bluuebunny/crossref_metadata_2025 huggingface dataset:
Chemical and Physicochemical Properties of Maize Starch After Industrial Nixtamalization
Authors: Toro‐Vazquez Jorge F. , Gómez‐Aldapa Carlos A.
Published: June 2007

Processing conditions similar to traditional nixtamalization are now used by the industry in the production of dry maize flours (DMF). The objective of this investigation was to evaluate the effect of industrial nixtamalization on maize starch. Thus, dent maize grains were sampled from storage silos and the starch isolated (S). From the same batch of maize, DMF was obtained and the starch isolated (S‐DMF). The amylose content in the starches was quite similar (21.5–23.4%) and characteristic of a dent maize. However, nixtamalization increased the calcium content in S‐DMF. The starches investigated exhibited the typical A‐type diffraction pattern after 40 days of storage at 11–84.1% rh. However, the differential scanning calorimetry (DSC) results showed that annealing of maize starch occurred during storage at 30°C. On the other hand, industrial nixtamalization has both a melting and annealing effect on maize starch. Thus, the operative glass transition temperature (Tg), and the DSC parameters that define starch gelatinization (Tp and ΔH) showed that the proportion between crystalline and amorphous regions within the starch granule and the extent of physical damage to starch were modified by nixtamalization. As an example, Tg for S was between 60 and 62.5°C, while the S‐DMF had a Tg of 45–55°C for damaged starch and 65–70°C for annealed starch. Additionally, the extraction of the nonconstitutive starch lipids provided starches with more consistent thermal properties, particularly in the behavior of gelatinization at different water content. This last observation might have important implications in the consistency of starch physicochemical properties and, consequently, in the quality of maize products such as tortillas.
Starch Characteristics of Waxy and Nonwaxy Tetraploid (Triticum turgidum L. var. durum) Wheats
Authors: Grant L. A. , Vignaux N. , Doehlert D. C. , McMullen M. S. , Elias E. M. , Kianian S.
Published: June 2007

Manufacture of pasta products is paramount for durum wheat (Triticum turgidum L. var. durum). The recent development of waxy durum wheat containing starch with essentially 100% amylopectin may provide new food processing applications and present opportunities for value‐added crop production. This investigation was conducted to determine differences in some chemical and functional properties of waxy durum starch. Starch was isolated from two waxy endosperm lines and four nonwaxy cultivars of durum wheat. One of the waxy lines (WX‐1) was a full waxy durum wheat whereas the other line (WX‐0) was heterogeneous, producing both waxy and nonwaxy seed. Effects on starch swelling, solubility, pasting, gelatinization, and retrogradation were examined. The full waxy starch had four times more swelling power than the nonwaxy durum starches at 95°C, and was also more soluble at three of the four temperatures used. Starch pasting occurred earlier and peak viscosities were greater for starches from both waxy lines than for the nonwaxy starches, but their slurries were less stable with continued stirring and heating. Greater energy was required to melt gelatinized waxy starch gels, but no differences were found in either refrigerated storage or freeze‐thaw retrogradation, as determined by differential scanning calorimetry. The results of this investigation showed some significant differences in the starch properties of the waxy durum wheat lines compared to the nonwaxy durum wheats.
Assessment of Heat‐Damaged Wheat Kernels Using Near‐Infrared Spectroscopy
Authors: Wang D. , Dowell F. E. , Chung D. S.
Published: June 2007

Heat damage is a serious problem frequently associated with wet harvests because of improper storage of damp grain or artificial drying of moist grain at high temperatures. Heat damage causes protein denaturation and reduces processing quality. The current visual method for assessing heat damage is subjective and based on color change. Denatured protein related to heat damage does not always cause a color change in kernels. The objective of this research was to evaluate the use of nearinfrared (NIR) reflectance spectroscopy to identify heat‐damaged wheat kernels. A diode‐array NIR spectrometer, which measured reflectance spectra (log (1/R)) from 400 to 1,700 nm, was used to differentiate single kernels of heat‐damaged and undamaged wheats. Results showed that light scattering was the major contributor to the spectral characteristics of heat‐damaged kernels. For partial least squares (PLS) models, the NIR wavelength region of 750–1,700 nm provided the highest classification accuracy (100%) for both cross‐validation of the calibration sample set and prediction of the test sample set. The visible wavelength region (400–750 nm) gave the lowest classification accuracy. For two‐wavelength models, the average of correct classification for the classification sample set was >97%. The average of correct classification for the test sample set was generally >96% using two‐wavelength models. Although the classification accuracies of two‐wavelength models were lower than those of the PLS models, they may meet the requirements for industry and grain inspection applications.
Isolation of Polar Lipid Classes from Wheat Flour Extracts by Preparative High‐Performance Liquid Chromatography
Authors: Papantoniou Eleni , Hammond Eugene W. , Scriven Fiona , Gordon Michael H. , Schofield J. David
Published: June 2007

A preparative high‐performance liquid chromatographic method was developed for the isolation of polar lipid classes of mono‐ and digalactosyldiacylglycerols (MGDG and DGDG), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), and phosphatidylcholine (PC) from wheat flour lipid extracts in relatively large quantities. The method allowed the separation of ≤100 mg/injection of lipid mixture. MGDG, DGDG, and PC were isolated as pure lipid classes, whereas PE was isolated in a mixture with PG, PC, and lysophosphatidylcholine (LPC). The availability of this methodology will facilitate research aimed at investigating the functional role of such lipids in foods.
Effect of Drying Treatment Conditions on Sensory Profile of Germinated Oat
Authors: Heiniö R.‐L. , Oksman‐Caldentey K.‐M. , Latva‐Kala K. , Lehtinen P. , Poutanen K.
Published: June 2007

Germination and subsequent drying of oat produced significantly different sensory profiles depending on processing parameters such as drying speed and temperature profile. The most salient sensory attributes for processed oat were roasted odor and flavor, sweet taste, intense odor, intense aftertaste, and hard, crisp, brittle texture (P < 0.05). High temperatures (>85°C) were necessary to produce these sensory attributes, and quick drying after germination resulted in higher levels of intensity of favorable sensory attributes. The total amount of volatile compounds was higher in native (ungerminated) oat than in processed oat. During germination, and particularly during the drying treatment, the profile of volatile compounds changed. The most abundant volatile compounds responsible for odor were dimethyl sulfide, hexanal, pentanal, and iso butanal. The relative amount of dimethyl sulfide increased as a function of temperature in drying, whereas hexanal, pentanal, and isobutanal disappeared during heating, as did several other small ketones, alcohols, and esters. The germinated oat dried at high temperatures (65–93°C and 65–85°C) was perceived as being roasted, sweet, and nutty. Sensory and instrumental profile analyses of selected volatile compounds using partial least squares (PLS) regression techniques showed that these sensory attributes were clearly related to dimethyl sulfides and isobutanol. A moist and earthy odor was related to cymene, limonene, and isobutanal. Phenolic compounds significantly influenced oat flavor, whereas lipids had a negligible effect.
Frequency Dependence of Viscoelastic Properties of Bread Crumb and Relation to Bread Staling
Authors: Wang F. C. , Sun X. S.
Published: June 2007

The viscoelastic behavior of bread crumb was studied using dynamic mechanical analysis (DMA) in the compression mode with the frequency sweep. The dynamic storage modulus (E′), loss modulus (E″), and tanδ (E″/E′) were measured for bread crumb aged up to three days at ambient temperature. The viscoelastic properties of bread crumb showed a characteristic frequency dependence similar to that of a soft rubberlike solid. Typical behavior of bread crumb involved a transition from rubberlike to glasslike consistency with increasing frequency. At a low frequency region, the E′ and E″ values were relatively small and nearly constant, showing characteristics of the rubbery plateau. Then, they increased rapidly with increasing frequencies and approached a glasslike state. Tanδ was low and almost constant at low frequencies before the transition, then went through a prominent peak with increasing frequency. The frequency at which the tanδ of bread crumb started to rapidly increase was defined as the onset frequency (ƒo) of the transition. The ƒo values increased with the aging of bread crumb samples, which correlated highly to bread staling (r = 0.942). Both dynamic moduli E′ and E″ at ƒo also increased with the aging of bread, which correlated highly to firmness obtained using a texture analyzer in a static compression mode (r = 0.941 and 0.943, respectively). DMA measurements could be helpful in characterizing bread staling.
Wheat Intercultivar Differences in Susceptibility of Glutenin Protein to Effects of Bug (Eurygaster integriceps) Protease
Authors: Sivri D. , Sapirstein H. D. , Bushuk W. , Köksel H.
Published: June 2007

Preharvest bug damage to wheat can cause significant losses in bread‐making quality. One of the most prevalent forms of bug damage which frequently occurs in most countries of the Middle East, Eastern Europe and North Africa can be attributed to Heteropterous insects, particularly Eurygaster spp. Intercultivar differences in the susceptibility of glutenin to proteolytic degradation by the bug Eurygaster integriceps were investigated using six breadwheat cultivars of Turkish origin. Crude enzyme extract was prepared with distilled water from bug‐damaged wheat. The freeze‐dried extract was blended with sound samples of ground wheat, and the mixture was incubated in distilled water for 30 and 60 min at 37°C and subsequently freeze‐dried. The proteolytic effects of bug damage were determined on large polymeric glutenin. The latter was measured as 50% 1‐propanol insoluble (50PI) glutenin extractable with 50% 1‐propanol in reductant dithiothreitol. The decreases in the amount of 50PI glutenin and the high and low molecular weight subunits were quantified using reversed‐phase HPLC. There was a substantial and progressive decrease in the quantity of 50PI glutenin and its subunits with increasing incubation time. Intercultivar differences were observed that were unrelated to intrinsic levels of proteolytic activity. After 60 min of incubation, the relative decrease in 50PI glutenin compared with control samples ranged from 43% (cv. Ankara) to 65 % (cv. Kirkpinar). Some cultivars (Lancer, Ankara and Gün) with similar levels of intrinsic proteolytic activity showed significantly different responses to bug protease. One cultivar (cv. Kirkpinar) with the lowest proteolytic activity was the most susceptible. High quality breadwheats (cvs. Bezostaya, Lancer, Kiraç and Gün) were generally more resistant to the bug protease, although Ankara, with both intermediate protease activity and breadmaking quality, was the most resistant cultivar. While the 50PI glutenin test was very effective in quantifying the damaging effects of bug protease on wheat protein quality, the nature of the intercultivar differences was unclear.
Contribution of Sourdough Lactobacilli, Yeast, and Cereal Enzymes to the Generation of Amino Acids in Dough Relevant for Bread Flavor
Authors: Thiele C. , Gänzle M. G. , Vogel R. F.
Published: June 2007

The amino acid release was determined in wheat doughs supplied with salt, acid, dithiothreitol, or starter cultures to evaluate the relevance of the amino acid concentration on bread flavor. Wheat flour proteinases almost linearly released amino acids and the highest activity of wheat flour proteinases was found in acidified and reduced doughs. The effects of starter cultures on amino acid concentrations depended on their composition. Yeasts exhibited a high demand for amino acids, however, the total amino acid concentrations were not markedly affected by lactic acid bacteria. The individual amino acid contents were determined by the pH during fermentation and microbial metabolism. The formation of proline was favored by values higher than pH 5.5, whereas release of phenylalanine, leucine and cysteine mainly occurred at lower pH. Ornithine was found only in doughs fermented with Lactobacillus pontis. To determine effects of the amino acid concentration on bread aroma, fermented doughs were evaluated in baking experiments. An increased intensity of bread flavor was obtained by preferments prepared with lactic acid bacteria. The roasty note of wheat bread crust could be markedly enhanced by L. pontis. This results support the assumption that flavor of wheat bread is enhanced by increasing the concentration of free amino acids and especially ornithine in dough.
Effects of Flour Particle Size and Starch Damage on Processing and Quality of White Salted Noodles
Authors: Hatcher D. W. , Anderson M. J. , Desjardins R. G. , Edwards N. M. , Dexter J. E.
Published: June 2007

Several reduction grinding conditions were used on a Canadian Western Red Spring (CWRS) farina to yield flours of comparable protein content within three specific particle size ranges (132–193, 110–132, 85–110 μm) at three starch damage levels (3.0, 3.9, 7.0 Megazyme units). White salted noodles (1% w/w NaCl) were initially processed at a fixed absorption (32%). Dynamic oscillatory and large deformation creep measurements indicated that doughs with lower starch damage, thick or thin, exhibited lower G′ (storage modulus), higher tan δ (G″ [loss modulus]/G′) values, and greater maximum strain during creep than doughs with higher starch damage. There were no clear trends between work input during sheeting and either starch damage or particle size. Instrumental texture analysis of raw noodles showed no significant differences due to either starch damage or flour particle size. Flours with fine particle size gave cooked noodles with the best textural attributes, whereas starch damage exhibited no consistent relationship with cooked noodle texture. Cooking loss was greatest in samples with highest starch damage and coarsest particle size; water uptake was inversely related to starch damage and particle size. Experiments were repeated at adjusted water absorptions (32–36.5%) for fine and coarse flours with highest and lowest starch damage. Differences in raw noodle dough rheological properties were largely eliminated, confirming that differences noted at constant absorption were primarily due to flour water absorption. Work input during sheeting was inversely related to starch damage and was higher for fine particle size. Cooking losses were highest for higher starch damage and fine particle size. Water uptake was highest for fine particle size, but in contrast to cooking loss, was higher at lower starch damage. Textural parameters indicated superior cooking quality when particle size was finer and starch damage was lower. Flour particle size and starch damage (as indicated by water absorption) are both primary quality determinants of white salted noodle properties and, to some extent, exert their influence independently.
Effects of Fortification and Enrichment of Maize Tortillas on Growth and Brain Development of Rats Throughout Two Generations
Authors: Stylianopoulos Chryssanthi , Saldívar Sergio O. Serna , MacKinney Guillermo Arteaga
Published: June 2007

The growth and brain development of laboratory rats fed typical indigenous tortilla‐based diets were determined throughout two generations. The experiment compared three different types of tortilla‐based diets: regular tortillas produced from dry masa flour (RDMF), tortillas obtained from fresh masa (FM), and tortillas produced from dry masa flour fortified with 6% defatted soybean and enriched with vitamins B1, B2, niacin, and folic acid and microminerals iron and zinc (FEDMF). Female rats were mated 58 days postweaning with males belonging to the same treatment with the objective of obtaining second generation pups that were further subjected to regular lactation and 28 day postweaned growth. A comparison between growth of first and second generation rats was determined. In addition, representative animals of each physiological stage were first exsanguineted for hematocrit determination and then slaughtered with the aim of obtaining femur and brain tissues. Cerebral DNA and number of neurons were determined in each of the brains sampled. Growth of rats fed FEDMF was significantly higher (P < 0.05) in both generations than counterparts fed RDMF or FM. The difference among treatments was more evident in second generation rats. Pregnancy rate, number of newborns per litter, litter weight, and pup's survival rate was higher for the control and FEDMF treatments. Femur growth was also higher (P < 0.05) for first‐generation male adult rats fed control and FEDMF. The concentration and total content of cerebral DNA and number of neurons in males and females belonging to the first generation was similar. However, for second generation rats, these values were lower for animals fed regular tortilla diets. This data clearly demonstrates that the negative effects of malnutrition on brain development of pups occurred during gestation and lactation.
Evaluation of a Near‐Infrared Reflectance Spectrometer as a Granulation Sensor for First‐Break Ground Wheat: Studies with Hard Red Winter Wheats
Authors: Pasikatan M. C. , Steele J. L. , Haque E. , Spillman C. K. , Milliken G. A.
Published: June 2007

A single wheat class or blended wheats from two wheat classes are usually milled in a flour mill. A near‐infrared (NIR) reflectance spectrometer, previously evaluated as granulation sensor for first‐break ground wheat from six wheat classes, was evaluated for a single wheat class, hard red winter (HRW) wheat, using offline methods. The HRW wheats represented seven cultivars ground by an experimental roller mill at five roll gap settings (0.38, 0.51, 0.63, 0.75, and 0.88 mm) which yielded 35 ground wheat samples each for the calibration and validation sets. Granulation models based on partial least squares regression were developed with cumulative mass of size fractions as a reference value. Combinations of four data pretreatments (log 1/R, baseline correction, unit area normalization, and derivatives) and subregions of the 400–1,700 nm wavelength range were evaluated. Models that used pathlength correction (unit area normalization) predicted well each of the four size fractions of first‐break ground wheat. The best model, unit area normalization and first derivative, predicted all the validation spectra with standard errors of performance of 3.80, 1.29, 0.43, and 0.68 for the >1041, >375, >240, and >136 μm size fractions, respectively. Ground HRW wheats have narrower particle size distribution and better sieving properties than ground wheat from six wheat classes. Thus, HRW wheat granulation models performed better than the previously reported models for six wheat classes.
Effects of Various Steeping Periods on Physical and Sensory Characteristics of Yukwa (Korean Rice Snack)
Authors: Chun Hyang Sook , Cho Sung Bin , Kim Hye Young L.
Published: June 2007

This experiment was conducted to investigate the effect of various steeping periods on the physical and sensory properties of yukwa, which is a traditional Korean oil‐puffed snack made of waxy rice, using milled waxy rices (cv. Shinsunchalbyeo) steeped for 0, 1, 3, 6, 9, 12, and 15 days. As the steeping period changed from 0 to 15 days, the cross‐sectional area and expansion ratio of yukwa evaluated by image analysis significantly increased from 226 to 437 mm2 and from 805 to 1,874%, respectively. Conversely, the ratio of length to height and density of yukwa significantly decreased with an increase in steeping period duration. The Hunter a value of yukwa tended to increase, whereas b value tended to decrease, as steeping period increased. Among the mechanical textural parameters, hardness was greatly affected by the steeping period range, with values ranging from 1,358 to 25,514 dyne/cm2. Sensory results showed that sour aroma, color uniformity, and original flavor tended to increase, but hardness, crispiness, color roughness, oil flavor, and oil aroma tended to decrease in yukwa with the longer steeping period. From these observations, it can be concluded that the steeping period of waxy rice has an influence on the physical and sensory properties of yukwa.
Prediction of Test Weight from a Small Volume Specific Gravity Measurement
Authors: Donelson J. R. , Gaines C. S. , Andrews L. C. , Finney P. F.
Published: June 2007

The specific gravity (cm3/g) of small (20 and 40 g) samples of soft wheats from three states were rapidly measured and compared with bulk density (g/cm3) measurements (microtest weights). Specific gravities were correlated with test weights for both cleaned and uncleaned samples. The relationship between specific gravity and test weight was linear unless the samples were severely shriveled. Operator effect was not statistically significant. Simple linear regression analysis produced equations that predicted with high R2 value microtest weights from specific gravity measurements. Both 20 and 40 g sample sizes were satisfactory. However, 40 g samples produced better statistical relationships.
Development of Standard Procedures for a Simple, Rapid Test to Determine Wheat Color Class
Authors: Ram M. S. , Dowell Floyd E. , Seitz Larry , Lookhart George
Published: June 2007

Growing conditions, kernel characteristics, and genetics affect wheat kernel color. As a result, red and white wheats sometimes cannot be differentiated by visual examination. Soaking wheat kernels in a sodium hydroxide solution enhances the difference in color; red wheat turns a darker red, and white wheat turns straw‐yellow. Previously, when NaOH was used for wheat determination of color class, only a visual assessment was made under arbitrary conditions, many times not suitable for field work. In the present work, visible reflectance spectroscopy and visual assessments were used to optimize NaOH (2 mL/g of wheat) soak time (10 min), concentration (5M or 20%), and temperature (60°C). The optimal procedure will provide users who are not laboratory trained with inexpensive, safe procedures to definitively assign wheat color class in the shortest time in field locations. Calibration and prediction of several wheat cultivars using partial least square regression were used to validate the optimal test procedure. The test differentiated even rain‐bleached wheat and cultivars that were difficult to classify visually. No distinct correlation occurred between predicted color value and the number of red genes.
Milling Value of Sorghums Compared by Adjusting Yields to a Constant Product Color
Authors: Awika Joseph M. , Suhendro Elly L. , Rooney Lloyd W.
Published: June 2007

A method of comparing milling values of sorghum by adjusting yields to standard L values was developed. The milling values of ‘Dorado’ (an excellent food‐type sorghum variety), ‘ATx399 × RTx430’ (a commercial red sorghum hybrid) and three ‘Warner 902W’ (commercial white food type hybrids with different levels of weathering designated W‐1, W‐2, and W‐3) were determined using a tangential abrasive dehulling device for various times. Color (L, a, b) was measured on the decorticated grain (grits) and the ground grits (flour). The yields (by weight) of flours adjusted to an L value of 85 were 93, 88, 86, 84, and 70% for Dorado, W‐2, W‐1, W‐3, and red, respectively. The b (yellow) values were highest for red and lowest for Dorado. The grits yields were 96, 89, 84.5, 81.5, and 56.5% when adjusted to an L of 67 for Dorado, W‐2, W‐1, W‐3, and red sorghums, respectively. Milling yields expressed at comparable flour or grit color clearly demonstrate that white food‐type sorghums have significantly better milling yields than red sorghums. Adjusting milling yields to a standard L value is an accurate and easy way to compare milling properties of sorghums for yield and product color.
Tensile Properties of Extruded Corn Protein Low‐Density Polyethylene Films
Authors: Herald Thomas J. , Obuz Ersel , Twombly Wesley W. , Rausch Kent D.
Published: June 2007

The strength of films extruded from powder blends of corn zein or corn gluten meal (CGM) with low‐density polyethylene was investigated. Tensile strength, percent elongation at break, and elastic modulus of the extruded films were measured. The tensile strength decreased from 13 MPa to ≈10.5 MPa with zein addition, while CGM addition resulted in tensile strength of ≈6 MPa. The higher the level of biological material (CGM or zein) in the films the lower the tensile properties. Films containing CGM exhibited significantly lower tensile properties than those containing zein. Extrusion processing of biological films is a step toward commercial viability.
Environmental Conditions During Wheat Grain Development Alter Temporal Regulation of Major Gluten Protein Genes
Authors: Altenbach Susan B. , Kothari Kerry M. , Lieu Dao
Published: June 2007

The accumulation of transcripts for the major gluten storage proteins was assessed during grain development in wheat plants (Triticum aestivum L. ‘Butte 86’) grown under seven controlled environments where temperature, water, and fertilizer conditions were varied after anthesis. Transcripts within the α‐, γ‐ and ω‐gliadin, low molecular weight glutenin subunit (LMW‐GS), and high molecular weight glutenin subunit (HMW‐GS) gene families followed similar patterns of accumulation throughout grain development under each environmental regimen. Under moderate daytime temperatures in plants that were well watered and fertilized, transcripts from all gene families were detectable by eight days postanthesis (8 DPA), were present at high levels until ≈34 DPA, and disappeared between 36 and 38 DPA. Under high temperature regimens, transcripts from all gene families appeared slightly earlier, but the time frame of accumulation was shorter. The presence or absence of postanthesis fertilizer did not alter the temporal regulation of the gluten genes under the moderate temperature regimen. However, under the high daytime temperature regimen, transcripts disappeared slightly earlier in kernels from plants that did not receive postanthesis fertilizer. Reverse transcriptase polymerase chain reaction (RT‐PCR) using primer pairs for specific HMW‐GS and LMW‐GS transcripts revealed that individual genes within each family exhibited identical patterns of temporal regulation under different environmental conditions.
Synergistic and Additive Effects of Three High Molecular Weight Glutenin Subunit Loci. II. Effects on Wheat Dough Functionality and End‐Use Quality
Authors: Beasley H. L. , Uthayakumaran S. , Stoddard F. L. , Partridge S. J. , Daqiq L. , Chong P. , Békés F.
Published: June 2007

Understanding the relationship between basic and applied rheological parameters and the contribution of wheat flour protein content and composition in defining these parameters requires information on the roles of individual flour protein components. The high molecular weight glutenin subunit (HMW‐GS) proteins are major contributors to dough strength and stability. This study focused on eight homozygous wheat lines derived from the bread wheat cvs. Olympic and Gabo with systematic deletions at each of three HMW‐GS encoding gene loci, Glu‐A1, Glu‐B1, and Glu‐D1. Flour protein levels were adjusted to a constant 9% by adding starch. Functionality of the flours was characterized by small‐scale methods (2‐g mixograph, microextension tester). End‐use quality was evaluated by 2‐g microbaking and 10‐g noodle‐making procedures. In this sample set, the Glu‐D1 HMW‐GS (5+10) made a significantly larger contribution to dough properties than HMW‐GS coded by Glu‐B1 (17+18), while subunit 1 coded by Glu‐A1 made the smallest contribution to functionality. These differences remained after removing variations in glutenin‐to‐gliadin ratio. Correlations showed that both basic rheological characteristics and protein size distributions of these flours were good predictors of several applied rheological and end‐use quality tests.
Comparison of Methods for Amylose Screening Among Amylose‐Extender (ae) Maize Starches from Exotic Backgrounds
Authors: Campbell M. R. , Yeager H. , Abdubek N. , Pollak L. M. , Glover D. V.
Published: June 2007

Breeding for high‐amylose corn requires a rapid analytical method for determining starch amylose so that generating wet chemistry values does not pose a major limitation in the volume of materials that can be screened. Two methods for determining apparent amylose content (AAC) were examined and compared with an iodine‐binding method involving the solubilization of isolated starch in a sodium hydroxide solution (method 1). These methods included one based on near‐infrared transmittance spectroscopy (NIRT) (method 2) and another iodine‐binding method involving the solubilizing of starch from ground whole corn with a DMSO‐iodine solution (method 3). These methods were chosen because, aside from initial set up costs, they are relatively rapid and inexpensive to perform. The materials evaluated consisted of various exotic corn populations including plant introductions and experimental materials generated from the Germplasm Enhancement of Maize (GEM) project. Crosses were made between these materials and a Corn Belt dent hybrid (OH43 × H99) converted with the amylose‐extender (ae) allele. Grain from F2 ears, presumed to be homozygous for the ae allele based on visual selection of mutant kernels on F1 ears from which they were planted, were then evaluated to identify possible modifiers of ae conditioning high starch AAC. From a total of 1,006 F2 ears, a core set consisting of 155 samples was established and only these were subjected to starch AAC analysis, using all three methods to compare the methods. Method 2 showed poor correlation to method 1 (r = 0.88), however, NIRT did appear to discriminate between samples converted to ae vs. those with a normal or possibly segregating endosperm type. Method 3 showed a slightly better correlation with method 1 (r = 0.92) and appeared to more fully discriminate among samples with AAC values >65% from those at ≈55%. Results from this study suggest that NIRT may be useful when a quick screening method is needed to discriminate mutant from nonmutant genotypes within grain samples of exotic germplasm especially when visual identification is difficult. In addition, method 3 could be used to replace the more time‐consuming method 1 when trying to identify high AAC levels among ae genotypes, even though some inconsistency was observed between the two methods. Finally, this study revealed that exotic germplasm may be an important source of new modifiers to the ae allele because values as high as 70% AAC were identified.
Mixing Properties, Baking Potential, and Functionality Changes in Storage Proteins During Dough Development of Triticale‐Wheat Flour Blends
Authors: Naeem Hamid A. , Darvey Norman L. , Gras Peter W. , MacRitchie Finlay
Published: June 2007

Flours from advanced lines or cultivars of six triticales and two prime hard wheats, along with triticale‐wheat blends, were investigated for mixing, extension (excluding blends), and baking properties using microscale testing. Percentage total polymeric protein (PPP) and percentage unextractable polymeric protein (UPP) of flours and doughs, including blends, mixed to optimal dough development were estimated using size‐exclusion HPLC to determine the changes in protein solubility and association with blend composition (BC), mixing properties, and loaf height. Each triticale was blended with flours of each of the two wheat cultivars (Hartog and Sunco) at 0, 30, 40, 50, 60, 70, and 100% of wheat flour. Nonlinear relationships between BC and mixograph parameters (mixing time [MT], bandwidth at peak resistance [BWPR], and resistance breakdown [RBD]) were observed. A linear relationship between BC and peak resistance (PR) was predominant. PPP of triticale flours was mostly higher than PPP of wheat cultivars. UPP of all triticales was significantly lower than wheat cultivars. PPP of freeze‐dried doughs was mostly nonsignificant across the blends and showed a curvilinear relationship with BC. The deviations from linearity of MT and PPP were higher in triticale‐Sunco blends than in triticale‐Hartog blends. UPP of blends was closer to or lower than the lower component in the blend. The deviations from linearity for MT and UPP were greater in triticale‐Hartog blends than triticale‐Sunco blends. A highly significant correlation (P < 0.001) was observed between BWPR and loaf height. This suggested that BWPR in triticale‐wheat flour blends could be successfully used for the prediction of loaf height. Triticale flour could be substituted for wheat flour up to 50% in the blend without drastically affecting bread quality. Dough properties of triticale‐wheat flour blends were highly cultivar specific and dependent on blend composition. This strongly suggested that any flour blend must be tested at the desired blend composition.
Effects of Glycerol and Moisture Redistribution on Mechanical Properties of White Bread
Authors: Baik Moo‐Yeol , Chinachoti Pavinee
Published: June 2007

Effects of glycerol and moisture redistribution on mechanical properties of bread were investigated. Firmness increased in all bread crumb over storage time but firming rate was dependent on the initial moisture content, storage method (stored with and without crust), and the presence of glycerol. Faster firming was observed when bread crumb had low initial moisture content and high glycerol level, and was stored with crust. The effect of glycerol was more pronounced when stored with crust, suggesting a critical role of water loss. Firmness showed a good correlation (r2 = 0.95) with the scale factor (C1) from a mathematical model. Recoverable work rapidly decreased in first three days of storage and then remained relatively unchanged thereafter. Hardening of aged bread (but not fresh bread) by glycerol may be explained by local dehydration of bread polymer due to osmotic dehydration or competition for water, which in turn promote more rapid amorphous network formation but less amylopectin recrystallization.
Germination and Malting Properties of Mutants Derived from Malting Barley cv. Triumph
Authors: Swanston J. S. , Sopena A. , Moralejo M. A. , Molina‐Cano J.‐L.
Published: June 2007

Four mutants, demonstrating a range of dormancy, were derived from the malting barley cv. Triumph. Although there were environmental effects on the rate of recovery from dormancy, relative performance of the genotypes was consistent. Recovery from water sensitivity was slower than recovery from dormancy for all genotypes, but a similar ranking of genotypes was observed with two mutants germinating more readily than the parental genotype. Exposure of the grain to the plant hormone abscisic acid (ABA) at the end of each wet phase during steeping had a highly significant effect on the malting performance of all samples. However, reduction in extract levels was significantly less in the two mutants that demonstrated more rapid recovery from dormancy. None of the mutants exceeded Triumph for hot water extract level after malting in two seasons at sites in Dundee (eastern Scotland) and Lleida (northeastern Spain). However, one mutant combined rapid recovery from dormancy with high extract levels when grown and malted under Scottish conditions and subjected to unithermal hot water extraction.
Determining Vitreous Subclasses of Hard Red Spring Wheat Using Visible/Near‐Infrared Spectroscopy
Authors: Wang D. , Dowell F. E. , Dempster R.
Published: June 2007

The percentage of dark hard vitreous (DHV) kernels in hard red spring wheat is an important grading factor that is associated with protein content, kernel hardness, milling properties, and baking quality. The current visual method of determining DHV and non‐DHV (NDHV) wheat kernels is time‐consuming, tedious, and subject to large errors. The objective of this research was to classify DHV and NDHV wheat kernels, including kernels that were checked, cracked, sprouted, or bleached using visible/near‐infrared (Vis/NIR) spectroscopy. Spectra from single DHV and NDHV kernels were collected using a diode‐array NIR spectrometer. The dorsal and crease sides of the kernels were viewed. Three wavelength regions, 500–750 nm, 750–1,700 nm, and 500–1700 nm were compared. Spectra were analyzed by using partial least squares (PLS) regression. Results suggest that the major contributors to classifying DHV and NDHV kernels are light scattering, protein content, kernel hardness, starch content, and kernel color effects on the absorption spectrum. Bleached kernels were the most difficult to classify because of high lightness values. The sample set with bleached kernels yielded lower classification accuracies of 91.1–97.1% compared with 97.5–100% for the sample set without bleached kernels. More than 75% of misclassified kernels were bleached. For sample sets without bleached kernels, the classification models that included the dorsal side gave the highest classification accuracies (99.6–100%) for the testing sample set. Wavelengths in both the Vis/NIR regions or the NIR region alone yielded better classification accuracies than those in the visible region only.
Lipid Extraction Process on Texturized Soy Flour and Wheat Gluten Protein‐Protein Interactions in a Dough Matrix
Authors: Ryan K. J. , Homco‐Ryan C. L. , Jenson J. , Robbins K. L. , Prestat C. , Brewer M. S.
Published: June 2007

Protein‐protein interactions between wheat flour and solvent‐extracted (SE) or nonsolvent extracted (NSE) texturized soy flours were compared. Doughs were prepared to contain varying ratios of texturized soy flour in combination with wheat flour. Sucrose esters (2.5%) were included in several formulations. Doughs were fractionated into soluble and insoluble fractions at pH 4.7 and pH 6.1. Fractions were dried, powdered, and analyzed using SDS‐PAGE and spectrophotometric techniques. Electrophoretic evaluation indicated interactions between wheat gluten proteins and texturized soy proteins in the absence of sucrose esters. Electrophoretic gels of the wheat‐soy flour mixtures maintained a characteristic soy protein band after acidification to the soy protein isoelectric point. Inclusion of sucrose esters increased the interaction. Texturization conferred effects similar to that of sucrose ester on both forms of lipid‐extracted soy. Sulfhydryl analyses using 7‐chloro‐4‐nitrobenzo‐2‐oxa‐4, 3‐diazole (NBD‐Cl) revealed no change in the relative amount of sulfhydryl groups present in doughs prepared from either the texturized soy flours or the doughs containing equal amounts of wheat starch. These data indicate that interactions between soy protein from texturized soy flours and wheat proteins are not covalent.
A Radioisotopic Study of the Entry of Calcium Ion into the Maize Kernel During Nixtamalization
Authors: Zazueta C. , Ramos G. , Fernández‐Muñoz J. L. , Rodríguez M. E. , Acevedo‐Hernández G. , Pless R. C.
Published: June 2007

The entry of calcium ions from the nixtamalization solution into maize kernels over time was followed in model experiments using radiolabeled calcium ions, with autoradiographic evaluation of the kernels after different cooking and steeping times. Calcium ions immediately entered the pericarp and were rapidly fixed at the outer boundary of the endosperm, especially at the external surface of the germ. Entry of calcium into the endosperm occurred gradually after long steeping times, except in the case of broken kernels, for which massive invasion by calcium was observed. After extended steeping times, a moderate amount of calcium‐45 was evident in the germ. Specific perforation of the outer layers of the grains provided a defined route of facilitated entry of calcium into the endosperm. No fundamental difference with respect to penetrability by calcium ion was seen in a comparison between flint‐type grains and grains containing only floury endosperm.
Production of Starch with Very Low Protein Content from Soft and Hard Wheat Flours by Jet Milling and Air Classification
Authors: Létang C. , Samson M.‐F. , Lasserre T.‐M. , Chaurand M. , Abécassis J.
Published: June 2007

Jet milling is a fluid energy impact‐milling technique generally used for the ultrafine reduction of higher value materials. The efficiency of jet milling combined with air classification appears very efficient to separate starch from other wheat flour aggregate components and to produce wheat starch with very low residual protein content. Indeed, residual protein content of the starch‐rich fraction can be reduced to <2% db with a series of successive grinding and air classification operations. Lipid and pentosan contents were also reduced in the starch‐rich fraction. Nevertheless, jet milling cannot eliminate grinding differences observed between different types of wheat. Wheat hardness continues to have an effect on milling and classification yields and on the composition of air classification fractions. To obtain starch‐rich fraction with only 2% protein content, hard wheat flour required a series of at least five grinding steps, whereas only three steps are necessary for soft wheat flour. Under these conditions, hard wheat flours give 24% mass yield with 12% starch damage compared with 39% yield and a low starch damage content (6.4%) for soft wheat flour. These results highlight new prospects for the development of cereal flours, especially soft wheat flours.
Microstructure of α‐Crystalline Emulsifiers and Their Influence on Air Incorporation in Cake Batter
Authors: Richardson G. , Langton M. , Fäldt P. , Hermansson A.‐M.
Published: June 2007

The microstructure of α‐gel and β‐crystalline emulsifiers and their effects on cake batter foam have been studied with polarized light microscopy, confocal laser scanning microscopy (CLSM) and image analysis, freeze‐etching, and transmission electron microscopy (TEM). The emulsifiers Colco and Aroplus, which are commercial α‐gels, and the monoglyceride Dimodan P in its α‐gel and β‐crystalline forms were added to the batter in concentrations of 0.8, 2.0, 3.1, and 4.2%. Dimodan P α‐gel was also prepared with three NaCl concentrations (0.05, 0.67, and 1.35‰). The distribution of air in the foam was evaluated with density measurements and with image analysis of bubbles in optically sectioned batter. In the cake batter, all the α‐gel emulsifiers decreased the density, thereby increasing the incorporation of air, more than the β‐crystalline emulsifier, which did not have any effect on the density. There were noticeable differences in microstructure between the different α‐crystalline emulsifiers. Large, regular α‐structures seemed to increase the batter volume and interfacial area more than smaller aggregates. Adding salt in the emulsifier gel changed the structure, probably into α‐lamellar liposomes, which impaired the aerating effect at lower concentrations.
Shortened Temperature Program for Application with a Rapid Visco Analyser in Prediction of Noodle Quality in Wheat
Authors: Crosbie G. B. , Chiu P. C. , Ross A. S.
Published: June 2007

The use of the Rapid Visco Analyser (RVA) for application in the screening of wheat breeding lines for starch quality and potential noodle quality has been limited by relatively low sample throughput. Current methods generally enable only 20–30 samples to be tested each day. This study sought to develop a more rapid time‐temperature profile that could be applied to whole meal samples. A profile that involved a total analysis time of 7.5 min/sample gave measurements of peak viscosity (PV) and breakdown (BD) on whole meal that were highly correlated with corresponding measurements obtained using a more conventional profile that had been applied to low‐extraction flours. BD and PV were also highly correlated with the total texture score of ramen (Chinese‐style alkaline noodles as manufactured in Japan), but only when 1 mM AgNO3 was used to eliminate the effects of α‐amylase.
Separation and Characterization of Barley Starch Polymers by a Flow Field‐Flow Fractionation Technique in Combination with Multiangle Light Scattering and Differential Refractive Index Detection
Authors: You S. , Stevenson S. G. , Izydorczyk M. S. , Preston K. R.
Published: June 2007

Flow field‐flow fractionation (flow FFF) with frit inlet and frit outlet mode (FIFO) was coupled online to multiangle light scattering (MALS) and refractive index (RI) detectors to investigate the molecular characteristics of normal and zero amylose barley starch polymers. Application of two different cross‐flows, 0.35 mL/min followed by 0.1 mL/min, and constant channel and frit flows of 0.1 and 1.0 mL/min, respectively, permitted a complete separation of amylose and amylopectin. The improved signals from the detectors due to application of the FIFO mode enabled the proper characterization of the small molecular weight species, as well as significantly enhanced the reproducibility of the measurements. The weight‐average molecular weight (Mw) and zaverage root‐mean‐square (RMS) radii of gyration (Rg) values for amylose and amylopectin in the normal starch samples were 2.3 × 106 and 280 × 106, and 107 and 260 nm, respectively. The Mw and Rg of amylopectin in the zero amylose starch samples were 360 × 106 and 267 nm, respectively. The slopes (α) obtained by plotting log Mw versus log Rg for amylose and amylopectin were 0.6 and 0.3, respectively. These results are in good agreement with the theoretical prediction of the molecular conformation of amylose and amylopectin.
Small‐Scale Reconstitution of Durum Semolina Components
Authors: Sissons M. J. , Gianibelli M. C. , Batey I. L.
Published: June 2007

Pasta prepared by extrusion from 25 g of semolina has been compared with that made from a standard laboratory extruder and found to have similar quality. Durum semolina was fractionated into its starch, gluten, water soluble, and residue fractions. The freeze‐dried components were reconstituted and the properties of the reconstituted semolina (ReSem) have been measured. Examination using a 2 g‐mixograph and micro‐extension tester has shown that ReSem behaves similarly to the original semolina. ReSem and semolina were made into pasta using a small‐scale pasta extruder and were of comparable cooking quality. The fractionation and reconstitution of durum semolina on this scale is a useful technique to evaluate the contribution of semolina components to pasta quality.
Effect of Stress Cracks on Corn Wet‐Milling Yields
Authors: Mbuvi Stephen , Eckhoff Steven R.
Published: June 2007

U.S. No. 2 yellow dent corn was randomly probe‐sampled from rail cars being shipped to a wet‐milling plant from a Corn Belt local elevator. The probe samples were blended together and kernels were sorted into four levels of stress cracks (0, 1, 2, or multiple). Each level of stress cracking was then laboratory wet‐milled in triplicate. The only statistically observed differences were in total fiber and in protein content of the gluten meal fraction. The starch yield difference between zero stress cracked corn and multiple stress cracked corn was smaller (0.8%) than would be expected if stress cracking were an indicator of damage to the wet‐milling characteristics of the corn.