bluuebunny/crossref_metadata_2025 huggingface dataset:
Mycoflora Distribution in Dry‐Milled Fractions of Corn in Argentina
Authors: Broggi L. E. , González H. H. L. , Resnik S. L. , Pacin A. M.
Published: June 2007

Corn samples and different commercial dry‐milled fractions collected from an industrial mill in Argentina were surveyed for fungal contamination. The percentage of Fusarium isolates in whole corn kernels among all fungi recovered was 2.0–97.0%; in corn grits, it was 2.6–50.0%. Maximum levels in the other fractions were 5.2 × 105 colony forming units per gram (CFU/g) in germ and bran, 5.0 × 103 CFU/g in C flour, and 2.7 × 103 CFU/g in corn meal. The high initial contamination from whole corn is reflected in germ and bran, which is destined for animal consumption, but not in corn meal. F. verticillioides and Aspergillus flavus were the most frequent species in the whole corn kernel, but F. verticillioides was prevalent in all the other industrial fractions. Other potentially toxigenic fungi that were isolated included Aspergillus parasiticus, Alternaria alternata, Penicillium citrinum, and P. funiculosum. In this first report about mold contamination in corn industrial dry‐milled fractions in Argentina, the high fungal contamination level observed in the stored corn could indicate the necessity to improve the hybrid quality and the storage conditions to diminish the risk of mycotoxin occurrence.
Free Lipids in Air‐Classified High‐Protein Fractions of Hard Winter Wheat Flours and Their Effects on Breadmaking Quality
Authors: Chung O. K. , Ohm J. B. , Guo A. M. , Deyoe C. W. , Lookhart G. L. , Ponte J. G.
Published: June 2007

Free lipids (FL) were extracted from straight‐grade flours (SF) and the air‐classified high‐protein fractions (ACHPF) of nine hard winter wheats. The mean values of FL contents in 10 g (db) SF and ACHPF were, respectively, 92.8 and 178.5 mg for total FL, 74.1 and 141.9 mg for nonpolar lipids (NL), 12.8 and 20.9 mg for glycolipids (GL), and 4.9 and 12.0 mg for phospholipids (PL). FL compositions of SF and ACHPF showed nonsignificant differences in NL (80.7 and 81.1% of the FL) but significant differences in GL (13.9 and 12.0% of the FL) and PL (5.4 and 6.9% of the FL). Fortification of SF with ACHPF by blending to reach 13% protein content increased gluten quantity and thereby loaf volume but decreased gluten index, loaf volume regression, and crumb grain scores. NL contents showed significant relationships with dry gluten contents (r = 0.79) and gluten index (r = ‐0.83) values, indicating that high NL content in ACHPF could decrease gluten quality of fortified flours. Thus, an optimum balance should be maintained during fortification.
Mechanical Behavior of Oats: Specific Groat Characteristics and Relation to Groat Damage During Impact Dehulling
Authors: Engleson J. A. , Fulcher R. G.
Published: June 2007

Oat damage has negative effects on milling yield and finished product quality. Interrelationships among groat characteristics and mechanical behavior were analyzed to better understand groat damage caused by impact dehulling (ID). Regression of the natural logarithm (ln) of apparent stiffness (Smax) on the contents of ferulic acid, syringic acid, and moisture suggests that ferulic acid or perhaps diferulate cross‐links increase groat stiffness, and syringic acid or perhaps syringate derivatives and moisture decrease groat stiffness. Polymer cross‐linking decreases extensibility, and moisture (a plasticizer) softens polymers. Regression of ln of apparent toughness (T) on β‐glucan and protein content implies that both polymers increase groat toughness. β‐glucan is a cell‐wall polymer, and the cell wall is known to confer toughness. The location of these polymers (perhaps concentrated in the bran) may also confer toughness. Regression of ln(ID) on moisture content, starch content, and T/Smax suggests that moisture decreases impact damage (as does T/Smax), and starch increases damage. Starch may act like filler, increasing stiffness and damage. According to the ratio of T/Smax, groats must be tough but not too stiff for low levels of damage.
Comparison of Physical Properties of Wheat Starch Gels with Different Amylose Content
Authors: Sasaki Tomoko , Yasui Takeshi , Matsuki Junko , Satake Takaaki
Published: June 2007

The effects of amylose content and other starch properties on concentrated starch gel properties were evaluated using 10 wheat cultivars with different amylose content. Starches were isolated from grains of two waxy and eight nonwaxy wheat lines. The amylose content of waxy wheat lines was 1.4–1.7% and that of nonwaxy lines was 18.5–28.6%. Starch gels were prepared from a concentrated starch suspension (30 and 40%). Gelatinized starch was cooled and stored at 5°C for 1, 8, 16, 24, and 48 hr. The rheological properties of starch gels were studied by measuring dynamic viscoelasticity with parallel plate geometry. The low‐amylose starch showed a significantly lower storage shear modulus (G′) than starches with higher amylose content during storage. Waxy starch gel had a higher frequency dependence of G′ and properties clearly different from nonwaxy starches. In 40% starch gels, the starch with lower amylose showed a faster increase in G′ during 48 hr of storage, and waxy starch showed an extremely steep increase in G′. The amylose content and concentration of starch suspension markedly affected starch gel properties.
Ascorbate Oxidase, Protein Disulfide Isomerase, Ascorbic Acid, Dehydroascorbic Acid and Protein Levels in Developing Wheat Kernels and Their Relationship to Protein Disulfide Bond Formation
Authors: Every D. , Griffin W. B. , Wilson P. E.
Published: June 2007

Developing wheat kernels of three New Zealand wheat cultivars at one to nine weeks postanthesis (WPA) were analyzed for kernel weight, salt‐soluble protein, salt‐insoluble protein, ascorbate oxidase (AOX), protein disulfide isomerase (PDI), ascorbic acid (AA), and dehydroascorbic acid (DHA). Kernel weight and salt‐soluble protein increased from one to five or six WPA then declined. The amount of salt‐insoluble protein per kernel rapidly increased from two to five or six WPA, then remained constant. AOX activity increased from one to two or three WPA then declined to almost zero at seven WPA. PDI activity increased from one to three WPA, stayed constant to six WPA, then declined about 25%. DHA increased from one to two or three WPA then declined to zero at seven WPA. AA increased from one to three or five WPA then declined to zero at seven WPA. When DHA, at similar concentrations (≈1 mM) to that found in one to six WPA kernels, was mixed with reduced‐gluten proteins, it was reduced to AA. The results are interpreted as a scheme showing that, during the formation of protein‐disulfide bonds, electrons are transferred from nascent protein thiols, ultimately to oxygen, through a series of electron carriers including PDI, AA‐DHA, and AOX.
Turbidity Assay for Rapid and Efficient Identification of High Protein Digestibility Sorghum Lines
Authors: Aboubacar Adam , Axtell John D. , Nduulu Lexington , Hamaker Bruce R.
Published: June 2007

Recently, our laboratory reported a protein digestibility assay based on SDS‐PAGE that distinguishes mutant high protein digestibility from wild‐type sorghum lines. Using that assay, high protein digestibility sorghum lines were identified both qualitatively (visual observation) and quantitatively by measuring the SDS‐PAGE band intensity of the undigested α‐kafirin protein. Here, we report on a new turbidity assay that can be used for an even quicker quantitation of the undigested proteins with much higher throughput for screening purposes. Proteins remaining after 1 hr of pepsin digestion were extracted with a buffer of SDS, 2‐mercaptoethanol, and borate and an aliquot of the extract was precipitated using 72% trichloroacetic acid (TCA). Absorbance of the resulting turbid solution was then read at 562 nm. Lower readings corresponded to more digestible lines. The turbidity of the suspensions developed quickly and reached a plateau at ≈5 min for high protein digestibility lines and 10 min for wild‐type lines. The turbid solutions remained stable for at least 1 hr. Two distinct groups, wild‐type and high protein digestibility sorghum lines, were obtained when the assay was compared with a standard pepsin digestibility procedure and to our recently developed SDS‐PAGE assay. A comparison with the bicinchoninic acid (BCA) assay of protein quantitation indicated that the turbidity assay is more efficient in differentiating between wild‐type and high protein digestibility sorghum lines. We have further refined the turbidity assay for microtiter plate analysis making it possible for a single operator to analyze ≈200 sorghum lines per day, compared to 60 lines when using the SDS‐PAGE assay.
Potent Natural Immunomodulator, Rice Water‐Soluble Polysaccharide Fractions with Anticomplementary Activity
Authors: Yamagishi Tatsunori , Tsuboi Takuma , Kikuchi Koichi
Published: June 2007

Water‐soluble polysaccharide fractions, fractionated with ammonium sulfate from the hot‐water‐extract of rice bran and endosperm, showed a potent anticomplementary activity. As compared with water‐soluble polysaccharide isolated from Angelica acutiloba, which is a well‐known medicinal herb, the rice fractions showed similar or higher potency. Protease digestion, periodate oxidation, and hydroxylamine treatments indicated that anticomplementary activity is due to polysaccharide moiety rather than protein moiety and the polyphenol moieties, ferulic acid, being an integral component in rice bran proteoglycan. These results suggest that a water‐soluble proteoglycan and a polysaccharide in rice modulate complement activity. This is a new example of natural biological response modifiers in food.
Effects of Controlled Ambient Aeration on Rice Quality During On‐Farm Storage
Authors: Ranalli R. P. , Howell T. A. , Siebenmorgen T. J.
Published: June 2007

Rice (Oryza sativa L., ‘Cypress’) quality is highly dependent on its handling; hence, new storage treatments must be analyzed for their impact on rice quality. Rough rice from the 2000 season was harvested, dried, and stored in six farm‐scale bins. Three of the bins were aerated with a thermostatically activated controller, and three were aerated under traditional methods. Rice was sampled periodically over 12 weeks, and quality parameters were analyzed. The effects of bin sample position (spatial), bin sample depth, aeration treatment, and storage duration were investigated for their impact on rice quality factors: moisture content, head rice yield, pasting properties, and water absorption. For both aeration treatments at most sampling durations, rice sampled from the center of the bins had significantly lower head rice yield than that sampled from the north and south areas. Overall, moisture contents were not significantly affected by sampling position, although, in some specific sampling time and aeration treatment combinations, significant variation was noticed for moisture content as a function of sampling position. Sample depth within the bin did not cause any changes in the values of the rice properties. Throughout the storage duration, the physicochemical properties of the rice treated with controlled aeration were consistent with the trends of the rice treated with manual aeration. Storage duration significantly influenced (P < 0.05) water absorption, peak viscosity, head rice yield (HRY), and moisture content, with all but moisture content increasing over the storage duration. In contrast, the moisture content of the grain slightly decreased over the storage period.
Protein Composition‐Functionality Relationships for a Set of Argentinean Wheats
Authors: Cuniberti M. B. , Roth M. R. , MacRitchie F.
Published: June 2007

Relationships between flour functional properties and protein composition were studied using a set of 138 Argentinean wheat samples. Among different protein groups, the incremental increase of gliadin with increasing grain protein content was highest followed by polymeric protein with albumin‐globulin content much lower. Functional properties could be divided into two groups based on dependence on protein composition. Properties such as dough extensibility and bake test loaf volume correlated highly with the percentage of polymeric protein in the grain. Properties such as mixograph dough development time were best correlated with the percentage of polymeric protein in the protein (PPP). Alveograph tenacity showed no significant dependence on PPP. as found previously for extensigraph maximum resistance, but it was correlated with the percentage of unextractable polymeric protein in the protein. Energy (W) appeared to be a more useful alveograph parameter for predicting flour quality.
Aryl‐Glycosidase Activities in Germinating Maize
Authors: Biely Peter , Ahlgren Jeffrey A. , Leathers Timothy D. , Greene Richard V. , Cotta Michael A.
Published: June 2007

Soluble protein extracts of germinating maize seedlings exhibited a limited ability to hydrolyze purified xylans, and specific assays were unable to confirm the presence of endo‐β‐1,4‐xylanase activity. However, extracts contained a variety of aryl‐glycosidase activities, including β‐glucosidase, β‐xylosidase, and α‐l‐arabinofuranosidase. These activities peaked in three‐ to four‐day seedlings and were particularly concentrated in shoot and root tissues. Maximal levels of β‐glucosidase were two orders of magnitude greater than those of β‐xylosidase or α‐l‐arabinofuranosidase. Isoelectric focusing gels revealed multiple forms of these enzymes. The principal β‐glucosidase and α‐l‐arabinofuranosidase protein species were clustered at pI 4.8–4.9 and pI 5.8–6.0, respectively. β‐Xylosidase activity appeared to be associated with both of these enzymes, and no evidence was obtained for a distinct β‐xylosidase.
Properties of Starches from Several Low‐Amylose Rice Cultivars
Authors: Noda Takahiro , Nishiba Yoichi , Sato Tetsuo , Suda Ikuo
Published: June 2007

The starch properties of five low‐amylose rice cultivars, Yawarakomachi, Soft 158, Hanabusa, Aya, and Snow Pearl, were compared with those of two normal amylose rice cultivars, Nipponbare and Hinohikari. There were no large differences in the distributions of the amylopectin chain length determined by high‐performance anion‐exchange chromatography, and the starch gelatinization properties determined by differential scanning calorimetry, between normal and low‐amylose rice cultivars. Results obtained using rapid viscosity analysis indicated that low‐amylose rice starches had lower peak viscosity, breakdown, and setback values than normal amylose rice starches. Starch granules from low‐amylose rice cultivars had a higher susceptibility to glucoamylase than those from normal amylose rice cultivars. The results of this study showed some differences between normal and low‐amylose rice starches in pasting properties and enzymatic digestibility.
Effect of Processing on Functional Properties of Wheat Gluten Prepared by Cold‐Ethanol Displacement of Starch
Authors: Robertson G. H. , Cao T. K.
Published: June 2007

Functional properties of gluten prepared from wheat flour are altered by separation and drying. Gluten was separated and concentrated by batterlike laboratory methods: development with water, dispersion of the batter with the displacing fluid, and screening to collect the gluten. Two displacing fluids were applied, water or cold ethanol (70% vol or greater, ‐13°C). Both the water‐displaced gluten (W‐gluten) and ethanol‐displaced‐ gluten (CE‐gluten) were freeze‐dried at ‐20°C as a reference. Samples were dried at temperatures up to 100°C using a laboratory, fluidized‐bed drier. Tests of functionality included 1) mixing in a mixograph, 2) mixing in a farinograph, and 3) the baked gluten ball test. Dough‐mixing functionality was assessed for Moro flour (9.2% protein) that was fortified up to 16% total protein with dried gluten. In the mixograph, CE‐gluten (70°C) produced improved dough performance but W‐gluten (70°C) degraded dough performance in proportion to the amount added in fortification. In the microfarinograph, there was a desirable and protein‐proportional increase in stability time for CE‐gluten (70°C) but no effect on stability for W‐gluten (70°C). Baking was evaluated using the baked gluten ball test and the percentage increase in the baked ball volume relative to the unbaked gluten volume (PIBV). PIBV values were as high as 1,310% for freeze‐dried CE‐gluten and as low as 620% for W‐gluten dried at 70°C. PIBV for CE‐gluten was reduced to 77% of the freeze‐dried control by fluid‐bed drying at 70°C. Exposure of CE‐gluten to 100°C air gave a PIBV that was 59% of the reference, but this expansion was still greater than that of W‐gluten dried at 70°C. The highest values of PIBV occurred at the same mixing times as the peak mixograph resistance.
Effects of Pearling on Falling Number and α‐Amylase Activity of Preharvest Sprouted Spring Wheat
Authors: Hareland Gary A.
Published: June 2007

Preharvest sprouted wheat is often characterized by the falling number (FN) test. FN decreases in preharvest sprouted wheat as enzymatic degradation of the starchy endosperm increases. Wheat with FN values <250–275 is often discounted at the time of sale. The intent of this investigation was to evaluate the effects of debranning or pearling on the flour quality traits of five samples of wheat rated as low, med‐low, medium, med‐high, and sound that exhibited a range in FN values of 62–425 sec. Replicates of each sample were pearled for 30, 60, and 120 sec to remove portions of the outer bran layers before milling. FN was highly correlated with α‐amylase activity (r > ‐0.97) in the med‐low, medium, and med‐high FN sample sets as pearling time increased. FN increased in the medlow, medium, and med‐high FN samples by 128, 123, and 80%, respectively, after 120 sec of pearling. Pearling had no effect on flour FN of the low FN sample but α‐amylase activity was significantly decreased. Pearling had little or no effect on FN and α‐amylase activity of the sound sample. FN was moderately to strongly correlated with Rapid Visco Analyser (RVA), alveograph, and farinograph properties, and poorly correlated with protein content, flour yield, and bread loaf volume. In subsequent breadmaking studies, bread loaf volume, and crumb characteristics of flour from pearled wheat were not significantly different from loaf volume and crumb characteristics of flour from the corresponding nonpearled wheat.
Capillary Electrophoresis of Gliadins as a Tool in the Discrimination and Characterization of Hulled Wheats (Triticum dicoccon Schrank and T. spelta L.)
Authors: Piergiovanni Angela R. , Volpe Nicola
Published: June 2007

Twenty‐two lines of emmer (T. dicoccon Schrank) and 10 of spelt (T. spelta L.) were analyzed using capillary electrophoresis for their gliadins. These proteins were separated on an uncoated fused‐silica capillary (30 cm long, 22 cm to detector, 50 μm i.d.) using the isoelectric buffer 40 mM aspartic acid, 4M urea, 0.5% (w/v) HEC, and 20% (v/v) acetonitrile. Samples were run for 20 min at 22kV and 42°C. By using these conditions, gliadins were separated into 21–30 components (peaks and shoulders). The major peaks eluted between 4.5 and 8.5 min. Electrophoregrams of tested lines showed qualitative and quantitative differences, including number of peaks, presence or absence of some major peaks, and areas of peaks. Lines belonging to the same species can be discriminated mainly on the basis of β‐ and ω‐gliadin patterns. The γ‐and ω‐gliadins seem to be more useful in the differentiation of emmer from spelt. The comparison of electrophoregrams relative to hulled and unhulled species evidenced the high similarity between species with the same genome composition (durum wheat‐emmer, and common wheat‐spelt).
Effects of Starch Amylose Content of Wheat on Textural Properties of White Salted Noodles
Authors: Baik Byung‐Kee , Lee Mee‐Ryung
Published: June 2007

White salted noodles were prepared through reconstitution of fractionated flour components with blends of waxy and regular wheat starches to determine the effects of amylose content on textural properties of white salted noodles without interference of protein variation. As the proportion of waxy wheat starch increased from 0 to 52% in starch blends, there were increases in peak viscosity from 210 to 640 BU and decreases in peak temperature from 95.5 to 70.0°C. Water retention capacity of waxy wheat starches (80–81%) was much higher than that of regular wheat starch (55–62%). As the waxy wheat starch ratio increased in the starch blends, there were consistent decreases in hardness of cooked noodles prepared from reconstituted flours, no changes in springiness and increases in cohesiveness. White salted noodles produced from blends of regular and waxy wheat flours became softer as the proportion of waxy wheat flour increased, even when protein content of flour blends increased. Amylose content of starch correlated positively with hardness and negatively with cohesiveness of cooked white salted noodles. Protein content of flour blends correlated negatively with hardness of cooked noodles, which were prepared from blends of regular (10.5% protein) and waxy wheat flours (> 16.4% protein).
Stress Relaxation Behavior of Wheat Dough, Gluten, and Gluten Protein Fractions
Authors: Li W. , Dobraszczyk B. J. , Schofield J. D.
Published: June 2007

Relaxation behavior was measured for dough, gluten and gluten protein fractions obtained from the U.K. biscuitmaking flour, Riband, and the U.K. breadmaking flour, Hereward. The relaxation spectrum, in which relaxation times (τ) are related to polymer molecular size, for dough showed a broad molecular size distribution, with two relaxation processes: a major peak at short times and a second peak at times longer than 10 sec, which is thought to correspond to network structure, and which may be attributed to entanglements and physical cross‐links of polymers. Relaxation spectra of glutens were similar to those for the corresponding doughs from both flours. Hereward gluten clearly showed a much more pronounced second peak in relaxation spectrum and higher relaxation modulus than Riband gluten at the same water content. In the gluten protein fractions, gliadin and acetic acid soluble glutenin only showed the first relaxation process, but gel protein clearly showed both the first and second relaxation processes. The results show that the relaxation properties of dough depend on its gluten protein and that gel protein is responsible for the network structure for dough and gluten.
Tentative Avenanthramide‐Modifying Enzyme in Oats
Authors: Bryngelsson Susanne , Sunnerheim Kerstin , Holm Carina , Dimberg Lena H.
Published: June 2007

A decrease of the concentration of the synthetic avenanthramide N‐(4′‐hydroxy‐(E)‐cinnamoyl)‐5‐hydroxyanthranilic acid in a buffered slurry of milled oat groats (Avena sativa L.) was temperature and pH‐dependent, with a maximum rate at 30°C and pH 9. The reaction was inhibited in the presence of 2‐mercaptoethanol, acetic acid and at high temperature; suggestive of enzymatically catalyzed nature. Among eight different synthetic avenanthramides tested, the tentative enzyme had highest affinity for avenanthramides comprising caffeic and p‐coumaric acids and lowest for those comprising sinapic and ferulic acids. The activity was found in samples from several oat cultivars and was equally pronounced in both bran and endosperm flour of oats. Steeping of oat grains did not influence the reaction.
Analysis of Dough Kneaders Using Numerical Flow Simulations
Authors: Jongen T. R. G. , Bruschke M. V. , Dekker J. G.
Published: June 2007

The objective of this work is to characterize the various deformations to which dough is subjected during kneading, and to investigate the influence of mixer configurations and operating conditions. Several kneader geometries are modeled as representative of the mixing mechanisms taking place in various mixers. Based on the time‐dependent velocity fields obtained, the type of deformation taking place in the mixers is characterized using relevant kinematic flow classification parameters. These parameters are then related to the mechanical action of the kneader. The results for the practical design of dough kneaders can be applied, and a complementary experimental program should fit within the design cycle.
Quantitative Assessment of Gas Cell Development During the Proofing of Dough by Magnetic Resonance Imaging and Image Analysis
Authors: van Duynhoven John P. M. , van Kempen Geert M. P. , van Sluis Robert , Rieger Bernd , Weegels Peter , van Vliet Lucas J. , Nicolay Klaas
Published: June 2007

The structure of bread crumb is an important factor in consumer acceptance of bakery products. The noninvasive monitoring of the gas cell formation during the proofing of dough can aid in understanding the mechanisms governing the crumb appearance in the baked product. The development of gas cells during the proofing of dough was monitored in a noninvasive manner using magnetic resonance imaging (MRI) at 4.7‐T. The acquired MRI time series were analyzed quantitatively using image analysis (IA) techniques. The effects of both kneading temperature and mechanical damage by molding were studied. When additional rheological stress was introduced during molding, a more heterogeneous (coarse) gas cell size distribution was observed, and the dough had a smaller specific volume (as measured by MRI). These characteristics were preserved in the bread crumb structure after baking. The fast‐deformation during molding also resulted in an isotropic growth of the dough during proofing, whereas slow‐deformation during molding resulted in anisotropic growth. This can be related to a better conservation of stress in the dough under a moderate molding operation. A higher temperature during kneading also resulted in a coarser distribution of the gas cells and a smaller MRI specific dough volume. No effect of kneading temperature on the growth anisotropy could be detected, however. This indicates that temperature has a smaller effect on the conservation of stress in the dough than molding. The current work illustrates the capability of MRI/IA for understanding and predicting the influence of food processing parameters on consumer‐relevant features in a food product (bread).
Wheat Tortilla Quality: Impact of Amylose Content Adjustments Using Waxy Wheat Flour
Authors: Guo G. , Jackson D. S. , Graybosch R. A. , Parkhurst A. M.
Published: June 2007

Amylose content is closely related to wheat flour pasting or thermal properties, and thus affects final food qualities. Fourteen flour blends with amylose content ranges of <1 to 29% were used to study tortilla production and quality parameters. Reduced amylose contents decreased dough stickiness and pliability; low amylose doughs were also very smooth in appearance. Very low flour amylose content was associated with earlier tortilla puffing and poor machinability during baking, darker color, low opacity, larger diameters, and reduced flexibility after storage. Tortilla texture analysis indicated that lowering amylose content gave fresh tortillas higher extensibility; after three or more days storage, however, low amylose flours required more force to break the tortillas and the rupture distances became shorter. These results, as reflected in covariate analysis, were not significantly affected by the flour blend's protein content, swelling volume/power, SDS‐sedimentation volume, mixograph dough development time, or mixograph tolerance score. Based on our observation of an initial increase in extensibility with reduced‐amylose tortillas, adding 10–20% waxy flour into wild‐type flours should be ideal for restaurant (on‐site) tortilla production or circumstances where tortillas are consumed shortly (within a day) after production. The optimal flour amylose content for hot‐press wheat tortilla products is 24–26%.
A Fast Colorimetric Method to Estimate Corn Quality Loss
Authors: Tosi E. A. , Ré E. D.
Published: June 2007

A fast method to estimate the loss of corn quality for wet milling as a result of excessive thermal treatment during drying is proposed. Proteins that remain soluble after drying were quantitatively extracted with a solution of phosphoric acid and ethanol. The soluble proteins were colorimetrically quantified using Coomasie Brillant Blue G dye and measuring at 595 nm. A decrease in absorbance values indicates a reduction in commercial quality of the corn. The application time of the proposed technique is ≈30 min.
Optimizing Extraction of Zein and Glutelin‐Rich Fraction During Sequential Extraction Processing of Corn
Authors: Hojilla‐Evangelista Mila P. , Johnson Lawrence A.
Published: June 2007

This study was conducted to improve yields and qualities of corn protein co‐products produced by the sequential extraction process (SEP), a process using ethanol to fractionate corn in producing fuel ethanol. A two‐stage extraction protocol was evaluated to recover zein and subsequently recover a glutelin‐rich fraction (GRF). After the simultaneous oil‐extraction and ethanol‐drying step of SEP, zein was extracted from the anhydrous‐ethanol‐defatted, flaked corn by using 70% (v/v) ethanol at 60°C for 1.5 hr in a shaking water bath. Zein was recovered by ultrafiltering and then drying in a vacuum‐oven. Zein yield was 65% of the available zein in the flaked corn. SDS‐PAGE band patterns of the recovered zein closely resembled that of commercial zein. After zein extraction, the GRF was extracted using 45% ethanol and 55% 0.1M NaOH at 55°C for 2 hr. The extract was concentrated by ultrafiltration and then freeze‐dried. GRF yield was ≈65% of the available protein. Freeze‐dried GRF contained 90% crude protein (db), which classified the protein as a protein isolate. As with the protein concentrate from the original SEP, the GRF isolate was highly soluble in water at pH ≥ 7, had good emulsifying and foaming properties, formed stable emulsions, and was heat‐stable.
Evaluation of Novel Precast SDS‐PAGE Gels for Separation of Sorghum Proteins
Authors: Bean S. R.
Published: June 2007

Precast polyacrylamide gels using novel buffer chemistry for enhanced resolution and shelf life stability of the gels were evaluated for separating sorghum proteins. Two gels with different acrylamide concentrations, 12 and 4–12%, were tested with two different buffer systems. Gels were evaluated for separation resolution, as well as protein solubility problems such as streaking. High‐resolution separations were obtained for all the major classes of kernel proteins using these gels. Run times were typically 45–60 min, producing relatively rapid separations. Resolution was significantly affected by the buffer system used. The use of precast gradient gels eliminates the need for casting gradient gels for routine analysis of sorghum proteins and avoids handling the toxic acrylamide monomer. This system will be useful for routine separations of sorghum proteins as well as for research programs using SDS‐PAGE to screen sorghum lines for digestibility or for other protein‐related quality factors.
Separation of Water‐Soluble Proteins from Cereals by High‐Performance Capillary Electrophoresis (HPCE)
Authors: Bean S. R. , Tilley M.
Published: June 2007

Most research concerning grain proteins has concentrated on the gluten storage proteins. The albumins and globulins are the water‐ and salt‐soluble proteins that contain biologically active enzymes and enzyme inhibitors. A free‐zone capillary electrophoresis method was developed to separate these proteins. Optimization included sample extraction method, capillary temperature, buffer composition, and additives. The optimal conditions for separation of these proteins was 50 μm i.d. × 27 cm (20 cm to detector) capillary at 10 kV (with a 0.17 min ramp‐up time) and 25°C. The optimum buffer was 50 mM sodium phosphate, pH 2.5 + 20% acetonitrile (v/v) (ACN) + 0.05% (w/v) hydroxypropylmethyl‐cellulose (HPMC) + 50 mM hexane sulfonic acid (HSA). Sample stability was an issue that was addressed by lyophilizing fresh extracts and redissolving in aqueous 50% ethylene glycol and 10% separation buffer. This method was successfully used in both wheat flour and whole meal samples. Comparisons were made of several wheats of different classes as well as several cereal grains. This methodology could be useful in screening cereal grains for important enzymes and their impact on end‐use quality such as food functionality, food coloration, and malting quality.
Measurement of Hard Vitreous Kernels in Durum Wheat by Machine Vision
Authors: Symons S. J. , Van Schepdael L. , Dexter J. E.
Published: June 2007

An imaging method that detects nonvitreous regions in sound kernels of durum wheat at high speed is described. Kernels are analyzed simultaneously for individual vitreousness and individual kernel size and shape are measured concurrently. The measurement of 500 kernels per sample is adequate for highly reproducible results. Significant agreement was found between inspector‐determined hard vitreous kernel percentages (HVK) and machine‐determined HVK scores for export cargo samples of Canadian Western Amber Durum (CWAD), with differences between the two methods of typically ±3%. For railcar samples of CWAD taken on delivery to the terminal, agreement between inspector‐determined and machine‐determined HVK scores were more variable. The variability between the two methods generally increased as the HVK score of the sample became lower. For inspector‐determined HVK scores of <50%, difference between inspector and machine HVK scores for some samples was substantial. Such large differences are partially attributable to the way in which weathered kernels are assessed. Weather‐damaged kernels were frequently classified as nonvitreous by the machine system due to disruption of the enveloping tissues, whereas inspector evaluations often classify weather‐damaged kernels as vitreous. The speed, accuracy, and reproducibility of the machine methodology gives it enormous potential as a replacement for visual inspection of CWAD for HVK in Canadian grain terminals.
Genetic and Environmental Effects on Dough Mixing Characteristics and Agronomic Performance of Diverse Hard Red Winter Wheat Genotypes
Authors: Budak H. , Baenziger P. S. , Graybosch R. A. , Beecher B. S. , Eskridge K. M. , Shipman M. J.
Published: June 2007

Wheat (Triticum aestivum L.) genotypes with short mixing times usually have low mixing tolerance values, which make them more sensitive to overmixing in commercial bread production. In this study, we evaluated the genotypic and environmental effects on agronomic performance and end‐use quality of 27 experimental genotypes (hereafter referred to as mixing tolerant genotypes) which were identified in an initial screen as having short mixing times and good mixing tolerances to 1) determine whether genotypes identified in a preliminary end‐use quality screen as lines with usually long tolerances but short mixing times were due to their genotype (G), the environment (E), or G × E; and as these results were unusual, 2) determine whether or not our initial screen predicts end‐use quality, and 3) determine the stability of both agronomic and end‐use quality traits. The 27 genotypes and five check cultivars were grown in a randomized complete block design with two replicates in nine environments in 1997 and 1998. All plots were harvested for grain yield. The harvested grain from the first replicate and random genotypes from the second replicate were micromilled to produce flour samples for evaluation of flour yield, protein content, and mixograph mixing time and mixing tolerance values. Seed diameter, thousand kernel weight, and kernel hardness were also measured in three environments. Environment, G, and G × E interaction effects (mainly changes in magnitude) were significant for most agronomic and end‐use quality parameters. Our initial screen, which had identified 27 genotypes, was partially effective in identifying genotypes that have shorter mixing time values compared with their mixing tolerance values. We identified four genotypes (15%) from the mixing tolerant genotypes that had a good mixing tolerance value and relatively shorter mixing time, as did the released cultivars ‘Agate’ and ‘Scout 66’. However, mixing characteristics values of all genotypes fell within the acceptable limits, indicating our screen effectively identified genotypes with acceptable quality. Mixing tolerant genotypes, which had been identified as having short mixing time scores and long mixing tolerance scores, were considered stable across environments.
Starch from Hull‐less Barley: Ultrastructure and Distribution of Granule‐Bound Proteins
Authors: Li J. H. , Vasanthan T. , Hoover R. , Rossnagel B. G.
Published: June 2007

Starch granules isolated from waxy, normal, and high‐amylose hullless barley grains were examined by transmission electron microscopy with cytochemical techniques. The micrographs showed two distinct regions of different sizes: 1) densely packed granule growth rings (which varied in size and number depending on the genotype), and 2) a loose filamentous network located in the central region of the granule. The granule ring width decreased with increasing amylose content. In all three genotypes, the growth rings closer to the granule surface were narrower in width than those within the granule interior. The waxy starch had wider intercrystalline amorphous growth rings, semicrystalline growth rings, and more open crystalline lamellae than normal and high‐amylose starches. Granule bound proteins (mainly integral proteins) were located in the central and peripheral (growth ring) regions of the granule.
X‐ray Image Analysis to Detect Infestations Caused by Insects in Grain
Authors: Karunakaran C. , Jayas D. S. , White N. D. G.
Published: June 2007

Insect infestations in stored wheat affect the chemical characteristics and baking qualities of wheat flour, and insect‐infested flours are unacceptable in the baking industry. The efficiency of the soft X‐ray method to detect infestations caused by Cryptolestes ferrugineus (Stephens), Tribolium castaneum (Herbst), Plodia interpunctella (Hübner), Sitophilus oryzae (L.), and Rhyzopertha dominica (F.) in wheat kernels was determined in this study. Wheat kernels infested by different insects were prepared by artificial implantation of insect eggs or by introducing adult insects in wheat samples. Kernels infested by different stages of the insects were X‐rayed until the adults emerged from the kernels. A total of 57 features using histogram groups, histogram and shape moments, and textural features were extracted from the X‐ray images and a linear‐function parametric classifier was used to identify the insect‐infested kernels. The parametric classifier identified more than 84% of infestations due to C. ferrugineus and T. castaneum larvae. The infestations by C. ferrugineus pupae‐adults and P. interpunctella larvae were identified with >96% accuracy. Kernels infested by different stages of S. oryzae and R. dominica larvae were identified with >98% accuracy. Using the Berlese funnel method, 67, 51, and 81% of first, second, and third instars of C. ferrugineus, respectively, were extracted in 6 hr. The same infested kernels were all categorized as infested by the parametric classifier. When kernels infested by different insects were pooled together, the parametric classifier correctly identified 74% of uninfested and 94% of infested kernels by the internal and external grain feeders. The 26% false positives identified from the independent test was caused by one sample infested by T. castaneum. When that sample was removed from the training set, the false positives were reduced to 16%, and 92.7% of infested kernels by different insects were correctly identified.
Effects of Boiling, Refrigerating, and Microwave Heating on Cooked Quality and Stability of Lipids in Macaroni Containing Ground Flaxseed
Authors: Lee Robert E. , Manthey Frank A. , Hall Clifford A.
Published: June 2007

Research was conducted to determine the effects of boiling, refrigerating, and microwave heating on the cooked quality and stability of lipids in macaroni containing 15% (w/w) ground flaxseed. Boiling increased brightness but decreased redness and yellowness of macaroni containing ground flaxseed. Boiled macaroni and boiled‐refrigerated‐microwave heated (BRMH) macaroni had similar appearance. After boiling, cooking loss was lower and cooked firmness was greater for macaroni dried at ultra‐high temperature (90°C) than at low temperature (40°C). Macaroni fortified with ground flaxseed had lower cooking loss than did nonfortified macaroni. Firmness was greatest with boiled, intermediate with boiled‐refrigerated (BR), and least with BRMH macaroni. Cooking in boiling water reduced extractable lipid content of macaroni with flaxseed. Boiled‐refrigerated and BRMH macaroni with flaxseed had similar extractable lipid contents and were lower than that for boiled macaroni with flaxseed. Free fatty acid content was greatest with dried, intermediate with boiled, and least with BR and BRMH macaroni with flaxseed. Boiling, refrigerating, and microwave heating did not affect conjugated diene content in lipid extracted from macaroni with flaxseed, regardless of drying temperature.
Effect of Selected Hofmeister Anions on the Secondary Structure and Dynamics of Wheat Prolamins in Gluten
Authors: Wellner Nikolaus , Bianchini David , Mills E. N. Clare , Belton Peter S.
Published: June 2007

The effect of selected salts (NaCl, NaBr, NaI) with increasingly chaotropic anions on gluten prolamin secondary structure and dynamics was studied using FT‐IR and NMR spectroscopy. FT‐IR spectra indicated a small increase in intermolecular β‐sheet structures when gluten samples were incubated with low levels of NaCl and NaBr. The β‐sheet content remained constant with further NaCl addition, but was reduced again with higher NaBr concentrations. NaI addition generally reduced the amount of β‐sheet and increased the amount of β‐turns. From these data, it could be concluded that, in the presence of chaotropic anions, the proteins tended to prefer the β‐turn helix structure characteristic of glutenin subunits in solution. 1H‐NMR relaxation showed that the molecules were more rigid in 1M NaCl than in pure water, and that the mobility of the prolamins in the presence of 1M NaCl, NaBr, and NaI increased in accordance with the position of the anions in the Hofmeister series. The increase in mobility appeared to be associated with the increase in β‐turn helical structures.
Identification of Sprout Damage in Oats
Authors: Doehlert Douglas C. , McMullen Michael S.
Published: June 2007

Sprout damage of oats can occur when mature grain is left in the field after maturity and rainfall induces the germination process in the seeds. Although characteristics of sprout damage have been described thoroughly in many grains including wheat, rye, triticale, and barley, such characteristics have not been identified in oats. During a field study of oat quality, one site exhibited much higher rates of groat breakage during dehulling than other sites. Determination of falling number values on groat flour and a visual inspection of the grain suggested that the higher rates of groat breakage were associated with sprout damage. This hypothesis was confirmed with artificially sprouted oats, where sprouted grain exhibited lower falling numbers and lower stirring number values, suggesting increased α‐amylase activity in the sprouted oats. Sprouted oats exhibited much more breakage during dehulling, decreased β‐glucan concentration, and decreased β‐glucan integrity, as evaluated from the viscosity of steamed groat flour slurries. We suggest that the increased breakage was a result of the weakening of cell walls, as evidenced by the loss of β‐glucan concentration and integrity.
Distribution and Structural Variation of Nonstarch Polysaccharides in Milling Fractions of Hull‐less Barley with Variable Amylose Content
Authors: Izydorczyk M. S. , Jacobs M. , Dexter J. E.
Published: June 2007

Three hull‐less barley genotypes containing starches with variable amylose content (23.8% normal, 4.3% waxy, 41.8% high‐amylose barley) were pearled to 10% and then roller‐milled to produce pearling by‐products (PBP), flour, and fiber‐rich fractions (FRF). PBP were enriched in arabinoxylans, protein, and ash and contained small amounts of starch and β‐glucans. FRF were considerably enriched in β‐glucans and arabinoxylans. The solubility of β‐glucans was higher in PBP than in FRF. The solubility of arabinoxylans was higher in FRF than in PBP. Small amounts of arabinogalactans detected in barley were concentrated in the outer portion of the barley kernel. The content and solubility of nonstarch polysaccharides (NSP) in various milling fractions was also dependent on the type of barley. To obtain more detailed information about the content and molecular structure of NSP, each milling fraction was sequentially extracted with water, alkaline [Ba(OH)2], again with water, and finally with NaOH. These extractions resulted in four sub‐fractions: WE, Ba(OH)2, Ba(OH)2/H2O, and NaOH. β‐Glucans and arabinoxylans exhibited structural heterogeneity derived from differences in their location within the kernel as well as from the genetic origin of barley. The WE arabinoxylans from FRF and flour had a substantially lower degree of branching than those from PBP. The WE arabinoxylans from FRF of high‐amylose and normal barley contained more unsubstituted Xylp residues but fewer doubly‐substituted and singly‐substituted Xylp at O‐2 than their counterparts from PBP. The WE arabinoxylans from FRF of waxy barley had a relatively high content of doubly‐substituted, but very few singly‐substituted Xylp residues. In all three barley genotypes, the ratio of tri‐ to tetrasaccharides in β‐glucans from PBP was higher than from flour and FRF. Substantial differences in the molecular weight of NSP in different milling fractions were also observed.
Milling Performance of North European Hull‐less Barleys and Characterization of Resultant Millstreams
Authors: Andersson A. A. M. , Courtin C. M. , Delcour J. A. , Fredriksson H. , Schofield J. D. , Trogh I. , Tsiami A. A. , Åman P.
Published: June 2007

Four hull‐less barley samples were milled on a Bühler MLU 202 laboratory mill and individual and combined milling fractions were characterized. The best milling performance was obtained when the samples were conditioned to 14.3% moisture. Yields were 37–48% for straight‐run flour, 47–56% for shorts, and 5–8% for bran. The β‐glucan contents of the straight‐run white flours were 1.6–2.1%, of which ≈49% was water‐extractable. The arabinoxylan contents were 1.2–1.5%, of which ≈17% was water‐extractable. Shorts and bran fractions contained more β‐glucan (4.2–5.8% and 3.0–4.7%, respectively) and arabinoxylan (6.1–7.7% and 8.1–11.8%, respectively) than the white flours. For those fractions, β‐glucan extractability was high (58.5 and 52.3%, respectively), whereas arabinoxylan extractability was very low (≈6.5 and 2.0%, respectively). The straight‐run white flours had low α‐amylase, β‐glucanase, and endoxylanase activities. The highest α‐amylase activity was found in the shorts fractions and the highest β‐glucanase and endoxylanase activities were generally found in the bran fractions. Endoxylanase inhibitor activities were low in the white flours and highest in the shorts fractions. High flavanoid, tocopherol, and tocotrienol contents were found in bran and shorts fractions.
Preparation and Characterization of Films Using Barley and Oat β‐Glucan Extracts
Authors: Tejinder S.
Published: June 2007

Films for potential food use were prepared from aqueous solutions of β‐glucan extracted from hulled barley, hull‐less barley, and oats. The extracts (75.2–79.3% β‐glucan) also contained proteins, fat, and ash. Glycerol was used as a plasticizer. The films were translucent, smooth, and homogeneous in structure on both sides. Water vapor permeability of films prepared from 4% solutions of β‐glucan extracts were higher than those from 2% solutions, despite similar values for water vapor transmission rate. Mechanical properties were influenced by both β‐glucan source and concentration. The oat β‐glucan films showed higher tensile strength and water solubility, and lower color, opacity, and deformation values than those of barley. Films prepared from hull‐less barley cv. HLB233 remained intact upon immersion in water for 24 hr.