bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimizing Conditions for Experimental Oat Dehulling
Authors: Doehlert Douglas C. , McMullen Michael S.
Published: June 2007

The determination of groat percentage in experimental oat breeding lines requires the dehulling of oats. Here, we report the results of our efforts to optimize dehulling conditions so that the most accurate and reliable result can be obtained. Hand dehulling was always reliable and accurate, however, it was the most time‐consuming and tedious of the methods studied. Two mechanical methods of oat dehulling, compressed‐air dehulling and impact dehulling, also frequently provided reliable results, however, results were strongly influenced by dehulling conditions. Optimal dehulling conditions represented compromises between unfavorable extremes. Correct aspiration strength was critical to accurate groat percentage determination. We have found that a secondary aspiration is highly desirable after compressed‐air dehulling to remove hulls remaining with the groats after dehulling. Also, increased mechanical stress on oats as exerted either by the number of passes through the impact dehuller, or by the air pressure in the compressed‐air dehuller, resulted in higher dehulling efficiency, but increased groat breakage as well. Dehulling efficiency decreased as moisture increased from 7.5 to 15%, but increased as moisture was further increased to 30%. In contrast, groat breakage with impact dehulling decreased as moisture increased from 7.5 to 30%. A new equation for groat percentage calculation has been introduced where the mass of hulled oats remaining after dehulling is subtracted from the mass of the original oat sample, so that poor dehulling efficiency does not influence the groat percentage.
Evaluation of a Near‐Infrared Reflectance Spectrometer as a Granulation Sensor for First‐Break Ground Wheat: Studies with Six Wheat Classes
Authors: Pasikatan M. C. , Haque E. , Steele J. L. , Spillman C. K. , Milliken G. A.
Published: June 2007

In flour milling, a granulation sensor for ground wheat is needed for automatic control of a roller mill's roll gap. A near‐infrared (NIR) reflectance spectrometer was evaluated as a potential granulation sensor of first‐break ground wheat using offline methods. Sixty wheat samples, ground independently, representing six classes and five roller mill gaps, were each used for calibration and validation sets. Partial least squares regression was used to develop the models with cumulative mass of size fraction as the reference value. Combinations of four data pretreatments (log (1/R), baseline correction, unit area normalization, and derivatives) and three wavelength regions (700–1,500, 800–1,600, and 600–1,700 nm) were evaluated. Unit area normalization combined with baseline correction or second derivative yielded models that predicted well each size fraction of first‐break ground wheat. Standard errors of performance of 4.07, 1.75, 1.03, and 1.40 and r2 of 0.93, 0.90, 0.88, and 0.38 for the >1,041‐, >375‐, >240‐, and >136‐μm size ranges, respectively, were obtained for the best model. Results indicate that the granulation sensing technique based on NIR reflectance is ready for online evaluation.
Study of a Small‐Scale Laboratory Wet‐Milling Procedure for Wheat
Authors: Wang D. , Chung D. S.
Published: June 2007

The objectives of this research were to study the effects of slurry specific gravity, starch table slope, slurry pumping rate, and their interactions on starch recovery and purity; and to propose a small‐scale laboratory wet‐milling procedure for wheat. First‐order and second‐order response surface regression models were developed to study the effects and interactions of slurry specific gravity, starch table slope, and slurry pumping rate on starch and gluten separation for a 100‐g wheat wet‐milling procedure. The starch and starch protein content data fit the first‐order models (R2 = 0.99 and 0.96) better than the second‐order models (R2 = 0.98 and 0.93). Regression results from the first‐order models indicated that specific gravity, table slope, pumping rate, and their interactions all had a significant effect on starch yield and purity. However, these effects could be simplified as the effect of the resident time of starch and gluten slurry on the starch table and the specific gravity. Starch yield increased as resident time increased and specific gravity decreased. Protein content in starch decreased as the resident time decreased and the specific gravity increased. The separation condition with specific gravity of 3 Bé, table slope of 1.04 cm/m, and pumping rate of 50 mL/min was recommended. Under this condition, starch recovery was 85.6% and protein content of starch was 0.42%, which was similar to the 1.5‐kg laboratory methods in starch recovery. Total solids recovery was 98.1%, which is similar to that from 1.5‐kg laboratory methods. These results indicated that precision of the 100‐g wheat wet‐milling procedure was similar to that of the 1.5‐kg laboratory methods.
Influence of Mixing Conditions and Rest Time on Capillary Flow Behavior of Wheat Flour Dough
Authors: Cuq Bernard , Yildiz Erhan , Kokini Jozef
Published: June 2007

The capillary flow properties of wheat flour dough were evaluated as a function of mixing time (3–60 min) and rest time (0 or 120 min) after mixing. The description of experimental flow properties was conducted using the classical Bagley approach. Long mixing times were more efficient in decreasing the resistance to elongational flow than in decreasing the resistance to shear flow. The effects of rest time on the rheological properties were estimated by calculating the percent changes in values during resting and appeared to depend on the mechanical history of dough (mixing conditions). The observed changes in rheological properties were related to possible changes in dough structure. Exponential models were used to describe the changes in farinograph consistency (R2 = 0.981) and extensional viscosity (R2 = 0.744 to 0.949) as a function of the mechanical energy input during mixing.
Changes in Nixtamalized Corn Flour Dependent on Postcooking Steeping Time
Authors: Fernández‐Muñoz J. L. , Rodríguez M. E. , Pless R. C. , Martínez‐Flores H. E. , Leal M. , Martinez J. L. , Baños L.
Published: June 2007

We studied the effect of steeping time on various physical and chemical properties of maize flour prepared by the traditional nixtamalization process as well as in oversaturated calcium ion conditions. The calcium content of the corn flour was measured by atomic absorption spectroscopy and was correlated with X‐ray diffraction, viscosity, and pH measurements. Calcium content of the flour showed a nonlinear dependence on steeping time, with a local calcium maximum occurring at ≈7 hr. The pH level of the corn flour increased with steeping time, thus roughly following the time trend shown by the steeping time dependence of the calcium content. Flour crystallinity and peak viscosity of water suspensions of the flour reached maximal values at ≈7–9 hr of steeping, in agreement with manufacturing experience showing that these are appropriate steeping times to prepare tortillas with the desirable rheological and organoleptic properties.
Effects of Product Temperature and Moisture Content on Viscoelastic Properties of Glutinous Rice Extrudates
Authors: Chao‐Chi Chuang George , Yeh An‐I
Published: June 2007

The viscoelastic properties of glutinous rice flour extruded at moisture contents of 45–55% and barrel temperatures of 75–95°C have been investigated using a small amplitude oscillatory rheometer. High moisture contents (50 and 55%) resulted in product temperatures 3–5°C lower than the barrel temperatures. It appeared that the moisture content was a key element in influencing the value of G′ and tan δ. Raising product temperature reduced the difference in G′ caused by the moisture content. When the product temperature was >85°C, the extrudates yielded a similar degree of gelatinization despite the difference in moisture content. Meanwhile, both G′ and G″ decreased due to the disintegration of starch granules. The relationship between the energy input, measured as specific mechanical energy, and the viscoelastic properties was also assessed.
Prediction of Texture of Cooked White Rice by Near‐Infrared Reflectance Analysis of Whole‐Grain Milled Samples
Authors: Meullenet Jean‐Francois , Mauromoustakos Andy , Horner Teri Bellman , Marks Bradley P.
Published: June 2007

Although much work has been done using near‐infrared (NIR) spectroscopy with rice, little is currently known about the effectiveness of NIR to predict functional attributes of rice such as cooked rice texture, especially as they are influenced by postharvest parameters. In this study, NIR spectroscopy was used for predicting cooked rice texture as affected by postharvest history. Cooked rice texture attributes were evaluated by a nine‐member trained descriptive panel, and milled white rice was scanned using a near‐infrared (NIR) spectrophotometer. Sensory attribute models were developed using partial least squares regression in combination with jack‐knife, a model optimization method, using NIR reflectance spectra (400–2,500 nm) and 1st and 2nd derivatives. Cooked rice adhesion to lips (R2 = 0.88), hardness (R2 = 0.79), cohesiveness of mass (three chews) (R2 = 0.79), and toothpack (R2 = 0.85) were satisfactorily fitted (n = 201–202) using the 2nd derivative spectra. Other attributes evaluated, such as cohesiveness of mass (eight chews) (R2 = 0.69), roughness of mass (R2 = 0.49), and toothpull (R2 = 0.76) were less successfully modeled. In addition, jack‐knife significantly improved model statistics. Overall, NIR spectroscopy had potential application for predicting cooked rice texture. This finding is especially significant for applications such as breeding programs, where the amount of material available is limited.
Steady and Dynamic Shear Rheological Properties of Starch and Decolorized Hsian‐tsao Leaf Gum Composite Systems
Authors: Lai Lih‐Shiuh , Liao Chih‐Lun
Published: June 2007

Rapid Visco Analyser (RVA) and dynamic rheological measurements were performed on a mixture of decolorized hsian‐tsao leaf gum (dHG) and starch as a function of starch‐to‐gum ratio (S/G 0:6, 1:5, 2:4, 3:3, 4:2, 5:1, and 6:0), starch type (wheat, corn, and tapioca), and total solid content (2, 3, and 4%). Under S/G of 5:1, 4:2 and 3:3, dHG interacted with starch synergistically, which resulted in a marked increase in viscosity during cooling. The storage modulus of the resulting mixed gel was higher than the loss modulus, and both moduli were almost frequency‐independent throughout the frequency range tested, indicating that the composite gels could be classified rheologically as elastic gels. Mixed systems with tapioca starch showed higher pseudo‐gel viscosity in the RVA test, but lower storage modulus in the dynamic test than those with wheat or corn starch. Such results implied that tapioca starch contributed a more viscous property but wheat and corn starch contributed a more elastic property to the mixed systems.
Effects of Heat‐Moisture Treatment and Lipids on Gelatinization and Retrogradation of Maize and Potato Starches
Authors: Miyoshi Emako
Published: June 2007

Effects of heat‐moisture treatment (HMT) and lipids on the structure and gelatinization of maize and potato starches were studied, and the retrogradation process of 20% HMT starch gels was also investigated. Maize starch was physically modified by HMT or by defatting. Potato starch was physically modified by HMT or by adding monoglycerides. The X‐ray pattern of the HMT maize starch was assigned to a combination of A and V patterns, which indicated that HMT formed crystallized amylose complexes and recrystallized amylose in maize starch granules. However, the X‐ray pattern of defatted maize starch did not change for HMT, so the lipids originally existing in starch granules were important to the formation of new crystallites during this treatment. Differential scanning calorimetry (DSC) results suggested that weaker structures in amylopectin crystallites were more susceptible to degradation after HMT, while crystallized amylose complexes developed thermal stability after treatment. The amylose contents increased with increasing degree of HMT, which suggested that the newly created amylose arose from exterior linear chains of amylopectin degraded by the treatment. Investigation of retrogradation process showed that HMT significantly promoted retrogradation of starch gels, especially the initiation of recrystallization.
Metabolite Profiling—A Fractionation Method for Analysis of Major and Minor Compounds in Rice Grains
Authors: Frenzel Th. , Miller A. , Engel K.‐H.
Published: June 2007

A metabolite profiling methodology was developed using rice as model crop. The approach is based on consecutive extraction of lipids and polar compounds and subsequent fractionations of both extracts. Transesterification‐solid phase extraction (lipids) and selective hydrolysis of silylated derivatives (polar compounds) are applied to separate major from minor constituents. The method covers a broad spectrum of chemical classes. Preliminary investigation of the four fractions by gas chromatography/mass spectrometry (GC/MS) analysis of silylated derivatives identified more than 100 compounds. This unbiased approach can serve as an additional analytical tool for the safety assessment of genetically modified crops and may help to increase the chance to detect unintended effects due to the application of recombinant DNA techniques.
Reflectance and Transmittance Spectroscopy Applied to Detecting Fumonisin in Single Corn Kernels Infected with Fusarium verticillioides
Authors: Dowell Floyd E. , Pearson Tom C. , Maghirang Elizabeth B. , Xie Feng , Wicklow Donald T.
Published: June 2007

Reflectance and transmittance visible and near‐infrared spectroscopy were used to detect fumonisin in single corn kernels infected with Fusarium verticillioides. Kernels with >100 ppm and <10 ppm could be classed accurately as fumonisin positive or negative, respectively. Classification results were generally better for oriented kernels than for kernels that were randomly placed in the spectrometer viewing area. Generally, models based on reflectance spectra have higher correct classification than models based on transmittance spectra. Statistical analyses indicated that including near‐infrared wavelengths in calibrations improved classifications, and some calibrations were improved by including visible wavelengths. Thus, the color and chemical constituents of the infected kernel contribute to classification models. These results show that this technology can be used to rapidly and nondestructively screen single corn kernels for the presence of fumonisin, and may be adaptable to on‐line detection and sorting.
Effect of Lactic Acid on Protein Solubilization and Starch Yield in Corn Wet‐Mill Steeping: A Study of Hybrid Effects
Authors: Dailey Oliver D.
Published: June 2007

To better understand the role of lactic acid (LA) in corn wet‐milling, steeping studies were performed on different yellow dent corn hybrids using four different solutions containing LA, sulfur dioxide (SO2), a combination of LA and SO2, or no added chemicals. Although there was variation in protein solubilization among the hybrids, protein release was consistently higher when LA was included in the steepwater than when it was excluded (both with and without SO2). Several groups have reported that starch recoveries are improved when steepwater contains LA. To explore the relationship between protein solubilization and starch yield as effected by LA, several yellow dent hybrids were steeped in 0.20% SO2 and 0.50% LA‐0.20% SO2 solutions and milled to recover starch by a 100‐g laboratory corn wet‐milling procedure. In all instances, both starch yields and protein solubilization were enhanced in solutions containing LA. These results support the hypothesis that direct dissolution of the endosperm protein matrix by LA contributes to the improved starch recoveries.
Oat Bran Fermentation by Rye Sourdough
Authors: Degutyte‐Fomins Laima , Sontag‐Strohm Tuula , Salovaara Hannu
Published: June 2007

Hydration of oat bran including fermentation by rye sourdough was studied. Three types of oat bran suspensions were prepared (a control, one with whole meal rye flour added, and one with rye starter added). The suspensions were incubated for 1, 2, 3 and 4 hr. β‐Glucan content and solubilities of protein and β‐glucan were analyzed. Viscosity of the supernatants of oat bran suspensions was determined. Neither the rye sourdough nor the rye flour alone had a significant effect on the total β‐glucan content of oat bran suspensions. However, the addition of rye, either as whole meal rye flour or as sourdough starter, markedly increased the solubility of β‐glucan and proteins and simultaneously decreased the viscosity of the water‐soluble fraction of oat bran suspension. This suggests that a hydrolysis of β‐glucan had occurred that could change the rheological properties of oat bran in baking and the physiological potential of oat bran in nutrition.
End‐Use Quality of Hard Red and Hard White Spring Wheat Contaminated with Grain of Contrasting Classes
Authors: Habernicht Debra , Martin John M. , Talbert Luther E.
Published: June 2007

Short growing seasons and lack of water limit the number of crops that can be productively grown in the Northern Great Plains, but wheat is uniquely adapted to the region. Growers interested in diversification of their operations are growing more than one class of wheat to target different markets. This has led to the challenge of maintaining class purity, in that contamination with alternate classes results in lower prices to the farmer. The primary rationale is that mixtures may have poor end‐use quality. In these experiments, we tested hard red spring wheat and hard white spring wheat contaminated with different levels of soft white spring wheat, durum wheat, hull‐less barley, and the hard wheat of the alternate kernel color for milling and baking quality. Our results showed that contamination of hard red and hard white spring wheat with soft white wheat and hull‐less barley often influenced end‐use quality in that flour yield was negatively affected at relatively low levels. Loaf volume was normally only affected at higher levels. Durum wheat contamination caused fewer quality problems at generally higher levels of contamination. Contamination of hard red or hard white wheat by hard wheat of the alternate color class rarely affected quality, and effects were both positive and negative, depending on quality attributes of the pure samples. Growers wishing to diversify by growing both hard red and hard white wheat would benefit if buyers and end users were willing to accept higher levels of contamination for alternate classes that are unlikely to cause problems in eventual end use.
Proteolytic Enzymes in Germinating Rye Grains
Authors: Brijs Kristof , Trogh Isabel , Jones Berne L. , Delcour Jan A.
Published: June 2007

The proteolytic activities during rye (Secale cereale L. ‘Humbolt’) grain germination were monitored using in‐solution methods and one‐ and two‐dimensional PAGE with gels that contained incorporated substrate proteins. The total proteolytic activity increased during the first three days of germination, but not after that. The proteinase activity was measured at pH 3.8, 6.0, and 8.0 in the presence and absence of class‐specific proteinase inhibitors. This indicated that enzymes from all four proteinase classes were present during the germination process. Germinated rye grain contained mainly aspartic and cysteine proteinase activities that are especially active at pH 3.8. Serine‐ and metallo‐proteinases were less abundant. Overall, the pattern of hydrolysis was very similar to that observed during barley and wheat germination.
Air Classification of Pin‐Milled Soybean Hulls
Authors: Wolf Walter J. , Sessa David J. , Wu Y. Victor , Thompson Arthur R.
Published: June 2007

Commercial soybean hulls (14.6% crude protein) were pin milled and then air classified into five fractions to determine whether the hull structure can be disrupted and the protein constituents concentrated. The number of pin millings had only a small effect on the weight distribution of the five fractions. After one grinding, the sum of fractions 1 and 2 (<15–18 μm) represented only 3% of total hulls, and on three grindings, they amounted to only 6% of the hulls. Fraction 3 (19–24 μm) shifted from 16 to 20% with three grindings, while fraction 4 (25–30 μm) remained unchanged at 5%. Fraction 5 (>30 μm) shifted from 75 to 69% on three pin millings to compensate for the shifts noted in fractions 1–3. Scanning electron microscopy revealed that fractions 1 and 2 consisted of the parenchymal cell layers (innermost portion) of the hulls; these fractions had three times the protein content and more than twice the amount of lipids found in the ground starting material. Fraction 3 contained many of the hourglass cells typically found in the middle layer of the hulls plus parenchyma cell material and exhibited about twice the amount of protein and lipid found in the starting hulls. Fraction 4 included large hourglass cells plus globular material and contained about twice the amount of protein and about one and one‐half times the lipid of the starting material. Fraction 5 consisted primarily of clumps of palisade cells (outer cellular layer) adhering to each other and had a lower protein and lipid content than the starting hulls. Thus, pin milling causes some selective disruption of the hulls where parenchyma cell layers and hourglass cells are partially released. The palisade cells, however, are the most difficult to disrupt and constitute the fraction most resistant to pin milling. Our findings suggest that pin milling soybean hulls in combination with air classification can be used to concentrate the proteins and lipids in the fines fractions.
Stress‐Strain Analysis and Visual Observation of Wheat Kernel Breakage During Roller Milling Using Fluted Rolls
Authors: Fang Chaoying , Campbell Grant M.
Published: June 2007

The endosperm and bran of a wheat grain have different mechanical properties and break differently under the same stresses. Stress‐strain analysis was used to model the factors affecting wheat kernel breakage during milling using fluted rolls. The planes of principal compressive and tensile stress and the maximum shear stresses, along which the kernel is most likely to be broken, were calculated for a sharp‐to‐sharp roll disposition. With the occurrence of compressive stress in the horizontal direction and shear stress in the vertical direction, a kernel tends to break along a principal tensile stress plane because the tensile strength of the endosperm is much smaller than its compressive strength. The model presented quantifies the mathematical relationship of three design and operational factors affecting the principal stresses and the maximum shear stresses: roll gap, differential, and roll diameter. High‐speed video was used to observe wheat breakage events during milling; the results show consistency with the theoretical analysis.
Fate of Bt Protein and Influence of Corn Hybrid on Ethanol Production
Authors: Dien B. S. , Bothast R. J. , Iten L. B. , Barrios L. , Eckhoff S. R.
Published: June 2007

Corn hybrids were compared to determine the fate of recombinant Bt protein (CRY1Ab from Bacillus thuringiensis) in coproducts from dry grind and wet‐milled corn during production of fuel ethanol. Two pairs of Bt and non‐Bt hybrids were wet milled, and each fraction was examined for the presence of the Bt protein. Bt protein was found in the germ, gluten, and fiber fractions of Bt hybrids. In addition, one set of Bt and non‐Bt hybrids were treated by the dry‐grind ethanol process and Bt protein was monitored during each step of the process. The Bt protein was not detected after liquefaction. Subsequent experiments determined that the Bt protein is rapidly denatured at liquefaction temperatures. Finally, five hybrids were compared for ethanol yield after dry grinding. Analysis of fermentation data with an F‐test revealed the percent of total starch available for conversion into ethanol varied significantly among the hybrids (P < 0.002), indicating ethanol yield is not exclusively dependent on starch content. No difference, however, was observed between Bt and non‐Bt corn hybrids for either ethanol productivity or yield.
Use of Partially Defatted Peanut Flour in Breakfast Cereal Flakes
Authors: Cheewapramong P. , Riaz M. N. , Rooney L. W. , Lusas E. W.
Published: June 2007

Extruded breakfast cereal flakes were made by replacing corn cones with nonroasted partially defatted peanut flour (PDPF) and roasted partially defatted peanut flour (R‐PDPF) at various levels (10, 20, and 30%). The mixtures were extruded using a corotating twin‐screw extruder to produce collets. The collets were flaked and then toasted. The extruded toasted flakes were analyzed for physical, physicochemical, and sensory characteristics. Moisture content, bulk density, hardness (force to break), color, bowl life, water absorption, and water solubility indices were significantly affected by the amount of PDPF and R‐PDPF added in the formulation. A sensory panel found extruded toasted flakes made from corn cones and up to 20% R‐PDPF were acceptable as control. Peanut flavor intensity was also evaluated. Surprisingly, peanut flavor intensity was the highest for flakes containing 30% PDPF, rather than those containing 30%R‐PDPF.
Physicochemical Properties of Sonicated Mung Bean, Potato, and Rice Starches
Authors: Chung Koo Min , Moon Tae Wha , Kim Hyunjung , Chun Jae Kun
Published: June 2007

Mung bean, potato, and rice starch solutions (5%, w/w) were sonicated for up to 5 min after heating, and their physicochemical properties were investigated. Alkaline viscosities, including the apparent and inherent viscosities of starches, decreased. The residues of the swollen starch granules after pasting and centrifugation were also reduced prominently by sonication. Average degree of polymerization did not change with sonication. The starch paste became more transparent, and the hot paste viscosity measured at 70°C decreased remarkably. Results indicate that changes in the physicochemical properties of starch were induced by the disruption of swollen granules rather than the breakage of glucosidic linkages with sonication.
Spelt (Triticum spelta L.) Pasta Quality: Combined Effect of Flour Properties and Drying Conditions
Authors: Marconi E. , Carcea M. , Schiavone M. , Cubadda R.
Published: June 2007

Three spelt genotypes (Rouquin, Redoute, and HGQ Rouquin= Rouquin improved for gluten quality), each characterized by either high or low protein content, were processed to manufacture spaghetti, which was dried at both low (60°C) and high temperature (90°C) to assess the effects of flour properties and drying conditions on spelt pasta quality. Protein content in the spelt flour was considered low at ≈11.4% db and high at ≈13.5% db. Gluten properties, assessed by SDS sedimentation and gluten index values and by alveograph and farinograph parameters varied widely, ranging from poor for Redoute to very good for HGQ Rouquin. Pasta quality was assessed by determining color (L*, a*, and b* values), furosine, and cooking quality (stickiness, bulkiness, firmness, and total organic matter [TOM]). Furosine and color (a* and b* values) were significantly influenced by the intensity of the drying process. TOM and organoleptic judgement (OJ) showed that spelt pastas dried at low temperature, independent of their protein levels, were very poor (TOM ≥ 2.7 g/100 g of dry pasta, OJ ≤ 40), except for HGQ Rouquin which was characterized by good gluten strength. On the other hand, the cooking quality of spelt pastas dried at high temperature showed good values (TOM ≤ 1.8 g/100 g of dry pasta, OJ ≥ 53). The combination of high protein content (≥13.5% db) and high‐temperature drying resulted in the production of satisfactory cooking quality pastas from spelt wheats (TOM ≤ 1.2 g/100 g of dry pasta, OJ ≥ 67).
Objective Texture Measurements of Commercial Wheat Flour Tortillas
Authors: Mao Yufeng , Flores Rolando A. , Loughin Thomas M.
Published: June 2007

Texture is a property of major importance in the evaluation of baked products. To determine a sample of commercial ranges for stretchability, rollability, firmness, and Kramer shear cell measurements for wheat flour tortillas using the TA‐XT2 texture analyzer, three separate sets of five tortilla brands purchased from stores in Manhattan, KS, were evaluated. Two brands had two formulations, regular and fat‐free. Significant differences (P < 0.05) in stretchability, firmness, and Kramer shear cell occurred between regular and fat‐free tortillas of one tortilla brand. Significant differences (P < 0.05) also were found among the sets of some tortilla brands. Kramer shear cell and stretchability measurements are recommended because Kramer shear cell measures the force combined with compression, shearing, and extrusion. Stretchability measurements were repeatable and are an important textural property of wheat flour tortillas. Ranges for textural properties for commercial wheat flour tortillas were determined, as well as the variability of the textural methods used.
Mathematical Modeling of Odor Deterioration of Millet (Pennisetum glaucum) Dough (fura) as Affected by Time‐Temperature and Product Packaging Parameters
Authors: Jideani V. A. , Nkama I. , Agbo E. B. , Jideani I. A.
Published: June 2007

Consumer panelists evaluated the influence of temperature (5, 25, 35°C), storage time, and packaging material (aluminum foil or low‐density polyethylene [LDPE]) on the sensory quality of millet dough (fura). The quality attributes of interest were mold growth, color, odor, and moisture. The odor sensory attribute changed significantly (P < 0.05) during storage and was influenced by storage time and temperature. Interactive effect of packaging‐temperature and temperature‐time affected odor changes significantly. A kinetic reaction model was used to analyze odor sensory data. The degradation of pleasant odor followed a first‐order reaction, and the temperature dependence of these reactions indicated an Arrhenius relationship. While an activation energy (EA) of 29.98 kJ/mol was calculated for samples stored in aluminum foil, a higher value of 49.04 kJ/mol was obtained for samples stored in LDPE. The negative values of enthalpy (ΔH*) in both packages indicate that deterioration change in fura is exothermic. The higher values of EA and free energy of activation (ΔG*) for fura stored in LDPE packages indicate a large change in quality. However, the lower values of free energy of activation (ΔG*) and negative values of entropy of activation (ΔS*) for fura stored in aluminum foil packages indicate a product that is more thermally stable, and odor deterioration is less influenced by temperature. There is no significant difference (P > 0.05) in the shelf life of fura stored at 20, 25, and 35°C in the two packaging materials. However, there were significant differences in shelf life of fura stored at 5°C.
Reduction of Moniliformin During Alkaline Cooking of Corn
Authors: Pineda‐Valdes Graciela , Ryu Dojin , Jackson David S. , Bullerman Lloyd B.
Published: June 2007

The incidence of moniliformin (MON) producing Fusarium spp. in selected corn (Zea mays L.) samples from Mexico and the United States and the effects of alkaline cooking and the tortilla manufacturing processes on the reduction of MON were determined. The percentage of infected kernels with Fusarium spp. ranged from 0 to 22% in eight foodgrade corn samples, including six from Mexico and two from the United States. Complete (100%) reduction of MON was observed when a naturally contaminated corn sample containing 1.4 μg of MON/g of corn was used in a pilot‐scale alkaline cooking and tortilla manufacturing process. In a companion laboratory‐scale study, using a cultured corn sample containing 17.6 μg of MON/g of corn, a 71% reduction of the toxin was observed during the process. Alkaline cooking appeared to be an effective method for reduction of MON in corn.
Salts and pH Induced Changes in Functional Properties of Amaranth (Amaranthus tricolor L.) Seed Meal
Authors: Mahajan A. , Dua S.
Published: June 2007

Amaranth meal is a rich source of proteins, carbohydrates, and minerals with a low amount of anti‐nutritional factors. It exhibits good functional properties. The effect of NaCl and NaHCO3 salts and pH level on the functional properties of amaranth meal was studied. The water absorption capacity and protein solubility were improved in the presence of the salts. Protein solubility was high at extreme pH values and minimum at pH 4. Foaming capacity was poor in the presence of the two salts, while foam stability was better at lower concentrations of NaCl (0.2–0.6M). Changes in pH had a pronounced effect on the foaming properties of amaranth meal. Salts did not change the emulsification properties but significantly increased the relative viscosity of amaranth seed meal at higher concentrations of NaCl and NaHCO3 (0.6–1.0M). Relative viscosity was highest at pH 10 and lowest at pH 4.
Starch Participation in Durum Dough Linear Viscoelastic Properties
Authors: Edwards N. M. , Dexter J. E. , Scanlon M. G.
Published: June 2007

The contribution of starch to dough rheological properties has been largely overshadowed by the role of gluten, receiving much less attention in comparison. The influence of starch granule surface properties on durum wheat dough linear viscoelasticity was investigated, and surface interactions between starch granules and gluten were assessed using a model system. Proportions of starch were substituted in dough on a volume basis with an inert filler (glass powder) with a similar particle size range. The doughs were subjected to dynamic and creep measurements. Dough linear viscoelastic properties were weakened on substitution of starch with glass powder at ≤50% substitution, inferring a reduction in adhesion at the matrix‐filler (starch and glass powder) interface with declining proportions of starch granules. Surface modification of starch granules or glass powder altered dough rheological properties, confirming the importance of starch granule surface characteristics and the nature of protein‐starch bonding on durum dough linear viscoelastic behavior.
Flour Characteristics Related to Optimum Water Absorption of Noodle Dough for Making White Salted Noodles
Authors: Park C. S. , Baik B.‐K.
Published: June 2007

Physicochemical properties of 34 wheat flours with various classes and different protein contents were related to optimum water absorption of noodle dough. Club and soft wheat flours generally exhibited higher water absorption (34–37%) of noodle dough than hard wheat flours (31–35%). Optimum water absorption of noodle dough in three hard wheat flours with five different protein contents was 33–37%. Optimum water absorption was negatively correlated with flour protein content and SDS sedimentation volume. Physical properties of flour, damaged starch content, NIRS hardness and water retention capacity, influenced optimum water absorption of noodle dough from club, soft and hard wheat flours. A prediction equation developed using protein content, water retention capacity and SDS sedimentation volume of flour provides a reliable estimation of the optimum absorption of noodle dough for making noodles.
Environmental Effects on Developing Wheat as Sensed by Near‐Infrared Reflectance of Mature Grains
Authors: Delwiche Stephen R. , Graybosch Robert A. , Nelson Lenis A. , Hruschka William R.
Published: June 2007

For 30 years, near‐infrared (NIR) spectroscopy has routinely been applied to the cereal grains for the purpose of rapidly measuring concentrations of constituents such as protein and moisture. The research described herein examined the ability of NIR reflectance spectroscopy on harvested wheat to determine weather‐related, quality‐determining properties that occurred during plant development. Twenty commercial cultivars or advanced breeding lines of hard red winter and hard white wheat (Triticum aestivum L.) were grown in 10 geographical locations under prevailing natural conditions of the U.S. Great Plains. Diffuse reflectance spectra (1,100–2,498 nm) of ground wheat from these samples were modeled by partial least squares one (PLS1) and multiple linear regression algorithms for the following properties: SDS sedimentation volume, amount of time during grain fill in which the temperature or relative humidity exceeded or was less than a threshold level (i.e., >30, >32, >35, <24°C; >80%, <40% rh). Rainfall values associated with four pre‐ and post‐planting stages also were examined heuristically by PLS2 analysis. Partial correlation analysis was used to statistically remove the contribution of protein content from the quantitative NIR models. PLS1 models of 9–11 factors on scatter‐corrected and (second order) derivatized spectra produced models whose dimensionless error (RPD, ratio of standard deviation of the property in a test set to the model standard error for that property) ranged from 2.0 to 3.3. Multiple linear regression models, involving the sum of four second‐derivative terms with coefficients, produced models of slightly higher error compared with PLS models. For both modeling approaches, partial correlation analysis demonstrated that model success extends beyond an intercorrelation between property and protein content, a constituent that is well‐modeled by NIR spectroscopy. With refinement, these types of NIR models may have the potential to provide grain handlers, millers, and bakers a tool for identifying the cultural environment under which the purchased grain was produced.
Association of Starch Granule Proteins with Starch Ghosts and Remnants Revealed by Confocal Laser Scanning Microscopy
Authors: Han Xian‐Zhong , Hamaker Bruce R.
Published: June 2007

Starch suspensions (0.25%) were gelatinized to 70 and 100°C, and starch ghosts (defined as gelatinized starch granule envelopes after the majority of internal starch polymers have been released) and remnants were collected by centrifugation and washed with water. Protein was revealed in isolated gelatinized normal starch ghosts using confocal laser scanning microscopy and a protein‐specific dye that fluoresces only after reaction with primary amines in protein. This technique eliminates background interference from residual dye. Observation of fluorescent‐labeled protein in the starch ghosts at different optical depths of field revealed that protein was concentrated in the envelopes of swollen, gelatinized potato, maize, and wheat starch ghosts. Only traces of protein were found in gelatinized starch granule remnants of waxy maize and amylose‐free potato starches after they were heated to 100°C, indicating that the proteins observed in gelatinized normal maize starch were largely granule‐bound starch synthase (GBSS). Moreover, fragility of the gelatinized waxy and amylose‐free starch granule remnants might be caused in part by the lack of GBSS. Gel electrophoresis of proteins in starch ghosts confirmed that GBSS in potato and maize was tightly associated with the starch ghosts. The study provides a structural explanation for a role of granule‐associated proteins in maintaining the integrity of starch ghosts and remnant structures, and their consequent effect on paste rheology.
Consequence of Starch Damage on Rheological Properties of Maize Starch Pastes
Authors: Han Xian‐Zhong , Campanella Osvaldo H. , Mix Nadege C. , Hamaker Bruce R.
Published: June 2007

Waxy and normal maize starches were damaged to different extents by ball milling, with waxy starch notably more susceptible to damage. Starch damage caused substantial decreases in shear stress or apparent viscosity in both waxy and normal maize starch pastes at a wide range of shear rates (5.6 to 400 1/sec). Shear stress or apparent viscosity decreases were more evident in waxy than in normal maize starch pastes at the same ball milling times. Values of storage moduli were much higher than values of loss moduli, and storage moduli decreased with increase in starch damage in both waxy and normal maize starches, indicating decrease in elastic property. The study showed that starch damage causes substantial rheological changes in gelatinized pastes and that waxy starch undergoes more pronounced changes than normal starch. These results can be used to understand the general behavior of damaged normal and waxy starches in processed foods.
Effect of Particle Size and Moisture Content on Viscosity of Fish Feed
Authors: Lam C. Desmond , Flores Rolando A.
Published: June 2007

A model was developed for the influence of particle size on the extrusion of a fish feed and the physical characteristics of the extrudates evaluated. The study was conducted using factorial experiments in a fractional replication design for four variables with three levels, and one‐third of the replicates (34 factorial in 27 units) were examined in a laboratory extruder. The torque‐screw speed measurement was used to develop a viscosity model equation that considered different shear rates, product temperature, initial moisture content, and particle size. When particle size decreased, the apparent viscosity became smaller. The barrel pressure was important in producing extrudate with a uniform volume over the range of processing conditions tested because it had a strong correlation with the volumetric expansion. The material with lower moisture and larger particles caused the specific mechanical energy to increase. The viscosity model developed in this study can be applied to the development of large‐scale extrusion models that determine the effect of particle size on the feed material extrudates.
Factors That Influence the Microwave Expansion of Glassy Amylopectin Extrudates
Authors: Boischot C. , Moraru C. I. , Kokini J. L.
Published: June 2007

The microwave expansion of glassy, unexpanded amylopectin pellets was studied. Amylopectin was extruded at three levels of specific mechanical energy (483, 809, and 846 kJ/kg), and 35–40% moisture content, without expansion at the die. Glassy pellets were obtained by drying and equilibrating the extrudates at five water activities (aw 0, 0.11, 0.33, 0.67, and 0.75). The pellets were characterized by measuring volume, porosity, and moisture content. The pellets were then expanded in a constant power microwave oven to determine the degree of expansion. When subjected to microwave heating, regardless of extrusion condition and initial aw, the pellets expanded from the center where the highest temperature was recorded and then expansion advanced in the whole volume. Maximum expansion was reached after 30 sec of heating, after which samples started to burn from the center. Samples simultaneously expanded and lost moisture, both processes being faster and more intense for pellets of higher initial aw. No expansion was observed for the pellets stored at aw 0, while collapse was observed for pellets stored at aw 0.73. A linear correlation between pellet expansion temperature and glass transition temperature was obtained. A hypothesis for the microwave expansion of glassy extrudates was formulated and represented on a state diagram.
Physiological Responses of Men and Women to Barley and Oat Extracts (Nu‐trimX). I. Breath Hydrogen, Methane, and Gastrointestinal Symptoms
Authors: Hallfrisch Judith , Behall Kay M.
Published: June 2007

While consumption of diets high in fiber is perceived to result in undesirable gastrointestinal symptoms, the fermentation of undigested carbohydrate in the large intestine may, in fact, have beneficial health effects. In this study, we compared the effects of oats, barley, and their extracts with a glucose control for 24 hr on breath hydrogen and methane production as a marker of colonic fermentation and also assessed gastrointestinal symptoms. Nine men and 11 women (35–57 yr) consumed 1 g/kg of body weight of carbohydrate as glucose or 0.66 g/kg of body weight sugar and 0.33 g/kg of body weight as oat bran, barley flour, oat extract, or barley extract (Nu‐trimX) in a Latin square design. Expired alveolar breath samples were collected after instruction at fasting, 2, 4, 5, 6, 7, 8, 9, 10, and 24 hr after consumption of the test meals. All test meals increased breath hydrogen and methane (both P < 0.0001). Hydrogen, but not methane, responses to barley, oats, and extracts of each were higher (barley > oats, P < 0.05) than responses to glucose (P < 0.0001). Reported gastrointestinal symptoms were not related to specific test meals. Oats and barley, as well as their extracts, can be consumed in greater amounts by Americans to increase soluble fiber and lower fat intake, and thus lower risk factors for chronic disease.
Jet Cooking of Waxy Maize Starch: Solution Rheology and Molecular Weight Degradation of Amylopectin
Authors: Byars Jeffrey A.
Published: June 2007

The effect of processing conditions in an excess steam jet cooker on the degradation of waxy maize starch was studied. The temperature of the steam, the flow rate of the starch slurry, and the concentration of starch were determined to influence the extent of degradation. The viscosity of concentrated solutions of the jet‐cooked product and the intrinsic viscosity of dilute solutions were used as measures of the extent of molecular degradation. The viscosity decreased at higher reaction temperatures, and at higher team‐to‐starch ratios. Multiple passes through the jet cooker decreased the viscosity dramatically for the first two passes, but little additional change was observed for further passes. The results show that mechanical and thermal degradation effects are both important in the jet cooking of waxy maize starch, although the primary effect is due to mechanical degradation.
Yield and Phytosterol Composition of Oil Extracted from Grain Sorghum and Its Wet‐Milled Fractions
Authors: Singh Vijay , Moreau Robert A. , Hicks Kevin B.
Published: June 2007

Corn fiber contains an oil with high levels of three potential cholesterol‐lowering phytosterol compounds. Little information is available about the levels and types of phytosterols in sorghum. In this study, phytosterols were evaluated in grain sorhgum and its wet‐milled fractions and were compared with the phytosterols in corn. The study showed that sorghum kernels can provide a significant source of two phytosterol classes, free phytosterols (St) and fatty acyl phytosterol esters (St:E). Most of these phytosterols are concentrated in the wet‐milled fiber fraction followed by the germ fraction. In addition to phytosterols, other lipid classes such as wax esters and an aldehyde (50% C28 and 50% C30) are also present in the sorghum oil. Comparison of sorghum and corn kernels show that corn has 72–93% more phytosterols than sorghum.
Effect of Dry Heating with Ionic Gums at Controlled pH on Starch Paste Viscosity
Authors: Lim H. S. , BeMiller J. N. , Lim S.‐T.
Published: June 2007

Waxy maize and potato starches were dispersed in pH 6.0 and 8.0 aqueous solutions (1%) of an ionic gum (sodium alginate, sodium carboxymethylcellulose, and xanthan). The mixture was dried at 45°C overnight and then heat‐treated 2 hr at 130°C. Effects on the paste viscosity of the products in a pH 7.0 buffer were examined. Heating with sodium alginate or sodium carboxymethylcellulose (CMC) increased the paste viscosity of waxy maize starch but reduced that of potato starch. In both starches, xanthan effected greater viscogram changes than did sodium alginate or CMC. Use of xanthan in the treatment produced products with restricted granular swelling and increased shear stability of the pastes. The pH of the starch‐gum mixtures affected the thermally induced viscosity changes. Mild acidity (pH 6.0) effected a viscosity decrease for the heat‐treated starch product, whereas alkalinity (pH 8.0) raised the viscosity regardless of the presence of gum. But pH 6 before heat treatment was favored for viscosity increase by sodium alginate, whereas pH 8 gave a greater increase in viscosity when xanthan was used. By using gum mixtures such as xanthan‐alginate and xanthan‐CMC, both viscosity increase and good shear‐stability were achieved.