bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of Starch Pasting Properties at Various Cooking Conditions Using the Micro Visco‐Amylo‐Graph and the Rapid Visco Analyser
Authors: Suh Dong Soon , Jane Jay‐lin
Published: June 2007

Pasting profiles of selected starches were compared by using a Micro Visco‐Amylo‐Graph (MVA) and a Rapid Visco Analyser (RVA). Effects of cooking (heating/cooling) rate and stirring speed on starch pasting properties were examined. The pasting viscosity of a starch suspension (8%, w/w, dsb) was measured at a fast (6°C/min) and slow (1.5°C/min) cooking rate while being stirred at either 75 rpm or 160 rpm. The pasting temperatures (PT) of all starches were higher when measured at the fast cooking rate than those at the slow cooking rate, except for wheat measured by using the RVA. PT was also higher when measured at the slow stirring speed (75 rpm) than at the fast stirring speed (160 rpm) in both RVA and MVA. When stirring speed increased from 75 rpm to 160 rpm, peak viscosity of all starch pastes except potato decreased measured by using the RVA, but increased by using the MVA. In general, amylograms of these starches obtained by using the MVA showed less breakdown, but greater setback viscosity than did that obtained by using the RVA. Differences in starch pasting properties between MVA and RVA, measured at the same cooking and stirring rates, were attributed mainly to the difference in spindle structure.
Role of Gluten and Its Components in Determining Durum Semolina Dough Viscoelastic Properties
Authors: Edwards N. M. , Mulvaney S. J. , Scanlon M. G. , Dexter J. E.
Published: June 2007

Gluten was isolated from three durum wheat cultivars with a range in strength. Gluten was further fractionated to yield gliadin, glutenin and high molecular weight (HMW) and low molecular weight (LMW) glutenin subunits (GS). The gluten and various fractions were used to enrich a base semolina. Enriched dough samples were prepared at a fixed protein content using a 2‐g micromixograph. Mixing strength increased with addition of gluten. Dynamic and creep compliance responses of doughs enriched with added gluten ranked in order according to the strength of the gluten source. Gliadin addition to dough resulted in weaker mixing curves. Gliadin was unable to form a network structure, having essentially no effect on dough compliance, but it did demonstrate its contribution to the viscous nature of dough (increased tan δ). Source of the gliadin made no difference in response of moduli or compliance. Addition of glutenin to the base semolina increased the overall dough strength properties. Glutenin source did influence both dynamic and compliance results, indicating there were qualitative differences in glutenin among the three cultivars. Enrichment with both HMW‐GS and LMW‐GS increased overall dough strength. Source of HMW‐GS did not affect compliance results; source of LMW‐GS, however, did have an effect. The LMW‐2 proteins strengthened dough to a greater extent than did LMW‐1. Mechanisms responsible for dough viscoelastic properties are described in terms of reversible physical cross‐links.
Studies on Effects of Microbial Transglutaminase on Gluten Proteins of Wheat. II. Rheological Properties
Authors: Bauer Nicole , Koehler Peter , Wieser Herbert , Schieberle Peter
Published: June 2007

The effects of microbial transglutaminase (TG) on the dough properties and the baking performance of wheat flour with strong gluten and high baking quality were studied by farinograph measurements, creep‐recovery tests with dough, extension tests with gluten, and baking tests. A very low concentration of TG caused a significant decrease in the maximum strain of the dough. This decrease was closely related to the TG concentration. Extension tests with gluten showed that increasing concentrations of TG led to a drastic decrease of the extensibility and an increase of the resistance to extension. When concentrations of TG were too high, a complete loss of dough and gluten structure was obtained. On the other hand, with low concentrations of TG, no difference could be detected between the control bread and the bread containing TG in the baking test. With higher concentrations of TG, dough handling became extremely difficult, and the loaf volume decreased substantially due to a loss of structure in the dough. Therefore, the use of TG to improve the dough properties and the baking performance is recommended for flours with weak gluten and poor baking performance.
Effect of Xanthan Gum and CMC on the Structure and Texture of Corn Flour Pellets Expanded by Microwave Heating
Authors: Gimeno E. , Moraru C. I. , Kokini J. L.
Published: June 2007

Third‐generation snacks obtained by microwave expansion of glassy cereal pellets are often hard and nonuniform and need to be improved to become acceptable to the consumer. Gums such as carboxymethyl cellulose (CMC) and xanthan gum (XG) have the ability to improve the volume, structure, and texture of expanded cereal products, due to their effects on moisture retention and rheological properties. This study investigates the effect of 1% addition of CMC and XG on the structural and mechanical properties of samples obtained by microwave expansion of glassy corn pellets. Unexpanded, glassy pellets were obtained by extrusion and subsequent equilibration at aw = 0.53 at room temperature. The equilibrated pellets were expanded by microwave heating. The addition of gums significantly improved the shape, structural and textural uniformity of the microwave‐expanded samples. These effects were attributed to the contribution of gums to the rheology and moisture sorption capacity of the matrix. It is our hypothesis that the extended hydrocolloid macromolecules interpenetrated the polymeric starch matrix and created a fine network of “holes” distributed relatively uniformly in the matrix, which served as additional nucleation sites for expansion. The conclusions of this study can be used in the design of high‐quality, fat‐free, third‐generation snacks.
Solvent Retention Capacities of Indian Wheats and Their Relationship with Cookie‐Making Quality
Authors: Ram Sewa , Singh R. P.
Published: June 2007

Ninety‐two wheat genotypes including 50 cultivars released in India and 42 germplasm lines were subjected to solvent retention capacity (SRC) tests using 1 g of flour and 1 g of whole meal to see the relationship with cookie‐making quality and the utility in breeding programs. Very high negative correlations (P < 0.001) were observed between cookie diameter and spread factor and alkaline water retention capacity (AWRC), and solvent retention capacities of both flour and whole meal samples. Multiple regression analysis showed that AWRC explained 43.8%, sodium carbonate SRC 27.3%, lactic acid SRC 15.1%, and protein content 13.8% of the total variability (multiple r = 0.87) in cookie diameter. Total variability (multiple r = 0.85) in spread factor was explained 40.3% by AWRC, 27.4% by SODSRC, 14.5% by LASRC, and 17.8% by protein content. When the technique was further used to reduce the number of parameters contributing to cookie diameter, AWRC explained 67.2% of the total variability (multiple r = 0.85) and the rest by lactic acid SRC and protein content. Surprisingly, multiple regression analysis of whole meal samples exhibited that lactic acid SRC and sodium carbonate SRC explained 88 and 12%, respectively, of the total variability (multiple r = 0.76) in cookie diameter and 78 and 22%, respectively, of the total variability (multiple r = 0.71) in spread factor. Among the soft wheat flour samples selected based on W > 7.70 cm, pentosan content as revealed by sucrose SRC explained 87.7% of the total variability (multiple r = 0.54) of cookie diameter and 83.8% of total variability (multiple r = 0.52) in spread factor. Clustering of genotypes based on SRC profiles using both flour and whole meal produced clusters with similar average cookie diameter and spread factor. The data clearly demonstrate that whole meal tests can be used in screening the recombinant lines as well as in selecting desirable genotypes for making crosses to enhance cookie‐making quality.
Effect of Baking Method and Fermentation on Folate Content of Rye and Wheat Breads
Authors: Kariluoto Susanna , Vahteristo Liisa , Salovaara Hannu , Katina Kati , Liukkonen Kirsi‐Helena , Piironen Vieno
Published: June 2007

The effect of baking method on folates of rye and wheat breads, as well as the effect of sourdough fermentation of rye, were examined. Sourdough fermentations were performed both with and without added yeast, and samples were taken throughout the baking process. Samples were analyzed microbiologically for their total folate content after trienzyme extraction. Individual folate vitamers were determined by HPLC after affinity chromatographic purification. The lowest folate contents for both rye and wheat breads were found from breads baked without added yeast. Total folate content increased considerably during sourdough fermentation due to increased amounts of 10‐HCO‐H2folate, 5‐CH3‐H4folate, and 5‐HCO‐H4folate. Baker's yeast contributed markedly to the final folate content of bread by synthesizing folates during fermentation. Proofing did not influence total folate content but changes in vitamer distribution were observed. Folate losses in baking were ≈25%. The variety of sourdoughs and baking processes obviously lead to great variation in folate content of rye breads. The possibilities to enhance natural folate content of rye bread by improving folate retention in technological processes and by screening and combining suitable yeasts and lactic acid bacteria should be further investigated.
Application of High‐Intensity Ultrasound and Surfactants in Rice Starch Isolation
Authors: Wang Linfeng , Wang Ya‐Jane
Published: June 2007

High‐intensity ultrasound was evaluated as an alternative method to isolate rice starch without the use of chemicals as in the traditional alkaline steeping method. Surfactants, including sodium dodecyl sulfate (SDS), sodium stearoyl lactylate (SSL), and Tween 80, at 0.1, 0.3, or 0.5% combined with high‐intensity ultrasound were also investigated for rice starch isolation. A rice flour slurry (33%) was subjected to sonication for 15, 30, or 60 min at an amplitude of 25, 50, or 75% and at 40 or 50°C. The starch yield was not significantly affected by the treatment temperature and ranged from 46.7 to 76.2% (starch dry basis) after the sonication treatment; the protein and damaged starch contents of the isolated starches were 0.9–1.7% and 3.1–3.5% (dry basis), respectively. The combination of 0.5% SDS and high‐intensity ultrasound improved the starch yield to 84.9% with low residual protein, however, little improvement was observed with SSL or Tween 80. The pasting properties of isolated starch as measured by a Rapid Visco‐Analyser were affected by the treatment temperature and by the amount of residual protein and damaged starch. The thermal properties of the isolated starch were not changed by sonication and the amylose content remained unchanged. The surface of the isolated starch was not damaged by sonication as shown by scanning electron microscopy. High‐intensity ultrasound, alone or combined with SDS, showed a great potential for rice starch isolation in a short period of time without generating alkaline effluent.
Influence of Nitrogen Fertilizer Treatments on Spring Wheat (Triticum aestivum L.) Flour Characteristics and Effect on Fresh and Frozen Dough Quality
Authors: Boehm David J. , Berzonsky William A. , Bhattacharya Monisha
Published: June 2007

Growers are targeting hard red spring wheat (Triticum aestivum L.) (HRSW) for frozen dough end uses. Consequently, it is important to determine whether increasing nitrogen (N) fertilizer rates and grain protein content (GPC) improve frozen dough quality. Four HRSW cultivars were grown in low‐N soils at three locations over two years in North Dakota and fertilized with N rates of 0 kg/ha, 67.2 kg/ha, and 134.4 kg/ha. End use characteristics were analyzed using farinograph, extensigraph, and baking tests. Fresh and frozen doughs were analyzed to determine the effects of N treatments on frozen storage. A cultivar × N treatment interaction existed for extensigram curve area of fresh dough. A significant increase in GPC existed between the 0 and 67.2 kg/ha N treatments. Farinograph water absorption, arrival times, and peak times increased significantly at the 67.2 kg/ha N treatment. Bread loaf volume of fresh dough increased significantly with all treatments, while loaf volume of frozen dough increased significantly only at the 67.2 kg/ha N treatment. Therefore, aside from fresh dough loaf volume, there appears to be no improvement in frozen dough quality with the use of higher than typical N application.
Optimizing a Small‐Scale Corn‐Starch Extraction Method for Use in the Laboratory
Authors: Ji Y. , Seetharaman K. , White P. J.
Published: June 2007

The objectives of this experiment were to determine the effects of altering starch extraction procedures designed for use in the laboratory on starch yield, protein content, and thermal properties. Public Corn Belt inbred line Mo17 was used in this study. The altered procedures that were examined included steeping time (24, 48, or 72 hr), numbers of corn kernels extracted (2, 5, or 10 kernels), and isolation method (sedimentation or centrifugation). Starch thermal properties were obtained by using differential scanning calorimetry (DSC). Starch yield and protein content were significantly different among the experimental treatments. In general, more kernels, and sedimentation rather than centrifugation, resulted in greater yields. Also, treatments involving more kernels or sedimentation rather than centrifugation, yielded starch with the lowest protein content. Starch extracted after steeping for 24 hr and purified by the sedimentation method had the lowest gelatinization onset temperature (by DSC) and the widest gelatinization temperature range among the treatments. The energy required to gelatinize starch did not differ among the treatments. The differences among treatments in onset temperature and temperature range were probably caused by annealing of starch that occurs over time, during steeping. Therefore, to obtain the purest starch quality, this study suggests that sedimentation is preferred over centrifugation, and 10 kernels is preferred over 2 or 5. Furthermore, soaking the seeds for less than 24 hr is preferred if minimal annealing is desired.
Study of Calcium Ion Diffusion in Components of Maize Kernels During Traditional Nixtamalization Process
Authors: Fernández‐Muñoz J. L. , Rojas‐Molina Isela , González‐Dávalos M. L. , Leal Myriam , Valtierra M. E. , Martín‐Martinez E. San , Rodríguez M. E.
Published: June 2007

Our report shows the calcium ion diffusion process through the different parts of maize kernels (pericarp, endosperm, and germ) during the traditional nixtamalization process as a function of steeping time (t) 0–24 hr. The cooking step of the nixtamalization process used 3 kg of maize kernels in 6L of water and 2% calcium hydroxide (w/w). The cooking temperature was 92°C for 40 min. The calcium content of the samples was measured using atomic absorption spectroscopy. We found that the whole instant corn flour, pericarp, endosperm, and germ, had a nonlinear relationship to steeping time, showing a local maximum at 9 hr. Analysis of the different parts of the nixtamalized kernels showed that in short steeping times (0–5 hr) calcium diffusion took place mainly in the pericarp. Calcium diffusion in the endosperm and germ occurred gradually over longer steeping times. However, the physical state of the kernels (broken kernels) accelerated the diffusion process. Calcium diffusion occurred first in the pericarp, followed by the endosperm and germ. Immediately after cooking (t = 0 hr), we found a 1.148% calcium content in the pericarp, 0.007% in the germ, and 0.028% in the endosperm. After 24 hr of steeping, the calcium contents were 2.714% in the pericarp, 0.776% in the germ, and 0.181% in the endosperm. In another study, the calcium content in the endosperm was measured by first separating the 10% from the outermost, followed by another 10% from the next endosperm tissue, and concluding with the remaining 80%. Calcium ions were present mainly in the outermost layers of the endosperm. The damaged kernels steeped for more than 5 hr showed greater calcium concentrations than the undamaged counterparts.
Effect of Freeze‐Thaw Cycles on the Gluten Fibrils and Crumb Grain Structures of Breads Made from Frozen Doughs
Authors: Naito S. , Fukami S. , Mizokami Y. , Ishida N. , Takano H. , Koizumi M. , Kano H.
Published: June 2007

The effects of freeze damage on the crumb grain and on the underlying gluten fibrils of baked breads were studied using scanning electron microscopy (SEM) and magnetic resonance imaging (MRI). Sweet and white bread doughs were stored at ‐20°C and subjected to freeze‐thaw cycles. SEM images of grain pore walls that were washed with distilled water (20°C) clearly showed that gluten fibrils forming the skeletal framework of pore walls were cut and became coarse and nonuniform strings and that many knots were generated on gluten fibrils from freeze damage. An increase in the number of freeze‐thaw cycles increased both the coarseness of the gluten fibrils and the size of the knots, although the apparent damage was not clearly detected on the crumb grain with MRI.
Relationship Between Protein Characteristics and Instant Noodle Making Quality of Wheat Flour
Authors: Park Chul Soo , Baik Byung‐Kee
Published: June 2007

We investigated the relationship between the protein content and quality of wheat flours and characteristics of noodle dough and instant noodles using 14 hard and soft wheat flours with various protein contents and three commercial flours for making noodles. Protein content of wheat flours exhibited negative relationships with the optimum water absorption of noodle dough and lightness (L*) of the instant noodle dough sheet. Protein quality, as determined by SDS sedimentation volume and proportion of alcohol‐ and salt‐soluble protein of flour, also influenced optimum water absorption and yellow‐blueness (b*) of the noodle dough sheet. Wheat flours with high protein content (>13.6%) produced instant noodles with lower fat absorption, higher L*, lower b*, and firmer and more elastic texture than wheat flours with low protein content (<12.2%). L* and free lipid content of instant noodles were >76.8 and <20.8% in hard wheat flours of high SDS sedimentation volume (>36 mL) and low proportion of salt‐soluble protein (<12.5%), and <75.7 and >21.5% in soft wheat flours with low SDS sedimentation volume (<35 mL) and a high proportion of salt‐soluble protein (>15.0%). L* of instant noodles positively correlated with SDS sedimentation volume and negatively correlated with proportion of alcohol‐ and salt‐soluble protein of flour. These protein quality parameters also exhibited a significant relationship with b* of instant noodles. SDS sedimentation volume and proportion of salt‐soluble protein of flours also exhibited a significant relationship with free lipid content of instant noodles (P < 0.01 and P < 0.001, respectively). Protein quality parameters of wheat flour, as well as protein content, showed significant relationship with texture properties of cooked instant noodles.
Nutrient Content in Buckwheat Milling Fractions
Authors: Skrabanja Vida , Kreft Ivan , Golob Terezija , Modic Mateja , Ikeda Sayoko , Ikeda Kiyokazu , Kreft Samo , Bonafaccia Giovanni , Knapp Martina , Kosmelj Katarina
Published: June 2007

Buckwheat seeds (Fagopyrum esculentum Moench) were milled into 23 fractions: seven fine flours, three coarse flours, four small semolina, two big semolina, six bran, and one husk fraction. A considerable variation in gross chemical composition was found among the milling fractions. The protein content varied from 4.4 to 11.9% (db) in flours and from 19.2 to 31.3% in bran fractions; starch varied from 91.7 to 70.4% in flours and from 42.6 to 20.3 in bran. The percentage of soluble dietary fiber contained in total dietary fiber was higher in flours than in semolina and bran fractions. Ash, Fe, P, tannin, phytate content, and color were also investigated. A unique distribution of phytate was found in starch. Correlation is significantly positive in husk, bran, and semolina fractions, while correlation is significantly negative in flour fractions. Depending on technological or nutritional demands, appropriate fractions may be chosen to achieve the desired end‐use product.
Effect of Moisture Content on Viscoelastic Properties of Hydrated Gliadin
Authors: Martling S. E. , Mulvaney S. J. , Cohen C.
Published: June 2007

The effect of moisture content on the linear viscoelastic properties of gliadin hydrated to 30 and 40% moisture content [gliadin(30%) and gliadin(40%), respectively] was determined. These two moisture contents bracketed the equilibrium moisture content of gliadin, which was 37.6%. Time‐temperature‐superposition was used to develop master curves of the elastic modulus (G′), viscous modulus (G″), dynamic viscosity (η′), and tan δ (G″/G′) from isothermal frequency sweep data obtained at 25–80°C. Smooth master curves were obtained for all of the viscoelastic functions for both gliadins. G′ and G″ showed a power law dependency on frequency (with G″ > G′) for frequencies <0.1 rad/sec for gliadin(30%) and <1 rad/sec for gliadin(40%). The low‐frequency‐limiting slopes on log‐log coordinates for G′ and G″ were 0.700 and 0.646 for gliadin(30%), respectively. Corresponding values were 0.658 and 0.614 for gliadin(40%). G′ crossed over G″ at a frequency of ≈0.3 rad/sec for gliadin(30%), while G′ and G″ for gliadin(40%) only became congruent at higher frequencies. Both gliadin samples showed appreciable frequency dependence of η′ over the entire frequency range, while η′ was greater for gliadin(30%) than for gliadin(40%) at all frequencies, but especially at the lowest frequencies. Tan δ increased gradually from a value of ≈1 at 0.1 rad/sec to ≈2 at the lowest frequency of 0.0002 rad/sec for both gliadins, but tan δ decreased rapidly for gliadin(30%) for frequencies >0.1 rad/sec. Thus, the main difference between gliadin(30%) and gliadin(40%) was that elastic effects (G′ > G″ and decreased tan δ were more prominent for gliadin(30%) at the higher frequencies. In addition, the frequency dependence of G′, G″, η′, and tan δ for the two gliadin samples was compared directly with two samples of poly(dimethylsiloxane) (PDMS) a linear silicone‐based entangled polymer with molecular weights (MW) of 140,000 and 385,000. The substantial differences in the magnitude and overall patterns of the frequency dependence of the viscoelastic functions between the gliadin and PDMS samples was attributed to the dominant effect that noncovalent secondary associations apparently have on the linear viscoelasticity of the gliadins. The energy of activation for flow (determined from the temperature dependence of the shift factors) for the gliadin samples for the range 25–45°C was higher than is typical for entangled linear polymer melts. The activation energy decreased for temperatures greater than ≈60°C for gliadin(30%) and ≈50°C for gliadin(40%). Thus, hydrated gliadin cannot be considered to be a simple viscoelastic liquid.
Potential of Triticale as a Substitute for Wheat in Flour Tortilla Production
Authors: Serna‐Saldivar Sergio O. , Guajardo‐Flores Sara , Viesca‐Rios Raquel
Published: June 2007

The potential of triticale as a partial or total substitute for wheat in flour tortilla production was evaluated. Different mixtures of triticale and wheat flours were tested in a typical hot‐press formulation. Both grains yielded similar amounts of flour. Wheat flour contained 1.5% more crude protein, 1.6× more gluten, and produced stronger dough than triticale. Triticale flour significantly reduced optimum water absorption and mix time of blends. Flour tortillas with 100% triticale absorbed 8% less water and required 25% of the mix time of the control wheat flour tortilla. The yield of triticale tortillas was lower than the rest of the tortillas due to lower moisture content and water absorption. Triticale dough balls required less proofing and ruptured during hot pressing, thus producing defective tortillas. The 50:50 flour mixture produced doughs with acceptable rheological properties and good quality tortillas. Addition of 1% vital gluten to the 75:25 triticale‐wheat flour mix or 2% to the 100% triticale flour significantly increased water absorption and mix time and improved dough properties and tortilla yields. Textural studies indicated that increasing levels of triticale flour reduced the force required to rupture tortillas. For all tortilla systems, rupture force gradually increased, and extensibility decreased during seven days of storage at room temperature; the highest rate of change occurred during the first day. Sensory evaluation tests indicated that triticale could substitute for 50% of wheat flour without affecting texture, color, flavor, and overall acceptability of tortillas. For production of 100% triticale flour tortillas, at least 2% vital gluten had to be added to the formulation.
Physicochemical Properties and Molecular Structures of Starches from Millet (Pennisetum typhoides) and Sorghum (Sorghum bicolor L. Moench) Cultivars in Nigeria
Authors: Gaffa Terna , Yoshimoto Yasushi , Hanashiro Isao , Honda Osamu , Kawasaki Sadamichi , Takeda Yasuhito
Published: June 2007

Some physicochemical properties and molecular structures of starches from millet (Pennisetum typhoides, Doro and Gero) and sorghum (Sorghum bicolor, red and white) in Nigeria were examined. Starch granules of millet and sorghum were 3–14 μm and 4–26 μm in diameter, respectively. Millet cultivars had similar peak viscosities (204–205 RVU) on pasting, while sorghum showed similar minimum viscosities (155–156 RVU). The actual amylose content (%) calculated from iodine affinity (IA, g/100 g) was 20.1 and 21.4 for sorghum and 21.3 for millet. The IA of amylopectin was high (1.27–1.42) and its average chain lengths were 20–21 with β‐amylolysis limit of 56%. Amylopectins showed a polymodal molecular weight distribution on a molar basis. The distributions differed among the samples with a higher amount of larger molecules in Doro and red sorghum. Weight‐ and molar‐based distributions of debranched amylopectins on HPSEC were polymodal with weight‐based distribution showing presence of long chains. Peak DP values for A+B1 and B2+B3 chain fractions were 13–16 and 42–43, respectively. The (A+B1)/(B2+B3) ratio on molar basis (9.0–11.5) was similar to maize and rice amylopectins. Peak DP on molar‐based distribution for white sorghum and millet amyloses were similar (490–540) and the DPn range was narrow (1,060–1,300), but weight‐based distribution profiles differed. The average chain lengths were 260–270 with 3.9–4.8 chains per molecule.
Development and Utilization of Reflectance Confocal Laser Scanning Microscopy to Locate Reaction Sites in Modified Starch Granules
Authors: Gray Jonathan A. , BeMiller James N.
Published: June 2007

A new method of locating reaction sites within modified starch granules was developed and applied. The method involves converting anionic groups introduced into starch granules into their silver salt form, reducing the silver cations to silver atoms, and locating the silver atoms by means of reflectance confocal laser scanning microscopy. The method was tested on three types of starch (normal maize, waxy maize, potato) containing two types of derivatizing groups (mono‐ and distarch phosphate ester groups and the 2‐hydroxy‐3‐sulfonylpropyl ether group). The method also revealed anionic sites in native granules, presumably due to proteins, ionic lipids, or native phosphate ester groups.
Characterization of Genes Encoding Wheat Grain Hardness from Chinese Cultivar GaoCheng 8901
Authors: Pan Z. , Song W. , Meng F. , Xu L. , Liu B. , Zhu J.
Published: June 2007

The puroindoline‐b (Pinb‐D1) gene from Chinese hard wheat cultivar GaoCheng 8901 (Triticum aestivum L.) was obtained using two pairs of primers designed based on the known Pinb‐D1 gene sequence and polymerase chain reaction (PCR) amplification. The PCR amplification was made using the genomic DNA of the wheat as a template and the specific fragment ≈450 bp in size was screened. The results indicated that the Pinb‐D1 gene in GaoCheng 8901 shared 99.78% and 99.32% homology in nucleotide acid sequence and amino acid sequence, respectively, compared with the Pinb‐D1 gene from hard wheat cultivars Wanser and Cheyenne. A new mutation in this Pinb‐D1 gene, different from the six known mutations in the Pinb‐D1 gene, was characterized with a change of a lysine to glutamic acid at position 45 in its protein sequence. This mutation, designated as Pinb‐D1l in this study, might contribute to the formation of grain hardness in GaoCheng 8901. The characterization of Pinb‐D1 gene would be helpful in manipulating grain hardness of wheat through genetic engineering.
Hydration Rates for Various Types of Mexican Maize Based on Single‐Kernel Measurements
Authors: Ramos Gonzalo , Pezet‐Valdez Marisol , O'Connor‐Sánchez Aileen , Placencia Celia , Pless Reynaldo C.
Published: June 2007

Hydration kinetics for sound maize kernels in liquid water, determined by single‐kernel measurements for three different Mexican maize types, yielded water diffusion coefficients ordered as Celaya corn > Toluca corn > Palomero corn, at all temperatures examined. These diffusion coefficients are lower than those reported earlier for maize grains, possibly due to the fact that in the present study damaged kernels were rigorously excluded. The energies of activation determined from the Arrhenius plots were ordered as Palomero corn > Celaya corn = Toluca corn and were similar in value to those reported earlier for other maize types. Damage to the surface of the maize kernels during the hydration experiments occurs at a significant frequency. Even minor surface lacerations can strongly affect the rate of hydration of the kernels. Experiments with maize grains selectively varnished in various parts of their surface show that the entry of water into the kernels occurs predominantly through the pericarp, not through the tip cap, though the tip cap has a higher water inflow per unit area.
Effects of Sorghum Cultivar on Injera Quality
Authors: Yetneberk Senayit , de Kock Henriette L. , Rooney Lloyd W. , Taylor John R. N.
Published: June 2007

Injera is an Ethiopian flat bread made from cereals, with tef preferred for the best quality injera. Because sorghum is less expensive in Ethiopia, there is great interest in improving the quality of sorghum injera. Effects of cultivar on injera quality were studied using 12 Ethiopian sorghum cultivars of varying kernel characteristics. White tef with good injera making quality was included as a reference. Injera quality was evaluated using two techniques: descriptive sensory analysis of fresh injera and instrumental texture analysis of injera stored over a storage period of 48 hr using a three‐point bending rig. Principal component analysis (PCA) of sensory data associated fresh injera from sorghum cultivars 3443‐2‐op, 76TI #23, and PGRC/E #69349 of varying endosperm texture, with positive injera texture attributes of softness, rollability, and fluffiness. Across the two seasons, texture analysis showed injera prepared from AW and CR:35:5, both with soft endosperm, required the least force to bend after 48 hr of storage. Bending force was negatively correlated with softness (r = ‐0.63, P < 0.05) and positively with grittiness (r = 0.75, P < 0.01) after 48 hr of storage. Sorghum cultivar has an influence on both injera making and keeping qualities.
Sorghum Bran as a Potential Source of Kafirin
Authors: da Silva Laura S. , Taylor John R. N.
Published: June 2007

Sorghum bran, a coproduct of sorghum dry milling, could be a source of protein for industrial applications. Condensed tannin‐free red and white sorghum samples were decorticated by abrasion until ≈10 or 25% grain by weight was removed. Kafirin was then extracted from the milling fractions using an aqueous ethanol based solvent system. The brans were darker and considerably higher in protein and fat compared with the whole grain flours and decorticated grain flours, with the 25% bran having higher protein than the 10% bran. This is due to increased contamination of the bran with protein‐dense, corneous endosperm. The protein extracted from all the milling fractions, including the brans, was pure kafirin. However, the yield of kafirin from the brans (15.9–26.7% of total protein present) was somewhat lower than that from whole grain and decorticated grain flours (45.0–57.9% of total protein present), due to the fact that kafirin is located solely in the endosperm. Also, the kafirin from bran was more contaminated with fat, polyphenols, and other substances, and more highly colored, particularly the kafirin from red sorghum. Thus, sorghum bran could be used as a source of kafirin but further purification steps may be necessary.
Combined Effects of Endoxylanases and Reduced Water Levels in Pasta Production
Authors: Brijs Kristof , Ingelbrecht Jeroen A. , Courtin Christophe M. , Schlichting Linda , Marchylo Brian A. , Delcour Jan A.
Published: June 2007

The combined effects on pasta properties of 1) varying dosages of endoxylanases (EC 3.2.1.8) from Aspergillus aculeatus and Bacillus subtilis and 2) lower levels of water during pasta dough processing were studied. The A. aculeatus endoxylanase has high selectivity toward water‐extractable arabinoxylan (WE‐AX), whereas B. subtilis endoxylanase preferentially hydrolyzes water‐unextractable arabinoxylan (WU‐AX). Pasta was produced on a microscale (50.0 g) from the semolinas of both a strong (AC Navigator) and a moderately strong (AC Avonlea) durum wheat cultivar. The levels of added water in endoxylanase‐treated pastas were adjusted to obtain the same maximal farinograph consistencies as for the control pastas. The extruded pastas were dried with drying cycles at 40, 70, or 90°C. Apart from increasing levels of solubilized arabinoxylans, these treatments had little effect on the color, optimal cooking time, and firmness of the resulting pasta. High enzyme concentrations and low (40°C) drying temperature resulted in clearly or much less checked final products for the B. subtilis and A. aculeatus enzyme, respectively. Upon cooking, the enzymically formed low molecular weight arabinoxylans were retained better in the pasta strands than their equally low molecular weight arabinogalactan counterparts.
Grain Quality Characteristics and Milling Performance of Full and Partial Waxy Durum Lines
Authors: Vignaux Nathalie , Doehlert Douglas C. , Hegstad Justin , Elias Elias M. , McMullen Michael S. , Grant Linda A. , Kianian Shahryar F.
Published: June 2007

Mutation of the gene coding for the granule bound starch synthase (waxy protein) leads to reduced amylose content in cereal endosperm. Durum wheat (Triticum turgidum L. var. durum) has one waxy locus in each of its two genomes. Full waxy durum wheat is produced when both genomes carry the waxy null alleles. When only one locus is mutated, partial waxy durum wheat is obtained. Partial and full waxy near‐isogenic lines of durum wheat developed by a breeding program were analyzed as to their quality characteristics. Amylose was largely eliminated in full waxy lines; however, no reduction in amylose content was detected in partial waxy lines. The waxy mutation did not affect grain yield, kernel size, or kernel hardness. Full waxy durum lines had higher kernel ash content, α‐amylase activity, and a unique nonvitreous kernel appearance. Protein quality, as evaluated by SDS microsedimentation value, gluten index, and wet gluten was slightly lower in the full waxy lines than in the other genotypes. However, comparisons with current cultivars indicated that protein quality of all derived lines remained in the range of strong gluten cultivars. Semolina yield was lowered by the waxy mutations due to lower friability that resulted in less complete separation of the endosperm from the bran. Waxy semolina was more sensitive to mechanical damage during milling, but modified tempering and milling conditions may limit the damage. Overall, quality characteristics of waxy durum grain were satisfactory and suitable for application testing.
Nonenzymatic Browning During Storage of Infant Cereals
Authors: Ramirez‐Jimenez A. , Garcia‐Villanova B. , Guerra‐Hernandez E. J.
Published: June 2007

The browning indicators furosine and color were determined in infant cereals and infant cereals containing powdered milk to evaluate the utility of these parameters for monitoring storage. Studies were made on seven infant cereal samples including both gluten and gluten‐free products. Samples were stored under laboratory conditions at 28°C for four or 16 weeks; or under modified water activity conditions at 25°C or 55°C for one, two, three, or four weeks; or under industrial conditions in air or nitrogen atmospheres at 32°C or 55°C for one, three, six, or 12 months. Furosine levels increased during the storage of infant cereals containing powdered milk under all time, temperature, and water activity (aw) conditions assayed, except drastic conditions (55°C, aw = 0.65). Color values increased in infant cereals with gluten (7‐cereal and 8‐cereal samples), regardless of milk content, when they were stored under drastic conditions (55°C or 25°C with normal or modified water activity). However, the gluten‐free infant cereals (rice‐corn and rice‐corn‐soy samples) that have a characteristic yellow color showed no increase in color during storage. The extent of the Maillard reaction was greatest in the infant cereals that included milk in their formulation.
Slowly Digestible Starch from Debranched Waxy Sorghum Starch: Preparation and Properties
Authors: Shin Sang Ick , Choi Hea Jin , Chung Koo Min , Hamaker Bruce R. , Park Kwan Hwa , Moon Tae Wha
Published: June 2007

Effects of debranching time, storage time, and storage temperature on production and structural properties of slowly digestible starch (SDS) were investigated. Waxy sorghum starch was hydrolyzed by isoamylase for various times (0–24 hr), and the variously debranched products were stored at ‐30, 1, and 30°C for 1–6 days. Optimal conditions for SDS production were isoamylase treatment for 8 hr and storage at 1°C for three days, resulting in SDS content of 27.0% in the optimum product. Microscopic observation revealed that rapidly digestible starch (RDS) and SDS were removed from the edges and surfaces of the optimum product by α‐amylase digestion. Digestion conditions that removed RDS and SDS resulted in a residue with a higher transition temperature and enthalpy than raw starch on a differential scanning calorimetric thermogram. Removal of RDS alone did not cause distinct decrements of peak temperature (Tp) and enthalpy (ΔH) compared with stored starch. The optimum SDS product showed an amorphous type of X‐ray diffractogram. Digestive removal of RDS from the optimum product gave a residue with X‐ray peaks similar to B type, which supports that it is partly crystalline. Removal of RDS and SDS gave broader peaks in the X‐ray pattern.
A Comparative Study of Fourier Transform Raman and NIR Spectroscopic Methods for Assessment of Protein and Apparent Amylose in Rice
Authors: Sohn Miryeong , Himmelsbach David S. , Barton Franklin E.
Published: June 2007

Fourier‐transform Raman (FT‐Raman) spectroscopy and near‐infrared (NIR) reflectance spectroscopy were used to compare calibration models for determining rice cooking quality parameters such as apparent amylose and protein. Samples from two seasons were used in each calibration set. The laboratory values ranged from 4.89 to 12.48% for protein and from 0.2 to 25.7% for amylose. The data for both FT‐Raman and NIR were preprocessed with orthogonal signal correction (OSC) for standardization. For both spectroscopic methods, five models were optimized by partial least squares regression (PLSR) and by Martens' uncertainty regression (MUR), including no processing, smoothing, normalization, first derivative (D1), and second derivative (D2). Based solely on standard error of cross‐validation (SECV), the FT‐Raman method was superior to the NIR method for protein. For amylose, the FT‐Raman and NIR methods resulted in similar calibration statistics with a high precision, with the FT‐Raman requiring fewer factors. The best FT‐Raman models were generated from OSC preprocessing with MUR for protein (SECV 0.15%, five factors) and from OSC without MUR for amylose (SECV 0.70%, seven factors). The best NIR models were obtained with D2 transform of OSC spectra for protein (SECV 0.22%, four factors) and with OSC spectra for amylose (SECV 0.57%, 11 factors).
Prediction of β‐Glucan Concentration Based on Viscosity Evaluations of Raw Oat Flours from High β‐Glucan and Traditional Oat Lines
Authors: Colleoni‐Sirghie Mirela , Jannink Jean‐Luc , Kovalenko Igor V. , Briggs Jenni L. , White Pamela J.
Published: June 2007

Rheological properties of raw oat flour slurries were determined in experimental high β‐glucan (≤7.8%) and traditional oat lines (4–5% β‐glucan) grown in two consecutive years. Three different media were used to disperse oat flours: deionized water, silver nitrate solution (to inactivate endogenous enzymes), and alkali solution (to solubilize both water‐soluble and water‐insoluble β‐glucans). Significant correlations (P < 0.05) between viscosity of slurries and β‐glucan concentration obtained in either deionized water (r = 0.833), silver nitrate (r = 0.940), or alkali (r = 0.896) solutions showed that β‐glucans were the main contributor to oat extract viscosity. The highest correlation was obtained in silver nitrate solution, suggesting that inactivating endogenous enzymes is important to obtain high correlations. Predictive models of oat β‐glucan concentration based on the viscosity profile were developed using partial least squares (PLS) regression. Prediction of β‐glucan concentration based on viscosity was most effective in the silver nitrate solution (r = 0.949, correlation coefficient of predicted vs. analyzed β‐glucans) and least effective in the alkali solution (r = 0.870). These findings demonstrate that the β‐glucan in oat could be predicted by measuring the viscosity of raw flours in silver nitrate solution, and this method could be used as a screening tool for selective breeding.
Production of Bihon‐type Noodles from Maize Starch Differing in Amylose Content
Authors: Tam Lai Ming , Corke Harold , Tan Wilson T. , Li Jiansheng , Collado Lilia S.
Published: June 2007

Maize starches extracted from selected maize cultivars with 0.2–60.8% amylose contents were used to produce bihon‐type noodles. Starch dough using a pregelatinized starch binder was prepared and extruded through a laboratory‐scale extruder simulating the traditional process of making bihon in the Philippines. The normal maize starches with amylose content of ≈28% were successfully used for bihon‐type noodle production, but waxy maize starches with 0.2–3.8% amylose content and high‐amylose maize starches with 40.0–60.8% amylose content failed to produce bihon‐type noodles. Viscoamylograph profile parameters and swelling volume are significantly correlated to amylose content of maize starch samples evaluated. These physicochemical properties may be used to indicate that the starch samples at normal amylose levels may be used for bihon‐type noodles. Starch noodles produced in the laboratory were not significantly different in terms of either cooking quality or textural properties from two commercially produced maize noodle samples, except for adhesiveness. The laboratory process and fabricated extruder can be used to produce bihon‐type noodles.
Genotype and Environmental Influences on Pasting Properties of Rice Flour
Authors: Dang Jennifer Minh‐Chau , Copeland Les
Published: June 2007

The pasting behavior of flour from several Australian rice (Oryza sativa L.) cultivars, differing in amylose content and grown in three different locations and three seasons, were determined using the Rapid Visco Analyser. Genotype, growth season, and growth location all affected the pasting behavior of rice flour. The amylose content of the same cultivar was significantly higher in the coolest growing season, resulting in RVA traces with lower peak viscosity and higher setback than samples with lower amylose content. When the same cultivar of rice was grown in different locations in the same season, there were no significant differences in the total starch, protein, lipid, and amylose content of the flour, but there were significant differences in the pasting behavior. This indicates that environmental as well as genetic factors influence the pasting behavior of rice flour. Flour from parboiled and quick‐cooking rice did not paste and had low viscosities compared with unprocessed rice. Results from this study showed that the pasting behavior of rice flour was related to genotype and was influenced by environmental factors that brought about subtle changes in the grains that were not picked up by chemical analyses.
Molecular Structure and Some Physicochemical Properties of Buckwheat Starches
Authors: Yoshimoto Yasushi , Egashira Tamami , Hanashiro Isao , Ohinata Hiroshi , Takase Yoshikazu , Takeda Yasuhito
Published: June 2007

The molecular structure and pasting properties of starches from eight buckwheat cultivars were examined. Rapid viscograms showed that buckwheat starches had similar pasting properties among cultivars. The actual amylose content was 16–18%, which was lower than the apparent amylose content (26–27%), due to the high iodine affinity (IA) of amylopectin (2.21–2.48 g/100 g). Amylopectins resembled each other in average chain‐length (23–24) and chain‐length distributions. The long‐chains fraction (LC) was abundant (12–13% by weight) in all the amylopectins, which was consistent with high IA values. The amyloses were also similar among the cultivars in number‐average DP 1,020–1,380 with 3.1–4.3 chains per molecule. The molar‐based distribution indicated that all the amyloses comprised two molecular species differing in molecular size, although the weight‐based distribution showed a single species. A comparison of molecular structures of buckwheat starches to cereal starches indicated buckwheat amylopectins had a larger amount of LC, and their distributions of amylose and short chains of amylopectin on molar basis were similar to those of wheat and barley starches.
Use of Size‐Exclusion High‐Performance Liquid Chromatography for Wheat Quality Prediction in Ethiopia
Authors: Labuschagne M. T. , Koen E. , Dessalegn T.
Published: June 2007

Wheat quality testing facilities in Ethiopia are limited. The aim of this study was to determine whether size‐exclusion high‐performance liquid chromatography (SE‐HPLC) could be used in breeding programs for quality testing. Thirteen Ethiopian and two South African wheat cultivars were evaluated in two diverse environments for milling and dough characteristics. SE‐HPLC was done on the same samples. Across environments, both SDS‐soluble and SDS‐insoluble polymeric proteins significantly influenced important quality characteristics such as SDS‐sedimentation and mixograph development time. The large monomeric proteins, which are mainly gliadins, had a consistently significantly negative effect on quality. The increase of polymeric protein as opposed to monomeric protein led to improvement of quality characteristics. The SDS‐soluble and SDS‐insoluble polymeric proteins were equally important in quality prediction. The amount of polymeric proteins was significantly higher in the high‐protein environment. Despite a large environmental effect on most fractions, a large ratio of polymeric proteins to monomeric proteins (both SDS‐soluble and SDS‐insoluble) can be a good indicator of baking quality. SE‐HPLC is therefore an option to use in breeding programs in Ethiopia for quality evaluation.