bluuebunny/crossref_metadata_2025 huggingface dataset:
Physicochemical Characterization of Barley Carbohydrates Resistant to Digestion in a Human Ileostomate
Authors: Botham R. L. , Cairns P. , Faulks R. M. , Livesey G. , Morris V. J. , Noel T. R. , Ring S. G.
Published: June 2007

Physicochemical techniques, monosaccharide, and linkage analysis, have been used to investigate the digestibility of different forms of cooked barley starch in an ileostomist model. An ileostomate volunteer consumed a flapjack‐type biscuit containing either barley flake, flour, or starch. Both starch and mucin were identified in the effluent and were found to make a significant contribution to the potentially fermentable substrate available to the large intestine. Chemical analysis of the effluents showed that the content of resistant starch in the effluent varied with presence and form of nonstarch polysaccharide and after consumption of barley flake and flour was 10.1 and 5.9% of the starch ingested, respectively. Wide‐angle X‐ray diffraction showed the excreted starch to be A‐type only, indicating that the starch consumed in all three flapjack types was ungelatinized. These data demonstrate the potential of physicochemical techniques in the analysis of physiological samples.
Comparison of Laboratory and Pilot‐Plant Corn Wet‐Milling Procedures
Authors: Singh S. K. , Johnson L. A. , Pollak L. M. , Fox S. R. , Bailey T. B.
Published: June 2007

One waxy and three regular yellow dent corn hybrids were wet milled by using two scales of laboratory procedures (modified 100‐g and 1‐kg) and a pilot‐plant procedure (10‐kg). The modified 100‐g and 1‐kg laboratory procedures gave similar yields of wet‐milling fractions. Starch yields and recoveries were significantly lower for the pilot‐plant procedure, whereas gluten and fiber yields were greater because of their high contents of unrecovered starch. Protein contents of the starches obtained by all three procedures were within commercially acceptable limits (<0.50% db for normal dent corn and <0.30% for waxy corn). Rankings for starch yields and starch recoveries for the four hybrids, having very different physical and compositional properties, were the same for all three procedures. The harder the grain, the lower the yield and recovery of starch. Least significant differences (P < 0.05) for starch yield were 0.8% for the modified 100‐g procedure, 1.2% for the 1‐kg procedure, and 2.0% for the pilot‐plant procedure.
Properties and Microstructure of Zein Sheets Plasticized with Palmitic and Stearic Acids
Authors: Lai Huey‐Min , Padua Graciela Wild , Wei Lun Shin
Published: June 2007

Interest in biodegradable materials for packaging and agricultural uses has grown in recent years. Plant proteins have been proposed as inexpensive, renewable, and abundant feedstock. Corn zein was investigated based on value‐added considerations and on the unique thermoplastic and hydrophobic properties of zein. Films prepared from zein are known to be tough and resistant, but also hard and brittle, thus requiring the addition of plasticizers to improve flexibility. The objectives of this research were to study the tensile properties, water absorption, and microstructure of zein sheets plasticized with palmitic and stearic acids. Both palmitic and stearic acids showed similar effects as plasticizers of zein. Tensile strength of zein sheets increased with the addition of low levels of plasticizers. However, beyond a critical point, tensile strength decreased with further addition of fatty acids. Water absorption decreased continuously with increasing fatty acid content. Kinetic parameters indicated fatty acids decreased water absorption by decreasing the saturation level of zein sheets. Coating zein with flax oil decreased the rate of water absorption by sealing off surface pores. Scanning electron micrographs of zein sheets showed the development of layered structures as fatty acid content increased. Zein‐fatty acid layers were believed to be responsible for the increased tensile strength of plasticized zein sheets and to have contributed to increased resistance to water absorption.
Effects of Prolamins Encoded by Chromosomes 1B and 1D on the Rheological Properties of Dough in Near‐Isogenic Lines of Bread Wheat
Authors: Redaelli R. , Pogna N. E. , Ng P. K. W.
Published: June 2007

Fourteen bread wheat near‐isogenic lines (NILs) with different alleles at 1B‐ and 1D‐chromosome loci Glu‐1, Glu‐3 and Gli‐1 coding for high molecular weight glutenin subunits (HMW‐GS), low molecular weight‐GS, and gliadins, respectively, were grown in replicated plots to investigate the individual and combined effects of glutenin and gliadin components on the rheological properties of dough as determined by the Chopin alveograph. NILs did not reveal significant differences in seed yield, protein content, kernel weight, test weight, flour yield, and starch damage. On the contrary, they had a large variation in alveograph dough tenacity P (55–93 mm), swelling G (17–26 mL) and strength W (140–252 J × 10‐4). The null alleles at the Gli‐D1/Glu‐D3 loci, and allele Glu‐D1d (HMW‐GS 5+10) were found to have a strong positive influence on dough tenacity and a remarkable negative influence on dough swelling (extensibility) when compared to alleles Gli‐D1/Glu‐D3b and Glu‐D1a (HMW‐GS 2+12), respectively. On the other hand, alleles Glu‐B1c (HMW‐GS 7+9) and Gli‐B1/Glu‐B3k gave greater G values than alleles Glu‐B1u (HMW‐GS 7*+8) and Gli‐B1/Glu‐B3b. The effects of individual Glu‐1, Gli‐1, or Glu‐3 alleles on P and G values were largely additive. The impact of the null allele at Gli‐D1/Glu‐D3 on gluten strength was highly positive in NILs possessing HMW‐GS 2+12, and negligible or negative in NILs containing HMW‐GS 5+10, suggesting that there is scope for improving dough quality by utilizing this allele in combination with HMW‐GS 2+12. Gli‐D1/Glu‐D3‐encoded prolamins were shown to play a major role in conferring extensibility to dough, and could account for the superior breadmaking characteristics of bread wheat as compared to durum wheat.
Cast Films from Soy Protein Isolates and Fractions
Authors: Kunte L. A. , Gennadios A. , Cuppett S. L. , Hanna M. A. , Weller C. L.
Published: June 2007

Glycerol‐plasticized soy protein films were cast from alkaline aqueous film‐forming solutions of laboratory‐prepared 7S, 11S, and soy isolate (LSI) fractions and from commercial soy isolate (CSI). Tensile strength (TS), elongation at break (E), water vapor permeability (WVP), total soluble matter (TSM), protein solubility (PS), and Hunter L, a, and b color values of these films were determined. The 11S films had greater TS than 7S films (P < 0.05), while LSI films had greater TS than CSI films (P < 0.05). No significant differences were detected among mean E values and among mean WVP values of all films (P > 0.05). The 7S films had higher TSM and PS values than 11S films (P < 0.05). CSI films were significantly darker (lower L value) and more yellow (greater positive b value) than LSI films (P < 0.05).
Purification and Characterization of a New Class of Insect α‐Amylase Inhibitors from Barley
Authors: Zhang Ningyan , Jones Berne L. , Tao H. Peggy
Published: June 2007

Barley seeds contain proteins that apparently protect them against attack by microorganisms and insects. Studies of these barley defensive proteins may lead to the development of barleys with improved natural resistance to pests. We have purified two low molecular weight proteins, designated BIα1 and BIα2, from barley grain, using ion‐exchange chromatography and reversed‐phase and gel‐permeation high‐performance liquid chromatography (HPLC). Both BIα1 and BIα2 inhibited insect (yellow meal worm, Tenebrio molitor) α‐amylase activities. For the T. molitor α‐amylase, the IC50 values of BIα1 and BIα2 were 80 μg/mL (12.5 μM) and 34 μg/mL (6.8 μM), respectively. Neither protein inhibited either human salivary α‐amylase, barley α‐amylase, or trypsin activities. N‐terminal amino acid sequences of the inhibitors were highly homologous with those of the plant proteins called defensins. The first 20 N‐terminal amino acids of BIα2 were identical to those of γ‐hordothionin, but neither BIα1 nor BIα2 protein showed any homology with the chloroform‐methanol (CM) soluble protein amino acid consensus sequence. The two inhibitors therefore apparently comprise another group of low molecular weight barley proteins that inhibit the α‐amylase activities of some insects that attack cereal grains.
Protein Distributions Among Hard Red Winter Wheat Varieties as Related to Environment and Baking Quality
Authors: Huebner F. R. , Nelsen T. C. , Chung O. K. , Bietz J. A.
Published: June 2007

Previous size‐exclusion high‐performance liquid chromatography (SEHPLC) studies of hard red spring (HRS) wheat proteins reported correlations of amounts of certain gliadin and glutenin fractions with general score, a quality descriptor based on loaf volume, mixing time, and other parameters. We now extended these studies to 12 hard red winter (HRW) wheats, each grown at six Midwestern locations. Gliadin and reduced glutenin fractions were isolated and fractionated by SE‐HPLC. Amounts of fractions corresponding to specific molecular weight (MW) ranges, determined by integrating peaks from SE‐HPLC elution profiles, were statistically correlated with various baking quality parameters. Amounts of one fraction rich in γ‐gliadins correlated well with loaf volume; correlations were better than found previously for HRS wheats. Correlations adjusted for overall protein (partial correlations) were >0.5 for 10 of the 12 samples, and >0.84 for six samples when estimated among samples, among locations, among samples at each location, and among locations for each sample. Because γ‐gliadins appeared well correlated to loaf volume, the gliadin fraction was also analyzed by reversed‐phase high‐performance liquid chromatography (RP‐HPLC), which provides better separations. Correlations of γ‐gliadin peak areas from RP‐HPLC with loaf volume were then 0.93–0.99 for different varieties grown in different locations. Narrow‐bore columns with shorter run times gave slightly higher correlations than did standard RP‐HPLC columns. It is evident that both genetics and environment affect the relationship of quantitative protein distribution to loaf volume.
Development of Crispness in Cookies During Baking in an Industrial Oven
Authors: Piazza L. , Masi P.
Published: June 2007

A phenomenological investigation was made of some physical processes that develop during an industrial baking operation of hard sweet biscuits (cookies). Samples were collected in different locations from a continuous belt oven corresponding to different baking times. The effects of time on volume, structure, weight, and color of cookies were monitored. Mechanical behavior was also investigated by submitting the cookies to a three‐point bending test. The modulus of elasticity correlated well with the sensory perception of cookie crispness. By comparing the kinetics of elasticity of cookies during baking with that of the observed physical phenomena taking place, it was possible to relate the development of crispness to physical processes occurring during baking.
Amylopectin Staling of Cooked Milled Rices and Properties of Amylopectin and Amylose
Authors: Villareal Corazon P. , Hizukuri Susumu , Juliano Bienvenido O.
Published: June 2007

Starches of waxy rices that showed varietal differences in hardness testing of cooked rice after amylopectin staling and high‐amylose content (AC) rices differing in gel consistency (GC) and starch gelatinization temperature (GT) were studied to determine the factors related to varietal differences in amylopectin staling of cooked rice. Intermediate‐ and high‐GT starches showed greater amylopectin staling of gelatinized rice by hardness testing values or differential scanning calorimetry (DSC) endotherm than did low‐GT starches in both waxy and nonwaxy rices. Isoamylase‐debranched amylopectins of waxy rices differed in the ratio of weight‐average degree of polymerization (DPw) fractions, but these fraction ratios were not simply related to differences in amylopectin staling of cooked rice. Among high‐AC rices, amylopectin from low‐GT starch was confirmed to have higher iodine affinity (2.3–2.5%) than amylopectin from intermediate‐GT starches (1.7–1.8%), regardless of GC. Within high‐AC starch of the same GT type, soft‐GC rice corresponded with more A + B1 DPw 16–18 and less B3 DPw 150–200 fractions of debranched amylopectin and low DPw of amylose. Amylopectin of amylose extender mutant of IR36 was confirmed to have a longer chain length than ordinary rice amylopectin: the debranched amylopectin has more B2 DPw 47–51 fraction, less A + B1 DPw fraction, but no B4 fraction with DPw > 200. Only high‐AC amylopectin had debranched fraction with DPw >120.
Changes in Water Absorption and Swollen Volume in Extruded Alkaline Peroxide Pretreated Rice Hulls
Authors: Larrea M. A. , Grossmann M. V. E. , Beléia A. P. , Tavares D. Q.
Published: June 2007

Rice hulls were pretreated with an alkaline (pH 11.5) solution of hydrogen peroxide (1%) and then extruded. Pretreatment of rice hulls (4% db) at 50°C for 12 hr promoted 94.4% silica reduction, caused lignin solubilization and increased water absorption index (54%) and swollen volume (44%). The effects of temperature (125, 175, and 225°C), moisture content (25, 30, and 35%) and screw speed (120, 140, and 160 rpm) on water absorption and swollen volume of rice hulls fiber were evaluated after extrusion in a single‐screw extruder. Operational conditions that produced the most modified product with regard to the functional properties were: 125°C, 35% moisture, and 120 rpm. Extruded fiber had a water absorption index 95% higher and swollen volume 138% higher than the unprocessed material. Microscopic examination showed a slight effect on the hulls epidermis after pretreatment, while extrusion promoted cellular structure disruption.
Fortifying Bread with Each of Three Antioxidants
Authors: Park H. , Seib P. A. , Chung O. K. , Seitz L. M.
Published: June 2007

White bread was fortified individually with fat‐coated l‐ascorbic acid (AsA), cold‐water‐dispersible (CWD) β‐carotene, and CWD all‐rac‐α‐tocopheryl acetate (ToAc) at levels of 64, 5, and 100 mg, respectively, of active ingredient per 100 g of flour (14% mb). The freshly baked puploaves retained 76, 67, and 96% of added antioxidant, respectively. To extract ToAc quantitatively from bread or dough, dimethyl sulfoxide (DMSO) gave better results than hexane, which indicated that ToAc was in a partially bound state. “Protein‐encased” (PE) β‐carotene did not impart a yellow color to bread crumb and had one‐fourth higher retention in fresh bread when compared to CWD β‐carotene. In loaves stored at 25°C for one to seven days, AsA disappeared rapidly and PE β‐carotene disappeared slowly; CWD β‐carotene and ToAc were stable. In spite of storage loss, bread fortified with PE β‐carotene retained significantly higher levels of β‐carotene when compared to CWD β‐carotene. One serving size (one slice, 28 g) of three‐day‐old bread fortified with one of the three antioxidants was calculated to provide 7, 120–150, and 13–16%, respectively, of the adult recommended daily allowances (RDA) for vitamins C, E, and A. When bread was fortified with both fat‐coated AsA and CWD β‐carotene and stored for five days, no protecting effect on the retention of the antioxidants was found.
Ultrastructure of Developing Hard and Soft Red Winter Wheats After Air‐ and Freeze‐Drying and Its Relationship to Endosperm Texture
Authors: Bechtel D. B. , Wilson J. D.
Published: June 2007

A transmission electron microscopic study was conducted on air‐ and freeze‐dried developing wheat to determine the effects of drying on the structure of the starchy endosperm. Field‐grown hard red winter wheat (Karl) and soft red winter wheat (Clark) were harvested at 15, 18, 21, 23, 25, 28, and 35 days after flowering (DAF). Wheat was dried by either air‐drying in the spike at 28°C or freeze‐drying following freezing in liquid nitrogen. Dried wheat was prepared for microscopy. Fresh samples of Karl and Clark were also harvested on the same days and prepared immediately for microscopy. The method of drying greatly affected cellular ultrastructure. The most pronounced change upon air‐drying of developing samples was disappearance of individual protein bodies and conversion of the cytoplasm into a matrix‐like material similar in appearance to storage protein matrix found in mature wheat endosperm. Freeze‐dried wheats maintained nearly natural ultrastructure but exhibited various amounts of freeze damage. Conversion of protein bodies to a matrix was not observed in freeze‐dried samples. The results suggest that hardness develops as a result of endosperm senescence rather than accumulation of particular grain components. Senescence may cause changes in the starch granule surface such that surrounding components bind tightly in hard wheats, whereas the binding is weaker in soft wheats. Therefore, the surface of starch granules might be more important than components the starch granules bind to in determining hardness.
Effect of Sodium Hydroxide, Calcium Hydroxide, and Potassium Hydroxide on Debranning of Corn
Authors: Singh S. K. , Singh N. , Du L. , Eckhoff S. R.
Published: June 2007

The effect of sodium hydroxide, calcium hydroxide, and potassium hydroxide, and processing conditions (alkali concentration and soaking time) on corn debranning was studied at a temperature of 55°C. Fiber yield, soluble dry matter loss, and total dry matter removed were determined for different alkalies and processing conditions. Sodium hydroxide and potassium hydroxide resulted in maximum fiber yields of 3.38 and 3.48%; maximum soluble dry matter loss of 7.63 and 10.96%; and maximum total dry matter removed of 10.52 and 13.26%. Calcium hydroxide at 6% concentration level resulted in negligible fiber yield, soluble dry matter loss, and total dry matter removed with soak times up to 16 hr. Sodium hydroxide has higher debranning action than potassium hydroxide at 3 and 6% concentration levels; whereas, at 9% concentration level, potassium hydroxide has higher debranning action.
Detection of O‐Glycosidically Linked Mannose Within the Structure of a Highly Purified Glutenin Subunit Isolated from Chinese Spring Wheat
Authors: Tilley K. A.
Published: June 2007

A low level of O‐glycosidically linked D‐mannose was detected on the 1Dx2 high Mr glutenin subunit of Chinese Spring wheat. Detection of the O‐glycosidic linkage was accomplished by subjecting the purified 1Dx2 protein to β‐elimination and reduction conditions that resulted in the specific cleavage of O‐glycosidically linked carbohydrates from the protein backbone and the reduction of the linkage (reducing end) sugars to alditols. Subsequently, acid‐catalyzed methanolysis was used to cleave glycosidic linkages on released carbohydrate as well as carbohydrate remaining on the protein. The repeat units were derivatized with trimethylsilyl and analyzed by gas chromatography and mass spectroscopy (GC‐MS). The 1Dx2 high Mr glutenin subunit of Chinese Spring wheat consisted of 1.2% carbohydrate containing D‐mannose and D‐glucose units. O‐Glycosidically linked D‐mannose residues represented 0.13% of the total mass of the 1Dx2 high Mr glutenin subunit. This represented <1 O‐glycosidically linked D‐mannose residue per protein molecule and provided some initial evidence that there may be various glycoforms of this subunit present in the preparation.
Effect of Mechanical Dough Development on the Extractability of Wheat Storage Proteins from Bread Dough
Authors: Bushuk W. , Hay R. L. , Larsen N. G. , Sara R. G. , Simmons L. D. , Sutton K. H.
Published: June 2007

Six wheat cultivars covering a range of quality parameters were mixed to various proportions of their optimum work input using mechanical dough development (MDD) mixers. Mixing and baking characteristics were determined and each dough was subsampled. The proteins were extracted for analysis by reversed‐phase HPLC. Considerable protein mobilization appeared to occur during the MDD process, but the changes appeared to be cultivar‐specific and did not indicate how mixing or baking behavior could be predicted. Protein content in extracted fractions was lowest for the weakest, poorest quality wheat but failed to consistently rank the stronger samples. Acetic acid insoluble protein level decreased with mixing as did extractable high molecular weight glutenin subunits. Gliadin protein level initially decreased with mixing before rising sharply with overmixing, while low molecular weight glutenin subunits displayed the reverse pattern. The rate of change of the extractability of the protein fractions with work input was greatest for the weakest samples and least for the stronger samples. However, when the protein quantity in the extractable fractions was plotted against relative work input, the rate of change of protein extractability did not appear to vary significantly between cultivars of different strengths.
Thermal Properties of Corn Starch Extraction Intermediates by Differential Scanning Calorimetry
Authors: Yamin F. F. , Svendsen L. , White P. J.
Published: June 2007

Thermal properties of corn starch extraction intermediates from four types of corn were studied using differential scanning calorimetry. Starch at four different stages of extraction, including a standard single‐kernel starch isolation procedure and three starch extraction intermediates, was isolated from mature corn kernels of B73 and Oh43 inbreds and the mutants of waxy (wx) and amylose extender (ae) in an Oh43 background. Differences in thermal properties and moisture and protein contents of starch from the extraction stages were statistically analyzed. Most thermal properties (gelatinization and retrogradation onset temperatures, gelatinization and retrogradation ranges, gelatinization and retrogradation peak temperatures, gelatinization and retrogradation enthalpies, peak height index, and percentage of retrogradation) of starches extracted at stage 3 intermediate (a procedure that did not include a final washing step) were similar to those of starch extracted by the standard single‐kernel isolation procedure. Values for gelatinization peak temperature, gelatinization enthalpy, and peak height index were different between the standard and the stage 3 intermediate. The values obtained from starches extracted at stage 3, however, were consistent and predictable, suggesting that this extraction intermediate might be used in screening programs in which many starch samples are evaluated. By using the stage 3 extraction, samples could be evaluated in three rather than four days and the procedure saved ≈0.5 hr of labor time. The other two starch extraction intermediates, which excluded filtering and washing or filtering, washing, and steeping, produced starch with thermal properties generally significantly different from starch extracted by the standard single‐kernel isolation procedure.
Microstructure of Seeds, Flours, and Starches of Legumes
Authors: Otto Terri , Baik Byung‐Kee , Czuchajowska Zuzanna
Published: June 2007

The microstructure of cotyledons and flours of both garbanzo beans and peas were examined by a scanning electron microscope (SEM) at low and high magnification. While the cells in the outer layer of the cotyledon were elongated and tightly packed in both garbanzo beans and peas, they were rounder and more loosely packed in the central part of the cotyledon, with many intercellular spaces. Cotyledon cells of garbanzo beans were smaller than those of the pea cultivars. Flour fractions from the inner layer of the cotyledon of garbanzo beans and pea cultivars had much finer particles; were lower in protein, lipid, ash and fiber; and contained more starch than those from the outer layer of the cotyledon. In prime starches isolated from garbanzo beans and smooth peas, protein, free lipid, and ash were lower than 0.41, 0.11, and 0.17%, respectively, indicating that the starches are highly pure. Garbanzo bean starch had smaller and smoother granules than those of smooth peas. Starch granules of wrinkled pea cv. Scout had a unique shape, with deep fissures and grooves, which could be partly responsible for difficulties encountered during the wet fractionation process.
Rheological Behavior of Undeveloped and Developed Wheat Dough
Authors: Campos Danilo T. , Steffe James F. , Ng Perry K. W.
Published: June 2007

Undeveloped wheat dough is essentially wheat flour that has become fully hydrated without being deformed. The rheological properties of this material were compared to dough (developed dough) made using the standard method involving a farinograph. Flow behavior of undeveloped and developed dough samples made from hard and soft wheat flours were tested using creep tests, frequency sweep oscillatory tests, and temperature sweep oscillatory tests. All experiments showed that the undeveloped dough requires less resistance for deformation than developed dough. The differences are due to the energy input received by the developed dough and the influence of this factor in forming the protein matrix associated with developed dough. To attain a comparable state as the dough made in the farinograph, an energy input must be applied to the undeveloped dough material. Understanding the differences between undeveloped and developed dough may lead to new products, equipment, and processes in the bakery industry.
Effect of Fusarium Head Blight on Semolina Milling and Pasta‐Making Quality of Durum Wheat
Authors: Dexter J. E. , Marchylo B. A. , Clear R. M. , Clarke J. M.
Published: June 2007

Ten durum wheat cultivars harvested in Manitoba in 1995, which were downgraded primarily because of fusarium‐damaged (FD) kernels, were subjected to mycological tests and evaluated for semolina milling and pasta‐making quality. Fusarium graminearum was the primary fungus infecting kernels. The ratio of FD to deoxynivlaenol (DON) level varied slightly among cultivars but was generally near unity. Retention of DON in semolina was about 50%. FD had a negative impact on kernel weight and test weight, resulting in lower semolina yield. Semolina ash content and bran specks were not affected by FD, but semolina became duller and redder. FD had no effect on protein content, but gluten strength was weaker probably due to a lower proportion of glutenins as shown by reversed‐phase high‐performance liquid chromatographic analysis of sequentially extracted gluten proteins. The influence of FD on gluten strength was not sufficient to alter pasta texture. FD had a strong adverse effect on pasta color. Even for the least damaged cultivars, which had FD levels near the limit of 2% established for the No. 3 and No. 4 Canadian Western Amber Durum (CWAD) grades, the deterioration in pasta color was readily discernible by eye, confirming that the strict FD tolerances for premium No. 1 CWAD (0.25%) and No. 2 CWAD (0.5%) grades are warranted.
Isolation and Characterization of Zein from Corn Distillers' Grains and Related Fractions
Authors: Wolf Walter J. , Lawton John W.
Published: June 2007

Corn distillers' grains with solubles (CDGS), the major coproduct of fermentation of corn to produce ethanol, were extracted with 0.1M NaOH, 0.1% dithiothreitol (DTT), and 0.5% SDS yielding 35% of the total nitrogen and ≈25% of the protein nitrogen. Gel electrophoresis revealed that the extractable proteins contained zein plus other proteins similar to the extractable proteins from corn flour. Although difficult to extract, the proteins isolated from the fermentation coproducts appeared undegraded and apparently survived gelatinization, fermentation, distillation, and drying during the production of ethanol. Extraction of CDGS with 60% ethanol at 60°C yielded 1.5–3.9% of crude zein. When the ethanol contained DTT, yields of crude zein were increased to 3.2–6.6%. Protein contents of the crude zeins were only 37–57%, indicating that lipids and pigments were coextracted with the ethanol. Gel electrophoresis showed that the protein fractions extracted by ethanol contained primarily α‐zein whereas the proteins extracted by ethanol + DTT contained α‐ + β‐zein. Further confirmation of the presence of zein in the crude prolamin preparations was obtained by amino acid analyses. The amino acid compositions of the crude zeins paralleled those of commercial zein and α‐zein.
Quality Characteristics of Waxy Hexaploid Wheat (Triticum aestivum L.): Properties of Starch Gelatinization and Retrogradation
Authors: Hayakawa Katsuyuki , Tanaka Keiko , Nakamura Toshiki , Endo Shigeru , Hoshino Tsuguhiro
Published: June 2007

The viscoelastic properties and molecular structure of the starch isolated from waxy (amylose‐free) hexaploid wheat (WHW) (Triticum aestivum L.) were examined. WHW starch generally had lower gelatinization onset temperature, peak viscosity, and setback than the starch isolated from normal hexaploid wheat (NHW). Differential scanning calorimetry (DSC) showed that WHW starch had higher transition temperatures (To, Tp, and Tc) and enthalpy (ΔH) than NHW starch. However, when compared on the basis of amylopectin (AP) content, ΔH of WHW starch was almost statistically identical to that of its parental varieties. Typical A‐type X‐ray diffraction patterns were observed for the starches of WHW and its parental varieties. Somewhat higher crystallinity was indicated for WHW starch. WHW starch was also characterized by having greater retrogradation resistance. The high‐performance size‐exclusion chromatography (HPSEC) of amylopectin showed that each amylopectin yielded two fractions after debranching. Although WHW amylopectin had somewhat long B chains, little difference was observed in the ratio of Fr.III/ Fr.II between WHW and its parental varieties.
Thermomechanical Behavior of Concentrated Starch‐Water Preparations
Authors: Rolee A. , Le Meste M.
Published: June 2007

The rheological behavior of concentrated starch preparations from various origins was studied by dynamic mechanical thermal analysis (DMTA). Four types of starch were used: wheat, potato, normal, and waxy corn adjusted to moisture contents in the 42–49% (w/w) range. The thermal treatments of the starch‐water mixtures consisted of heating to 85°C and cooling to room temperature, both at a rate of 1°C/min. During heating, the storage modulus (E′) appearance was first characterized by an increase with a maximum at ≈70°C (or potato starch at 63°C) followed by a decrease to 85°C. During cooling, storage modulus increased steadily down to room temperature. The magnitude of these variations depended on the starch type. Despite some differences, all the loss tangent curves showed a decrease during heating from 60–70°C to 85°C, followed by a plateau during cooling. To propose an interpretation for the DMTA results, we measured, by laser‐light diffraction, the influence of heating (up to the maximum E′ peak) on the distribution of the granule sizes of the different starches. Moreover, differential scanning calorimetry (DSC) was used to measure the temperature range where the melting of starches ordered regions occurred. Partial melting enthalpies were plotted against temperature. The hypothesis of a relationship between swelling and an increase in rigidity during heating seemed to be confirmed by laser‐light diffraction, whereas DSC indicated the decrease in rigidity was caused predominantly by order‐disorder transitions. During cooling, amylose gelation plays a major role in the rigidity increase, but a contribution of amylopectin is not excluded.
Production of Textile Fibers from Zein and a Soy Protein‐Zein Blend
Authors: Zhang Menglin , Reitmeier Cheryll A. , Hammond Earl G. , Myers Deland J.
Published: June 2007

Zein fibers were successfully prepared by a wet‐spinning technique from a zein suspension formulated with 15% zein, 60% water, 22% 0.4N sodium hydroxide, and 3% urea by weight. Tenacities were measured with an Instron machine, and flexibility was determined by noting the smallest diameter rod around which a fiber could be looped without breaking. After spinning, the tenacity of the zein fibers was improved by modification with several agents: acetic anhydride for acetylation, glutaraldehyde, and dialcohols for cross‐linking and physical stretching. The tenacity and flexibility of the fibers were measured at 11, 65, and 100% rh. Untreated fibers had tenacities of 3.41, 2.65, and 0.17 g/tex at 11, 65, and 100% rh, respectively. A combination of chemical treatments (20% glutaraldehyde and 95% acetic anhydride) and 115% stretching increased tenacities to 6.89. 6.56, and 1.17 g/tex at 11, 65, and 100% rh, respectively. Control zein fibers had flexibilities of 5 and 2.5 mm at 11 and 65% rh, respectively, whereas the treated fibers had flexibilities of 1.5 mm at both humidities. Extrusion of zein fibers was not successful. Zein‐soy protein mixture could be extruded, but properties of wet‐spun fibers of zein‐soy blends were not much improved over those of soy protein alone. The tenacity of blended soy protein‐zein fibers was greater than that of soy protein fibers at 11% rh.
Molecular Characterization of Barley β‐Glucans by Size‐Exclusion Chromatography with Multiple‐Angle Laser Light Scattering and Other Detectors
Authors: Knuckles B. E. , Yokoyama W. H. , Chiu M. M.
Published: June 2007

Molecular characteristics were determined for mixed‐linkage (1→3) (1→4)‐β‐d‐glucans (β‐glucans) extracted from Azhul, Crystal, Waxbar, and Prowashonupana barleys. β‐Glucans in extracts (with or without α‐amylase, protease, hemicellulase, or xylanase treatment) were separated from other components by high‐performance size‐exclusion chromatography and detected with multiple‐angle laser light scattering, refractive index, and fluorometry following postrefractive index treatment with Calcofluor. Pretreatment of barley with 70% ethanol (80°C, 4 hr) reduced β‐glucanase activity by ~20%. Hot‐alcohol treatment also reduced β‐glucan extraction at 23 and 65°C by 42 and 14%, respectively. Molecular weights of β‐glucans in the first water extract were generally higher than in succeeding water and alkali extracts. Weight average molecular weights ranged from 0.44 × 106 to 2.34 × 106 g/mol after α‐amylase treatment to remove interfering starch. Interference due to pentosans was not demonstrated using enzyme treatments.
Prediction of Cooked Rice Texture Quality Using Near‐Infrared Reflectance Analysis of Whole‐Grain Milled Samples
Authors: Windham William R. , Lyon Brenda G. , Champagne Elaine T. , Barton Franklin E. , Webb Bill D. , McClung Anna M. , Moldenhauer Karen A. , Linscombe Steve , McKenzie Kent S.
Published: June 2007

Rice quality is based on chemical and physical properties affecting its appearance, flavor, and texture characteristics. Sensory quality can be assessed by a combination of descriptive sensory and physicochemical property evaluations. The purpose of the present study was to assess the potential of near‐infrared reflectance spectroscopy (NIRS) and NIRS in combination with other physicochemical measurements for the determination of sensory texture attributes in whole‐grain milled rice samples. Six rice samples representing combinations of variety and growing locations received treatments of two degrees of milling and five drying conditions to achieve final moisture levels of 12 or 15% (n = 120). Quality measurements of the cooked rice included sensory and instrumental texture analyses. Quality measurements of the uncooked rice included amylose and protein (chemical reference), whiteness, transparency, and degree of milling (appearance units of milled rice), and NIRS analyses. Partial least squares (PLS) regression was used to reveal the relationships between the different types of measurements. The sensory texture attributes: manual adhesiveness (MADHES), visual adhesiveness (VADHES), and stickiness to lips (STICKI) were related to deep‐milled samples and positively correlated to amylose, whiteness, and milling degree. The attribute roughness (ROUGH) was related to light‐milled samples and positively correlated to protein and negatively correlated to amylose. The main variation in sensory attributes was a result of amylose and protein contents of the rices. A noise‐compensation value, relative ability of prediction (RAP), was used to express the degree of prediction (1.0 = best possible prediction). NIRS gave the best prediction results for the texture attributes: MADHES, VADHES, and STICKI with an RAP of 0.57, 0.54, and 0.56, respectively. NIRS is best at predicting texture characteristics of cooked rice perceived in the visual, tactile, and initial oral phases of sensory evaluation. The calibration of NIRS plus physicochemical variables did not improve the predictability of sensory texture over NIRS alone. The prediction of sensory texture in rice by NIR needs to be further investigated on a large number of samples with different varieties, growing locations, cultivation methods, harvesting methods, and processing after harvesting.
Effect of l‐Ascorbic Acid and Superoxide Anion Radical on the Rheological Properties of Wheat Flour‐Water Dough
Authors: Nakamura M. , Kurata T.
Published: June 2007

l‐Ascorbic acid (AsA) plays an important role in the rheological properties of bread dough and as an improver. Addition of AsA and iron, as heavy metal ions, affected the rheological properties, especially hardness of flour‐water dough prepared under aerobic conditions. Addition of both AsA and iron increased the hardness of regular flour‐water dough as compared with control dough; using oxygen‐saturated water further increased the dough hardness. Dough mixed with AsA under nitrogen gas showed significantly decreased dough hardness when compared with dough mixed with AsA under air. The improved effect of AsA on dough hardness may be due to oxygen radicals generated during AsA oxidation. The effect of the superoxide anion radical (O2‐) on dough hardness was examined by using both O2‐ scavenging and O2‐ generating systems. In an O2‐ generating system (xanthine and xanthine oxidase), dough hardness increased. In an O2‐ scavenging system (superoxide dismutase and catalase), dough hardness was similar to that of the control. It was strongly indicated that hardness of dough containing AsA was much influenced by the O2‐ generated in the oxidation process of AsA.
Characterization of Protein Fractions of Rice Bran to Devise Effective Methods of Protein Solubilization
Authors: Hamada J. S.
Published: June 2007

Proteins from the defatted brans of representative rice cultivars were fractionated into albumins, globulins, prolamins, and acid‐soluble glutelins, accounting for 34, 15, 6, and 11% of the total bran proteins, respectively. The remaining insoluble residue protein, after treatment with 0.1M sodium hydroxide, resulted in the solubilization of 95% of the residue protein, representing 32% of the total bran protein. The relative molecular mass (Mr) values determined by size‐exclusion HPLC were 10–100 kDa, 10–150 kDa, 33–150 kDa, and 25–100 kDa for the fully dissociated polypeptides of albumins, globulins, prolamins, and acid‐soluble glutelins, respectively. Despite a breakdown of disulfide bonds of the residue protein during sodium hydroxide solubilization, the Mr of the majority of the fully dissociated polypeptides of this fraction ranged from 45 to 150 kDa. Insolubility of residue protein was due mainly to its strong aggregation and extensive disulfide bond cross‐linking. Efficient methods may be developed for solubilizing up to 98% of rice bran protein by the use of dissociating and disulfide breaking agents currently in use in the food industry.
Hydrocyclone Separation of Dry‐Milled Corn
Authors: Dickey L. C. , Dallmer M. F. , Radewonuk E. R. , Parris N. , Kurantz M. , Craig J. C.
Published: June 2007

Corn milled to <1 mm using a screen mill was sieved and the particles >590 μm were soaked for 1 hr in solutions with a range of glucose concentration providing liquid specific gravities above and below that of the lighter fraction (corn germ). A suspension of these particles was pumped through a hydrocyclone to separate the germ particles and to rinse watersoluble compounds from the corn. The specific gravity of the hydrocyclone streams (suspensions), as well as liquid phase (after solids settling) was measured, and product compositions and particle sizes were determined. This work shows that a germ‐enriched fraction of corn ground to <1 mm, can be separated with a hydrocyclone. To enable computer simulation of the corn‐treatment process, the experimental data was used to construct a two‐component model of the hydrocyclone separation of the milled corn. In the model, the milled and sieved corn is virtually separated into germ and endosperm streams that are fed to paired hydrocyclone models. Hydrocyclone bypassing streams that simulate particles entrained to the contrary outlet (underflow for germ and overflow for endosperm particles) were included in the simulation to bring the model into agreement with the experimental product compositions.
Light‐Scattering Molecular Weights and Intrinsic Viscosities of Processed Waxy Maize Starches in 90% Dimethyl Sulfoxide and H2O
Authors: Millard Merle M. , Dintzis Frederick R. , Willett J. L. , Klavons Jerome A.
Published: June 2007

Waxy maize starch was treated by a variety of gentle and severe methods: direct dispersion‐solubilization into 90% dimethyl sulfoxide (DMSO) and H2O solvent, extrusion followed by dispersion‐solubilization of the ground exudate into solvent, or jet‐cooking or stirred autoclaving of an aqueous starch slurry followed by transfer into solvent. Intrinsic viscosities [η] and multiangle light‐scattering measurements were made in 90% DMSO‐H2O. A Mark‐Houwink relation, [η] = (0.28–1.2) Mw0.29 ± 0.04, was obtained over a molecular weight range of ≈30–700 million. However, there was a large amount of scatter in the data when [η] were >140 mL/g. The power law relationship Rg ∝ Mw0.41±0.04 was noted between radii of gyration and molecular weights. We infer from our data that over the entire range of Mw distributions, the amylopectin existed in solution as relatively compact molecules or aggregates and that in the higher molecular weight region, the size and possibly the shape of the “dissolved” amylopectin was highly sensitive to the method of dispersal and treatment.
Effects of Granular Structures on the Pasting Behaviors of Starches
Authors: Tsai Mei‐Lin , Li Chin‐Fung , Lii Cheng‐Yi
Published: June 2007

Japonica (Tainung 67 [TNu67]) and waxy (Taichung 70 [TCW70]) rice, normal and waxy corn, and cross‐linked waxy rice and corn starches were used in an investigation of the influence of the granular structure on the pasting behavior of starch, using small amplitude oscillatory rheometry. Both normal corn and normal rice (TNu67) starches had the highest storage moduli (G′), followed by their cross‐linked versions; native waxy corn and rice starches had the lowest. Native waxy starches showed paste characteristics (G′ < 500 Pa; tan δ > 0.2) at concentrations of up to 35%. However, cross‐linked waxy starches exhibited gel behavior at 10% concentration (cross‐linked TCW70) or higher (cross‐linked waxy corn starch). The degrees of swelling power were in the order: TCW70 > native waxy corn > TNu67 ≅ cross‐linked TCW70 ≅ normal corn ≅ cross‐linked waxy corn starches. Solubilities were in the order: normal corn > TNu67 > native waxy > cross‐linked waxy starches. The addition of 2% purified amylose from indica rice (Kaohsiung Sen 7) did not induce gelation of waxy corn starch. Swelling powers of normal corn, TNu67, and crosslinked waxy starches were similar, but normal corn and TNu67 had much higher G′ value. Such results implied that the formation of gel structure was governed by the rigidity of swollen granules and that the hot‐water soluble component could strengthen the elasticity of the starch gel or paste.
Separation of Wheat Proteins by Two‐Dimensional Reversed‐Phase High‐Performance Liquid Chromatography Plus Free Zone Capillary Electrophoresis
Authors: Bean S. R. , Lookhart G. L.
Published: June 2007

Gliadins and glutenins from four hard red winter wheat cultivars were separated by a novel two‐dimensional (2D) technique. Protein extracts were separated by reversed‐phase high performance liquid chromatography as the first dimension with each 30‐sec interval collected separately. Those fractions were then separated by free‐zone capillary electrophoresis (FZCE) for the second dimension. Data was combined into 2D surface contour plots similar to traditional gel electrophoresis 2D maps. For HPLC, C8 and C18 columns were used in the first dimension to separate gliadins and glutenins, respectively. Uncoated fused silica capillaries (27 cm × 25 μm, i.d.) were used for the 2D FZCE separations. Differences in the 2D maps of both gliadin and glutenin fractions were found between pairs of both closely related and sister lines that varied in quality.
Influence of Gliadin‐Rich Subfractions of Glenlea Wheat on the Mixing Characteristics of Wheat Flour
Authors: Hussain A. , Lukow O. M.
Published: June 2007

The effect of gliadin‐rich subfractions of extra‐strong wheat on the mixing properties of Canada Prairie Spring (CPS) wheats and Canada Western Extra Strong Red Spring wheat (CWES) cv. Glenlea was determined by the 2‐g mixograph. Thirteen subfractions isolated from the single ethanol extract of Glenlea showed differences in their SDS‐PAGE patterns of total proteins, low molecular weight glutenin subunits, the ω‐gliadin component, and acid‐PAGE electrophoregrams. High molecular weight glutenin subunits were found only in one subfraction isolated by increasing the concentration of ethanol. Subfractions that remained solubilized in the water phase after removal of ethanol from the extract were deficient in ω‐gliadins and contained a number of fast‐moving protein bands. These fractions caused a significant delay (from 2.64 to 5.41 min and from 5.75 to 8.16 min) in the mixograph peak development of CPS and Glenlea flours, respectively. On the contrary, the water‐insoluble subfractions reduced the mixing time requirement (from 2.6 to 1.08 min and from 5.8 to 1.7 min for CPS and Glenlea flours, respectively) and caused a rapid decline in the dough stability as the mixing continued. Both base flours showed an increase in peak height with the addition of ethanol‐extractable protein subfractions. Mixograph development time and energy to peak increased with the addition of water‐soluble subfractions but decreased with water‐insoluble subfractions of the 70% ethanol extract. The band width at peak increased when water‐soluble subfraction 6.5 was added to CPS flour but decreased when it was added to Glenlea flour. Removal of ethanol‐extractable components from flours resulted in loss of viscoelasticity. Adding subfraction 1.5 back to the flour residue caused a return of this physicochemical attribute. Addition of a nonwater‐ dispersible subfraction (1.5) to CPS flour or CPS flour residue caused a significant increase in the formation of gluten. Approximately 35–42% of the added gliadins were incorporated into the gluten network of CPS flour and 34–52% into the flour residue.
Interactions of Protein and Starch Studied Through Amyloglucosidase Action
Authors: Guerrieri Nicoletta , Eynard Lucia , Lavelli Vera , Cerletti Paolo
Published: June 2007

The access of amyloglucosidase to the carbohydrate molecule was taken as a measure of interactions occurring among starch, amylose, amylopectin, β‐dextrin and purified gluten, gliadins, high molecular weight glutenin subunits, or bovine serum albumin when they were mixed together and gelatinized before digestion. The most relevant decrease in liberated glucose, denoting coverage of some reaction sites for amyloglucosidase, occurred when gliadins were mixed with the carbohydrates. Other proteins were not as effective as gliadins. Amylopectin was not affected by any protein. Comparison of results allows some hypothesis to be formulated about the influence of structure on molecular interactions.