bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oxidation of Potato Starch by Hydrogen Peroxide
Authors: Parovuori Petteri , Hamunen Antti , Forssell Pirkko , Autio Karin , Poutanen Kaisa 
Published: November 2006

AbstractPotato starch was oxidized by hydrogen peroxide in alkaline and acidic reaction conditions with copper, iron and tungstate catalysts in order to introduce carboxyl and carbonyl groups to the starch molecule. Carbonyl contents up to 6.6 per 100 glucose units could be obtained, whereas carboxyl content remained low (up to 1.4). Starch yields in the alkaline and acidic reactions were 90 and 99%, respectively. The molecular weight decreased markedly with the degree of oxidation, and was dependent on the catalyst used. Rheological measurements revealed that when the molecular weight of the moderately oxidized starch was high, a very firm gel (G' = 40kPa) was obtained with 25% starch concentration. When the degree of oxidation increased, the storage modulus G' decreased. The more the oxidized starch contained carbonyl groups, the higher was the gelatinization temperature.
Complexes of Oppositely Charged Ionic Starches
Authors: Willett Julious L. 
Published: November 2006

AbstractPolyelectrolyte complexes (PECs) have been prepared by mixing solutions of carboxymethyl starch and diethylethylamino starch at ionic substituent mixing ratios of 0.2, 0.5, and 0.8. The complexes were insoluble in water, although they did swell to some extent. Interactions between ionic groups were examined using turbidity measurements and FTIR spectroscopy. Supernatant turbidity was the lowest when the mixing ratio was equal to 0.5. The degree of carboxylate neutralization as measured by FTIR increased with mixing ratio. Complex formation was completely suppressed when NaCl was present in concentrations greater than approximately 0.10m. These results indicate that complex formation was due to ionic crosslinks between the oppositely charged starch molecules.
Standardization of Methodology for Chemical Functions in Starch Dervatives. Part 1
Authors: Mitchell G. , Wijnberg A. C. 
Published: November 2006

AbstractAt a plenary meeting of the International Standard Organization, Technical Committee 93 (ISO TC/93) in 1986, it was agreed that International Standards be developed for the determination of functional groups in starch derivatives, especially those intended for use in food.The secretariat of the Work Group 3, WG3, charged with this task is the Nederlands Normalisatie Instituut (NNI). The functional groups studied are acetyl, carboxyl, adipyl, hydroxypropyl and carboxymethyl, even though the last named is not used in food.Following a screening of all available methods, an enzymatic technique for determining acetyl groups was developed, and subjected to collaborative testing, with a successful outcome. The well known titration method for carboxyl content has also been validated in another collaborative exercise. Draft International Standards have been made of these two methods so they can be voted on by members of ISO and the European Committee for Standardization (CEN) in a parallel process.Work on the other functions is proceeding and will be reported as Part 2 of this paper.
Surface Energy of Extruded and Jet Cooked Starch
Authors: Lawton J. W. 
Published: November 2006

AbstractContact angles of water and other liquids were measured on films and extruded ribbons of normal, high amylose and waxy cornstarch using a Chan dynamic contact angle analyzer. The contact angles were then used to calculate the critical surface energy of the starch via a Zisman plot. Attempts were also made to use the contact angles to calculate the surface energy of starch via the harmonic‐mean method. No differences were found for the critical surface energy due to starch type. Using a composite of all contact angles for the three different starches, an average critical surface energy of 40 dynes/cm was calculated. This value was close to the literature value of 39 dynes/cm found for starch. The surface energy of starch, calculated from the harmonic‐mean method, was more variable and ranged from 35‐42 dynes/cm. The harmonic‐mean method not only calculates the surface energy, but it also estimates the polar and non‐polar components of surface energy. The estimate calculated for the polar portion for the surface energy of starch was too low for a polar solid like starch. Values for the polar component range from 0.3 to 10 dynes/cm. A theoretical argument is made for the surface energy of starch being greater than the 39 dynes/cm now reported in the literature.
Starch Ferrates
Authors: Tomasik Piotr , Jane Jay‐Lin , Spence K. , Andernegg J. W. 
Published: November 2006

AbstractFerric chloride forms with starch inclusion complex which can be readily hydrolyzed into the starch‐Fe(O)OH complex. Contrary to it carbonyl iron powder reacts with starch paste at 37°C to give starch ferrałłe. Structure assignments were made based on measurements of aqueous solubility and water binding capacity as well as interpretation of results of differential scanning calorimetry and X‐ray photoelectron spectra of prepared compounds.
Facile Route to Anionic Starches. Succinylation, Maleination and Phthalation of Corn Starch on Extrusion
Authors: Tomasik P. , Wang Y. J. , Jane Jay‐Lin 
Published: November 2006

AbstractCorn starch can be acylated on extrusion with succinic, maleic and phthalic anhydrides as well as with butane tetraioic dianhydride in the presence of carbonate buffer. Such reaction mixtures containing 30% moisture gave highly hydrophobic products of low or moderate water binding capacity.
Biofragmentation of Acetylated Starch by the α‐Amylase of Aspergillus oryzae
Authors: Coma Véronique , Copinet Alain , Couturier Yves , Prudhomme Jean‐Claude 
Published: November 2006

AbstractVarious partially acetylated starches obtained by two different processes were tested for their biofragmentability, using the α‐amylase of Aspergillus oryzae. The measure of percentage of biofragmentation and calculation of catalytic efficiency show that, one the one hand, the process and, on the other hand, the substitution degree of acetylation have a great influence on the biofragmentation or enzymatic susceptibility of starch substrates. So, the percentages of biofragmentation obtained after 9h of incubation are between about 55 and 100% for all tested substrates. A complementary study by HPLC method with refractometry detector is in accordance with the precedent results.
Über ein unerwartetes Phänomen bei der Substitutionsgradbestimmung von Stärkefettsäureestern mit zwei unterschiedlichen Substituenten
Authors: Otto A. H. 
Published: November 2006

AbstractEs wird gezeigt, daß die Bestimmung der Verseifungszahl kein universelles Verfahren zur Ermittlung des Durchschnittssubstitutionsgrades (DS) von Stärkeestern mit zwei verschiedenen Estergruppen ist. Bei ungünstiger Zusammensetzung der zu untersuchenden Verbindungen kann diese Methode vollständig versagen.Es wird empfohlen, vor der Analyse eine Abschätzung der zu erwartenden Zusammensetzung vorzunehmen und gegebenenfalls auf alternative Verfahren zur DS‐Bestimmung auszuweichen.
Synthesis and Processing of Graft Copolymers Prepared from Cereal Flour and Methyl Acrylate
Authors: Patil Damodar R. , Mn Crookston, , Fanta George F. 
Published: November 2006

AbstractCeric‐initiated graft polymerizations of methyl acrylate onto corn and wheat flour were carried out in a 2‐gallon reactor to provide pound quantities of these polymers for characterization and processing. Conversions of monomer to poly(methyl acrylate) (PMA) were nearly quantitative, although considerable homopolymer was formed along with grafted PMA. The resulting polymers were extrusion processed into plastic ribbons, and films were also prepared from these polymers by extrusion blowing. Tensile properties of the products were determined. Comparison of the preparation and properties of PMA‐grafted flour with our earlier research on starch‐g‐PMA revealed some important differences between the two polymerization systems. Graft polymerizations onto flour required a higher concentration of ceric initiator to give a near quantitative conversion of monomer to polymer and yielded a higher percentage of ungrafted homopolymer. Also, extruded ribbons obtained from PMA‐grafted flour generally exhibited lower UTS, higher % elongation and higher tear strength than extrudates prepared from PMA‐grafted starch. In contrast to our findings with PMA‐grafted starch, flour‐g‐PMA could be processed into continuous extrusion films, even though flour was graft polymerized in the granular state and was not dissolved/dispersed in water prior to graft polymerization. The percent shrinkage of extrusion blown flour‐g‐PMA at room temperature and 100% relative humidity was less than that observed for analogous starch‐based films.
Production and Characterization of Branched Oligosaccharides from Liquefied Starch by the Action of B. Licheniformis Amylase
Authors: Lee Sung‐Joon , Yoo Sang‐Ho , Kim Myo‐Jung , Kim Jung‐Wan , Seok Ho‐Moon , Park Kwan‐Hwa 
Published: November 2006

AbstractA branched oligosaccharides (BOS) mixture was produced from liquefied starch solution using a maltogenic amylase of Bacillus licheniformis (BLMA). The BOS mixture was produced by both α‐1,4‐bond hydrolyzing and α‐1,6‐transglycosylation activities of BLMA, and it contained 58.3% of various branched oligosaccharides. Small branched oligosaccharides such as isomaltose, isopanose, and panose were identified in the mixture by various analyses including high performance ion‐chromatography (HPIC). Major branched DP4 and DP5 molecules in the mixture were determined as 62‐O‐α‐maltosylmaltose, 63‐O‐α‐maltosyl‐maltotriose and 62‐O‐α‐maltotriosyl‐maltose, respectively. Time course study of BOS production suggested that the hydrolysis and transglycosylation reactions catalyzed by BLMA were coupled. BLMA was likely to transfer a sugar moiety hydrolyzed from a non‐reducing end of maltooligosaccharide, mainly maltose, to another moiety of sugar via the formation of α‐1,6‐linkage. Immobilization of BLMA was attempted as an effort to achieve a continuous process for BOS production. the immobilized enzyme showed improved thermal stability and slight loss of enzyme activity was observed during repeated usage.
Depolymerization of Molten‐Moisturized‐Starch Molecules by Shearing‐Force under High Temperature
Authors: Fujio Y. , Igura N. , Hayakawa I. 
Published: November 2006

AbstractPotato, corn and wheat starch containing 20% moisture were treated with a flow tester under heated and heated‐sheared conditions. Then heated and heated‐sheared starch specimens were prepared from three kinds of intact starches. Small amount of glucose was detected in water‐soluble fractions of heated and heated‐sheared specimens in spite of almost no detection in intact starches. By viscometry, the viscometric molecular weight of intact potato, intact corn and intact wheat starch with 20% moisture were 104kDa, 527kDa and 605kDa, respectively. While for heated specimens their molecular weights were depolymerized into 986kDa, 34kDa and 511kDa, respectively, and for heated‐sheared specimens, they were significantly depolymerized into 539kDa, 169kDa and 279kDa, respectively. Those facts were also supported from gel filtration profiles. As the results from glucose formation, viscometric molecular‐weight depolymerization and gelfiltration profiles, the considerable depolymerization in melt starchmolecules is yielded by the physical shearing‐force on starch melt despite starch varieties.
Legume and Cereal Starches — Why Differrences in Digestibility? Part 1: Isolation and Composition of Legume (Greengram and Bengalgram) Starches
Authors: Madhusudhan Basavaraj , Tharanathan Rudrapatnam N. 
Published: November 2006

AbstractA range of starch granule populations varying in size and shape characteristics was isolated from greengram (CG) and Bengalgram (BG) flours. All the starches were non‐ionic and exhibited single state swelling with hihg solubility in water, but extensive solubility in DMSO. The starch content of the different populations varied from 40‐80%, whereas the protein and lipid contents of the isolates I to III were lower than those of the isolate IV. Their amylose content ranged between 32‐46%. Brabender viscograms indicated low values for peak and setback viscosities in the case of BG starch compared to GG starch. Fatty acid analysis of the lipid fractions indicated predominance of palmitic acid. GG starch exhibited a slightly higher in vitro digestibility than BG starch.
Distribution of Nitrogen in the Cationized Potato Starch Granule
Authors: Hamunen Antti 
Published: November 2006

AbstractThe distribution of a cationic reagent in the potato starch granule derivatized by reaction with 1,2‐epoxypropyl trimethylammonium chloride was studied by ESCA spectroscopy. It was possible to detect and quantify the contents of nitrogen derived from proteinous material and nitrogen derived from the cationizing reagent on the surfaces of starch preparations.The results show that the differences in nitrogen distribution between cationic starches prepared by different (dry or wet) methods are negligible. According to the result it seems that the cationization takes place more easily in the amorphous material of the inner parts of the granule than in the crystalline amylopectin layer of the surface.
Studies on the Carbohydrate Content of Breadfruit (Artocarpus communis Forst) From South‐Western Nigeria
Authors: Adewusi Steve R. A. , Udio J. , Osuntogun Bolanle A. 
Published: November 2006

AbstractThe proximate composition of the peel, pulp and core of breadfruit revealed that the highest moisture, ash, protein, fat and crude fibre contents can be found in the core while the pulp contained the highest levels of carbohydrate, starch, nitrogen free extract and organic matter. Total free and reducing sugars were highest in the core and lowest in the peel. Sucrose, glucose and fructose followed a similar pattern as the reducing sugars while the flatus‐producing oligosaccharides raffinose (0.1%) and stachyose (0.05%) were present in the core. Only raffinose was present (0.05%) in both the peel and the pulp. Extracted starch from the breadfruit pulp was 58% of the total starch content on dry weight basis with minimal levels of ash, fat, protein and 98.6% starch. The extracted starch was 98% pure and contained only 2.3% damaged starch. The starch swelling and solubility properties showed a two‐stage pattern while the Brabender amylograms showed patterns very typical of starches from most normal non‐waxy cereals. The kinetics of carbohydrate breakdown under different storage conditions showed a biphasic first order, slow in the first 8h and thereafter accelerated. Carbohydrate breakdown as an indicator of fruit deterioration was highest when breadfruit was stored at room temperature, while there was only a little difference in those stored in water, formaldehyde solution or in the refrigerator.
Physical Properties of Starch from Two Genotypes of Amaranthus cruentus of Agricultural Significance in China
Authors: Wu Huaixiang , Yue Shaoxian , Sun Hongliang , Corke Harold 
Published: November 2006

AbstractStarches were isolated from the two genotypes of Amaranthus cruentus most widely cultivated in China, R104 and K112. These starches, plus a corn starch standard were mixed with either distilled water or a 1% NaCl solution and characterized for gelatinization parameters by Differential Scanning Calorimetry (DSC), pasting properties using a Rapid Visco‐Analyzer (RVA), and texture of the cooled gels. Significant findings were: 1. A. cruentus starches had higher gelatinization temperature and higher endothermic energy than corn starch; 2. Wide differences in pasting properties were found between the two A. cruentus genotypes, although the waxy line R104 had lower hot‐paste viscosity and set‐back than K112; 3. The pasting properties (peak viscosity and set‐back), of K112 were similar to those of corn starch. 4. In 1% NaCl solution, compared to distilled water, corn starch set‐back decreased while that of the A. cruentus starches increased. Where Amaranthus starch is to be used in food processing applications, careful selection of genotype is necessary to achieve desired functionality.
Gelatinization of Sweet Potato, Tania and Yam Tuber Starches
Authors: Valetudie Jean‐Claude , Guadeloupe La , Colonna Paul , Bouchet Brigitte , Gallant Daniel J. 
Published: November 2006

AbstractMorphological changes that occur in starch granules of sweet potato, tania and yam tubers from native to cooked states, were studied both by electron microscopy and differential scanning calorimetry. In the first stages of heating, the same event was observed in all samples: a central cavity appeared at hilum level of the starch granules just before granule expansion started. Differences in gelatinization behaviour between these three starches were enhanced by mechanism by which amylose leached out. In the sweet potato starch granules, amylose was released through micropores formed in the starch granules during the phase of expansion whereas in tania starch granules, both micropores and pin‐holes were observed. In yam starch granules, amylose escaped only by pin‐holes formed across the starch granules. When cooking was achieved, spongy‐like structures were observed in cooked sweet potato parenchyma cells while folded gelatinized granules remained in yam. In cooked tania tuber, both types of cell contents were observed. Sweet potato, tania and yam starches presented DSC endotherms at 72.7, 69.9 and 74.4°C with enthalpy change of 13.6, 12.9 and 20.9J/g, respectively.
Effect of Starch Induced Bacterial Growth and Amylase Production in Bacillus subtilis
Authors: Ensari N. Yavuz , Otludil Birol , Aytekin M. Cetin 
Published: November 2006

AbstractThe amylases produced by a Bacillus subtilis were purified from three different media which occurred nonstarch, starched and after eight hours shocked by starch media. Purified enzymes were compared each other Km, purification steps, thermal stability, pH and bacterial growth. In shocked medium, bacterial growth and amylase production are much more than in starched medium. The enzyme was stable at 65°C in three media. Km values were found different in three media where maltose inhibited the amylase activity. This inhibition is a competitive inhibition.
Gelatinization Properties of Navy Bean Starch
Authors: Lee James J. , Uebersax Mark A. , Zabik Mary E. , Steffe James F. 
Published: November 2006

AbstractGelatinization properties of navy bean (Phaseolus vulgaris) starch under different combinations of concentration (6, 8, 10 and 12%) and cooking temperature (75, 85 and 95°C) were studied using a rotational viscometer. The torque response due to swelling and/or breakdown of starch granules approached equilibrium after either a gradual increase or a relatively rapid increase to a peak followed by a decline during cooking. For every condition, the difference between the final torque values obtained for the rapid and the slow heating processes was not significant. In general, the viscosity of the paste increased as the starch concentration and/or cooking temperature increased. However, cooking temperature of 75°C did not cause a significant gelatinization or swelling of starch granules in pastes of 6 or 8% concentration. Maximum final viscosity values were obtained at 85°C for all starch concentrations except for a maxium at 95°C for 6%. Thixotropic breakdown was observed at 10 and 12% concentrations during initial shearing at 85 and 95°C. The threshold concentration for singnificant viscosity effects in this study was in the range of about 8 to 10% or 95°C. The calculated activation energy (14.5 Kcal.g−1 mole−1) of navy bean starch gelatinization was similar to values reported for rough rice and rice starches.
Microscop of Rice Starch Granules During Cooking
Authors: Rani M. R. Sandhya , Bhattachrya K. R. 
Published: November 2006

AbstractStarch from five cultivars of rice was pasted in the Brabender viscograph and then held at 95°C for 60min. Granules were examined by light and scanning electron microscopy. In concentrated (12%) pastes, low‐amylose rice starch showed total granule disintegration after 60min of cooking at 95°C, but highamylose granules showed only marginal disorganization. Waxy starch granules were disintegrated even at 70°C. In dilute (1%) pastes, on the other hand, granules swelled without appreciable disruption, apparently more in low than in high amylose starch. Clearly low amylose starch granules were weak and fragile and so swelled as well disintegrated easily, while high amylose rice starch was relatively strong and rigid and so resisted swelling as well as disintegration. This relative regidity/fragility of starch granules seemed to be the key to differences in rice quality.
Sedimentation Field Flow Fractionation Combined with Multi Angle Laser Light Scattering Applied for Characterization of Starch Polymers
Authors: Hanselmann R. , Ehrat M. , Widmer H. M. 
Published: November 2006

AbstractSedimentation Field Flow Fractionation in combination with multi angle laser light scattering was applied to fully destructured potato and waxy corn starches to investigate the molecular weight and radius distributions of the starch components. In a range of radii betwen 50 and 500nm, information could be obtained about the influence of the medium conditions on the distributions. The averages of molecular weight and particle radius were found to decrease when holding the solution at a given temperature for an extended period of time (from 20min up to 60min) and when the temperature was increased (from 160°C up to 175°C). The molecular weight and radii of gyration of the dissolved starch species typically panged from 106 to 109 daltons and 50nm‐500nm respectively. Changes in the distributions due to different conditions during the dissolution process where also recognized by changes in the shape of the distribution curve. Thus the applied technique gave satisfactory results in a high molecular weight region where SEC fails.
Mechanische Eigenschaften stärkegefüllter Polymerverbunde
Authors: Endres Hans‐Josef , Pries Andreas 
Published: November 2006

AbstractIn Fortführung der in [10] beschriebenen Untersuchung wurden wichtige mechanische Kenngrößen nativer Kartoffel‐, Mais‐ und Weizenstärkekörner ermittelt. Daraus konnten unter Voraussetzung einer ausreichenden Grenzflächenqualität die resultierenden mechanischen Eigenschaften der stärkegefüllten Verbundwerkstoffe theoretisch vorhergesagt werden. Diese theoretisch berechneten mechanischen Eigenschaften wurden abschließend durch Zugversuche an verschiedenen stärkegefüllten Verbundwerkstoffen verifiziert. Zur Bewertung der Grenzflächenqualität wurde ein Versagensmodell unidirektional verstärkter Werkstoffe herangezogen, auf die untersuchten partikelverstärkten Verbundwerkstoffe übertragen und am Beispiel weniger, ausgewählter, biologisch abbaubarer Verbundwerkstoffe näher diskutiert.Die Ergebnisse der hier vorgestellten Untersuchungen zeigten, daß durch das Füllen von Kunststoffen mit nativen Stärkekörnern die mechanischen Eigenschaften der Matrixwerkstoffe z.T. verbessert werden können. Parallel dazu läßt sich aufgrund des günstigen Stärkerohstoffpreises von ca. 1 DM/kg [1] mit zunehmendem Stärkefüllgrad der endgültige Werkstoffpreis des Verbundwerkstoffes gegenüber dem reinen Matrixwerkstoff reduzieren und das Abbauverhalten deutlich beschleunigen.Der maximale Stärkefüllgrad war jedoch auf Werte um 40 wt‐% begrenzt. Bis zu diesem Stärkefüllgrad konnten die untersuchten thermoplastischen Werkstoffe nahezu problemlos verarbeitet werden.