bluuebunny/crossref_metadata_2025 huggingface dataset:
Solution Viscoelastic Properties of OATRIM‐10 and Cooked Oat Bran
Authors: Carriere C. J. , Inglett G. E.
Published: June 2007

The solution rheological behaviors of OATRIM‐10 and cooked oat bran were investigated. The rheological properties of the materials were investigated using both thixotropic loop and small‐amplitude oscillatory shear experiments. The cooked oat bran exhibited shear‐thinning behavior during a thixotropic loop experiment over a shear rate range of 0–250/sec. The shear‐thinning behavior was reproduced during the measurement of a second thixotropic loop. In contrast, OATRIM‐10 exhibited an unexpected region of shear‐thickening behavior at 20–80/sec. The shear‐thickening and subsequent shear‐thinning regions for OATRIM‐10 could be described by a transient network model indicating that the shear‐thickening behavior is caused by a shear‐induced entangled network that is partially disentangled at higher shear rates. Subsequent thixotropic loop experiments displayed the shear‐thickening region for OATRIM‐10, indicating that the network structure can be reformed during the imposition of a shear field. Small‐amplitude oscillatory shear data for cooked oat bran can be described reasonably well using a generalized linear viscoelastic (GLV) model. The oscillatory shear data obtained for OATRIM‐10 could not be described by the GLV model. OATRIM‐10 exhibited a distinctive plateau centered at 10/sec, and the low frequency response of storage modulus G′ decreased with a much larger slope in frequency than was predicted by the GLV model.
A Rapid Method for Quantitation of Insoluble Polymeric Proteins in Flour
Authors: Bean S. R. , Lyne R. K. , Tilley K. A. , Chung O. K. , Lookhart G. L.
Published: June 2007

The baking properties of several genotypes of U.S. hard wheats grown in state nurseries for the Wheat Quality Council (WQC) were analyzed by the Hard Winter Wheat Quality Laboratory. Flours (250 mg) from each individual line and location were extracted three times with 50% 1‐ propanol (1 mL) for 5 min each. Samples were vortexed continually during extraction. This method was effective in removing most monomeric proteins. Negligible detectable protein was found in the third extract. Significant amounts of polymeric glutenin were also extracted. Pellets were oven‐dried (130°C) for 1 hr and analyzed for protein content using nitrogen combustion analysis. Protein remaining in the pellet consisted mainly of polymeric protein. The amount of gliadin and soluble polymeric protein could also be measured by separating the supernatant by size‐exclusion chromatography. Good correlations between dough strength parameters and amounts of pellet protein and the relative amount of pellet protein (pellet protein/flour protein) were found for all samples. This procedure was simple and rapid, with the potential of analyzing large numbers of samples per day with good reproducibility.
Predicting Protein Composition, Biochemical Properties, and Dough‐Handling Properties of Hard Red Winter Wheat Flour by Near‐Infrared Reflectance
Authors: Delwiche Stephen R. , Graybosch Robert A. , Peterson C. James
Published: June 2007

Breadmaking quality in wheat is one of several considerations that plant breeders face when developing new cultivars. In routine breeding programs, quality is assessed by small‐scale dough‐handling and bake tests, and to some extent, by biochemical analysis of gluten proteins. An alternative, not yet fully examined, method for wheat flour quality assessment is near‐infrared reflectance (NIR) spectrophotometry. The present study was performed on 30 genotypes of hard red winter wheat grown during two crop years at eight to nine locations in the Great Plains area of the United States. Biochemical testing consisted of measuring protein fractions from size‐exclusion HPLC (M
r > 100k, M
r 25–100k, and M
r < 25k designated as glutenin, gliadins, and albumin and globulins, respectively), pentosan content, and SDS sedimentation volume. Dough‐handling properties were measured on a mixograph and recorded as the time to peak dough development, the peak resistance, the width of the mixing curve, and the width of the curve at 2 min past peak. Partial least squares analyses on diffuse NIR spectra (1,100–2,498 nm) were developed for each constituent or property. When applied to a separate validation set, NIR models for glutenin content, gliadin content, SDS sedimentation volume, and mixograph peak resistance demonstrated reference vs. predicted correlations ranging from r = 0.87 to r = 0.94. Such models were considered sufficiently accurate for screening purposes in breeding programs. NIR spectra were responsive to each constituent or property at a level higher than expected from a correlation between the constituent or property and protein content (recognizing that protein content is modeled by NIR with high accuracy).
Glucose Oxidase in Breadmaking Systems
Authors: Vemulapalli V. , Miller K. A. , Hoseney R. C.
Published: June 2007

The mechanism of glucose oxidase action in breadmaking was investigated by studying the baking performance of glucose oxidase, the active ingredient that it produced, and its effect on the rheological properties of dough. Glucose oxidase improved the loaf volume of bread made by 45‐, 70‐, and 90‐min fermentation processes. Although the increase in loaf volume was significant, it was less than that obtained with an optimum level of KBrO3. With the 90‐min fermentation process, the crumb grain of bread was similar for loaves oxidized with optimum levels of glucose oxidase or KBrO3. The rheological properties of doughs containing glucose oxidase and doughs containing no oxidant were compared. Doughs made with glucose oxidase had higher G′ and G″ and lower tan δ values than doughs made without an oxidant. Hydrogen peroxide was responsible for a drying effect in doughs. This drying effect of glucose oxidase was reduced significantly by incorporation of free radical scavengers into the dough.
Heat‐Induced Fragmentation of the Maize Waxy Protein During Protein Extraction from Starch Granules
Authors: Mu Helen He , Mu‐Forster Chen , Bohonko Monica , Wasserman Bruce P.
Published: June 2007

The starch granule of maize contains a characteristic set of tightly bound polypeptides. Granule‐associated polypeptides are typically extracted from starch granules by heating starch granule suspensions at 90–100°C in a detergent such as SDS. Solubilized proteins are recovered by centrifugation and analyzed by gel electrophoresis. Previously identified tightly bound granule intrinsic proteins consist of the 85‐kDa starch‐branching enzyme IIb, the 76‐kDa starch synthase I, and the 60‐kD waxy (Wx) protein, also known as granule‐bound starch synthase I. However, SDS extracts from starch granules of maize also contain a cluster of proteins ranging in mass between 47 and 32 kDa In this study, we analyzed this group of granule‐associated proteins and found that each was recognized by the Wx antibody. A 15 amino acid N‐terminal sequence from the 47‐kDa polypeptide was identical to the predicted N‐terminus of the Wx protein. Further analysis revealed that each immunoreactive polypeptide between 47 and 32 kDa was a heat‐induced fragmentation product of the Wx protein. Conditions for the extraction of granule proteins were evaluated. Our results demonstrate that granule proteins are effectively released by mild extraction (10‐min incubation at 72°C). Relative to the Wx protein, starch synthase I and starch branching enzyme IIb were less susceptible to thermal fragmentation. These results demonstrate that the 85‐, 76‐, and 60‐kDa polypeptides are authentic granule‐intrinsic proteins, and that the majority of polypeptides between 47 and 32 kDa are artifacts of high‐temperature granule extraction procedures.
Enhancement of Protein Foam Stability by Formation of Wheat Arabinoxylan‐Protein Crosslinks
Authors: Sarker D. K. , Wilde P. J. , Clark D. C.
Published: June 2007

The foam stability properties of a defined mixed solution of Tween 20 and bovine serum albumin was evaluated as a function of arabinoxylan concentration. A marked increase in the foam stability was observed with low concentrations of arabinoxylan. Maximum improvement in the foam stability was obtained with 0.2–0.3 mg/mL of arabinoxylan. Enhancement of foam stability due to a combination of bulk viscosity changes and surface effects was identified. The relative contribution of arabinoxylan to bulk viscosity and adsorbed layer structure was studied by examination of the properties of thin liquid films and the macroscopic air‐water interface. Arabinoxylan reduced the rate of thin film drainage, increased the equilibrium thickness of the films, slowed the lateral diffusion of a fluorescent probe molecule located in the adsorbed layer, and increased the surface elasticity. These data are congruent with arabinoxylan‐mediated crosslinking of adsorbed protein. These observations may be of significance in gas retention during breadmaking. In addition, this naturally occurring polysaccharide offers potential for use in the control of protein foam stability.
Effect of Wheat Starch Structure on Swelling Power
Authors: Sasaki Tomoko , Matsuki Junko
Published: June 2007

Starches were isolated from the endosperm of 12 wheat samples with a wide swelling power range in the wholemeal. Starch amylose content (24.8–34.2%) correlated negatively with the swelling power of isolated starch (18.3–26.9), but starch lipid content showed no such correlation. Higher proportions of long chains (DP ≥ 35) in amylopectins contributed to increased starch swelling. Native starch gelatinization temperatures and enthalpy measured by differential scanning calorimetry correlated positively with swelling power, which also correlated significantly with the regelatinization enthalpy of retrograded starches stored at 5°C for two and four weeks.
Factors Affecting Cake Firmness and Cake Moisture Content as Evaluated by Response Surface Methodology
Authors: Lahtinen S. , Levola M. , Jouppila K. , Salovaara H.
Published: June 2007

Values of initial fat temperature, mixing intensity, mixing time, and mass ratio of fat and sucrose (F/S ratio) were varied in the preparation of fat‐sugar cream. The dependence of cake firmness and cake moisture content on these values, the size of sucrose particles, and storage time were studied using response surface methodology. The logarithm of storage time and F/S ratio proved to be the best predictors for both cake firmness and cake moisture content in the creamed cake. An interaction between fat temperature and F/S ratio had a notable influence and size of sucrose particles had a slight influence on cake firmness. Besides logarithm of time and F/S ratio, mixing intensity was the only factor that affected cake moisture content significantly.
Factors Controlling Gas Cell Failure in Bread Dough
Authors: Hayman D'Anne , Sipes Kelly , Hoseney R. C. , Faubion J. M.
Published: June 2007

Stress relaxation in the wall of a gas bubble, as measured by the alveograph, was used to study surface tension at the gas‐dough interface of doughs from flours producing differing bread crumb grains. The surface tensions in the various wheat flour doughs were not different. Dough rheological properties, as measured by both dynamic oscillatory rheometry and lubricated uniaxial compression, were not different for doughs made from wheat flours that gave breads with different crumb grains. However, when the effect of starch granule size on gas cell wall stability was tested, the presence of a greater proportion of large starch granules in wheat flour dough was sufficient to result in gas cell coalescence and open crumb grain in the final baked product. This suggests that starch granule size is at least one of the factors that affects the crumb grain of bread.
Effects of Production by Microwave Heating After Conventional Baking on Moisture Gradient and Product Quality of Biscuits (Cookies)
Authors: Bernussi A. L. M. , Chang Y. K. , Martínez‐Bustos F.
Published: June 2007

After conventional (forced‐convection heating) baking at 240°C for 4 min, biscuits (cookies) were baked further in a microwave oven at medium and high settings (617.3 and 745.5 W, respectively) to study the effects of microwave baking on the moisture gradient and overall quality of the cookies. Microwave baking significantly (P < 0.05) reduced the moisture gradient and total moisture content of the cookies. Initially, a complete factorial design at baking times of 15, 20, 30, and 40 sec with microwave ovens at high and medium power settings was used to evaluate the moisture gradient and total cookie moisture content. Applying high and medium microwave settings for 30 or 40 sec, respectively, avoided cracking, although the products were slightly darker. Treatment at a high power setting for 20 sec resulted in a moisture gradient of 1.11%/cm and 2.8% cracking. Gradients >1.5%/cm produced significant levels of cracking. Cookies postbaked at a medium microwave power setting for 29 sec produced the same moisture gradient as a high microwave power setting for 23 sec, which was significantly (P < 0.05) lower than the control (cookies baked using the traditional process). The cookies were softer and the color did not differ significantly from that of the control. The expansion ratio of the control sample (11.3) was significantly higher than the combined process sample (10.7), showing a shrinkage effect attributed to the microwave treatment. The removal of the residual moisture during microwaving also increased product weight losses (from 0.912 to 0.956 g).
Relating Electrolyte Leakage to Shelled Corn Storability
Authors: Marks Bradley P. , Stroshine Richard L.
Published: June 2007

Corn from three growing seasons was harvested, dried, and stored in small bins. Samples taken at harvest and after various periods of bin storage (up to 77 months) were evaluated by two primary tests: carbon dioxide evolution during accelerated storage at ≈20.5% moisture content and 26°C and electrolyte leakage from bulk (100 g) samples soaking in deionized water. The initial (t < 72 hr) slope of carbon dioxide evolution rate curves (SLOPE72) was used as a base measure of storability (i.e., potential for safe storage without significant mold invasion). In electrolyte leakage tests, both test temperature and initial sample moisture content influenced results. Additionally, water conductivity after 10 min was correlated (r = 0.79) with SLOPE72, implying that electrolyte leakage has the potential to provide rapid information regarding future storability.
Quantitative Description of Fracturability Changes in Puffed Corn Extrudates Affected by Sorption of Low Levels of Moisture
Authors: Barrett Ann H. , Kaletunc Gonul
Published: June 2007

Fracturability is a defining textural characteristic of extruded and crunchy products such as puffed snacks and cereals. Even low levels of moisture can significantly affect deformation properties and texture due to changes in the distribution of fracture intensities. The fracturability of puffed corn extrudates produced at two specific mechanical energy (SME) levels, which greatly influenced extrudate structure and deformation behavior, was measured by compression testing before and after equilibration of samples at 33% rh. Significant changes in fracturability due to moderate moisture sorption were manifest in a reduced total number of fractures occurring during compression, an indication of plasticization that was confirmed independently by differential scanning calorimetry (DSC) studies as reductions in glass transition temperature (Tg). However, in both instances, mean fracture intensity and average compressive resistance increased after equilibration, indicating a qualitative toughening or hardening of the products, despite increased moisture and decreased Tg. These textural developments were also reflected in changes in the parameters of fitted fracture intensity distributions. Thus, the influence of processing conditions (quantified in terms of SME) on the creation of new micro and macrostructures, and the effect of low levels of moisture on these structures, can be identified by using fracturability characteristics and Tg. Furthermore, fracturability parameters can demonstrate complexity in the deformation patterns of products that thermal measurements confirm to be plasticized.
Factors Affecting the Slope of Head Rice Yield vs. Degree of Milling
Authors: Reid J. D. , Siebenmorgen T. J. , Mauromoustakos A.
Published: June 2007

Milling data of four long‐grain rice cultivars were analyzed to determine the uniformity in the slope of their curves for head rice yield (HRY) versus the corresponding degree of milling (DOM). The data set for each cultivar comprised samples that had been subjected to various drying air conditions and durations and milled over a range of moisture contents. All treatment combinations were split and milled for either 15, 30, 45, or 60 sec in a McGill no. 2 laboratory mill to obtain HRY versus DOM data. Linear relationships between HRY and DOM, as observed in past research, were confirmed. This implies that as rice is milled to greater extents (higher DOM), the HRY decreases linearly. Within the bounds of the experimental levels tested, neither the drying air condition nor drying duration affected the rate at which HRY changed with DOM. However, the cultivar and the moisture content at which the rice was milled significantly (P < 0.05) influenced this rate. At higher milling moisture contents, the decrease in HRY per unit of increase in the DOM was greater than at lower moisture contents. While not conclusive, there was an indication of a relationship between the average kernel thickness of a cultivar and the HRY versus DOM slope.
Effects of Roasting and Malting on Physicochemical Properties of Select Cereals and Legumes
Authors: Griffith L. D. , Castell‐Perez M. E.
Published: June 2007

Pearl millet, teff, cowpea, and peanut used in the formulation of experimental weaning foods were evaluated for changes in physicochemical properties resulting from roasting and malting. The particle size index (PSI) value for cowpea was significantly higher, indicating a finer flour than that obtained from pearl millet. Pearl millet and teff flours did not have significantly different PSI values, water absorption index values, or gruel viscosities. Viscosities for control and roasted cowpea gruels (15%, w/v) were significantly higher than those obtained from peanut gruels. Malting had the greatest impact on physicochemical properties for all grains, whereas roasting produced no significant differences from control flours. Malting yielded apparent increases in grain protein content, and malted seeds yielded finer flours with reduced water absorption and pasting qualities.
Influence of Botanical Source and Processing on Formation of Resistant Starch Type III
Authors: García‐Alonso Alejandra , Saura‐Calixto Fulgencio , Delcour Jan A.
Published: June 2007

Influence of botanical source and gelatinization procedure (autoclaving or boiling) on resistant starch (RS) formation was investigated in starches from wheat, corn, rice, and potato. RS yields did not vary within the same sample but differed among samples with different starch botanical sources. Differences also existed in RS contents in native and retrograded starches. Slight or minor variations in RS values were found after both gelatinization procedures, although no clear pattern was found in the behavior of samples based on gelatinization procedure. The degree of polymerization (DP) of retrograded samples was assigned using high‐performance anion exchange chromatography with pulsed amperometric detector (average DP 50–60), with no differences between autoclaved and boiled samples.
Characteristics of Noodle Flours from Japan
Authors: Jun W. J. , Seib P. A. , Chung O. K.
Published: June 2007

The compositions and physical properties of Japanese salt and alkaline noodle flours were contrasted and compared to those of flours from U.S. hard white and soft white wheats (HWW and SWW) and from Australian SWW wheats often segregated for salt noodles. The alkaline noodle flours averaged 11.5% protein, which was 3% higher than the salt noodle flours, and they had lower ash content (0.35 vs. 0.41%). Granulation of the salt noodle flours showed the same proportion of small particles (<38 μm) as in soft wheat flours but different levels of intermediate and large particles. The level of small particles was ≈10% greater in salt noodle flours than in the alkaline noodle flours. The alkaline noodle flours had ≈8% more fine particles and 2.5% more damaged starch than the HWW flours, which is consistent with fine grinding of hard wheat flour in the noodle flour. Starch damage also was higher in the salt noodle flours (5.3%) than in the SWW flours. The salt noodle flours had a higher sodium dodecyl sulfate (SDS) sedimentation volume and a higher gluten index than the SWW flours from the United States. The SDS volume and gluten index were lower for the alkaline noodle flours than for the HWW flours, showing the preference for a mellow gluten of low‐intermediate strength in alkaline noodle flour. Mixograph data also supported the conclusions of mellow gluten in alkaline noodle flour. The swelling powers (1.7% at 92.5°C) for Australian SWW, salt noodle, U.S. HWW, U.S. SWW, and alkaline noodle flours, were 19.4, 18.1, 17.0, 16.1, and 15.8 g/g, respectively, showing the preferences for high‐ and low‐swelling starch, respectively, in the salt noodle and the alkaline noodle flour. A similar order of flour swelling was indicated by peak viscosity of flours heated at 12% solids in starch paste viscosity analysis. Water holding capacity of flour was correlated highly (r = 0.95, P < 0.01) with swelling power, both measured at 1.7% flour solids at 92.5°C.
Effects of Break‐Roll Speed Differential on Product Yield and Semolina Granulation in a Durum Pilot Mill System
Authors: Hareland G. A.
Published: June 2007

Changes in break‐roll speed differential in a 25‐quintal (55‐cwt) durum pilot mill system (136 kg/hr feed rate capacity) affected total yield of semolina, flour, and bran; semolina yield from different purifiers; and semolina granulation (150‐ to 841‐μm particle size range). By adjusting the speed differential of the break and chunk roll pairs from 1.5:1 to 2.5:1 to 3.5:1, semolina yield increased significantly from 55 to 67 to 72%, respectively, and bran yield decreased significantly from 24 to 15 to 11%, respectively. Shorts yield was not affected by speed differential. At 1.5:1, semolina contained 9% flour, compared with 5% flour at 2.5:1 and 3.5:1.
Tortilla Bending Technique: An Objective Method for Corn Tortilla Texture Measurement
Authors: Suhendro E. L. , Almeida‐Dominguez H. D. , Rooney L. W. , Waniska R. D. , Moreira R. G.
Published: June 2007

An objective bending technique was developed to measure corn tortilla texture. During the test, tortilla strips were bent to a 40° angle. The bending technique detected differences in uniformity, thickness, and puffing. Thick tortillas required more force to bend and had greater moduli of deformation values than thin tortillas. The bending technique detected changes in tortilla texture during storage and textural differences among commercial corn tortillas purchased at supermarkets. Experimental error of the method was low for both commercial and laboratory‐prepared tortillas. Parameters measured by the bending technique were significantly correlated with subjective rollability and flexibility test scores. The bending technique was sensitive to sample characteristics, fast, simple, repeatable, and provided information regarding the relationship between force (stress) and distance, which could be used to determine the linear region of viscoelastic materials.
Effect of Oxidation on the Dynamic Rheological Properties of Wheat Flour‐Water Doughs
Authors: Miller K. A. , Hoseney R. C.
Published: June 2007

Oxidation increased the strength of the dough. Addition of ascorbic acid or azodicabonamide (ADA) to dough increased both elastic modulus (G′) and viscous modulus (G″), while addition of cysteine decreased both values. Hydrogen peroxide, from either calcium peroxide or glucose oxidase, increased G′ and G″ and decreased tan δ (G″/G′) values. In addition to strengthening the dough, hydrogen peroxide dried the dough, but ADA did not. The absorption of doughs containing 20 GU of glucose oxidase (source of hydrogen peroxide) could be increased by ≈5% without altering the rheological properties. Presumably, the mobility of water in the gel formed by oxidative gelation decreased, thereby causing a drying of the dough.
Molecular Characterization of Wheat Amylopectins by Multiangle Laser Light Scattering Analysis
Authors: You Sangguan , Fiedorowicz Maciej , Lim Seung‐Taik
Published: June 2007

Weight‐average molecular weight (Mw) and chain length of eight amylopectins isolated from one Australian, two United States, and five Korean wheats were measured using multiangle laser light scattering (MALLS) and refractive index (RI) detectors operated in a microbatch mode, and in a high‐performance size‐exclusion chromatography (HPSEC) mode. The Mw of amylopectins measured in the microbatch mode ranged from 29 × 106 to 349 × 106. Three amylopectins (Geuru, Tapdong and WW) showed significantly high Mw values over 200 × 106. The Mw measured by HPSEC mode with MALLS‐RI detectors (42 × 106 to 73 × 106) were significantly less than those obtained in the microbatch mode with exception of dark northern spring hard wheat (DNS) amylopectin, indicating the possible variation of Mw by the analysis mode. Root‐mean square of the radius of gyration (Rg) also was greater when the microbatch mode was used (122–340 vs. 95–116 nm). Chain length distributions of debranched amylopectins of different cultivars, measured by the HPSEC‐MALLS‐RI system, were similar. Weight average degrees of polymerization (DPw) of A, B1, and larger B chains (B≥2) had ranges of 13–22, 26–46, and 58–73, respectively, and mass ratios of A and B chains ranged from 0.7 to 1.1.
Effect of Temperature and Screw Speed on Stability of Fumonisin B1 in Extrusion‐Cooked Corn Grits
Authors: Katta S. K. , Jackson L. S. , Sumner S. S. , Hanna M. A. , Bullerman L. B.
Published: June 2007

Corn grits spiked with fumonisin B1 (FB1) at a level of 5 μg/g were extrusion cooked in a corotating twin‐screw extruder at different temperatures (140, 160, 180, and 200°C) and screw speeds (40, 80, 120, and 160 rpm). Good recoveries of FB1 were obtained from the nonextruded as well as the extruded grits by using high‐performance liquid chromatography. Both the barrel temperature and the screw speed significantly (P ≤ 0.05) affected the extent of fumonisin reduction in extruded grits. As expected, the FB1 recovered decreased with an increase in temperature and a decrease in screw speed. The amount of FB1 lost from cooking grits at the different extrusion parameters used in this study ranged from 34 to 95%. About 46–76% of the spiked FB1 was lost when the grits were cooked at temperatures and screw speeds that resulted in acceptable product expansion and color.
Single Wheat Kernel Color Classification by Using Near‐Infrared Reflectance Spectra
Authors: Wang D. , Dowell F. E. , Lacey R. E.
Published: June 2007

An optical radiation measurement system, which measured reflectance spectra, log (1/R), from 400 to 2,000 nm, was used to quantify single wheat kernel color. Six classes of wheat samples were used for this study, including red wheat that appears white and white wheat that appears red. Partial least squares regression and multiple linear regression were used to develop classification models with three wavelength regions, 500–750, 500–1,700, and 750–1,900 nm, and three data pretreatments, log (1/R), first derivative, and second derivative. For partial least squares models, the highest classification accuracy was 98.5% with the wavelength region of 500–1,700 nm. The log (1/R) and the first derivative yielded higher classification accuracy than the second derivative. For multiple linear regression models, the highest classification accuracy was 98.1% obtained from log (1/R) spectra from the visible and near‐infrared wavelength regions.
Relationship Between Kernel Size Features and Test Weight in Triticum durum
Authors: Troccoli A. , di Fonzo N.
Published: June 2007

Test weight or bulk density in durum wheat is a physical quality characteristic considered by semolina millers. High test weight values are desirable because they positively influence market grade and price. This study reports data on kernel size features, determined on a sample size of only 25 kernels, replicated three‐times, of 16 commercial durum wheat cultivars grown in two locations in southern Italy, to ascertain whether some kernel traits could be related to test weight. For each year and cultivar, the analysis of variance for all of characteristics showed that sample size effect was not significant, enabling the use such a small sample for further investigations. The kernel trait with the highest variation for year was kernel width. The absolute variation of 1994 with respect to 1993 growing season was 30.9%. While kernel weight or volume did not correlate with test weight, a negative association with kernel length (r = ‐0.61, P = 0.05) and perimeter (r = ‐0.57, P = 0.05) was found. The kernel shape factors, rectangular aspect ratio (RAR) and circularity shape factor (CSF), showed a positive correlation with test weight (r = 0.51, P = 0.05 and r = 0.59, P = 0.05, respectively). The shape factors were negatively correlated both with kernel length and perimeter and positively with kernel width. A predictive model for test weight (TW = 38.7 + 5.1·ETW, where the estimated test weight [ETW] was computed as individual kernel weight/estimated kernel volume [EKV] ratio), was highly correlated with actual test weight values (r = 0.82, P = 0.001). The effectiveness of the linear model was confirmed when a set of 10 advanced lines of durum wheat were considered, although a slightly lower correlation (r = 0.73, P = 0.05) between actual and predicted test weight values was found. Because the extent of predictability of this approach might be more effective in early‐generation lines, the application of the findings in a durum wheat breeding program would be advisable.
Molecular Mobility in Glassy Bread: A Multispectroscopy Approach
Authors: Roudaut Gaëlle , Maglione Mario , van Dusschoten Dagmar , Le Meste Martine
Published: June 2007

The molecular mobility in low‐moisture (<9%, web) white bread was studied as a function of temperature using pulsed‐proton nuclear magnetic resonance (NMR), and dielectric and dynamic mechanical spectroscopies. The water was mobile, even in glassy samples. Different processes below glass transition temperature (sub‐Tg) were observed, and a relaxation map of the studied system was drawn. These results have been interpreted and extrapolated to suggest that the Tg is not a universal predictive parameter for the physical stability of glassy food.
Mixograph Absorption Determination by Response Surface Methodology
Authors: Ingelin M. E. , Lukow O. M.
Published: June 2007

The advantages of using the mixograph to determine dough mixing properties include minimal flour requirements (2–35 g) and an efficient mixing process that rapidly resolves mixing peaks. A disadvantage to using this instrument is that it lacks an objective absorption measurement. This article describes an analysis system, RsMix, that objectively determines water absorption and statistically evaluates (R2 and probability values) this measurement. The RsMix system also exports files that produce response surface plots. These plots illustrate the response of the dough to different combinations of mixing time and absorption. Each data set analyzed by the RsMix system was composed of an absorption series run at 2% absorption increments. The RsMix system attempts to maximize power input over data collected over absorption and time ranges. These data can be input manually or automatically acquired from MixSmart data files. To measure the precision of the RsMix system, a replicated absorption series composed of four to six different amounts of added water was analyzed. Depending on the mixer and formulation used, calculated standard deviations for optimum absorptions ranged from 0.8 to 2.0%. A regression comparing flour protein content to 2‐g mixograph absorption had r2 = 0.80. A similar regression comparing 2‐g mixograph to 50‐g farinograph absorption had r2 = 0.81. Mixograph parameters could also account for 90% or more of the variation in bake absorption, bread volume, and total bread scores.
Rheological Method for Evaluating Endoproteolytic Enzyme Activity
Authors: Bleukx Wouter , van Oort Maarten G. , Delcour Jan A.
Published: June 2007

A rheological method for evaluating endoproteolytic enzyme activity was developed. The decrease in viscosity as a function of time of dispersion of commercially available modified wheat gluten protein in water (15%, w/w) was measured with a rapid visco analyzer (RVA). Measurement of the RVA viscosity signal at a chosen temperature was continuous and reproducible. As described, the method also can be used to determine the temperature optima of endoproteolytic enzymes at pH values exceeding 5.5 and for partial pH‐activity profiles at different temperatures. The method is simple, reproducible, and sensitive and has obvious advantages over more labor‐intensive methods in which changes in the rheological properties (elongational viscosity, stretch ratio) of a gluten‐starch dough are evaluated as a function of time.
Effects of Low Molecular Weight Carbohydrates on Farinograph Characteristics and Staling Endotherms of Wheat Flour‐Water Doughs
Authors: Duedahl‐Olesen L. , Zimmermann W. , Delcour J. A.
Published: June 2007

Glucose, maltose, maltotriose, maltotetraose, α‐ and γ‐cyclodextrins, and maltodextrins from potato starch (average degree of polymerization [DP] of 17) and maize starch (average DP of 20) were added to wheat flour‐water doughs at levels of 1.0 and 3.0% (based on dry flour weight). Additions of 3.0% (w/w) α‐ and γ‐cyclodextrins increased the 500 farinograph unit (FU) consistency by 174 and 193 FU, respectively, while the same levels of potato and maize starch dextrins increased the consistency by 32 and 21 FU, respectively. Expressed in an alternative way, the water absorption corresponding to 500 FU consistency was increased by 4.2 and 4.6% after addition of 3.0% (w/w) α‐ and γ‐cyclodextrins, respectively. Differential scanning calorimetry was used to evaluate the direct effects of addition of low molecular weight carbohydrates on amylopectin recrystallization in baked flour‐water doughs. A significant reduction in amylopectin recrystallization was found after the addition of 3.0% (w/w) γ‐cyclodextrin after seven days of storage of the baked wheat flour‐water dough.
Use of the Rubber Elasticity Theory to Characterize the Viscoelastic Properties of Wheat Flour Doughs
Authors: Leonard A‐L. , Cisneros F. , Kokini J. L.
Published: June 2007

The viscoelastic properties of durum wheat flour doughs were measured using the extensigraph in uniaxial extension and the Rheometrics mechanical spectrometer in oscillatory shear. The research examined the effect of increasing density of cross‐links on rubber elasticity in these systems. The stress‐strain behavior of durum wheat flour dough was not well simulated by Mooney‐Rivlin type nonlinear elasticity. Addition of increasing amounts of iodate made the dough show appreciable strain thickening behavior, approximating the behavior of natural rubbers The estimated apparent molecular weight between cross‐links ranged from 10,500 to 16,000, much larger than that of rubbers, for which values are in the range of 500–1,000. When the Mooney‐Rivlin equation was tested, it appeared to approximate only moderately well the extensional behavior of iodate‐added wheat flour doughs at finite but low extensions, where the finite extensibility of chains is not a factor. It is hypothesized that the cross‐linked network is highly diluted with hydrogen and hydrophobic bonds that limit the applicability of rubberlike elasticity theories. Increasing the cross‐linked density using iodic acid developed matrices that moved the behavior of durum flour doughs closer to Mooney‐Rivlin behavior.
Starch‐Lipid Interactions in Common, Waxy, ae du, and ae su2 Maize Starches Examined by Differential Scanning Calorimetry
Authors: Villwock V. Kurtis , Eliasson Ann‐Charlotte , Silverio José , BeMiller James N.
Published: June 2007

Four maize genotypes (common, waxy, ae du, and ae su2) were examined by differential scanning calorimetry (DSC) in the presence of four surfactants (sodium dodecyl sulfate [SDS], dodecyltrimethylammonium bromide [DOTAB], sodium hexadecyl sulfate [SHS], 1‐monolauroyl‐rac‐glycerol [ML]) to characterize the starch‐lipid complexes produced and provide evidence of differences in starch structure. The ionic surfactants with a C12 hydrocarbon tail reduced the gelatinization onset temperature, a phenomenon that does not occur typically with neutral surfactants or with surfactants with longer hydrocarbon tails. Subtracting the DSC curves, the exotherm we suspected was caused by starch‐lipid complexation, which occurs concomitantly with the gelatinization endotherm, was identified and provided evidence of the existence of amylopectin‐lipid interactions. Apparent starch amylose content correlated well with enthalpies of amylose‐lipid complexes. Complexes formed from DOTAB produced DSC endotherms that were broad and shallow and that shifted to lower temperatures as the DOTAB concentration increased. This was in contrast to other surfactants that normally produce amylose‐lipid complex endotherms at temperatures independent of surfactant concentration.
Evaluation of a Two‐Step Baking Procedure for Convenience Sponge Cakes
Authors: Grau H. , Wehrle K. , Arendt E. K.
Published: June 2007

Typical examples of convenience foods in the bakery section include partially baked bread, rolls, croissants, and crumpets. The effects of processing variables on sponge cake characteristics were studied in a two‐step baking procedure. A fractional two‐factorial design was applied to describe the effects of the predictor variables on product properties. Flour type, oven type, and baking time in each baking phase were selected as categorical predictor variables on the basis of preliminary baking tests. The performance of a microwave oven was compared with that of a conventional oven. The properties of the new twice‐baked products were characterized and compared with those of a standard product by using the results derived from baking tests, color measurements, and texture analyses. Correlation analysis was used to detect relationships between the response variables. Significant relationships between baking test values and texture analysis values closely related to aspects of microwave cooking were found.
Increase in Bone Calcification in Young Rats Fed Breads Highly Fortified with Calcium
Authors: Ranhotra G. S. , Gelroth J. A. , Leinen S. D.
Published: June 2007

Breads were prepared with flour fortified with calcium (Ca) at four levels: 211 (U.S. enrichment standard), 446, 924, and 1,412 mg/100 g of flour. Corresponding diets prepared with these breads and fed to growing rats for four weeks provided 25 (diet A), 50 (diet B), 100 (diet C), and 150% (diet D) of their Ca requirement. After four weeks, the Ca content of the femurs of these rats had increased significantly as Ca in the diet increased up to 100% of requirement but not beyond. The increase in femur strength was significant only between diet A and diet B. Apparent Ca absorption increased as Ca in the diet increased, but Ca absorbed from diet D was not retained any better than that absorbed from diet C. Overall, the data suggested that Ca in highly fortified breads was well absorbed and retained, and that the rats' Ca status early in life was greatly improved. Flour fortified with Ca up to the 924‐mg level (4.4× the mandated enrichment level) had no adverse effect on bread quality. These breads can be labeled a “good source of ” or “high in” Ca.
Development of a Panel of Specific Monoclonal Antibodies to High Molecular Weight Glutenin Subunits and Their Application in Genetic Screening
Authors: Giersch Thomas M. , Hill Amanda S. , Skerritt John H.
Published: June 2007

High molecular weight glutenin subunits (HMW‐GS) encoded by different chromosomal loci and alleles (1, 2, 5, 7, 10, and 12) were purified using reversed‐phase HPLC from reduced, aqueous propanol extracts of flour from aneuploid or null wheat lines. Unlike previous libraries of monoclonal antibodies developed in our laboratory to SDS‐extracted or alkylated HMW‐GS, several of the monoclonal antibodies (mAb) developed in this study had a range of specificity patterns for HMW‐GS in enzyme‐linked immunosorbent assay (ELISA) and on immunoblots. A subset of the mAb bound either x‐ or y‐type HMW‐GS but not other gluten proteins, while a few antibodies bound one (mAb 110622, 110421, 140820), or two (mAb 101319, 110804, 140705, 1410460) HMW‐GS expressed in each cultivar tested. In most cases, antibodies bound equally to the subunits encoded by different HMW‐GS alleles. The more specific antibodies should be useful in research on the quantitative variation of HMW‐GS expression and in studies of the role of particular HMW‐GS in dough structure. The mAb 101319, which was prepared to subunit 1, bound to HMW‐GS 1Bx subunits in ELISA and on immunoblots. This antibody also provided a higher absorbance value in ELISA with extracts of wheat lines expressing the Glu‐Ble allele (HMW‐GS 20) compared with the Glu‐Bli allele (HMW‐GS 17+18). Another mAb (110622) detected subunit 2 more strongly than subunit 5 in ELISA and produced a higher signal in immunoblots with subunit 2 even though these subunits are >98.7% homologous in amino acid sequence. An ELISA assay using this antibody was optimized for discrimination of wheat lines with the allelic pairs of subunits 1Dx5‐1Dy10 from those with 1Dx2‐1Dy12, with the former lines providing stronger dough properties and superior breadmaking quality. The performance of this assay was unaffected by other variations at HMW‐GS loci and was demonstrated in sets of biotypes, doubled haploid, and cross‐bred breeder's lines.
Chemical Composition of Barley Cultivars Fractionated by Weighing, Pneumatic Classification, Sieving, and Sorting on a Specific Gravity Table
Authors: Elfverson C. , Andersson A. A. M. , Åman P. , Regnér S.
Published: June 2007

Five different barley cultivars, including covered and naked samples containing low, normal, or high‐amylose starches were fractionated by weighing, pneumatic classification, sieving, or sorting on a specific gravity table, and analyzed for content of starch, protein, ash, and β‐glucan. For ash content, almost no variation could be found between different fractions. Protein content was minimum in the intermediate fractions for all cultivars when sorted by weighing. For the other fractionation methods, the differences in protein content were small. A tendency for decreasing content of starch with increasing grain mass and size could be seen when fractionating grains by weighing and sieving, respectively. The clearest trend was seen in differences in β‐glucan content for all cultivars and all methods used. The main interpretation of our results is, however, that the chemical composition within the cultivars studied is very similar for all fractions, and that the differences between the unfractionated barley samples are larger.
Enthalpic Transitions in Native Starch Granules
Authors: Sahai D. , Jackson D. S.
Published: June 2007

Crystalline properties of native starch granule fractions that varied in apparent density and size were investigated using differential scanning calorimetry (DSC). Endotherms obtained at 80% hydration showed significant variations in enthalpy between the six fractions. Typical bi‐phasic endotherms exhibiting significant variation in start temperature were obtained for the six fractions at 50% hydration. However, on annealing at 50°C/50% hydration for 48 hr, all fractions showed a single endotherm without any significant variability in endotherm characteristics. At 10% hydration, the six fractions exhibited single high‐temperature endotherms with significant differences in their peak temperatures. It was observed that mechanically damaging starch, resulted in the disappearance of any enthalpic transition. These observations could not be satisfactorily explained on the basis of prevailing concepts about DSC enthalpic transitions.
Effect of Infrared Baking on Wheat Flour Tortilla Characteristics
Authors: Martínez‐Bustos F. , Morales S. E. , Chang Y. K. , Herrera‐Gómez A. , Martínez M. J. L. , Baños L. , Rodríguez M. E. , Flores M. H. E.
Published: June 2007

A new and improved method for baking wheat flour tortillas was evaluated. The method was faster and reduced tortilla dehydration. The aim of the study was to evaluate the efficiency of the infrared baking method on rollability, puffing, layering, color (lightness), and texture (cutting force and tensile strength) characteristics of wheat tortillas formulated and formed by the traditional (hand‐rolled) and commercial (hot‐press) methods. These tortillas were also compared with traditional tortillas cooked on a hot griddle and commercial tortillas cooked in a three‐tier, gas‐fired oven. In the infrared radiation (IR) method, tortillas were baked for 17 or 19 sec by IR using black‐body radiation at a selected wavelength band and emission temperatures of 549 or 584°C. IR‐baked tortillas showed good characteristics of rollability, puffing, layering, color, and texture. The loss of moisture during baking of the tortillas formed by hot‐pressing and baked by IR was significantly lower than that of tortillas baked by traditional and commercial methods. X‐ray diffraction of tortillas prepared by the traditional process and baked by the IR method showed a pattern similar to that of homemade tortillas baked on a hot griddle. The average energy used by the IR oven was less than that used in the commercial method which, in turn, is more efficient than the traditional hot griddle method.
Protein Distribution in Gluten Products Isolated During and After Wet‐Milling of Maize Grains
Authors: Landry J. , Delhaye S. , Di Gioia L.
Published: June 2007

The protein distribution in five gluten samples isolated during and after wet‐milling of maize grains (slurry before and after filtration, total industrial gluten meal, and coarse and fine fractions obtained after sieving) was investigated by sequential extraction. Six fractions (FI‐FVI), including residue, were isolated. Heating filtered slurry to draw water away did not alter protein distribution. Compared with values reported in the literature for endosperm protein, we found a decrease in FI and FIV, respectively, extracted with salt alone and with reductant, due to proteolysis and partial elimination of nonprotein nitrogen during slurry filtration, and an increase in FII and decrease in FIII, alcohol‐soluble proteins extracted without and with reductant, respectively, due to the presence of SO2 in the steeping liquor. Gluten, with respect to the endosperm from which it originated, was richer in zeins (FII + FIII) and glutelins (FV + FVI) due to partial removal of salt‐soluble proteins (FI + FIV) during the isolation process.