bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Compatibility of Rice Starch and Pectins by Glass Transition and Sub‐Tg Endotherms and the Effect of Compatibility on Gel Viscosity and Water Loss
Authors: Lai Yu‐Chi , Sung Po‐Hou , Chien John T.
Published: June 2007

Differences in molecular structure and hydrophilicity may affect the compatibility of food components in a highly concentrated solution. Mixtures of TNuS19 rice starch (RS) and pectins with three different degrees of esterification (22, 64, and 92%) were used as a model system to evaluate the components' compatibility in a low‐moisture system. When analyzed individually by differential scanning calorimetry (DSC), RS, low methoxyl pectin (LMP), intermediate methoxyl pectin (IMP), and high methoxyl pectin (HMP) showed the presence of a glass transition temperature (Tg) at 75.2, 96.2, 96.4, and 93.5°C, respectively. Among mixtures, the compatible RS‐HMP exhibited only a single Tg between the Tg values of the two components, whereas the incompatible RS‐LMP showed two Tg values that were close to those of the individual components. The sub‐Tg endotherms of all three mixtures (1:1) were lower than the means of the corresponding components. The degree of decrease was more pronounced in the RS‐HMP mixture than in the others. The above results imply that the interaction, which led to close contact between side chains of the two components, was more intense in the compatible RS‐HMP mixture than in the RS‐IMP and RS‐LMP mixtures. The decrease of the sub‐Tg endotherm can be used as an index to evaluate the degree of compatibility as well as the interaction occurring between the two molecules. The above findings were further verified by dynamic mechanical analyses. Both viscosity and water retention of the compatible RS‐HMP mixed gel were significantly higher than those of the RS‐IMP and RS‐LMP mixed gels. This evidence further suggests that RS and HMP are compatible and exhibit a strong intermolecular interaction that increases gel viscosity and decreases water loss during high‐temperature heating.
NIR Transmittance Estimation of Free Lipid Content and Its Glycolipid and Digalactosyldiglyceride Contents Using Wheat Flour Lipid Extracts
Authors: Ohm J. B. , Chung O. K.
Published: June 2007

Free lipids (FL) in 72 hard winter wheat flours were extracted and dissolved in hexane. Absorbance (log 1/T) values were measured using a scanning spectrophotometer with a 2‐mm cuvette, and used to develop calibration models for estimating flour FL content and glycolipid (GL) and digalactosyldiglyceride (DGDG) contents. Fifty‐one calibration samples were selected based on the cutoff point of 0.3 of Mahalanobis distance, and the remaining twenty‐one samples were used for validation. The best model for the estimation of FL content showed coefficients of determination (R2) of 0.95 for the calibration set and R2 = 0.89 for the validation set. Glycolipid contents could be estimated by a model which had R2 = 0.87 for the calibration set and R2 = 0.89 for the validation set. For DGDG, the best model showed R2 = 0.94 for the calibration set and R2 = 0.88 for the validation set.
In Vitro Polymerization of Wheat Glutenin Subunits with Inorganic Oxidizing Agents. II. Stepwise Oxidation of Low Molecular Weight Glutenin Subunits and a Mixture of High and Low Molecular Weight Glutenin Subunits
Authors: Veraverbeke Wim S. , Larroque Oscar R. , Békés Frank , Delcour Jan A.
Published: June 2007

High and low molecular weight glutenin subunits (HMW‐GS and LMW‐GS) were isolated from wheat flour. LMW‐GS and a 1:2 (w/w) mixture of HMW‐GS and LMW‐GS were polymerized in vitro at pH 3.0 by stepwise oxidation with different oxidants (KBrO3, KIO3, H2O2). In analogy with the oxidation of HMW‐GS, KBrO3 produced smaller polymers for LMW‐GS than KIO3 or H2O2. While similar average sizes were found with flow‐field flow fractionation for LMW‐GS polymerized with KIO3 and H2O2, multilayer SDS‐PAGE and size exclusion HPLC indicated that size distributions were different. Significantly fewer monomers remained after polymerization of LMW‐GS than with HMW‐GS. The higher polymerization efficiency of LMW‐GS was also obvious during polymerization of a mixture of HMW‐GS and LMW‐GS. Mixed polymerization of HMW‐GS and LMW‐GS had no observable effect on the polymer size. Multilayer SDS‐PAGE of remaining monomers during polymerization revealed differences in polymerizing efficiency between structurally different glutenin subunits, with x‐type HMW‐GS and B‐LMW‐GS showing higher degrees of incorporation than y‐type HMW‐GS and C‐LMW‐GS, respectively.
Effect of Partial Gelatinization and Lipid Addition on α‐Amylolysis of Barley Starch Granules
Authors: Lauro M. , Poutanen K. , Forssell P.
Published: June 2007

The effect of partial gelatinization with and without lipid addition on the granular structure and on α‐amylolysis of large barley starch granules was studied. The extent of hydrolysis was monitored by measuring the amount of soluble carbohydrates and the amount of total and free amylose and lipids in the insoluble residue. Similarly to the α‐amylolysis of native large barley starch granules, lipid‐complexed amylose (LAM) appeared to be more resistant than free amylose and amylopectin. Partial gelatinization changed the hydrolysis pattern of large barley starch granules; the pinholes typical of α‐amylase‐treated large barley starch granules could not be seen. Lipid addition during partial gelatinization decreased the formation of soluble carbohydrates during α‐amylolysis. Also free amylose remained in the granule residues and mostly amylopectin hydrolyzed into soluble carbohydrates. These findings indicate that lysophospholipid (LPL) complexation with amylose occurred either during pretreatment or after hydrolysis, and free amylose was now part of otherwise complexed molecules instead of being separate molecules. Partial gelatinization caused the granules to swell somewhat less during heating 2% starch‐water suspensions up to 90°C, and lipid addition prevented the swelling completely. α‐Amylolysis changed the microstructure of heated suspensions. No typical twisting of the granules was seen, although the extent of swelling appeared to be similar to the reference starch. The granules with added LPL were partly fragmented after hydrolysis.
Rice Quality by Spectroscopic Analysis: Precision of Three Spectral Regions
Authors: Barton F. E. , Himmelsbach D. S. , McClung A. M. , Champagne E. T.
Published: June 2007

Three types of spectroscopy were used to examine rice quality: near infrared (NIR), Raman, and proton nuclear magnetic resonance (1H NMR). Samples from 96 rice cultivars were tested. Protein, amylose, transparency, alkali spreading values, whiteness, and degree of milling were measured by standard techniques and the values were regressed against NIR and Raman spectra data. The NMR spectra were used for a qualitative or semiquantitative assessment of the amylose/amylopectin ratio by determining the 1–4 to 1–6 ratio for glucans. Protein can be measured by almost any instrument in any configuration because of the strong relationship between the spectral response and the precision of the reference method. Amylose has an equally strong relationship to the vibrational spectra, but its determination by any reference method is far less precise, resulting in a 10× increase in the standard error of cross‐validation (SECv) or standard error of performance (SEP) with R
2 values equal to that of the protein measurement.
Lipidemic Response of Hamsters to Rice Bran, Uncooked or Processed White and Brown Rice, and Processed Corn Starch
Authors: Kahlon T. S. , Chow F. I.
Published: June 2007

This study was undertaken to evaluate the lipidemic response of rice bran and the possible enhancement of its healthful properties by using raw or processed white or brown rice in place of corn starch. All diets contained 10% total dietary fiber, 15% fat, and 0.5% cholesterol. Weanling male golden Syrian hamsters were fed cellulose control (CC), processed corn starch (PCS), cellulose with processed brown rice (CPBR), rice bran (RB), RB with white rice (RBWR), RB with processed white rice (RBPWR), RB with brown rice (RBBR), and RB with processed brown rice (RBPBR) diets. After three weeks, the PCS diet significantly lowered total plasma cholesterol (TC) compared with the CC, CPBR, RBWR, and RBPBR diets. RB and RBBR diets significantly lowered TC and LDL‐C compared with CPBR diet. All the RB‐containing and PCS diets significantly lowered liver cholesterol and liver lipid content. Processing white rice increased TDF content 240% and insoluble dietary fiber (IDF) 360%, whereas soluble dietary fiber (SDF) decreased by 25%. Uncooked brown rice contained 7 times as much TDF as uncooked white rice. Processing brown rice decreased its TDF, IDF and SDF contents by 12, 6, and 42%, respectively. The data suggest that a possible mechanism for cholesterol‐lowering by rice bran, with or without added raw or processed rice (white or brown), is by decreasing lipid digestibility and increasing neutral sterol excretion, whereas cholesterol‐lowering by processed corn starch is mediated through other mechanisms.
Effects of Temperature, Sonication Time, and Power Settings on Size Distribution and Extractability of Total Wheat Flour Proteins as Determined by Size‐Exclusion High‐Performance Liquid Chromatography
Authors: Morel M.‐H. , Dehlon P. , Autran J. C. , Leygue J. P. , Bar‐L'Helgouac'h C.
Published: June 2007

The size‐exclusion (SE) HPLC profile of total protein extract obtained by sonication of flour samples at ambient temperature showed marked instability on reinjection. Instability was related to the presence of flour proteases that were inactivated by thermal treatment of flour samples at 60°C. Extraction of flour protein by sonication was a function of ultrasonic energy (sonication time × power product) delivered to flour sample. As protein solubility increased, the proportions of the earliest eluted SE‐HPLC fractions (F1 and F2) increased. Oversonication of proteins evidenced by a decrease in F1 amount at the benefit of F2 occurred below the sonication energy level needed for total protein extraction. Ultrasonic energy level was adjusted to allow total protein extraction while limiting oversonication. The sonication procedure was applied on 27 flour samples of contrasting dough strength to extract total proteins. Absolute amount of protein extractable by sonication, determined from SE‐HPLC area, was strongly correlated with flour protein content. Very significant and equivalent relationships were found between alveographic W index and absolute amount of either unextractable protein extract or F1 of SE‐HPLC profile from total protein extract.
Effects of Incorporated Glutenins on Functional Properties of Wheat Dough
Authors: Uthayakumaran S. , Stoddard F. L. , Gras P. W. , Bekes F.
Published: June 2007

The development of reduction‐oxidation methods to open the native gluten polymer, incorporate monomers, and repolymerize the modified polymer, has allowed new types of investigation of the effects of glutenin subunits on dough characters. These methods were used to incorporate bulk high molecular weight glutenin subunits (HMW‐GS) and bulk low molecular weight glutenin subunits (LMW‐GS) from four cultivars into the parent flours to modify the HMW‐GS‐to‐LMW‐GS ratio. In addition, the glutenins from the four cultivars were added to a single base flour of differing glutenin subunit composition. Finally, HMW‐GS 7, 8, 5, and 10 were incorporated singly and in pairs into two base flours. The mixing time, peak resistance, maximum resistance to extension, and loaf height increased with increases in HMW‐GS‐to‐LMW‐GS ratio. There was a decrease in resistance breakdown observed with increase in HMW‐GS‐to‐LMW‐GS ratio. The maximum resistance to extension slightly increased with increases in HMW‐GS‐to‐LMW‐GS ratio (strongly in cultivar Hartog). Dough extensibility decreased with increase in HMW‐GS‐to‐LMW‐GS ratio (except in Osprey derivative). In the incorporation studies of single and paired glutenin subunits, HMW‐GS 5+10 gave a synergistic effect increasing mixing time, maximum resistance to extension, and loaf height as compared with HMW‐GS 5 or 10 separately. In contrast, HMW‐GS 7+8 showed an additive effect and HMW‐GS 7 incorporated separately had a higher mixing time, maximum resistance to extension, and loaf height than those of HMWGS 7+8 and HMW‐GS 8.
Physical Properties of Poly(Lactic Acid) and Starch Composites with Various Blending Ratios
Authors: Ke Tianyi , Sun Xiuzhi
Published: June 2007

Two‐phase polymer blends of poly(lactic acid) (PLA) and corn or wheat starches at various ratios were prepared by using a laboratory‐scale twin‐screw extruder and compression molding. The blends were characterized for thermal transitions, mechanical properties, and water absorption. Starch and PLA were immiscible polymers, and the thermal behavior of PLA was not affected by starch. Crystallinity of the blends decreased in some degree as starch content increased 20–40%. Tensile strength and elongation of the blends decreased as starch content increased, but modulus increased as starch content increased up to 70%. As starch content increased to >60%, the PLA phase became discontinuous, and water absorption of the blends increased sharply. Blends made from wheat starch gave slightly better mechanical properties than those made from corn starch, and no differences in other properties were observed.
Effects of Nitrogen and Sulfur Fertilizer on Protein Composition, Mixing Requirements, and Dough Strength of Four Wheat Cultivars
Authors: Wooding A. R. , Kavale S. , MacRitchie F. , Stoddard F. L. , Wallace A.
Published: June 2007

Two field trials using four New Zealand wheat cultivars were undertaken to observe the effects of nitrogen and sulfur fertilization on protein composition, mixing requirements, and dough strength and to compare the results with that observed with a single cultivar, Otane. The results confirmed that adequate sulfur fertilization was necessary to ensure lower dough mixing requirements. The existence of a nexus between mixing requirements and dough strength was confirmed and genotype has significant effects on it. Variation in the content of HMW‐GS in the protein corresponded to changes in dough mixing requirement of Otane. Across the four cultivars, dough mixing requirements (mechanical dough development work input and mixograph development time) and dough strength (Extensigraph resistance to extension) depended on different aspects of protein composition. As the content of polymeric proteins increased, MDD work input increased, but mixograph development time decreased, while the effect on Rmax was small. Rmax, however, was more affected by either the content of small monomerics in the flour or the ratio between HMW‐GS peak area to total gliadin peak area. The ratio of MDD work input to Rmax was largely explained by the gliadin content of the flour. Thus, depending on the genetic background, it should be possible to adjust dough mixing requirements by modifying overall HMW‐GS, LMW‐GS, or gliadin content while maintaining dough strength.
Analytical Techniques for Understanding Nixtamalized Corn Flour: Particle Size and Functionality Relationships in a Masa Flour Sample
Authors: Sahai D. , Buendia M. O. , Jackson D. S.
Published: June 2007

Instant masa flour finds extensive use in the food industry for making tortillas, taco shells, tamales, corn chips, and tortilla chips, and as an ingredient in extruded snacks. Due to lack of standard techniques for measuring masa functionality, processors and end‐users use masa flour particle‐size distribution and rheological characteristics in an attempt to predict its end use. In this study, a commercial masa flour sample was characterized by fractionating on the basis of particle size. Physicochemical and functional properties of masa flour fractions were investigated to establish structure‐composition and functionality relationships. It was observed that Rapid Visco Analyser (RVA) pasting profiles of flour fractions and textural properties of dough prepared on rehydration were related to particle size, yet, upon regrinding, RVA profiles did not change as markedly as expected. Differences in RVA measurements of the sized fractions could not be explained on the basis of hydration rate or total starch content. It was concluded that masa dough textural and RVA characteristics may be influenced by the status of starch polymer structures formed during nixtamalization.
Effects of Wheat Cultivar and Nitrogen Application on Storage Protein Composition and Breadmaking Quality
Authors: Johansson Eva , Prieto‐Linde Maria Luisa , Jönsson Jan Ö.
Published: June 2007

Influences of cultivar and nitrogen application on protein concentration and composition, and amount and size‐distribution of different protein components, were investigated in 10 spring wheat cultivars (Triticum aestivum L.) with widely varying gluten strength, grown under four nitrogen fertilizer conditions. The results showed that cultivar differences in gluten strength were determined by storage protein composition, differences in total amount of HMW glutenin subunits, the glutenin‐to‐gliadin ratio, and the relationship between SDS‐soluble and SDS‐insoluble protein polymers. Negative correlations were found between protein parameters related to gluten strength and bread volume. No cultivar stability for gluten strength in relation to differences in nitrogen application was found. Thus, the gluten strength was influenced by the nitrogen application in all the investigated cultivars. Increased nitrogen supply correlated significantly to an increase in all protein components containing gliadins and glutenins, but not to those containing albumins and globulins. The increase in protein components containing gliadins and glutenins correlated significantly with an increase in protein concentration and bread volume.
Effect of Lipid Oxidation on Dough Bleaching
Authors: Mercier M. , Gélinas P.
Published: June 2007

The effect of lipid composition and oxidation on dough bleaching has been determined. At >2.25% (flour basis), pure linoleic acid was very efficient in degrading β‐carotene in dough, unlike colza, corn, peanut, soy, or sunflower oil, which were mainly characterized by different polyunsaturated fatty acids content. In a very oxidized state, as determined by a peroxide index of >15 meq/kg of oil, sunflower oil (rich in polyunsaturated fatty acids) had a major bleaching activity on β‐carotene when compared with colza oil (less polyunsaturated), especially in combination with long mixing times. A combination of lipase (815 U), slightly oxidized oil (peroxide index of 2–5 meq/kg of oil), and linoleic acid (90 mg/100 g of flour) significantly degraded flour pigments (P < 0.05).
Effect of Alternative Milling Techniques on the Yield and Composition of Corn Germ Oil and Corn Fiber Oil
Authors: Singh Vijay , Moreau Robert A. , Hicks Kevin B. , Eckhoff Steven R.
Published: June 2007

The effects of alternative corn wet‐milling (intermittent milling and dynamic steeping (IMDS), gaseous SO2 and alkali wet‐milling) and dry grind ethanol (quick germ and quick fiber with chemicals) production technologies were evaluated on the yield and phytosterol composition (ferulate phytosterol esters, free phytosterols, and fatty acyl phytosterol esters) of corn germ and fiber oil and compared with the conventional wet‐milling process. Small but statistically significant effects were observed on the yield and composition of corn germ and fiber oil with these alternative milling technologies. The results showed that the germ and fiber fractions from two of the alternative wet‐milling technologies (the gaseous SO2 and the IMDS) had, for almost all of the individual phytosterol compounds, either comparable or signficantly higher yields compared with the conventional wet‐milling process. Also, both of the modified dry grind ethanol processes (the quick germ and quick fiber) with chemicals (SO2 and lactic acid) can be used as a new source of corn germ and fiber and can produce oils with high yields of phytosterols. The alkali wet‐milling process showed significantly lower yields of phytosterols compounds in germ but showed significantly higher yield of free phytosterols, fatty acyl phytosterol esters and total phytosterols in the fiber fraction.
In Vitro Binding of Puroindolines to Wheat Starch Granules
Authors: Bloch Helle A. , Darlington Helen F. , Shewry Peter R.
Published: June 2007

Puroindoline (pin) preparations made from flours of hard and soft wheats contained a mixture of pin‐a, 0.19/0.53 α‐amylase inhibitor, and purothionins. Starch granule preparations from the same cultivars were treated with proteinase to remove surface proteins and incubated with solutions of the pin preparations. Binding of pin‐a and purothionins but not the 0.19/0.53 inhibitor was observed with no apparent differences between the behavior of the pin preparations or starch granule preparations from hard or soft types. No binding was observed when several other proteins (bovine serum albumin, total albumins, a commercial preparation of wheat α‐amylase inhibitors, and barley β‐amylase) were incubated with the starch granules under the same conditions, indicating that in vitro binding can be used to study specific starch granule and protein interactions.
N‐Terminal Amino Acid Sequence Analysis of Endosperm Proteins in Japanese Hexaploid Wheat
Authors: Nakamura Hiro
Published: June 2007

Semidry electroblotting is convenient and allows a rapid and efficient protein transfer from two‐dimensional polyacrylamide gel electrophoresis (2D‐PAGE) gels onto sequencer stable supports for protein microsequence analysis in a gas‐phase sequencer. Using this technique, I determined the amino acid sequences of the endosperm proteins in Japanese hexaploid commercial wheats (Triticum aestivum). Based on sequence determination of the Japanese hexaploid wheats, the endosperm protein could be easily characterized. Wheat endosperm protein, extracted in the presence of 2‐mercaptoethanol and SDS, fractionated into many protein polypeptides using 2D‐PAGE under dissociating conditions. These components were grouped into HMW glutenin subunits, α‐, β‐ or γ‐gliadins, and novel protein polypeptides by using the N‐terminal amino acid sequences. The novel endosperm protein polypeptides were detected, and two new types of N‐terminal amino acid sequences have been found for protein poly‐peptides. These polypeptides have much faster electrophoresis mobility during 2D‐PAGE and are therefore probably a much smaller size than any other peptides of endosperm protein groups found in hexaploid wheat. Ten protein polypeptides have been purified from cultivars of Japanese wheat. Some differences in the contents of amino acids for four protein polypeptide spots were apparent in Japanese wheat.
Apparent Dough Stickiness of Selected 1BL/1RS Translocated Soft Wheat Flours
Authors: Schwarzlaff Sabine S. , Uriyo Maria G. , Johnson Janet M. , Barbeau William E. , Griffey Carl A.
Published: June 2007

A new method, called the Schwarzlaff‐Shephard Dough Stripping Method, was used to determine apparent dough stickiness in seven 1BL/1RS translocated soft, red, winter wheat (SRWW) lines and five SRWW lines without the translocation. Pairwise comparisons of all 1BL/1RS versus all non‐1BL/1RS lines indicated that doughs made from the 1BL/1RS lines were significantly stickier, on average, than doughs made from the non‐1BL/1RS lines. However, there was no significant difference in the apparent dough stickiness of one set of sister lines that shared a similar pedigree, 1BL/1RS line VA 93‐54‐18 versus its non‐1BL/1RS sister line VA 94‐54‐21. Another 1BL/1RS line, VA 92‐52‐22, ranked last in apparent dough stickiness and was significantly less sticky than two non‐1BL/1RS lines. VA 92‐52‐22 has a distinctly different pedigree from the other 1BL/1RS lines that we evaluated. These findings suggest that there are strong genotypic effects on dough stickiness, making it possible to develop non‐sticky cultivars of 1BL/1RS SRWW.
Characterization of Extruded Plant Protein and Petroleum‐Based Packaging Sheets
Authors: Obuz Ersel , Herald Thomas Joseph , Rausch Kent
Published: June 2007

Extruded packaging sheets (EPS) were manufactured from wheat gluten (WG) or sorghum flour (SF) in combination with (10, 25, 50, 75, and 100%) low density polyethylene (LDPE) or metallocene‐catalyzed ethylene‐butene copolymer (MCEBC), and plasticized successfully with sorbitol at a weight ratio of 1:1. Physical analyses were used to characterize the extruded packaging materials. Tensile strengths and elongations of the sheets significantly decreased as the WG or SF increased. Sheets formulated with ≈1:1:2 wheat gluten, sorbitol, and MCEBC exhibited similar elastic properties compared with a 100% MCEBC sheet. Young's modulus and percent elongation at break values decreased as WG‐sorbitol or SF‐sorbitol level increased in the EPS.
Release of β‐Glucan from Cell Walls of Starchy Endosperm of Barley
Authors: Kanauchi Makoto , Bamforth Charles W.
Published: June 2007

β‐Glucan can be solubilized from barley by warm water, with increasing solubilization as the temperature is increased. Substantially less glucan is extracted if the barley is dehusked using sulfuric acid, particularly if the dehusked barley is denatured. This indicates that enzymes capable of solubilizing glucan are present in barley. Various purified enzymes promote the solubilization of glucan from denatured and dehusked barley. Apart from endo‐β‐(1→3)(1→4)‐glucanase, these enzymes include endo‐xylanases, arabinofuranosidase, xyloacetylesterase, and feruloyl esterase. Ferulic acid and, probably, acetyl groups are esterlinked to arabinoxylan, not β‐glucan, in the cell walls of barley starchy endosperm, so the ability of the esterases, xylanases, and arabinofuranosidase to solubilize glucan indicates the pentosan component of the cell wall can restrict the extraction of glucan.
A Rapid Protein Digestibility Assay for Identifying Highly Digestible Sorghum Lines
Authors: Aboubacar Adam , Axtell John D. , Huang Chia‐Ping , Hamaker Bruce R.
Published: June 2007

Protein digestibility in sorghum (Sorghum bicolor (L.) Moench) lines was determined using two standard procedures (pepsin digestibility and pH‐stat) and compared with a newly developed, rapid electrophoresis‐based screening assay. The new assay was based on the rate of α‐kafirin disappearance after pepsin digestion. α‐Kafirin, the major sorghum storage protein, makes up ≈60–70% of the total protein in the grain. In the new assay, samples were first digested with pepsin for 1 hr, and undigested proteins were then analyzed by SDS‐PAGE. The intensitizes of the undigested α‐kafirin bands were measured. Higher band intensity indicated lower protein digestibility. The new assay was significantly correlated with the standard pepsin digestibility assay (r = −0.96, n = 16) after which it was patterned. The same was true of the pH‐stat procedure (r = −0.85, n = 16). This implies that the new assay is comparable to existing procedures and can be used for screening sorghum lines for protein digestibility. Two groups consisting of high‐protein digestibility and wild‐type sorghum lines were identified when the new assay was tested on 48 sorghum lines derived from crosses of wild‐type and mutant high protein digestibility lines, indicating that the new assay was efficient in differentiating between the two groups. Advantages of the new assay over the standard procedures include considerable reduction in analysis time and sample size required for the analysis. For example, analysis time was reduced by 20% and sample size by 10% when the new assay was used as compared with the pH‐stat procedure. We estimate that ≈60 sorghum lines can be screened in a day by a single operator using the new assay.
Influence of Temper Duration and Weight Distance on System Output in the Corn Dry‐Milling Process
Authors: Mehra S. K. , Eckhoff S. R.
Published: June 2007

Initial uniform distribution of moisture in the corn kernel is transformed into nonuniform distribution through tempering to facilitate easy fractionation of corn components. Proper temper duration is essential for effectiveness of the tempering process: a short temper time is insufficient to cause necessary nonuniformity; a long temper duration may allow moisture to redistribute uniformly. Untempered corn suffers from lack of beneficial swelling stress and therefore produces lower yields of flaking grits, coarse grits, and germ. For tempered corn, the system throughput exponentially decreases with temper duration and then stabilizes; the period of stabilization is dependent on weight distance. Throughput values are lower at longer weight distances. At a temper duration of 0.066 m, throughput was ≈33–50% at 0.053 m weight distance. Tail stock fraction rapidly and nonlinearly decreases with increase in temper duration; the rate of decrease is higher at longer weight distance. The peak values of flaking grits can exceed 50% at some combinations of weight distance and temper duration. Coarse grit yields were 9–19% and 16–24% for the shorter and longer weight distances, respectively. Germ recovery improved due to tempering, and differed only by ≈0.5% at the two weight distances. Tempering lowered the oil content of flaking grit, but the temper duration did not have much influence on moisture content of various fractions.
Mechanical Properties of Wheat Seed Coats
Authors: Mabille F. , Gril J. , Abecassis J.
Published: June 2007

The crumbliness of starchy endosperm and the resistance of bran are key characteristics that enhance milling behavior of wheat and are dependent on the genetic origin and moisture content of the grain. A method was developed to measure the mechanical properties of bran samples based on the measurement of tensile stress and strain. Tests conducted with this highly reproducible and sensitive method documented cultivar and moisture‐content effects (6.3, 13.8, and 18%, wb) on rheological behavior of wheat seed coats. A moisture‐dependent reduction in stress to fracture (‐15 to ‐30%) and in Young's modulus (‐45 to ‐55%) was quantified. An increase in deformation to fracture of seed coats was also correlated with bran size differences after milling. The energy required to fracture a sample (from 0.4 to 1.3 J/mm3) was considered the most valid of all presented parameters for assessing the milling behavior of wheat seed coats and the size of bran fractions.
Accessibility of Starch Granules to Fatty Acyl Amides
Authors: Gray Jonathan A. , BeMiller James N.
Published: June 2007

Microscopic techniques were used to determine accessible regions in various starches under different swelling conditions. Fatty acyl chlorides of increasing chain length (C6–C16) were reacted with 2‐aminopyridine to produce the corresponding fatty acyl amides. Starch granules (common corn, waxy maize, potato) were treated with the series of fluorescent amides under a variety of conditions: anhydrous (hot pyridine), aqueous (no heat), and aqueous alkali (49°C, with and without swelling‐inhibiting salts). Isolated granules were then viewed by confocal laser scanning microscopy to determine reagent analog penetration. All populations of granules were heterogeneous with respect to fatty acyl amide penetration, but general patterns could be discerned. Observations also indicated that the area surrounding the hilum was more easily penetrated than was the rest of the granule matrix. No substantial differences in penetration of the fluorescent fatty acyl amides as the chain length increased (C6–C16 was observed in hot pyridine‐swollen common corn starch granules. Common corn and potato starch granules swollen in room temperature water showed cutoffs for granular exclusion at C14 and C12, respectively. Common corn, waxy maize, and potato starch granules treated under industrial etherification conditions (heat, pH ≈ 11, swelling‐inhibiting salts) were less accessible to C6, C8, and C10 fluorescent amides when sodium citrate was present than when sodium sulfate was used, and less accessible in either case than in water alone or in hot anhydrous pyridine. However, appreciable differences between inhibition by sodium sulfate and sodium citrate were not observed in every case.
Detection of Wheat Preharvest Sprouting Using a Pregelatinized Starch Substrate and Centrifugation
Authors: Donelson J. R. , Gaines C. S. , Donelson T. S. , Finney P. L.
Published: June 2007

Wheat sprouting in the field before harvest is a serious negative quality attribute. Even low levels of preharvest sprouting affect the economic value of the grain. Unreleased test lines of wheat should be screened for resistance to preharvest sprouting. However, screening large numbers of test lines is relatively time‐consuming or expensive, depending on the existing method used. A new screening test for preharvest sprouting was developed and compared with the viscograph and α‐amylase activity (AAA) methods. The new method used the activity of sprout‐related elevation in α‐amylase to partially degrade added pregelatinized starch. The hydrolytic products were centrifuged and the weight of the centrifugate was expressed as a percentage of the original weight of the added pregelatinized starch plus the original meal or flour weight. The result reflected the AAA on pregelatinized starch (AAAPGS) as a measure of the degree of preharvest sprouting. The AAAPGS test had less standard error and was more sensitive at low levels of preharvest sprouting than the AAA method. Three grinders to produce wheat meal were compared for their effect on AAAPGS values. Flours produced slightly lower AAAPGS values than meals, but the coefficients of variation of each were comparable and both were less than that of the AAA method. The lowest levels of sensitivity to preharvest sprouting that could be detected by the AAA and AAAPGS methods were identified as areas of uncertainly, below which very low levels of preharvest sprouting could not be differentiated from sound, unsprouted background values. The new AAAPGS method was equally rapid and will be more economical than the AAA method or the viscograph when used for preharvest sprouting susceptibility of large numbers of samples.
Thermal Properties and Paste and Gel Behaviors of Starches Recovered from Accessions Used in the Germplasm Enhancement of Maize Project
Authors: Singh S. K. , Johnson L. A. , White P. J. , Jane J.‐L. , Pollak L. M.
Published: June 2007

The objective of this study was to screen starches recovered from the corn accessions used in the Germplasm Enhancement of Maize (GEM) project for unusual thermal properties and paste and gel behaviors, so that they could be exploited in corn breeding programs to enhance traits important to corn utilization. In general, the values for gelatinization temperatures and peak height indices were greater, but heat of gelatinization values were less for the starches recovered from the GEM accessions (particularly BRA 052051 (SE 32)) than for starches from commercial Dent corn hybrids (11.3 vs. 13.6 J/g). Generally, retrogradation properties were similar among the GEM accessions, although there were specific accessions (particularly Lima 13) that possessed modestly lower percentage retrogradation (34 vs. 42%). Generally, peak viscosities, cold paste viscosities, and viscosity breakdowns were greater for the starches of the GEM accessions (particularly ARZM 01150, Antiqua 3, and URZM 01089, respectively) than for the starches of commercial hybrids. Pasting temperatures were about the same for all starches. Both 1‐day and 7‐day gel strengths were considerably greater for the starches recovered from the GEM accessions (particularly BRA 052051 (SE 32), 21.0 g for 1‐day and FS8A(T), 66.2 g for 7‐day). Although the differences in starch properties were statistically different, only the higher gel strengths of the starches recovered from the GEM accessions were of practical significance to the starch industry.
Compositional, Physical, and Wet‐Milling Properties of Accessions Used in Germplasm Enhancement of Maize Project
Authors: Singh S. K. , Johnson L. A. , Pollak L. M. , Hurburgh C. R.
Published: June 2007

Forty‐nine accessions used in the Germplasm Enhancement of Maize (GEM) project, two commercial hybrids (Pioneer Brand Hybrids 3394 and 3489), and two Corn Belt inbreds (B73 and Mo17) were evaluated for compositional, physical, and wet‐milling properties. GEM accessions had lower starch contents (65.9–69.1% vs. a mean of 72.2% for the commercial hybrids) and greater protein contents (12.0–14.4% vs. a mean of 8.2% for the commercial hybrids) than did the improved Corn Belt material. Absolute densities were consistently higher for the GEM accessions compared with the commercial hybrids (1.320 vs. 1.265 g/cm3, respectively). The wet‐milling characteristics of the GEM accessions were not nearly as good as for the commercial hybrids. Mean starch yields were only 54.3% for the GEM accessions versus 64.8% for the commercial hybrids. Residual protein levels in the starches recovered from the GEM accessions were much greater (0.45–2.03%) than for commercial corn hybrids (<0.3%).
Effects of Postharvest Parameters on Functional Changes During Rough Rice Storage
Authors: Pearce M. D. , Marks B. P. , Meullenet J.‐F.
Published: June 2007

The expansion of value‐added uses for rice has created a demand for quantitative models of functional changes during postharvest handling. Consequently, this study evaluated the effects of postharvest parameters on the functional properties of long‐grain (cvs. Cypress and Kaybonnet) and medium‐grain (cv. Bengal) rice. The experimental treatments included rough rice drying conditions (low vs. high temperature drying), storage moisture content (10, 12, and 14%), storage temperature (4, 21, and 38°C), and storage duration (up to 36 weeks). Milling, cooking, and amylograph pasting properties were analyzed. Polynomial models (up to third‐order) were developed to describe the effects of postharvest factors on the functional properties. Drying treatments, storage moisture content, and storage duration affected (P < 0.05) all of the functional properties. Storage temperature influenced (P < 0.01) cooking and pasting properties, but not milling properties. Overall, there were significant interactions among the postharvest parameters. Additionally, these factors were related to the functional properties by higher‐order relationships.
Cultivar‐by‐Environment Interactions for Wheat Quality Traits in Semiarid Conditions
Authors: Mladenov Novica , Przulj Novo , Hristov Nikola , Djuric Veselinka , Milovanovic Milivoje
Published: June 2007

Knowledge of the presence and magnitude of cultivar‐by‐environment (C × E) interactions is important to plant breeders in making decisions regarding the development and evaluation of new cultivars. In this study, 16 winter wheat cultivars were grown in 11 environments in a randomized complete block design with three replicates. The winter wheat (Tritcum aestivum L.) cultivars displayed a broad range of quality, and the different environments represented a broad range of environmental conditions. Test weight (TW), grain protein content (GP), sedimentation value (SED), wet gluten (WG), farinograph absorption (FAB), farinograph dough development time (FDT), quality number (FQN), resistance to extension (ER), loaf volume (LV), and baking score (BS) were measured. Highly significant differences were detected among the environments and cultivars for each of the quality variables. Significant C × E interactions indicated that the breadmaking quality evaluations must be undertaken for several environments. The WG trait showed a significant positive correlation with TW, GP, SED, LV, and BS. Path analysis indicated that GP, the most important component of quality, exhibited not only large direct effects but also large indirect ones on LV through SED, WG, FAB, and FDT. The correlation among the selected traits may be useful in future breeding programs.
Genetic Analysis of Kafirins and Their Phenotypic Correlations with Feed Quality Traits, In Vitro Digestibility, and Seed Weight in Grain Sorghum
Authors: Hicks C. , Bean S. R. , Lookhart G. L. , Pedersen J. F. , Kofoid K. D. , Tuinstra M. R.
Published: June 2007

Twenty‐three entries of grain sorghum (Sorghum bicolor (L.) Moench), including eight inbred lines (five males and three females) and 15 hybrids, were evaluated to determine the proportion of γ, αII, and β‐αI‐kafirins and their association with contents of crude protein, fat, and starch; protein digestibility; in vitro dry matter disappearance; and seed weight. The male lines included three normal‐seeded lines (TX2737, TX435, and P954063) and two large‐seeded lines (Eastin1 and PL‐1). Female lines consisted of three common U.S. seed parent lines (Wheatland, Redlan, and SA3042). The lines and their hybrids were grown under dryland conditions at two locations in Kansas using a randomized complete block design. The effects of genotype, location, and males were significant for all kafirins. Wide variations in composition and general combining ability (GCA) for kafirin content were noted among parent lines and hybrids, with TX2737, Eastin1, and PL1 having the largest GCA values for γ (1.37), αII (1.99), and β‐αI (2.57), respectively. Correlations among kafirins ranged from ‐0.89 to 0, whereas those of kafirins with feed quality traits, digestibility, and seed weight ranged from ‐0.45 to 0.48.
Noodle Quality as Related to Sorghum Starch Properties
Authors: Beta Trust , Corke Harold
Published: June 2007

Starch was extracted from 10 sorghum genotypes and physicochemical properties (amylose content and pasting, textural, and thermal properties) were evaluated. The amylose content was 24–30%. DC‐75 starch had the highest peak viscosity (380 Rapid Visco Analyser units). Gelatinization peak temperature occurred over a narrow range (67–69°C). Genotypes Kasvikisire and SV2 produced white starches. Starches from other genotypes were different shades of pink. The starch noodles prepared were, accordingly, either white or pink. Cooking enhanced the pink coloration of noodles. Cooking loss, noodle rehydration, and elasticity were evaluated. Cooking loss was low (mean 2.4%). Noodle elasticity was highly correlated with starch pasting properties of hot paste viscosity (HPV) (r = 0.81, P < 0.01) and cold paste viscosity (CPV) (r = 0.75, P < 0.01). Noodle rehydration was significantly correlated to the initial swelling temperature of starch (Ti) (r = ‐0.91, P < 0.001) and gelatinization peak temperature (Tp) (r = 0.69, P < 0.05). The findings suggest a potential area of food application for sorghum genotypes of different grain colors. Evaluation of starch properties could be a good starting point for selecting sorghum genotypes with superior noodle‐making properties.
Structural Properties of Starch in Bread and Bread Model Systems: Influence of an Antistaling α‐Amylase
Authors: Hug‐Iten S. , Escher F. , Conde‐Petit B.
Published: June 2007

The influence of an antistaling α‐amylase on bread crumb and on wheat starch gels was investigated taking into account different levels of structural hierarchy. Bread was prepared by a conventional baking procedure. Starch gels were produced by heating a concentrated starch dispersion in closed molds. Bread and starch gels were characterized by compression tests, light microscopy (LM), differential scanning calorimetry, and X‐ray measurements. The α‐amylase enhanced the initial firmness of starch gels and reduced the firming rate of bread and starch gels on aging. LM revealed that amylose and amylopectin phase‐separated within the starch granules and that freshly baked control bread and starch gels showed weak birefringence which became more intense during aging. Amylase‐containing bread and starch gels exhibited strong birefringence in the amylose rich region of the granules directly after baking which did not significantly increase during aging. The enzyme hindered the retrogradation of amylopectin as detected by differential scanning calorimetry, whereas X‐ray diffraction indicated that the enzyme induced low levels of starch crystallinity which did not change during aging. It is hypothesized that the antistaling effect of the amylase is based on the capacity to partially degrade amylopectin and, by this, to hinder its recrystallization. On the other hand, the enzyme slightly degrades amylose by an endo‐mechanism which, in turn, promotes the rapid formation of a partly crystalline amylose network in fresh bread and hinders amylose rearrangements during aging.
Surface Properties of Gluten Investigated by a Fluorescence Approach
Authors: Sironi Elena , Guerrieri Nicoletta , Cerletti Paolo
Published: June 2007

The surface properties of glutens isolated from a durum wheat cultivar (Capeiti) and two bread wheats (Riband and Hereward) were investigated using intrinsic and extrinsic fluorescence. Intrinsic fluorescence decreased on increasing protein concentration and increased after urea addition. The extrinsic fluorescence was evaluated by a titration with 8‐anilino‐1‐naphthalene sulphonate (ANS), an hydrophobic probe. The saturating concentration for ANS and its dissociation constant (Kd) were determined. The hydrophobicity of durum and bread wheat gluten showed a different behavior increasing the protein concentration: Capeiti was not influenced, but there was a change on the gluten surface for Riband and Hereward. The significance in understanding gluten structure and the relevance of the surface properties are discussed.
Effects of Falling Number Sample Weight on Prediction of α‐Amylase Activity
Authors: Finney P. L.
Published: June 2007

Reports vary on the effects of falling number (FN) sample weight on test precision, reproducibility, and predictability of α‐amylase activity. Straight grade flours of 200 samples (25 cultivars × 2 locations × 2 N2 levels × 2 repetitions) were assayed for α‐amylase activity and FN. Location significantly affected α‐amylase activity and FN values. The coefficients of variation (CV) for the FN tests were 5.75, 2.12, 1.93, 1.72, 4.27, and 14.47%, when assayed with sample weights of 7, 6, 5.5, 5, 4.5, and 4 g, respectively. The FN test with the greatest reproducibility between sample replicates (lowest LSD and highest ratio of range/LSD) was also produced using the 5‐g sample weight. By reducing FN sample weight from 7 to 5 g, FN values that averaged 350 sec, considered essentially sound, averaged 215 sec, thus shortening the FN test time by an average of 2 min and 15 sec when assaying sound wheat flour. The results suggest a review of the 7‐g stipulation of AACC Approved Method 56‐81B for FN in favor of reduced sample weight.
Optimizing Quantitative Reproducibility in High‐Performance Capillary Electrophoresis (HPCE) Separations of Cereal Proteins
Authors: Bean S. R. , Lookhart G. L.
Published: June 2007

High‐performance capillary electrophoresis (HPCE) is capable of producing high‐resolution, rapid separations of cereal proteins. Furthermore, HPCE is highly reproducible in terms of migration time. However, little work has focused on the quantitative reproducibility of cereal protein separations. Several factors such as sample matrix, sample evaporation, voltage ramp‐up time, sample injection time, and capillary end‐cut were evaluated for involvement in quantitative reproducibility. These experiments showed that preventing sample evaporation, using optimum injection times, and ensuring a clean, square cut on the capillary all improved the reproducibility of peak areas. Combining these factors into an optimized procedure produced reproducibility with peak areas varying by 1.76% relative standard deviation (RSD). Migration time was also excellent under these conditions, varying by only 0.45% RSD. Other variables such as peak area percent, peak height, and peak height percent also showed good reproducibility with RSD < 4%. Increasing the voltage ramp‐up time from 0.17 to 0.68 increased peak efficiency by ≈150%. This factor had no effect on quantitative reproducibility, however. The gradual buildup of contaminants on the capillary walls occurred over time and decreased both separation efficiency and reproducibility. Rinsing capillaries periodically with appropriate solvents delayed this effect. Peak efficiency was a good marker for capillary performance and lifetime.