bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of High Pressures Treatment on Starches
Authors: Stute R. , Heilbronn  , Klingler R. W. , Boguslawski S. , Eshtiaghi M. N. , Knorr D.
Published: November 2006

The effects of ultra‐high pressure (UHP) on 25 starches were characterized via microscopy and DSC. Furthermore, the swelling behaviour, digestibility, paste viscosity and gel formation was determined. With few exceptions B‐starches were shown to be more pressure resistant than A‐ and C‐type starches. The pressure range in which the gelatinization occurs is typical for the corresponding starch. Only some starches (e.g. waxy corn starch) show the extensive swelling and almost complete desintegration of the granules, which usually is observed after a heat gelatinization. Typical for a UHP‐gelatinization is, that most starches show very little swelling and maintain their granular character. These starches develope very little viscosity at normal paste concentrations and form pastes of smooth texture, resp. rigid gels at concentrations above 15%.

Due to the limited swelling without any resp. very little solubilization of the amylose obviously the retrogradation occurs within the granules, which probably is a further reason for the quite different paste and gel properties of UHP‐gelatinized starches in comparison to heat gelatinized ones.
Molecular Origin for the Thermal Stability of Waxy‐rice (Kogane) Starch
Authors: Tako Masakuni
Published: November 2006

The non‐Newtonian behavior and dynamic viscoelasticity of waxyrice starch (Kogane) in aqueous solution were investigated. The flow curves, at 25°C, of starch showed plastic behavior at various concentrations. The viscosity increased a little with increase in temperature up to 5 or 10°C, then it stayed at a constant value with further increase of the temperature. The dynamic viscoelasticity showed very large values and stayed constant during increase of the temperature at various concentrations. The dynamic modulus decreased a little upon addition of urea (4.0M) and in 85% DMSO during increase in the temperature. The dynamic modulus, however, showed very low value in 0.10N NaOH solution. Intramolecular associations of waxy‐rice starch molecules might play a dominant role in the thermal stability for viscosity and dynamic viscoelasticity in aqueous solution.
Non‐volatile Reaction Products by Heat‐induced Degradation of α‐Glucans. Part I: Analysis of Oligomeric Maltodextrins and Anhydrosugars
Authors: Kroh Lothar W. , Jalyschko Walentina , Häseler Jörg
Published: November 2006

The non‐volatile reaction products of the thermolysis of maltodextrines and soluble starch in a closed system at 180°C are analysed and are compared with those of the thermolysis of D‐glucose and 1,6‐anhydro‐β‐D‐glucose. Without derivatization the methods of AMD/HPTLC and HPAEC/PAD are suitable for the quantitative determination of mono‐ and oligomeric saccharides. On the reaction conditions used the thermolysis/hydrothermolysis of polymeric α‐glucanes first leads to the formation of D‐glucose and predominant to 1,4‐linked maltooligosaccharides. These intermediates undergo further reactions such as hydrothermolysis, transglycosylation, dehydration, and isomerisation. As a result of these reactions non‐volatile degradation products with sugar structure such as monomeric sugars (D‐glucose), anhydrosaccharides, fructose containing sugars and short chain, partly branched, maltodextrines are formed. These reaction products can act as starting material for non‐enzymatic browning reactions and produce either typical caramelisation products, connected with changes of the sugar structure, or Maillard‐reaction products in the presence of amino compounds.
Staling in Starch Breads: The Effect of Antistaling α‐Amylase
Authors: Morgan Keith R. , Hutt Lower , Gerrard Juliett , Every Dale , Ross Marcela , Gilpin Margy
Published: November 2006

A novel starch bread that contained no gluten was found to firm at a rate comparable to a normal standard bread made from wheat flour. Treatment of both the starch and the standard bread with Novamyl, an antistaling enzyme mix, inhibited firming. 13C CP/MAS NMR studies showed that the decreased firming of the Novamyl‐treated starch bread was correlated with decreased starch retrogradation. For the Novamyl‐treated bread the increase in retrograded starch over six days following baking was about 11% compared to an increase of over 200% for the untreated bread. These results suggests that starch retrogradation is sufficient to cause bread firming.
Purification and Characterization of an Oligo‐1,6‐glucosidase from the Caldoactive Thermophile Bacillus caldotenax
Authors: Suzuki Y. , Sugita N. , Kishimoto T.
Published: November 2006

An oligo‐1,6‐glucosidase (dextrin 6‐α‐D‐glucanhydrolase, EC 3.2.1.10) of the caldoactive thermophile Bacillus caldotenax KP 1213 (YT‐G, DSM406) was purified to homogeneity. Its relative molecular weight, Stokes radius, sedimentation coefficient at 20°C in water, molar absorption coefficient at 280nm and pH 6.8, and isoelectric point were estimated to be 64,000, 3.3nm, 4.8S, 122,000M−1cm−1, and 4.9, respectively. The enzyme N‐terminal sequence of twenty residues was determined to be Met1‐Glu‐Trp‐Ala‐Trp‐Lys‐Glu‐Ala‐Val‐Val‐Tyr‐Gln‐Ile‐Tyr‐Pro‐Arg‐Met‐Phe‐Tyr20. The enzyme shared its antigenic groups in part with the homologue from Bacillus thermoglucosidasius KP1006 (DSM2542, obligate thermophile). The B. caldotenax enzyme was most active at 70°C and at pH 6.0–6.8. The best substrate for the enzyme was isomaltotriose of naturally‐occurring oligo‐ and polysaccharides tested. The enzyme half‐life at pH 6.8 was 10min at 75°C. The enzyme (Pro, 5.93mol%) fairly matched with a positive relationship between the thermostability of its six bacillary counterparts and their proline mol% contents. This relationship has been found to hold for sixteen bacterial enzymes from other four different groups (α‐glucosidases, pullulanases and 3‐isopropylmalate dehydrogenases).
Measurement of Starch Properties During Staling of Arabic Bread
Authors: Sidhu Jiwan S. , Caceres P. G. , Behbehani Montaha
Published: November 2006

The DSC and X‐ray diffraction data showed that the starch crystallinity increased in Arabic bread (khaboos) samples during the storage period. The appearance of crystalline regions during ageing as shown by X‐ray diffraction data could serve as an indication of the extent of staling that was observed in these khaboos samples. The information obtained from scanning electron microscopy could not be used for assessing the extent of staling of Arabic bread, but showed interesting differences in the gelatinization behaviour of starch granules in the crumb and crust areas. The crust areas, when viewed under the scanning electron microscope, show intact small as well as large starch granules. The limited amount of water available in the crust area of khaboos may be responsible for the incomplete gelatinization of starch granules.
Naßklassierung von Stärke — eine physikalische Beeinflussungsmöglichkeit der technologisch wichtigen Eigenschaften von Stärke
Authors: Bickert Götz , Stahl Werner , Witt Willi
Published: November 2006

Da die Anforderungen an eine scharfe Klassierung von Stärke durch bekannte Verfahren nicht erfüllt werden, wurde eine Klassiermethode zur Gegenstromtrennung im Zentrifugalfeld entwickelt. Mit diesem neuartigen Verfahren können enge Stärkefraktionen gewonnen werden, die sich in ihren viskosen Eigenschaften, ihrer Zusammensetzung (Asche, Protein, Fett) und anderen relevanten Stärkeeigenschaften unterscheiden. Die Korngröße, bei der die Trennung erfolgt, kann bei diesem Zentrifugalverfahren durch eine Variation der Betriebsparameter (Durchsatz und Drehzahl der Zentrifuge) beeinflußt und mittels einer angegebenen Gleichung bestimmt werden. Die Qualität der Klassierung hängt von Stoffeigenschaften (Stärke‐ und Pentosananteil in der Suspension) und Betriebsparametern (Wasserverhältnis) ab. Nach der Vorstellung eines typischen Klassierergebnisses (Grobgut 3%< 10μm; Feingut 70%< 10μm) werden der Einfluß der Betriebsparameter auf die Klassierung sowie die Eigenschaften der Produkte diskutiert.
Effect of Aqueous Ethanol Cationization on Functional Properties of Normal and Waxy Starches
Authors: Kweon M. R. , Sosulski F. W. , Han H. S.
Published: November 2006

Cationic starch ethers of normal and waxy corn, normal and waxy barley and normal pea starch were prepared by an aqueous alcoholic process for evaluation of their functional properties as compared to the native starch controls. The native starches exhibited a wide range in average granule size (10–21 μm diameter), amylose content (0–34%) and swelling power (13–31). Cationization to degrees of substitution (DS) of 0.030–0.035 with 3‐chloro‐2‐hydroxypropyltrimethylammonium chloride resulted in marked increases in swelling power of all starches, with little corresponding increases in starch solubility. Cationization also decreased the onset of endothermic transitions and pasting temperatures quite substantially, and promoted the development of sharp peak viscosities in the amylographs of all normal and waxy starches, including that of pea starch. Final cold viscosities of the cationic starches exhibited positive setbacks, and the cooked starch gels, after storage for 7 days at 4°C and −15°C, showed no syneresis. All cationic starches except for waxy corn were more susceptible to α‐amylase hydrolysis than native control starches. The general improvement in functional properties, especially in the waxy corn, waxy barley and pea starches, due to the aqueous alcoholic‐alkaline cationization process would greatly enhance their industrial applications.
Starches in Semidilute Aqueous Solution
Authors: Aberle T. , Burchard W.
Published: November 2006

Nine starches from different plants were studied in the semidilute concentration regime. The amylose content varied between 0% (waxy starch) and 76%. The applied concentration range of 5 to 30% (w/v) corresponds to typical concentrations used for thickeners in food and non‐food industries. With the exception of the amylose rich starches the maximum concentration was at least 4 times larger than the overlap concentration. Up to a certain concentration a common master curve was found for all starches but at high concentrations this master curve was superimposed by association and aggregation phenomena. The aggregation is promoted by the presence of amylose. The onset of aggregation is shifted to lower concentrations when the amylose content in the starches was high. The aggregation proceeds in time. It could be followed by dynamic light scattering and quantitatively be evaluated. The time dependent ageing of the solutions and the finally formed gels gave evidence for a liquid‐solid phase separation that is kinetically hampered by the presence of the branched amylopectin.
Preparation and Characterization of Carboxymethyl Starch (CMS) Products and Their Utilization in Textile Printing
Authors: Ragheb A. A. , El‐Sayiad H. S. , Hebeish A.
Published: November 2006

Starch and oxidized starches of different molecular sises were carboxymethylated under identical conditions. The degree of substitution (DS) of the so obtained. CMS samples increases by decreasing the molecular sise of starch which, indeed, is a manifestation of higher extents of oxidation. The latter was effected using different sodium hypochlorite concentrations and the extent of oxidation was expressed as chlorine consumption. Pastes of these CMS samples exhibit pseudoplastic behaviour and their apparent viscosity decreases as the extent of oxidation increases, when used as thickeners in printing polyester fabric with disperse dyes, these pastes bring about prints the colour strength (K/S) of which are comparable with these for conventional thickeners, namely commercial CMS and sodium alginate. Mixing of sodium alginate with the prepared CMS samples increases the efficiency of the latter to act as the thickening agent. The highest K/S is obtained with CMS derived from starch oxidized using 1.25g active chlorine/1. Mean while, the colour fastness properties of the prints towards rubbing, washing and perspiration are nearly equal to those fabrics printed using the conventional thickeners such as sodium alginate or commercial CMS.
Interference of Cyclodextrins with Amylolytic Activity Assays of Cyclodextrin Glycosyltransferases
Authors: Pedersen Lars Haastrup , Christensen Hans J. S. , Mathiesen Flemming , Larsen Kim L. , Zimmermann Wolfgang
Published: November 2006

Cyclodextrin glycosyltransferases (CGTases) catalyse the cyclisation of starch dextrins to cyclodextrins and concomitantly show amylolytic activity which is commonly determined by the starch‐iodine assay. In the present study it was found that cyclodextrins interfere with this assay. Adding cyclodextrins in concentrations ranging from 0.01mM to 0.6mM to starch‐iodine complex solution resulted in a significant decrease in absorbance at 600nm due to α‐ and β‐cyclodextrin competing with starch in the iodine complex formation. The largest reduction was caused by α‐cyclodextrin. Therefore, the use of the starch‐iodine assay will result in an overestimation of the amylolytic activity of CGTases – particularly when the enzyme has a high α‐cyclodextrin production activity. In contrast, determination of the amylolytic activity by measurement of released reducing sugars with CuSO4/bicinchonate was not disturbed by cyclodextrins.
The Effect of Acid Hydrolyis on Native Starch Granule Structure
Authors: Jenkins Paul J. , Donald Athene M.
Published: November 2006

A study has been made of the effect of hydrolysis on the structure of three types of starch and their subsequent gelatinisation behaviour. The techniques utilised are simultaneous small and wide angle X‐ray scattering (SAXS and WAXS respectively) using a synchrotron source, and differential scanning calorimetry. By fully fitting the small angle scattering curve to identify the behaviour of the different regions within the starch granule, it is possible to understand how the SAXS peak can get less pronounced upon hydrolysis, while the WAXS peaks get more intense. The breadth of the DSC gelatinisation endotherm also increases with extent of hydrolysis. All three findings can be related to the preferential destruction of the amorphous background region during the hydrolysis process.
Effects of Additions of Konjac and Curdlan to Corn Starch on Solubility of Extrudates
Authors: Hirata Takeshi , Bhatnagar Sandeep , Hanna Milford A.
Published: November 2006

To obtain water resistance in extruded corn starch, additions of polysaccharides konjac and curdlan were examined. Solubility of extrudates increased as the starch moisture content decreased. Solubility of extruded starch with 3% curdlan added was 38% of that of control. On the other hand, in case of addition of konjac, solubility of extrudates was increased regardless of additive amount. Solubility of extrudates was linearly related to expansion ratio, specific volume, swelling power and shear strength. It was suggested that the structure of extrudates with addition of curdlan were tight and more resistant to absorption of water than the control. Solubility of ground extrudates was linearly related to that of intact extrudates. Extrudates with addition of curdlan exhibited rigid surface and internal structures.
Kinetics and Modelling of the Enzyme Hydrolysis of Maltose with Free and Immobilized Glucoamylase
Authors: Yankov Dragomir , Beschkov V. , Rouleau Denis
Published: November 2006

The kinetics of the maltose hydrolysis by means of free and immobilized in polyacrylamide gel glucoamylase has been investigated. The kinetic constants in the Michaelis‐Menten's equation have been determined. In the case of immobilized enzyme two different methods have been used, the one giving intrinsic constant values and the other – affected by the diffusion resistances. The obtained kinetic parameters were compared with these determined for free enzyme system.

A mathematical model of the process has been constructed. The inhibition effect of the product and the reversibility of the reaction have been taken into account. The model has been solved using already determined kinetics parameters. Very good correlation between calculated and experimental data was found.
Statistical Evaluation of an International Collaborative Study Concerning the Improved Gas Chromatographic Determination of Adipate in Starch
Authors: Brunt Kommer , Mitchell Gordon A.
Published: November 2006

Recently an improved gas chromatographic method to determine the total and free adipate content of acetylated cross‐linked starches has been developed. Within the auspices of an ISO/TC 93 work group, these protocols were validated in 1993 by an international collaborative study. Statistical evaluation is essential to confirm validation, but the recommended protocols to apply have evolved with time. When the test was first done, the Dutch Normalisation protocol NEN 6303 (1988) based on ISO 5725 (1986) was current. However, in 1994 a revised ISO 5725 was issued, which should now be the preferred version of statistics. A study of the respective protocols shows that they differ in respect to the criteria applied for outlier detection and removal. When making an evaluation with each of the statistical protocols, somewhat different values for reproducibility and repeatability are obtained.

Applying the latest version of ISO 5725, the validation of the international collaborative study gave the following results: (1) for the total adipate determination the repeatability (r) and reproducibility (R) are respectively 60 and 120ppm adipic acid, and (2) for the free adipate determination the repeatability (r) and the reproducibility (R) are respectively 10.1 and 55.4ppm adipic acid.
Biodegradable Films Made from Low Density Polyethylene (LDPE), Ethylene Acrylic Acid (EAA), PolyCaprolactone (PCL) and Wheat Starch for Food Packaging Applications: Part 3
Authors: Arvanitoyannis Ioannis , Psomiadou Eleni , Biliaderis Costas G. , Ogawa Hiromasa , Kawasaki Norioki , Nakayama Atsuyoshi
Published: November 2006

The mechanical properties and gas/water permeabilities of extrudates of low density polyethylene (LDPE), wheat starch and ethylene acrylic acid (EAA) or polycaprolactone (PCL) were studied after their conditioning at various relative humidities. Satisfactory agreement was found between the experimental values, pertaining the mechanical properties, and estimates obtained by applying several semiempirical equations. The presence of starch contents (> 30%) or PCL had an adverse effect on the mechanical properties of LDPE/starch blends, whereas EAA acted as a compatibilizer by increasing the percentage elongation of the blends. Gas permeability and water vapour transmission rate increased proportionally to the starch/PCL content in the blend. Several theoretical and semiempirical calculation were also applied for gas permeability and possible interpretations were provided for the occasionally observed deviations between the experimental and the theoretical values.
Experiences with a Reverse Osmosis Pilot Plant for the Concentration of Potato Fruit Water in the Potato Starch Industry
Authors: Rüffer Hans , Kremser Ulrich , Seekamp Meinhard
Published: November 2006

The potato as an agricultural raw material contains 76% potato fruit water with a solid content of 5%. Protein separation, evaporation, agricultural application and aerobic/anaerobic wastewater treatment are able to use one part of these solids. Reverse osmosis for concentration of potato fruit water increases the percentage of reusable contents. A high tendency to biofouling on cellulose acetate membranes however requires microbiological and pH‐control of the incoming, foamfree potato fruit water as well as daily cleaning and disinfection of the membranes. Because of the special fruit water composition the rejections of inorganics are higher than expected. Estimations of total costs show that the reverse osmosis in combination with the other steps of starch process increases the economy.
Initial Phase Solubilization of Normal Corn Starch by Methyl Sulfoxide (DMSO): Evidence from Scanning Electron Microscopy and Size Exclusion Chromatography
Authors: Mua John P. , Rosowski James R. , Jackson David S.
Published: November 2006

Initial structure and solubility changes of normal corn and starch granules, dispersed in varying methyl sulfoxide (DMSO) concentrations were investigated by scanning electron microscopy (SEM) and high‐performance size exclusion chromatography (HPSEC). Larger granules from starches held for 6 or 15min and air dried showed increased surface etching with increasing DMSO concentration (0–70%): smaller granules showed surface peeling at 70% DMSO. At 90% DMSO, larger granules fractures into smaller pieces, while smaller granules showed full surface erosion. At 100% DMSO, large chunks eroded off both large and small granules. With 100% DMSO, a sheet‐like layer formed over a mass of ruptured granules during drying, suggesting that in the absence of water, DMSO dissolves part of the granule, forming a viscous solution which may limit further DMSO granule dispersion. Granules processed with critical‐point drying showed additional evidence of attack. HPSEC polymer solubility increased with DMSO concentration (0–90%). At 100% DMSO, however, there was no measured solubility. Similar solubilities for starches held at 6 or 15min (0–90% DMSO) suggest that DMSO may require an external force such as heat to facilitate polymer solubility. More amylopectin of a lower molecular weight was solubilized at 6min, while more amylose was solubilized at 15min. This suggests that granule surfaces were mostly composed of amylopectin under development, while amylose was mostly confined to amorphous regions inside the granule.
Preparation of Amphoteric Starches During Aqueous Alcoholic Cationization
Authors: Kweon M. R. , Sosulski F. W. , Bhirud P. R.
Published: November 2006

Use of an aqueous alcoholic‐alkaline solvent allowed cationization and phosphorylation to be combined in simultaneous or sequential processes in the production of amphoteric starch. Degrees of substitution required by the paper industry were obtained in normal corn, pea and barley starches, and in waxy corn and barley starches without the need for drying and heating the cationic starches to complete the phosphorylation reaction. The amphoteric starches had increased welling power, lower gelatinization temperatures, improved paste consistency and stability, and increased α‐amylase digestibility than native controls, while gel syneresis after cold storage was eliminated.
Structural Change of Potato Starch Granules by Ball‐mill Treatment
Authors: Tamaki Shinji , Hisamatsu Makoto , Teranishi Katsunori , Yamada Tetsuya
Published: November 2006

Molecular change of potato starch granule by ball‐mill treatment was investigated. Starch granule still retained its whole figure after 320h, treatment, but its surface changed extremely rough. Water absorption activity extremely increased by 10h treatment. Amylase susceptivity of starch increased according to treatment time. X‐ray diffraction pattern lost its peak and enthalpy on DSC decreased 70% after 20h treatment. Iodine color reaction value decreased 30% and λ max shifted hypso‐chromic 15nm in the both cases of debranched and non‐debranched samples after 20h treatment, and this indicates amylose was also degraded by the treatment. However, the peak of amylose decreased 10% and the peak of amylopectin decreased 10% on each GPC of branched and non‐debranched samples after 20h treatment. GPC (Toyopearl HW‐65) of 320h treated sample shows only one peak, but its debranched sample shows similar pattern to that of non‐treated sample on HPAEC. 13C‐solid state NMR spectra suggest that total disruption frequency is fairly low after long this treatment.
Comparison Between Amylose‐free and Amylose Containing Potato Starches
Authors: Visser Richard G. F. , Suurs Luc C. J. M. , Bruinenberg Peter M. , Bleeker Ido , Jacobsen Evert
Published: November 2006

This paper describes the comparison of potato amylose‐free starches obtained by two different approaches: mutation induction of the gene encoding the key‐enzyme in amylose biosynthesis Granule Bound Starch Synthase (GBSS) and antisense inhibition of the expression of GBSS, with that of normal amylose containing potato starch. One of the most prominent differences between the amylose‐free and amylose‐containing starches was their phenotype after staining with iodine. The amylose‐free starch obtained via mutation induction stained completely red whereas the amylose‐free starch obtained by the antisense approach always had a very small dark‐blue staining core in a further entirely red staining granule. Amylose‐containing starch stained blue with iodine. Differences were also observed with regard to the absence of GBSS protein and activity in the amylose‐free potatoes. Furthermore the lambda max and the blue value of the amylose‐free starches was markedly different as would be expected since they almost completely lacked (< 0.1%) amylose in both types of amylose‐free starches. Determination of a number of different chemical parameters including particle size distribution, ion content, as well as phosphate levels of the starch indicated that these were not different in the amylose‐free containing starches as compared to the normal amylose containing starches. The absence of amylose resulted in improved gel stability and paste clarity of gels even after prolonged durations at 5°C and at room temperature.
Some Physicochemical Properties of Amylose‐free Potato Starch
Authors: Visser Richard G. F. , Suurs Luc C. J. M. , Steeneken P. A. M. , Jacobsen Evert
Published: November 2006

In this paper some physico‐chemical characteristics of amylose‐free potato starch are described and compared to those from amylose containing potato starches. The availability of these high‐amylopection or amylose‐free starches has opened up new possibilities to assess the relationship between structural characteristics and physico‐chemical properties of potato starch. At the same time it should be possible to determine more precisely the role of the amylose in the starch on several properties and characteristics. In all different analyses it was clear that amylose‐free starch displayed unique properties. Not only was the response to heating much faster; it also occurred at much higher temperatures as demonstrated by viscographs, differential scanning calorimetry and swelling experiments. Rheological analyses demonstrated that gels formed from amylose‐free starch were less rigid, smoother and shorter. The breaking of amylose‐free gels furthermore required much less strength than that of amylose‐containing gels. This aspect was also evident when threads were made from both starches; amylose‐free threads were much shorter before breaking than threads made from amylose‐containing starch.
Effect of Cross Linking on Functional Properties of Cationic Corn Starch
Authors: Quan Y. , Kweon M. R. , Sosulski F. W.
Published: November 2006

Native corn starch was cross linked with phosphorus oxychloride (POCl3) before and after cationization to DS 0.04 in an aqueous ethanolic‐alkaline solvent with no adverse effects on the cationization reaction rate. Cross linking at six levels of POCl3 (7.5–120μ1/50g starch) demonstrated that the gelatinization temperatures of cationic starch increased but enthalpies of gelatinization (ΔH) decreased in proportion to the amount of added POCl3. Amylograph viscosities increased with level of POCl3 up to a maximum of 45μl POCl3 and then decreased markedly at higher concentrations of POCl3. At 30–45μl POCl3, the amylograph viscosities of cationic corn starch increased very rapidly and remained uniformly high throughout the rest of the heating and cooling cycle. At this level of cross linking and cationization, the modified starch could be used industrially as an adhesive or in paper manufacture at more dilute concentrations and with less energy input for mixing the slurry than would be required for cationic starches which exhibit high peak viscosities but negative setbacks on cooling.
Effect of Fiber Degrading Enzymes on Wet Milling and Starch Properties of Different Types of Sorghums an Maize
Authors: Moheno‐Pérez Jorge A. , Almeida‐Dominguez Helbert D. , Serna‐Saldivar Sergio O.
Published: November 2006

A factorial experiment (4 × 2 × 2) was carried out to study the effect of a fiber degrading enzyme complex on starch yield, SO2 steeping time and starch properties of normal red sorghum (RS), heterowaxy (WHWx) and waxy (WWx) white sorghums compared to regular yellow maize (YM). Starch yields and total starch recovery for the sorghums ranged from 53–64% and 70–85%, respectively. Sorghum starch recovery values were significantly lower (p < 0.05) than maize (66% starch yield and 88% recovery). However, the WWx yielded more starch with lower protein and ash contents (P < 0.05) than the RS and WHWx sorghums. In the RS, the fiber degrading enzymes reduced steep time while owing the same starch recovery. The WWx starch required lower temperature to initiate gelatinization and had higher peak viscosities and lower retrogradation than the other starches. The WHWx starch had intermediate viscoamylograph properties between the regular and waxy starches.
Standardization of Methodology for Chemical Functions in Starch Derivatives. Part 2
Authors: Mitchell G. , Wijnberg A. C.
Published: November 2006

The work of Work Group 3, of the International Standards Organization Technical Committee 93 (ISO/TC 93/WG3), concerning the determination of functional groups in starch derivatives, has been progressed. The Netherlands Normalisatie Instituut (NNI) is the secretariat and Part I of this paper outlined the total work programme and reported the finalised work on acetyl and carboxyl functions.

Following modifications, the available methodology for the adipyl function was improved, and has been validated. The methodology for the determination of the carboxymethyl function by titration of the carboxyl group, has also been refined and validated by collaborative testing. Draft International Standards have been made of these two methods so that they can be voted on by members of ISO and the European Committee for Standardization (CEN) in a parallel process.

Work on the hydroxypropyl function has not yet come to a successful conclusion. A colorimetric method showed poor reproducibility, due probably to its empirical nature; little support was found for gas chromatographic methods. However, the use of proton NMR might yield a satisfactory means. While all members of the Work Group are not equipped with the required instrument, a preliminary study will be done with the help of other laboratories.
Structural Aspects of Partially Acetylated Degraded Amylopectins — A 13C NMR Study
Authors: Falk Heinz , Stanek Michael , Wutka Reinhold
Published: November 2006

13C NMR signal assignments were achieved for amylose and amylopectin triacetates and a series of partially acetylated, acid degraded amylopectin derivatives. Using the relative intensities of several of these signals for the latter materials the following could be deduced. First, within the molar substitution range of 0.47 and 0.72 the acetylation of partially degraded amylopectins takes place randomly distributed at all glucan moieties of the polysaccharide. Second, the probabilities of substitutions of hydroxyl groups in positions 2, 3, and 6 of a discrete glucan moiety are equivalent.
Physicochemical Properties and Functionality of Highly Carboxymethylated Starch
Authors: Kwon Kisung , Auh Joong Hyuck , Kim Jeong‐Weon , Park Kwan Hwa , Park Chan Heun , Ko Cheul Jong
Published: November 2006

Highly carboxymethylated potato starches (HCMS) with various degrees of substitution ranging 0.48‐0.60 were produced and their physicochemical and functional properties were examined. The degree of substitution could be increased by prior treatment of starch with acid, although the longer the treatment the percentage of low molecular weight starches increased slightly. HCMS showed a pseudoplastic flow having the power law index less than 1.0. HCMS swelled readily in cold water (15°C), formed a clear solution, and were resistant to retrogradation. The viscosity of HCMS prepared without or with 15min acid treatment was similar or higher than that of native starch at the beginning of amylography, however, it decreased gradually from the rest of the stage. HCMS prepared with longer acid treatments exhibited extremely low viscosity throughout the test period. The digestibility of HCMS by α‐amylase decreased greatly in proportional to the degree of substitution. Scanning electron microscopic observation revealed fine fissures and grooves on the surface of HCMS granules, suggesting part of amylose has been leached by the acid treatment.
Evaluating Sodium Salts as Pushing Agents on High‐Performance Anion‐Exchange Chromatography with Pulsed Amperometric Detection for Maltodextrin Analysis
Authors: Lu Ting‐Jang , Lacourse William R. , Jane Jay‐Lin
Published: November 2006

Sodium hydroxide and sodium salts of acetate, nitrate and sulfate were chosen as pushing agents for maltodextrin analysis by high‐performance anion‐exchange chromatography with pulsed amperometric detection (HPAEC‐PAD). Different concentrations of sodium hydroxide solution, 100 mM to 500 mM, were used for direct detection of maltodextrins on a set of gold working and saturated calomel reference electrodes. Chromatographic capacity factors, k′, of maltodextrins increased as molecular size increased. Sodium hydroxide alone was not adequate for an optimal maltodextrin separation. Sodium salts of acetate, nitrate, and sulfate were tested as pushing agents.

The salts were compatible with the system, increased the separation selectivity and enhanced the detector response of PAD. The ability of pushing agents to decrease k′ followed the order of sulfate > nitrate > acetate > hydroxide. After being eluted with pushing agents, the column regeneration time of CarboPac PA1 was 180, 240 and 360 min for the acetate, nitrate, and sulfate salts, respectively. An alternate process to shorten the regeneration time for maltodextrin separation was demonstrated. Sodium azide, as a preservative, did not affect the separation and quantification of the analysis. Sodium nitrate was the best pushing agent for the homologous maltodextrin separation.
The Interaction Between Surfactants and 2‐Hydroxy‐3‐(N,N‐dimethyl‐N‐dodecylammonium)‐propyloxy Starches
Authors: Jonhed Anna , Järnström Lars
Published: November 2006

The phase behavior of temperature‐responsive hydrophobically modified starches and the interaction between oxidized potato amylose and hydrophobically modified potato amylopectin have been investigated by rheology, turbidity measurements and differential scanning calorimetry. When oxidized amylose was mixed with hydrophobically modified amylopectin, a viscosity peak was observed, indicative of a guest‐host interaction between the oxidized amylose and the hydrophobically modified amylopectin. A series of oxidized and hydrophobically modified potato starches were investigated in the presence of an anionic and cationic surfactant. A coil‐helix transition of the investigated starches was observed in the presence of surfactant, with the exception of a cationic surfactant combined with a hydrophobically modified zwitterionic starch of high positive net charge. The destabilizing mechanism (the phase separation) of the hydrophobically modified starches was studied as well as the difference in stabilizing capacity between the investigated cationic and anionic surfactants.
Retrogradation of Ethylenebisformamide and Sorbitol Plasticized Corn Starch (ESPTPS)
Authors: Yang Jin‐hui , Yu Jiu‐gao , Ma Xiao‐fei
Published: November 2006

Several thermoplastic starches (TPSs), i.e. ethylenebisformamide, sorbitol and ethylene‐sorbitol plasticized (EPTPS, SPTPS and ESPTPS) were prepared and their retrogradation was investigated by X‐ray diffraction, Fourier‐transform infrared spectroscopy (FT‐IR) and scanning electron microscopy (SEM). These studies revealed that the mixture of ethylenebisformamide (E) and sorbitol (S) was a good plasticizer for corn starch, restraining the retrogradation of the TPSs. The mechanical properties were also investigated of the TPSs after conditioning for 150 days at ambient atmosphere. It indicated that TPS produced by mixed plasticizer possessed better mechanical properties than TPS produced using a single plasticizer (ethylenebisformamide or sorbitol). From the analysis of X‐ray, FT‐IR and SEM data it was hypothesized that some interaction between ethylenebisformamide and sorbitol occurred, which could prevent the plasticizer form separating out of the TPS matrix. As a result, the retrogradation of ESPTPS was limited, resulting in better mechanical properties compared with those of EPTPS and SPTPS.
An Aqueous Film‐coating Formulation based on Sodium Carboxymethyl Mungbean Starch
Authors: Kittipongpatana Ornanong S. , Chaichanasak Nadda , Kanchongkittipoan Sitanan , Panturat Akanit , Taekanmark Tipawan , Kittipongpatana Nisit
Published: November 2006

No abstracts.
Physicochemical Properties of Pin Oak (Quercus palustris Muenchh.) Acorn Starch
Authors: Stevenson David G. , Jane Jay‐lin , Inglett George E.
Published: November 2006

Physicochemical properties of acorn (Quercus palustris) starch were studied. Acorn starch granules were spherical or ovoid, with diameters ranging from 3–17 μm. Acorn starch exhibited A‐type X‐ray diffraction pattern, an apparent amylose content of 43.4% and absolute amylose content of 31.4%. Relative to other A‐type starches, acorn amylopectin had a comparable weight‐average molar mass (3.9×108 g/mol), gyration radius (288 nm) and density (16.3 g mol−1nm−3). Average amylopectin branch chain‐length corresponded to DP 25.5. Onset gelatinization temperature was 65.0°C and peak gelatinization temperature was considerably higher (73.7°C). The enthalpy change of gelatinization was very high compared to non‐mutant starches (20.8 J/g). An amylose‐lipid thermal transition was not observed. Starch retrograded for 7 d at 4°C had very high peak melting temperature (54.2°C) relative to other A‐type starches. Final (260 RVU) and setback (138 RVU) viscosity of an 8% acorn starch paste was high relative to other starches and pasting temperature was 71.5°C.
Synthese und Struktur des tetrameren Tris(trimethylsilyl)silylindium(I) und neuer silylsubstituierter Indiumverbindungen
Authors: Bühler Martina , Linti Gerald
Published: November 2006

Synthesis and Structure of Tetrameric Tris(trimethylsilyl)indium(I) and of New Silyl substituted Indium Compounds

The reaction of InCp* with [LiSi(SiMe3)3·3thf] yielded in the first silylsubstituted tetrahedrane of indium [In4{Si(SiMe3)3}4] (1). It crystallizes together with [In{Si(SiMe3)3}3] (2) in dark green crystals. Colourless crystals of [Li(OH)(OSiMe3)In{Si(SiMe3)3}2]2 (3) were isolated as a byproduct from this reaction. It's structural core are three connected four membered rings made up of In‐, Li‐ and O‐atoms. From the reaction of [InOSO2CF3] with [LiSi(SiMe3)3·3thf] colourless crystals of [In{Si(SiMe3)3}2OSO2CF3·thf] (4) were isolated. InCp* reacted with [LiSiMe(SiMe3)2·3thf] to form the orange‐coloured monoindane [In{SiMe(SiMe3)2}3] (5). 1 – 4 were characterized by X‐ray crystal structure analyses.
Apoptosis‐inducing factor (AIF) inhibits protein synthesis by interacting with the eukaryotic translation initiation factor 3 subunit p44 (eIF3g)
Authors: Kim Jong-Tae , Kim Kwang Dong , Song Eun Young , Lee Hee Gu , Kim Jae Wha , Kim Jung Woo , Chae Suhn-Kee , Kim Eunhee , Lee Myeong-Sok , Yang Young , Lim Jong-Seok
Published: November 2006

Apoptosis‐inducing factor (AIF) is a ubiquitous FAD‐binding flavoprotein comprised of 613 amino acids and plays an important role in caspase‐independent apoptosis. During apoptotic induction, AIF is translocated from the mitochondrial intermembrane space to the nucleus, where it interacts with DNA and activates a nuclear endonuclease. By performing a yeast two‐hybrid screen with mature AIF, we have isolated the eukaryotic translation initiation factor 3 subunit p44 (eIF3g). Our deletion mutant analysis revealed that the eIF3g N‐terminus interacts with the C‐terminal region of AIF. The direct interaction between AIF and eIF3g was confirmed in a GST pull‐down assay and also verified by the results of co‐immunoprecipitation and confocal microscopy studies. Using an in vitro TNT coupled transcription–translation system, we found that mature AIF could inhibit newly‐translated protein synthesis and this inhibition was significantly blocked by eIF3g competitively. These results were also confirmed in cells. In addition, mature AIF overexpression specifically resulted in the activation of caspase‐7, thereby amplifying the inhibition of protein synthesis including eIF3g cleavage. Our data suggest that eIF3g is one of the cytosolic targets that interacts with mature AIF, and provide insight into the AIF's cellular functions of the inhibition of protein synthesis during apoptosis.
Damage detection by the UvrABC pathway: Crystal structure of UvrB bound to fluorescein‐adducted DNA
Authors: Waters Timothy R. , Eryilmaz Jitka , Geddes Stella , Barrett Tracey E.
Published: November 2006

UvrB is the damage recognition element of the highly conserved UvrABC pathway that functions in the removal of bulky DNA adducts. Pivotal to this is the formation of a damage detection complex that relies on the ability of UvrB to locate and sequester diverse lesions. Whilst structures of UvrB bound to DNA have recently been reported, none address the issue of lesion recognition. Here, we describe the crystal structure of UvrB bound to a pentanucleotide containing a single fluorescein‐adducted thymine that reveals a unique mechanism for damage detection entirely dependent on the exclusion of lesions larger than an undamaged nucleotide.
Site specific changes of redox metabolism in adipose tissue of obese Zucker rats
Authors: Galinier Anne , Carriere Audrey , Fernandez Yvette , Caspar-Bauguil Sylvie , Periquet Brigitte , Periquet Alain , Penicaud Luc , Casteilla Louis
Published: November 2006

Adipose tissues are differently involved in lipid metabolism and obesity according to their type and location. Increasing reports stress on the impact of redox metabolism on obesity and metabolic syndrome. The aim of this work is to investigate the site‐specific redox metabolism in three different adipose tissues and its changes occurring in obesity. We analysed enzymatic and non‐enzymatic parameters, and focused on the reduced/oxidized glutathione and coenzyme Q couples. In lean compared with obese non‐diabetic Zucker rats, interscapular brown fat seems well protected against oxidative stress and epididymal adipose tissue shows a more reduced glutathione redox state, associated with a higher susceptibility to lipophilic oxidative stress than inguinal adipose tissue. Epididymal adipose tissue redox metabolism significantly differs from inguinal one by its limited redox metabolism adaptation. Our results demonstrate site‐specific managements of reactive oxygen species metabolism in obese Zucker rats. These results are not consistent with the classic deciphering of inflammatory situation and produce a new conception of the redox parameters implication in the development of the metabolic syndrome.
NAD+‐specific d‐arabinose dehydrogenase and its contribution to erythroascorbic acid production in Saccharomyces cerevisiae
Authors: Amako Katsumi , Fujita Kazuyo , Shimohata Taka-aki , Hasegawa Etsuko , Kishimoto Ritsuko , Goda Kiyoshi
Published: November 2006

Erythroascorbic acid (eAsA) is a five‐carbon analog of ascorbic acid, and it is synthesized from d‐arabinose by d‐arabinose dehydrogenase (ARA) and d‐arabinono‐γ‐lactone oxidase. We found an NAD+‐specific ARA activity which is operative under submillimolar level of d‐arabinose in the extracts of Saccharomyces cerevisiae. The hypothetical protein encoded by YMR041c showed a significant homology to a l‐galactose dehydrogenase which plays in plant ascorbic acid biosynthesis, and we named it as Ara2p. Recombinant Ara2p showed NAD+‐specific ARA activity with K

m

= 0.78 mM to d‐arabinose, which is 200‐fold lower than that for the conventional NADP+‐specific ARA, Ara1p. Gene disruptant of ARA2 lost entire NAD+‐specific ARA activity and the conspicuous increase in intracellular eAsA by exogenous d‐arabinose feeding, while the double knockout mutant of ARA1 and ARA2 still retained measurable amount of eAsA. It demonstrates that Ara2p, not Ara1p, mainly contributes to the production of eAsA from d‐arabinose in S. cerevisiae.
ErbB2 overexpression in p53‐inactivated mammary epithelial cells
Authors: Yang Jin Won , Lee Eva Y.-H.P. , Kang Keon Wook
Published: November 2006

Functional loss of p53 and ErbB2 overexpression are the frequent genetic alterations in human breast carcinomas. Here, we found that ErbB2 expression was upregulated in primary cultured mammary epithelial cells (MECs) isolated from mice with a defect in exons 5 and 6 of the p53 gene (p53
Δ5,6). The reporter gene activity in the p53
Δ5,6 MECs transfected with the −756 bp flanking region of the hErbB2 gene was higher than the wild type MECs. p53 inactivation selectively increased the level of AP‐2α, but not AP‐2β and AP‐2γ and a mutation of the two AP‐2 binding sites completely inhibited the reporter activity.
Catalytic reduction of dinitrogen to ammonia at a single molybdenum center
Authors: Weare Walter W. , Dai Xuliang , Byrnes Matthew J. , Chin Jia Min , Schrock Richard R. , Müller Peter
Published: November 2006

Since our discovery of the catalytic reduction of dinitrogen to ammonia at a single molybdenum center, we have embarked on a variety of studies designed to further understand this complex reaction cycle. These include studies of both individual reaction steps and of ligand variations. An important step in the reaction sequence is exchange of ammonia for dinitrogen in neutral molybdenum(III) compounds. We have found that this exchange reaction is first order in dinitrogen and relatively fast (complete in <1 h) at 1 atm of dinitrogen. Variations of the terphenyl substituents in the triamidoamine ligand demonstrate that the original ligand is not unique in its ability to yield successful catalysts. However, complexes that contain sterically less demanding ligands fail to catalyze formation of ammonia from dinitrogen; it is proposed as a consequence of a base-catalyzed decomposition of a diazenido (Mo

N

NH) intermediate.
Rapidly evolving zona pellucida domain proteins are a major component of the vitelline envelope of abalone eggs
Authors: Aagaard Jan E. , Yi Xianhua , MacCoss Michael J. , Swanson Willie J.
Published: November 2006

Proteins harboring a zona pellucida (ZP) domain are prominent components of vertebrate egg coats. Although less well characterized, the egg coat of the non-vertebrate marine gastropod abalone (
Haliotis
spp.) is also known to contain a ZP domain protein, raising the possibility of a common molecular basis of metazoan egg coat structures. Egg coat proteins from vertebrate as well as non-vertebrate taxa have been shown to evolve under positive selection. Studied most extensively in the abalone system, coevolution between adaptively diverging egg coat and sperm proteins may contribute to the rapid development of reproductive isolation. Thus, identifying the pattern of evolution among egg coat proteins is important in understanding the role these genes may play in the speciation process. The purpose of the present study is to characterize the constituent proteins of the egg coat [vitelline envelope (VE)] of abalone eggs and to provide preliminary evidence regarding how selection has acted on VE proteins during abalone evolution. A proteomic approach is used to match tandem mass spectra of peptides from purified VE proteins with abalone ovary EST sequences, identifying 9 of 10 ZP domain proteins as components of the VE. Maximum likelihood models of codon evolution suggest positive selection has acted among a subset of amino acids for 6 of these genes. This work provides further evidence of the prominence of ZP proteins as constituents of the egg coat, as well as the prominent role of positive selection in diversification of these reproductive proteins.