study of the Conditions of Hydrolysis
Authors: Franco Célia M. L. , Preto São José Dorio , Ciacco C. F.
Published: November 2006

In this research, the susceptibility of starch granules to enzymatic hydrolysis was studied. Cassava and corn starches were hydrolysed by bacterial α‐amylase with and without amyloglucosidase under several conditions of incubation. The highest percentage of hydrolysis was obtained in the presence of both enzymes. Elimination of the soluble hydrolysis products by dialysis increased the degradation of the starch granules, especially with cassava starch.
Studies on the Susceptibility of Granular Cassava and Corn Starches to Enzymatic Attack. Part 2: Study of the Granular Structure of Starch
Authors: Franco Célia M. L. , Ciacco C. F. , Tavares Débora Q.
Published: November 2006

The starch granules remaining after enzymatic hydrolysis were analyzed. Enzymatic corrosion efficiency was related to granule diameter. The intrinsic viscosity of enzymatically treated cassava and corn starches was gradually lowered by hydrolysis. X‐ray analysis and observation under a polarizing microscope suggested that enzymatic corrosion must occur in amorphous areas of the granules. Scanning electron microscopy showed that, for cassava granules, enzymatic corrosion occured mainly at the surface. Corn starch granules displayed considerable surface corrosion, as well as deep radial corrosion channels.
Molecules to Granules: A Comprehensive Starch Review
Authors: Zobel H. F.
Published: November 2006

The molecular composition and physical aspects of starch structure are examined in relation to starch properties and utility. The structures and molecular properties of amylose and amylopectin are further considered for their effects on properties of starch granules and pastes, and whether or not they act independently or in concert with one another. Discussion of amylopectin focuses on models featuring clusters of short chain molecules that are interlinked and regularly spaced. Low and wide angle X‐ray diffraction studies are cited to confirm the cluster model and the role of amylopectin in starch crystallinity. The diversity of starch is evident by its depostion in one or more sites within a plant and by the variety of plants in which the starch is found. In addition, starches differ widely in size, shape and composition.
Molecular Structure of Corn Starch
Authors: Takeda Y. , Shitaozono T. , Hizukuri S.
Published: November 2006

The molecular structures of corn starches, which were prepared from kernels steeped in water, and sulfite and alkaline solutions, and a commercial product from kernels of the same source, were investigated. The amyloses obtained were small molecules (number and weight average degrees of polymerization, respectively: 930‐990, and 2270–2550), and comprised nearly equal numbers of branched (5.3 chains on average) and unbranched molecules. The amylopectins had average chain lengths of 21–22 and ß‐amylolysis limits of 58–60%. Their relatively high iodine affinities (1.05–1.25 g/100 g) and chain length distributions suggested the presence of long B‐chains with widely spaced side chains. All the starches showed similar structures, but their phosphorus contents (5‐122 ppm) varied with the steeping conditions.
Simultaneous Solid Phase Fermentation and Saccharification of Cassava Fibrous Residue for Production of Ethanol
Authors: Jaleel S. A. , Srikanta S. , Ghildyal N. P. , Lonsane B. K.
Published: November 2006

A total of 16.5% reducing sugars in the saccharified pulp of cassava fibrous residue are achieved with the use of 30% slurry. The yield of ethanol was highest and the amount of residual reducing sugars was lowest with the use of 2.5% acid. The increase in dose of glucoamylase leads to improved yields of ethanol without any lowering in the residual reducing sugars. The ethanol yield and productivity were better and the residual reducing sugars were lower in solid phase fermentation as compared to the fermentation of liquid hydrolysate obtained by hydraulic pressing of the saccharified pulp. The slightly lower yield of ethanol in large batch static fermentation probably due to poor mass transfer and limited contact of yeast cells as well as enzyme with their substrates could be effectively overcome by employing appropriate strategies.
Effects of Attrition Milling on Air Classification Properties of Hard Wheat Flours
Authors: Sosulski F. W. , Nowakowski D. M. , Reichert R. D.
Published: November 2006

Effects of attrition milling on yield and composition of air‐classified fractions from fifth break and first middling flours of HRS wheat were investigated using image analysis to characterize flour particle size distributions. Roller‐milled flours had high proportions of particles < 45 μ diameter but particles > 105 μm diameter constituted most of the flour volume. Attrition milling caused less starch damage than pin milling but increased the degree of reduction (<45 μm diameter), based on volume, from 10.3 to 100% for fifth break and from 6.9 to 100% for first middling flours. Two cuts on the air classifier produced a high protein fraction with high ash (30.5% protein, 41% starch, 2% ash, 14% moisture basis), which would have application as a gluten substitute in baking, and a medium protein fraction (14% protein, 66% starch, 0.65% ash) which could be blended into Bakers Patent. The major fraction of air classified middlings flour contained 6.5% protein, 77% starch and 0.3% ash.
The Properties of Glucoamylase Soluble and Immobilized on DEAE‐Cellulose. Part I. Kinetics and Thermodynamics of Enzyme Reaction
Authors: Przybyt M. , Sugier H.
Published: November 2006

The hydrolysis kinetics of starch and maltose solution with soluble and adsorbed on DEAE‐cellulose glucoamylase were examined. The observed changes of kinetic and thermodynamic properties of enzyme in the course of its immobilization were tried to be explained on the ground of conformation changes of glucoamylase and diffusion limitation of starch.
Insect‐Damaged Wheat – Effects on Starch Characteristics
Authors: Lorenz K. , Meredith P.
Published: November 2006

Damage to the baking quality of wheat due to attack by insects has been reported in many countries. The insects responsible for the problem have been identified as Eurygaster integriceps and Aelia rostrata in Europe and the Near East and as Nysius huttoni in New Zealand. Damage to the protein in affected wheats in very apparent and damage to the starch seems possible. It was the purpose of this study to look for damage to the starch of wheat caused by specific insects.

At the flowering stage of wheat, cages were placed over the wheat plots and different insects were introduced and kept in the respective cages until harvest. Starch was isolated from affected wheats for determination of physico‐chemical properties and functional characteristics. Scanning electron micrographs showed that starch granule damage due to insect attack can be severe. However, the damage was confined to a rather small area around the bite mark. This damage was not extensive enough to cause adverse effects on physico‐chemical properties of the starch. Bread baking potential of the starch was not significantly affected.
Chemical Factors Affecting Preparation of Carboxymethyl Starch
Authors: Hebeish A. , Khalil M. I.
Published: November 2006

Preparation of carboxymethyl starch using chloroacetic acid and sodium hydroxide was investigated under different conditions. The carboxymethylation reaction was studied with respect to the degree of substitution (D. S.) of the carboxymethyl starch and the reaction efficiency (R. E.) of carboxymethylation variables studied included concentration of reactants and liquor ratio as well as reaction time and temperature. D. S. and R. E. were greatly enhanced by decreasing the liquor ratio. D. S. and R. E. increased also by increasing the reaction time. On the other hand, increasing the monochloroacetic acid concentration was accompanied by enhancement in the D. S. and decrement in the R. E., while both the D. S. and R. E. exhibited maximum values at 4N sodium hydroxide. The combined effect of increasing both monochloroacetic acid and sodium hydroxide concentrations was to bring about increased D. S. and decreased R. E. irrespective of the reaction temperature. Of particular interest were the results obtained at 100°C for 1 h; carboxymethyl starch of D. S. 0.436 with R. E. of ca. 79% could be achieved using solid reactants/liquor ratio of 1: 1.
The Properties of Glucoamylase Soluble and Immobilized on DEAE‐Cellulose. Part II. Thermostability of Glucoamylase
Authors: Przybyt M. , Sugier H.
Published: November 2006

The stability of glucoamylase as a catalyst of starch hydrolysis reaction against heat denaturation was examined for enzyme adsorbed on DEAE‐cellulose as well as in solution. The protective action of the substrate against inactivation of enzyme and the influence of the amount of enzyme adsorbed on its stability was studied.
Synthesis of Vinyl Polymer‐Starch Composites to Serve as Size Base Materials
Authors: Hebeish A. , El‐Alfy E. , Bayazeed A.
Published: November 2006

Starch was polymerized independently with acrylamide, acrylic acid, methacrylic acid and acrylonitrile (AN) using potassium persulphate (K2S2O8) as initiator. The products of the polymerization reaction consisted of free starch, grafted starch, homopolymer and oxidized starch. The ratios of these composite constituents were found to differ considerably depending upon the nature of monomer as evidenced by differences in viscosity curves (amylograph‐viscograph) as well as sizeability of the composites and their ease of removal from cotton yarns during desizing. Also studied was the dependence of the extent of polymerization (grafting and homopolymerization) of AN to starch on K2S2O8 and AN concentrations, polymerization temperature, starch/AN ratio and starch + AN/liquor ratio; and the onset of these factors on the apparent viscosity of the composite obtained thereof. Results indicated that the extent of polymerisation increased by increasing the persulphate concentration to 6 g K2S2O8/100 g starch then levelled off; the same held good for apparent viscosity but the latter decreased upon using concentrations higher than 6 g K2S2O8/100 g starch. While the extent of polymerization increased over a range of 8‐32g AN/100 g starch, apparent viscosity decreased. Raising the polymerization temperature from 30 to 60°C caused significant enhancement in the extent of polymerization but with the certainty that maximum apparent viscosity was attained at 50°C. The extent of polymerization was much favoured at higher AN ratio, but maximum apparent viscosity was attained at starch/AN ratio of 83:17. On the other hand, the extent of polymerization decreased by increasing starch + AN/liquor ratio upto 1:75 then remained almost constant upto a ratio of 1:12.5; meanwhile maximum apparent viscosity was observed at a material/liquor ratio of 1:7.5. The results were interpreted in terms of differences in the magnitude of constituents of the poly (AN) ‐ starch composite and their affinity for and swellability in water.
Influence of Germination on Physico‐chemical Properties of Amaranth Flour and Starch Microscopic Structure
Authors: Paredes‐López O. , Cárabez‐Trejo A. , Pérez‐Herrera S. , González‐Castañeda J.
Published: November 2006

A basic procedure was developed to germinate amaranth seeds (Amaranthus hypochondriacus). The “true” protein/total crude protein ratio decreased slightly after 36 h of germination. However, some of its rheological properties (e. g., farinographic and viscographic performances) were substantially improved by such simple treatment. Ultrastructural changes of the starch, as assessed by scanning electron microscopy, were also followed during this process. The smooth surface and dense packing of the starch in untreated seeds were outstandingly modified during germination. This procedure might contribute to widen the restricted food uses of this nutritious crop.
Extrusion Cooking of Cassava Starch for Ethanol Production
Authors: Grossmann M. V. E. , El‐Dash A. A. , Carvalho J. F.
Published: November 2006

Response surface methodology was used to study the effect of extrusion variables on gelatinization and viscosity of cassava starch with the aim to reduce energy consumption in alcohol production. None of the variables significantly affected the degree of gelatinization and moisture content of starch was the only significant variable affecting cold viscosity. Torque was affected by all the variables moisture being the most important. Extrusion was an efficient pre‐treatment for simultaneous saccharification and fermentation of cassava starch, resulting in 92.4% ethanol conversion. The best conditions for continuous process were: 100°C. 70 rpm, 4 mm die opening and 25‐27% moisture. For discontinuous process, when the extruded starch would be dried and ground 200°C, 190 rpm, 4 mm die opening and 20% moisture is recommended.
Presence of Starch/Protein Aggregates in the Endosperm of Corn
Authors: Goossens J. , Derez F. , Bahr K. ‐H.
Published: November 2006

It is common knowledge that the presence of so called “grits” and other structures in process streams of the corn wet milling process leads to starch yield losses by incomplete starch/gluten separation. The nature of these problematic structures was investigated by isolating them from the process streams and analysing their morphology by means of epifluorescence microscopy using specific dyes. Additional evidence was obtained by specific enzymatic degradation and subsequent microscopic observation. Using the same technique on thin cross sections from whole corn kernels, the location and source of these structures could be identified. Grits are dense particles from the horny endosperm, consisting of a three dimensional honeycomb like protein matrix filled with small starch granules. Many grits show the regular cell shape found in endosperm cells and are still enclosed by the fibrous cell wall. In other process streams, aggregates of protein lumps with trapped large and small starch granules occur frequently. A small fraction of fibrous material was also found to be enclosed in the protein matrix. These “sticky” aggregates often occur along with a large percentage of extremely small starch granules or fragments. Occasionally, very small “grits”‐like particles were present. Based on these findings, explanations can be found for the loss of starch and for the difficulties in the starch‐gluten separation stage in the industrial corn wet milling process.
The Development and Properties of the Tuber of the Potato (Solanum tuberosum) Part I: Variability of Tubers
Authors: Meredith P. , Meredith Peter
Published: November 2006

A series of studies that show the great variability of tubers between plants and within one plant. “Twinning”, the tendency for a plant to bear several tubers of similar size, is introduced, and a relationship between size and specific gravity of tubers is shown briefly.
Sugar and Sucrose Ester Effects on Maize and Wheat Starch Gelatinization Patterns by Differential Scanning Calorimeter
Authors: Buck J. S. , Walker C. E.
Published: November 2006

The gelatinization of various starch‐sugar‐sucrose ester combinations was examined by differential scanning calorimetry. Onset and peak temperatures and enthalpy of maize starch were higher in all cases than of corresponding wheat starch samples (67.8°C. 71.6°C and 2.42 cal/g vs. 59.1°C, 63.5°C and 1.94 cal/g, respectively). The addition of any of the three sugars tested, sucrose. glucose and fructose. at 50% of the starch weight increased onset and peak temperatures but decreased enthalpy required for gelatinization.

The addition of sucrose ester at 1 and 3% to the starches and starchsugar combinations affected both gelatinization temperature and enthalpy only in the case of the wheat starch/sucrose combination. With increasing ester concentration the onset and peak temperatures increased and the enthalpies decreased in this sample. This has interesting implications for the baking industry, which uses mainly wheat starch in combination with sucrose.
Effects of Hydroxypropylation on Themal Properties, Starch Digestibility and Freeze‐Thaw Stability of Field Pea (Pisum sativum cv Trapper) Starch
Authors: Hoover R. , Hannouz D. , Sosulski F. W.
Published: November 2006

Field pea starch with an amylose content of 34.2% was hydroxypropylated with propylene oxide and sodium hydroxide to give products with molar substitutions (MS) ranging from 0.04 to 0.12. Increasing the degree of MS resulted in progressive decreases in enthalpy of gelatinization. gelatinization temperatures, pasting temperatures and syneresis. and increases in paste viscosities at 95 and 50°C. The digestibility with a‐amylase decreased with increases in MS only up to the level of 0.08 and further increases in MS caused an increase in digestibility which was higher than that observed for native starch. These results were confirmed by scanning electron microscopy on hydrolyzed starch.
Hydrolytic Depolymerization of Starch Raw Materials
Authors: Abraham T. Emilia , Krishnaswamy C. , Ramakrishna S. V.
Published: November 2006

The common commercially available starchy sources in India namely cereals like wheat, corn, rice, sorghum were taken for the studies and compared with cassava. Starches from various sources need different type of liquefaction and saccharification procedures. The relative depolymerization procedures with viscosity and oligosaccharide profiles are reported. Rice flour gives very good conversion percentages, but the liquefaction step should be more drastic than other starchy raw materials. Wheat flour, maize flour, and maize starch could be hydrolysed by both acid‐enzyme and enzyme‐enzyme methods to give good conversion rates. Sorghum starch was found to be most difficult to hydrolyse and gave only 84% conversion.
Dextrose Equivalent Measurements on Commercial Syrups
Authors: Delheye G. , Moreels E.
Published: November 2006

The difficulties in the calculation of the dextrose equivalent of industrially prepared syrups from HPLC and Freezing Point Depression measurements arise from the unknown molecular weight distribution of the oligo‐ and polysaccharides. We therefore investigated the influence of the molecular weight distribution of acid‐enzymatic, enzymatic‐enzymatic prepared syrups on the results of the Lane‐Eynon oxydation‐reduction titration, HPLC and Freezing Point Depression measurements.
The Interaction Between Cibacron® Blue 3G‐A Dyed Amyloses and Microcrystalline Cellulose
Authors: Stevenson D. L. , Kennedy J. F. , White C. A.
Published: November 2006

It has been shown with the aid of chemical analysis, gel permeation chromatographic analysis of malto‐oligosaccharide mixtures produced by the action of α‐amylase (1, 4,‐α‐D‐glucan glucanohydrolase, E. C. 3. 2. 1. 1.) and photomicroscopy, that dyed amylosic fragments, produced by the conventional action of α‐amylase on Cibacron® Blue 3G‐A dyed amylose substrates, can become adsorbed by microcrystalline cellulose. The adsorption occurs between the aromatic residues of the dye molecule and the surface of microcrystalline cellulose, and only when the amount of solubilisation of the dyed amylose substrate is high. Thus, under these circumstances erroneously low values for α‐amylase activity will be obtained when using such a chromogenic substrate due to adsorption of soluble dyed fragments onto the surface of microcrystalline cellulose, thereby escaping detection. When α‐amylase levels are low, thereby causing little solubilisation of the dyed substrate, as is frequently the case in clinical chemistry, the amount of absorption cannot be detected and therefore the use of microcrystalline cellulose as a tablet binder to facilitate the routine use of these dyed amylose chromogenic substrates is permissible.
Production of a Novel Inulin Fructotransferase (DFAI producing) by Arthrobacter globiformis S14‐3
Authors: Seki K. , Haraguchi K. , Kishimoto M. , Kobayashi S. , Kainuma K.
Published: November 2006

A microorganism producing a novel inulin fructotransferase was isolated from a soil sample. The enzyme converted inulin into di‐D‐fructofuranose 1,2':2,1' dianhydride (DFAI) and a small amount of oligosaccharides. Through taxonomical studies, the microorganism was identified as Arthrobacter globiformis S14‐3. The method for preparation of DFAI from inulin was investigated and established. The enzyme showed maximal activity at pH 6.0 and 40°C. The enzyme was stable up to 70°C at pH 6.0.