bluuebunny/crossref_metadata_2025 huggingface dataset:
Plant Sterols in Cereals and Cereal Products
Authors: Piironen V. , Toivo J. , Lampi A.‐M.
Published: June 2007

The total plant sterol contents (free sterols and covalently bound structures) of the main cereals cultivated in Finland were determined. Furthermore, sterol contents were determined for different flour and bran fractions in the milling process of wheat and rye, as well as plant sterol contents in various milling and retail bakery products. The sample preparation procedure included acid and alkaline hydrolysis to liberate sterols from their glycosides and esters, respectively. Free sterols were extracted and, after recovery using solid‐phase extraction, derivatized to trimethylsilyl ethers for gas chromatography (GC) analysis. We used GC with a mass spectrometer (MS) for identification. When two cultivars of rye, wheat, barley, and oats grown in the same year were compared, the highest plant sterol content was observed in rye (mean content 95.5 mg/100 g, wb), whereas the total sterol contents (mg/100 g, wb) of wheat, barley, and oats were 69.0, 76.1, and 44.7, respectively. In addition, the 10 rye cultivars and breeding lines compared had total sterol contents of 70.7–85.6 mg/100 g. In the milling process of rye and wheat, the plant sterols fractionated according to the ash content of the corresponding milling product. In all cereal grain and milling product samples, sitosterol was the main sterol. The level of stanols differed in the different milling process samples; it was lower in the most refined rye and wheat flours (≈15%) than in the bran fractions (≈30% in the bran with 4% ash content). Rye bread with whole meal rye flour as the main or only ingredient was a good source of sterols. Sterol content was higher than that of wheat bread, whereas plant sterol content of other bakery products was affected by the type and amount of fat used in baking.
Tetraploid Wheat—A Resource for Genetic Improvement of Durum Wheat Quality
Authors: Sissons M. J. , Hare R. A.
Published: June 2007

The tetraploid relatives (subspecies) of commercial durum wheat (Triticum turgidum L. subsp. turgidum conv. durum (Desf.) MacKey) offer a source of economically useful genes for the genetic improvement of durum cultivars. Tetraploid wheat subspecies show a wide diversity in grain protein composition and content, which are major factors determining the pasta‐making quality of durum cultivars. In this study, the specific focus was the identification of accessions expressing one or more superior pasta‐making traits. In all, 33 accessions were surveyed representing five different subspecies; var. durum (13 accessions), polonicum (7 accessions), persicum (3 accessions), turanicum (6 accessions), and turgidum (4 accessions). These accessions and the durum cultivars Wollaroi and Kamilaroi (in both years) and Yallaroi (in 1998 only) were grown at Tamworth, Australia in 1997 and 1998. Grain, semolina, and spaghetti cooking quality were evaluated using a range of tests. Several accessions were identified with larger grain size and protein content and higher semolina extraction. Although many of the accessions were weaker in dough strength, a few were equal to the commercial cultivars and produced pasta of comparable quality. The main disadvantage with these accessions was the low yellow color. These quality defects can be corrected by conventional breeding.
Swelling Index of Glutenin Test. II. Application in Prediction of Dough Properties and End‐Use Quality
Authors: Wang C. , Kovacs M. I. P.
Published: June 2007

Small‐scale tests, including SDS and Zeleny sedimentation, gel protein, insoluble glutenin content, and a newly developed method, the swelling index of glutenin (SIG), were compared with dough and gluten rheological parameters and end‐use quality parameters for 20 wheat cultivars or breeders lines. The SIG test is equal to or slightly better than the other small‐scale tests in prediction of dough strength. Quality parameters were divided into two groups according to associations with insoluble glutenin content and glutenin quality. The glutenin quality is defined as the glutenin swelling properties with short swelling time (≤5 min) that are contributed by soluble and insoluble glutenin content and their swelling properties. Parameters in the first group were mainly dependent on insoluble glutenin content and appeared to reflect gluten strength. Parameters in the second group were dependent not only on glutenin content, but also on glutenin quality. Small‐scale tests are best to predict quality parameters within the same group, but not those in the other group. The glutenin swelling curve, obtained with different swelling times, was correlated with mixograph or farinograph data. Dough development time in farinograph and mixing time in mixograph were strongly related to the swelling time of peak SIG value in the swelling curve (r = 0.92, r = 0.86, respectively, P < 0.001). Farinograph stability was significantly related to the time of swollen stage in swelling curves (r = 0.62, P < 0.01). Similar to mixograph or farinograph data, the glutenin swelling curves can be used to differentiate some strong cultivars that can not be differentiated by sedimentation, gel protein, and insoluble glutenin values.
Swelling Index of Glutenin Test for Prediction of Durum Wheat Quality
Authors: Wang C. , Kovacs M. I. P.
Published: June 2007

The swelling index of glutenin (SIG) was assessed for suitability as a screening procedure for durum wheat gluten strength. Five sets of samples with a wide range of gluten strength values were collected according to gluten strength parameters and characterized for SIG. Statistical analysis revealed that the SIG and SDS sedimentation tests were both able to satisfactorily account for variations in gluten strength in all sets of samples. However, for most samples, the SIG test was more reliable than the SDS sedimentation test for predicting gluten strength. Furthermore, the SIG test can differentiate samples with glutenin swelling properties that could not be accounted for by intercultivar variation of SDS sedimentation volumes. The percentage of insoluble glutenin in protein is usually a better predictor for gluten strength than the percentage of insoluble glutenin in flour. Similarly, when the SIG values were divided by the protein content of the samples, the resulting proportions were better predictors of gluten strength than the absolute values. Analysis of protein fractions revealed that the insoluble glutenin was the protein fraction most responsible for the SIG value and gluten strength. Extensibility of dough was significantly related to the soluble glutenin content, while the alveograph G index was related to monomeric protein content. The results suggest that screening based on the SIG test would be valuable for comparing durum wheat lines and cultivars for gluten strength and pasta‐making quality.
Effect of Partial Waxy Wheat on Processing and Quality of Wheat Flour Tortillas
Authors: Waniska Ralph D. , Graybosch Robert A. , Adams Janet L.
Published: June 2007

The processing and quality of wheat flour tortillas prepared with partial waxy and normal flour were evaluated. Control procedures and formula were utilized with water absorption varied to obtain machineable doughs. Amylose content was lower in most partial waxy compared with normal wheats. The type of wheat starch did not affect most dough properties or tortilla diameter. Tortilla height and opacity were adversely affected by the decreased amount of amylose in partial waxy wheats. Sufficient leavening reactions occurred early in baking (after 10 sec) to yield an opaque disk, but some baked tortillas lost opacity and become partially transparent after baking. Starch gelatinizes, disperses, and retrogrades concurrently with the leavening reaction during the short (<30 sec) baking time. Amylose functionality during baking and cooling appears to be involved in the retention of air bubbles in tortillas.
Characterization of Italian Durum Wheat Semolina by Means of Chemical Analytical and Spectroscopic Determinations
Authors: Brescia Maria Antonietta , Di Martino Giuliano , Fares Clara , Di Fonzo Natale , Platani Cristiano , Ghelli Stefano , Reniero Fabiano , Sacco Antonio
Published: June 2007

Proton high‐resolution magic angle spinning nuclear magnetic resonance (1H HR‐MAS NMR) has been applied for the analysis of two cultivars of durum wheat produced in different Italian geographical areas. Furthermore, on the same samples, isotopic ratios were measured by mass spectrometry (IRMS). The application of chemometrics to these results permitted the discrimination of semolina by cultivar and geographical origin. A similar approach has been applied to the results obtained from chemical analyses. The comparison showed that NMR spectroscopy can provide a faster method for the detection of differences among the durum wheat semolina according to geographical and varietal origin. Furthermore, IRMS data are suitable to provide information about the geographical origin of samples. This present investigation is part of an extensive research project to find a scientific method capable of classifying wheat foods for the assignment of a “denomination of origin” trademark.
Influence of Fat on Expansion of Glassy Amylopectin Extrudates by Microwave Heating
Authors: Ernoult V. , Moraru C. I. , Kokini J. L.
Published: June 2007

The effect of solid fat (melting point 70°C) and liquid fat (melting point ‐20°C) on the microwave expansion of extruded glassy amylopectin pellets was investigated. Glassy, unexpanded amylopectin extrudates containing ≤10% fat were equilibrated at different water activity levels (aw) and then expanded by microwave heating. Expanded products were characterized by analyzing degree of expansion, structure, and texture. For the aw range studied, expansion increased with increasing aw of the pellets until a maximum at aw = 0.605 and then decreased. Completely dehydrated samples did not expand at all. This demonstrated that moisture was the driving force in the microwave expansion of the pellets. The addition of solid fat contributed greatly to expansion. The highest degree of expansion was obtained for pellets containing 6% solid fat at all aw levels. Due to the effect on expansion, the addition of solid fat also affected the microstructure and texture of the expanded products. Concentrations of solid fat >2% resulted in expanded products with a large number of cells, uniform in size, with thin cell walls. Liquid fat addition had a negative effect on microwave expansion. The expanded products obtained from pellets that contained liquid fat had a lower expansion volume and a coarser structure.
Effect of Small and Large Wheat Starch Granules on Thermomechanical Behavior of Starch
Authors: Chiotelli Eleni , Le Meste Martine
Published: June 2007

The physicochemical properties of small‐ and large‐granule wheat starches were investigated to reveal whether gelatinization properties and rheological behavior differ between size classes of wheat starch. All samples contained 60% water (w/w, wb). The starch granule size and shape were examined by scanning electron microscopy in the separated A‐ and B‐type granule populations and in the whole wheat starch granule population. Differential scanning calorimetry (DSC) and electron spin resonance (ESR) analyses were performed in parallel with rheological measurements using dynamic mechanical thermal analysis (DMTA) to relate the viscoelastic changes to modifications in dynamic properties of aqueous solutions and structural disorganization of starch. The small (B‐type) granules had slightly higher gelatinization temperature and lower gelatinization enthalpy than did the large (A‐type) granules. Also, B‐type granules had higher enthalpy for the amylose‐lipid complex transition. Moreover, our results suggested that small granules have higher affinity for water at room temperature. It seems that there is a less ordered arrangement of the polysaccharide chains in the smaller granules when compared with the larger ones. These differences in functional properties of small and large granules suggested that the granule size distribution is an important parameter in the baking process.
Effect of Storage Time on In Vitro Digestibility and Resistant Starch Content of Nixtamal, Masa, and Tortilla
Authors: Rendon‐Villalobos Rodolfo , Bello‐Pérez Luis Arturo , Osorio‐Díaz Perla , Tovar Juscelino , Paredes‐López Octavio
Published: June 2007

Nixtamal, masa, and tortilla samples were stored for 24–96 hr and their chemical composition, retrogradation, and in vitro starch digestibility features were evaluated. Ash and fat contents in the three products were smaller than in the original corn sample, but protein levels were higher, all in accordance with previous studies. In general, a minor decrease in available starch (AS) content was observed with storage time. Masa showed the greatest AS values, followed by tortilla and nixtamal. Tortilla presented slightly higher retrograded resistant starch (RS3) values (1.1–1.8%, dmb) than masa (0.7–0.9%) and nixtamal (0.7–0.8%) and only minor increases were observed after 24 hr of storage, suggesting that retrogradation phenomenon in these samples takes place very rapidly and is more pronounced in the final product (tortilla). The development of RS3 explains the observed decrease in AS. Higher total resistant starch values were found in all samples at a range of 2.1–2.6% for nixtamal and masa, and a range of 3.1–3.9% in tortilla. This indicates that, apart from retrograded resistant starch, some ungelatinized fractions appear to contibute to the indigestible content of these products. The α‐amylolysis rate of the three materials decreased with storage. Tortilla showed the greatest hydrolysis indices. Differential scanning calorimetry (DSC) analysis showed that the nixtamal, masa, and tortilla did not show differences in amylopectin crystal melting temperature with storage time, but tortilla exhibited higher enthalpy values after 72 hr of storage, in accordance with the greater total RS contents recorded after prolonged storage.
Structural Characteristics of Water‐Extractable Nonstarch Polysaccharides from Barley Malt
Authors: Cyran M. , Izydorczyk M. S. , MacGregor A. W.
Published: June 2007

Water‐extractable (WE) material was isolated from a Canadian barley malt (cv. Harrington). The purified WE material contained mainly arabinoxylans, β‐glucans, proteins, and small amounts of arabinogalactans and mannose‐containing polymers. WE material was treated with specific enzymes to obtain two fractions: one enriched in arabinoxylan (AX) and another enriched in β‐glucan (BG). The AX fraction was further fractionated by stepwise precipitation in (NH4)2SO4 into five arabinoxylan subfractions. 1H‐NMR spectroscopy and sugar analyses revealed a relatively high content of unsubstituted xylose residues (48–58%) as well as a relatively high content of doubly substituted xylose residues (28–33%) in the structure of the arabinoxylans. β‐Glucans constituted a minor portion of water‐extractable malt polysaccharides and were characterized by high levels of tri‐ and tetrasaccharide residues (93.4%) with a molar ratio of 2.19 for cellotriosyl to cellotetraosyl units. Size‐exclusion chromatography revealed that the WE material contained several polymer populations. One population had a very high molecular weight that appeared to be the result of aggregation. The AX fraction contained higher molecular weight polymers than the BG fraction.
Differences Between Sensory Profiles and Development of Rancidity During Long‐Term Storage of Native and Processed Oat
Authors: Heiniö R.‐L. , Lehtinen P. , Oksman‐Caldentey K.‐M. , Poutanen K.
Published: June 2007

Changes in the sensory attributes, lipid composition, and amounts of volatile and phenolic compounds of native and processed (germinated and dried) crushed oat were followed during a 12‐month storage period. The influence of the chemical attributes on the sensory profiles of oats was analyzed by statistical multivariate techniques (PLS regression). During the storage period, significant changes in the sensory profiles of the native and processed oat groats were observed. The stability of oat groats was significantly increased through germination and subsequent drying because the chemical changes causing rancidity and bitterness developed more slowly in the processed oat when compared with the native oat. In native oat, the most intensive changes due to deteriorat ion had already occurred after one month of storage, whereas in processed oat, these changes were perceived considerably later. Stored oat that had deteriorated was evaluated as being musty and earthy in odor and bitter and rancid in flavor. The accumulation of free fatty acids and volatile compounds related to lipid oxidation were closely correlated with the development of the undesired sensory attributes described above. The total amount of phenolic compounds, as well as the volatile aromatic and branched chain compounds derived mainly from protein degradation, showed a significant relationship with favorable sensory attributes such as roasted odor and flavor. Lipid oxidation occurred during the storage and was observed both in the polar and in the nonpolar lipid classes of native oat, whereas in the processed oat, these changes were nonsignificant. Photo‐oxidation of acylated fatty acids may significantly contribute to the development of volatile lipid oxidation products during storage.
Composition and Quality of Wheat Grown Under Different Shoot and Root Temperatures During Maturation
Authors: Guedira Mohammed , McCluskey Patrick J. , MacRitchie Finlay , Paulsen Gary M.
Published: June 2007

Diminished quality of wheat (Triticum aestivum L.) from high temperature during maturation is usually attributed to direct effects of the stress on the shoots or grain. However, the upper soil temperature approaches the air temperature, and roots are highly sensitive and interact profoundly with other plant parts. The objective of this study was to determine the effect of differential shoot and root temperatures on quality of hard red spring wheat (cv. Len). Plants were grown in hydroponic containers at 15/10°C day/night until 10 days after anthesis, when shoot/root treatments of 15/15°C, 15/30°C, 30/15°C, and 30/30°C were imposed until the grain ripened. Both high shoot and high root temperature affected quality of the grain. Kernel size and weight were diminished more by high root than by high shoot temperature, but flour yield was decreased significantly only by the 30/30°C treatment. The percentage of starch in B granules was reduced by high shoot temperature, and the diameter of A granules was decreased by all heat treatments. Amylose concentration was increased by high temperatures of both shoot and root, resulting in decreased pasting characteristics. Flour protein increased after all heat treatments, but high shoot temperature decreased the polymer‐to‐monomer ratio and unextractable polymeric protein and it affected dough mixing. We concluded that stress on roots directly affects properties of the grain that are important for milling and baking.
Characterization of Functional Properties of Gluten Proteins in Spelt Cultivars Using Rheological and Quality Factor Measurements
Authors: Schober Tilman J. , Clarke Charmaine I. , Kuhn Manfred
Published: June 2007

Wet glutens of 27 European spelt (Triticum aestivum ssp. spelta (L.) Thell.) cultivars were examined using fundamental rheological methods (oscillatory and creep tests) in conjunction with the determination of moisture contents of these glutens and the wet gluten contents of the flours. Furthermore, SDS sedimentation volumes were determined. A special baking test for spelt was developed that encompassed the characteristic elements used in the production of traditional German spelt speciality breads. Various significant correlations between gluten properties and baking results were found for three sets of spelt cultivars obtained from different demographic locations and years of harvest. Furthermore, the relationship between baking results (response) and gluten properties (predictors) could be modeled quite well with the help of multiple linear regression analysis. Radar charts used to profile the gluten properties of a particular cultivar showed a great amount of diversity within the spelt material, but there were also similarities between several cultivars. The differences between spelt cultivars should be taken into account when characterizing spelt in general terms or when comparing spelt and modern wheat.
Effect of Specific Mechanical Energy on Properties of Extruded Protein‐Starch Mixtures
Authors: Gropper Maoz , Moraru Carmen I. , Kokini Jozef L.
Published: June 2007

The effect of the specific mechanical energy (SME) during extrusion of a protein‐starch mixture was studied by analyzing the glass transition temperature (Tg) and starch gelatinization. We found that the SME values of 344 to 2108 kJ/kg did not significantly change the Tg of the product. To explain the insensitivity of Tg to SME in spite of reported fragmentation taking place during extrusion, we studied the effect of the molecular weight (MW) on Tg in a model system consisting of dextrans of varying molecular weights. We found that the effect of the molecular weight on the Tg reached a plateau at 6.7 × 104. Because the reported size of the fragments created during the extrusion process is larger than this, we were able to explain the apparent insensitivity of Tg to SME in the protein‐carbohydrate matrix studied. However, we found that starch gelatinization varied with SME, the degree of gelatinization being higher for systems exposed to higher SME.
Physicochemical and Structural Characteristics of Flours and Starches from Waxy and Nonwaxy Wheats
Authors: Abdel‐Aal E.‐S. M. , Hucl P. , Chibbar R. N. , Han H. L. , Demeke T.
Published: June 2007

A waxy spring wheat (Triticum aestivum L.) genotype was fractionated into flour and starch by roller and wet‐milling, respectively. The resultant flour and starch were evaluated for end‐use properties and compared with their counterparts from hard and soft wheats and with commercial waxy and nonwaxy corn (Zea mays L.) starches. The waxy wheat flour had exceptionally high levels of water absorption and peak viscosity compared with hard or soft wheat flour. The flour formed an intermediate‐strength dough that developed rapidly and was relatively susceptible to mixing. Analysis by differential scanning calorimetry and X‐ray diffractometry showed waxy wheat starch had higher gelatinization temperatures, a greater degree of crystallization, and an absence of an amylose‐lipid complex compared with nonwaxy wheat. Waxy wheat and corn starches showed greater refrigeration and freeze‐thaw stabilities than did nonwaxy starches as demonstrated by syneresis tests. They were also similar in pasting properties, but waxy wheat starch required lower temperature and enthalpy to gelatinize. The results show analogies between waxy wheat and waxy corn starches, but waxy wheat flour was distinct from hard or soft wheat flour in pasting and mixing properties.
Fine Structures of Starches from Long‐Grain Rice Cultivars with Different Functionality
Authors: Patindol James , Wang Ya‐Jane
Published: June 2007

The structural features of rice starch that may contribute to differences in the functionality of three long‐grain rice cultivars were studied. Dried rough rice samples of cultivars Cypress, Drew, and Wells were analyzed for milling quality, grain physical attributes, and starch structures and physicochemical properties. Drew was lower in head rice yield and translucency and higher in percentage of chalky grains compared with Cypress and Wells. Apparent amylose content (21.3–23.1%), crude protein (8.3–8.6%), and crude fat (0.48–0.64%) of milled rice flours were comparable, but pasting properties of rice flours as measured by viscoamylography, as well as starch iodine affinity and thermal properties determined by differential scanning calorimetry were different for the three cultivars. Drew had higher peak, hot paste, and breakdown viscosities, and gelatinization temperature and enthalpy. Molecular size distribution of starch fractions determined by high‐performance size‐exclusion chromatography showed that the three samples were similar in amylose content (AM) (20.0–21.8%) but differed in amylopectin (AP) (64.7–68.3%) and intermediate material (IM) (10.9–13.5%). Drew had highest AP and lowest IM contents, whereas Cypress had the lowest AP and highest IM contents. High‐performance anion‐exchange chromatography of isoamylase‐debranched starch indicated that the AP of Drew was lower in A and B1 chains but higher in B2, B3, and longer chains.
Frozen and Unfrozen Water Contents of Wheat Flours and Their Components
Authors: Roman‐Gutierrez Alma Delia , Guilbert Stéphane , Cuq Bernard
Published: June 2007

The properties of frozen and unfrozen water in two different wheat flours (hard and soft), and in their main components (gluten, starch, damaged starch, water‐soluble and water‐insoluble pentosans), were described using modulated differential scanning calorimetry (DSC). As a reference, enthalpy values of crystallization (298 J/g) and melting (335 J/g) of pure water were determined from the total heat flow curves. The separation of thermal events between the reversing and nonreversing heat flows with modulated DSC was not effective due to disturbances in the modulated temperature scan. For wheat flours and their components, linear regressions described well the changes in frozen water content calculated from enthalpies of freezing (R2 = 0.970–0.982) or melting (R2 = 0.783–0.996). The unfrozen water content (UFWC) calculated for the hard wheat flour (29–31%, db) was close to that calculated for the soft wheat flour (30–32%). The UFWC of wheat gluten (38–47%), starch (38–42%), damaged starch (37–40%), water‐soluble pentosans (51%), and water‐insoluble pentosans (40–44%) were higher than the corresponding values for the flours. The simple summation of the contributions of each component cannot be used to estimate the overall behavior of flours.
Pasting Properties and Surface Characteristics of Starch Obtained from an Enzymatic Corn Wet‐Milling Process
Authors: Singh Vijay , Johnston David B.
Published: June 2007

Recently, we reported the development of an enzymatic corn wet‐milling process that reduces or eliminates sulfur dioxide requirements during steeping, considerably reduces steep time, and produces starch yields comparable to that of conventional corn wet‐milling. The best results so far, using the enzymatic corn wet‐milling procedure, were achieved when a particular protease enzyme (bromelain) was used. In this study, pasting properties and surface characteristics of starch obtained from six different enzyme treatments (three glycosidases [β‐glucanase, cellulase, and xylanase] and three proteases [pepsin, acid protease, and bromelain]) using the enzymatic corn wet‐milling procedure were evaluated and compared with those from starch obtained using the conventional corn wet‐milling procedure. Significant effects from enzymatic milling were observed on all the three starch pasting properties (peak, shear thinning, and setback). The setback viscosities of starch from all enzyme treatments were significantly lower compared with those of the control sample, indicating that starch polymers from enzymatic corn wet‐milling do not reassociate to the same extent as with the control. Comparison between bromelain treatment and the control sample showed that starch samples obtained from bromelain treatment are very similar to control starch in water‐binding capacity, molecular breakdown, and time to swell when cooked in water. Significant effects from enzymatic milling were observed on the surface characteristics of starch granules. The glycosidase treatments, especially the β‐glucanase samples, showed holes in the starch granules. No visual differences were observed in starch granules between bromelain and control samples.
Enhancing β‐Carotene Content in Asian Noodles by Adding Pumpkin Powder
Authors: Lee Chi‐Ho , Cho Jin‐Kook , Lee Seung Ju , Koh Wonbang , Park Woojoon , Kim Chang‐Han
Published: June 2007

The influence of ripened pumpkin powder on the characteristics and qualities of noodles was investigated. Varying amounts of pumpkin powder levels (0, 2.5, 5.0, and 10%) were added in making instant fried noodles. These four samples were then evaluated for β‐carotene content, physical dough properties, color, cooking properties, and sensory characteristics. Adding more pumpkin powder increased the level of β‐carotene in the noodles. Amylograph maximum viscosity and temperature and farinograph water absorption and stability decreased as the amount of pumpkin powder increased. Noodles made with more pumpkin powder had a more yellow color than those with less pumpkin powder. Cooked weight and volume were increased by 37 and 59%, respectively, when 5.0% pumpkin powder was added to the flour sample. Gumminess was lowest in the noodles with 5.0% pumpkin powder, while chewiness and hardness were lowest in the noodles with 10.0% pumpkin. Noodles with 5.0% pumpkin powder were the most favorable in appearance, taste, texture, and acceptability among the four samples.
Rapid Assessment and Prediction of Wheat and Gluten Baking Quality With the 2‐g Direct Drive Mixograph Using Multivariate Statistical Analysis
Authors: Dobraszczyk B. J. , Schofield J. D.
Published: June 2007

A computerized 2‐g direct drive mixograph was used to study the mixing characteristics of flours milled from a range of breadmaking cultivars obtained from five separate locations around the UK, providing 54 flour samples. Fifteen parameters were extracted from each mixograph trace using the Mixsmart software program and correlated with baking volume using partial least squares multiple regression statistical analysis to give a prediction of baking volume. Location had a considerable influence on the prediction of baking volume. Excellent predictions of baking volume were obtained from flours from individual locations (R2 = 0.805–0.995), but predictions based on all cultivars without discriminating locations were poor. When mixograph and baking volume data for each cultivar were averaged over all five locations, a very high correlation was obtained (R2 = 0.999). Preparation of flour samples using rapid, small‐scale milling procedures (Brabender Quadrumat Jr. mill and Perten 3100 hammer mill) did not have any adverse effect on prediction of baking volume. Mixograph parameters obtained from six commercial glutens of varying quality gave good correlations with test baking volumes, based on 6% gluten addition to a control flour.
Endoxylanase Inhibition Activity in Different European Wheat Cultivars and Milling Fractions
Authors: Gebruers K. , Courtin C. M. , Goesaert H. , Van Campenhout S. , Delcour J. A.
Published: June 2007

Twenty‐three wheat samples from 19 different European wheat cultivars (Triticum aestivum L.) were tested for their quantitative and qualitative variation in inhibition activity against family 11 endoxylanases of Aspergillus niger, Bacillus subtilis, and Trichoderma viride and a family 10 endoxylanase of A. aculeatus. Under the experimental conditions, the A. aculeatus enzyme was not inhibited by the wheat extracts, the A. niger and B. subtilis endoxylanases were affected to a similar extent, while the T. viride enzyme was much more inhibited. The inhibition activities in the different wheat samples against the A. niger, B. subtilis, and T. viride endoxylanases varied between 36.0 and 11.7, 34.0 and 12.9, and 86.2 and 46.6 IU/100 mg of dry whole meal, respectively. One IU (inhibition unit) corresponds to the amount of inhibitor resulting in 50% inhibition of endoxylanase activity under the conditions of the assay. The inhibitor activities were linearly related, indicating that the levels of different endoxylanase inhibitors with different endoxylanase specificities in the dormant wheat grains are also linearly related or that one (or more) of these inhibitors are predominantly present or has much higher specific activity, consequently causing almost all of the inhibition activity measured. Wheat flour accounted for ≈57% of the total inhibition activity in wheat grains, while the shorts and bran fractions each contained ≈21% of the total activity. On dry weight basis, the inhibition activities were about three times higher in shorts and about two times higher in bran than in flour. The results obtained may be useful in explaining differences in functionality of different endoxylanases in biotechnological processes in which wheats of different cultivars, or fractions thereof, are used as well as in screening endoxylanases for applications in wheat‐based processes.
Biochemical Studies of Proteins in Nondeveloped, Partially Developed, and Developed Doughs
Authors: Lee L. , Ng P. K. W. , Steffe J. F.
Published: June 2007

Nondeveloped, partially developed with shear and extensional deformations, and developed doughs represent different stages of dough development. To understand the relationship between gluten proteins and dough rheology, this study used disulfide‐sulfhydryl analyses, gel filtration chromatography, SDS‐PAGE, acid polyacrylamide gel electrophoresis (A‐PAGE), and densitometry to examine proteins in the four types of doughs mentioned. Free sulfhydryl content was the lowest in native flour and nondeveloped dough, and the highest in partially developed doughs, while a reverse trend was observed for disulfide content. For each flour sample, the protein elution profile from gel filtration chromatography shifted with the level of dough development. With respect to the smallest sized molecules, native flour had the most, followed by nondeveloped, partially developed, and then developed doughs. SDS‐PAGE and A‐PAGE exhibited similar protein patterns among the same chromatographed protein fractions of each native flour and its different doughs. Densitometric data showed that the amount of high molecular weight (HMW) glutenins increased and the amounts of low molecular weight (LMW) glutenins, gliadins, and albumins/globulins decreased with progressive stages of dough development. In conjunction with previously published results, indications are that the increase in the size and the amount of HMW glutenins is related to the strength of dough and the amount of protein matrix present in the dough.
Lupin Flours as Additives: Dough Mixing, Breadmaking, Emulsifying, and Foaming
Authors: Pollard N. J. , Stoddard F. L. , Popineau Y. , Wrigley C. W. , MacRitchie F.
Published: June 2007

The nutritional quality of various food products could be improved by supplementation with grain legumes to increase protein content and to improve the balance of essential amino acids. The lupin grain is a good candidate for this role, given its yield potential in a range of climatic environments and soil types. To establish the practicality of extending the use of lupins as food additives, the functional properties of various species and cultivars of lupin were studied for their effect as additives to baked products and their ability to provide foaming and emulsifying properties. Of the two lupin species that are commonly cultivated commercially, Lupinus albus showed the greater potential as a bread additive; loaf height and structure were maintained when lupin flour was substituted for wheat flour at levels up to 5%. This level of substitution offered the advantage of reducing mixing time. The detrimental effects at higher substitution levels appeared to be associated with the nonprotein components of the lupin flour. L. albus showed better functionality than L. angustifolius in emulsifying attributes, although L. angustifolius showed greater potential as a foaming agent. Defatting the lupin flour may be necessary to show these properties to best advantage. Certain cultivars (within each species) showed preferable performance, indicating the potential for plant breeding to provide germplasm better suited to uses as food additives.
Esterases in Barley and Malt
Authors: Ward Robert E. , Bamforth Charles W.
Published: June 2007

Several esterases from barley and malt have been separated on polyacrylamide gels. The slowest moving bands appear to represent a single enzyme displaying a spread of migration owing to differences in surface charge. During malting, this enzyme, which is located in the starchy endosperm, shifts to a more migratory form. Two other main esterase groups are identified through gel electrophoresis, notably a highly anionic, highly labile enzyme, MW 62,000, located in the aleurone. The slowest and fastest moving bands have been partially purified using salt fractionation and ion‐exchange chromatography. The former, MW 47,000, has strong capability for hydrolyzing acetylxylan and it is speculated that its role in the starchy endosperm is as part of the enzyme system that hydrolyzes the cell walls.
Stabilization of Lipids in a Biodegradable Zein‐Oleate Film by Incorporation of Antioxidants
Authors: Kleen Dawn , Padua Graciela , Engeseth Nicki
Published: June 2007

Zein has been studied extensively for use as an edible, biodegradable food film. To function as such, as much as 40–50% oleic acid is added as a plasticizing agent. Over the course of time, these films became discolored and developed off‐odors. It was speculated that this was due to oxidation of incorporated oleic acid. This study sought to reduce oxidative changes in film lipids by incorporation of antioxidants. Incorporation of 4,000 ppm of BHA into the films eliminated peroxide formation during accelerated UV storage conditions. Gas chromatography and headspace (GC‐HS) chromatography revealed that total volatile components of UV‐treated control films were 9× higher than fresh control volatiles. Comparison of the profiles led to the demonstration of major differences in peaks of a specific region, suggesting the presence of oxidation products in that region. Differences in UV‐treated BHA films and UV‐treated control films appeared in the same specific region of the chromatogram. Solid‐phase microextraction analysis of volatile components of the various film components and films also demonstrated a major increase in peaks associated with oxidation due to UV treatment and reduction of oxidative products in UV‐treated BHA films. Antioxidant treatment was thus found to protect the films against oxidative deterioration.
Effects of Maturity on Corn Starch Properties
Authors: Jennings S. D. , Myers D. J. , Johnson L. A. , Pollak L. M.
Published: June 2007

The effect of maturity on the quality of starch for two corn hybrids harvested at three different stages of development was measured by differential scanning calorimetry, rapid viscosity analysis, scanning electron microscopy, and image analysis. The onset of gelatinization and peak temperatures were 2–5°C higher for starch from immature grain than starch from mature grain. The gelatinization temperature range was 5°C larger as the grain matured. Peak and trough viscosities decreased with maturity, while pasting temperature increased. Between the two hybrids, the late maturing hybrid yielded a larger peak viscosity and trough. The early maturing hybrid exhibited a higher pasting temperature. Image analysis data showed that the starch granules from mature grain showed an increase in size compared with the starch granules from grain that were harvested at the late milk line stage for one, but not both hybrids.
Preparation and Characterization of Low Oil Uptake Rice Cake Donuts
Authors: Shih F. , Daigle K.
Published: June 2007

Cake donuts were prepared using wheat flour (WF), long grain rice flour (LGRF), and waxy rice flour (WRF). They were also prepared with the flours partially replaced by pregelatinized rice flour (PGRF) or propylene glycol alginate (PGA). The dough consistency was maintained at a comparable predetermined level by adjusting the water content. Without PGRF or PGA in the formulation, the WRF donut had the lowest oil uptake (11.8%) and the WF donut the highest (23.6%). With modified flour formulations, the oil uptake decreased for LGRF donuts and WF donuts. Oil uptake of the LGRF donut decreased with increased PGRF. Up to 30% PGRF could be used, with characteristics comparable to the traditional WF donuts but as much as 54% lower in oil uptake on a dry basis.
Single Kernel Sampling Method for Maize Starch Analysis While Maintaining Kernel Vitality
Authors: Yao Yuan , Guiltinan Mark J. , Shannon Jack C. , Thompson Donald B.
Published: June 2007

A nondestructive protocol for maize kernel starch sampling was developed, enabling starch preparation from a single kernel for analysis of starch structure while also maintaining the vitality of the seed. To develop the single kernel sampling (SKS) method, maize genotypes varying in starch structure including ae, wx, su2, du and normal in the W64A inbred line were used. Crude endosperm material was removed from the kernel crown, soaked, ground, washed, and dissolved in 90% DMSO. The sample represented ≈10% of the total kernel. Endosperm starch was also isolated from the same genotypes by a standard multikernel isolation (MKI) method. Starches isolated by the two methods were debranched and analyzed by high‐performance size‐exclusion chromatography (HPSEC) and fluorophore‐assisted carbohydrate electrophoresis (FACE). HPSEC and FACE showed similar results for the two sampling methods for degree of polymerization (DP) ≤ 50. We concluded that the material obtained by SKS could be used for identifying amylopectin structural differences among genotypes. Kernel sampling for SKS had no effect on germination, thus plants could be grown for subsequent genetic crosses and analysis. The SKS method may be useful for the screening of populations of maize kernels from genotypes producing novel amylopectin structure, and allow the growth of novel genotypes for further analysis.
Determination of Molecular Weights of C Hordeins by Matrix‐Assisted Laser Desorption/Ionization Mass Spectrometry (MALDI‐MS)
Authors: Savage A. W. J. , Saletti R. , Foti S. , Shewry P. R. , Tatham A. S.
Published: June 2007

The molecular weights of nine C hordein proteins, including all of the major components identified by SDS‐PAGE have been determined by MALDI‐MS. Most were in the range 43,561 to 46,857, with a single component of Mr 57,606. These are higher than the masses previously reported based on the sequences of cloned genes. This indicates that reliance on masses determined solely by gene sequencing is not valid, presumably because these may not encode the major expressed proteins.
Effects of Sucrose Ester, Dough Conditioner, and Storage Temperature on Long‐Term Textural Stability of Shelf‐Stable Bread
Authors: Barrett Ann , Cardello Armand , Maguire Paul , Richardson Michelle , Kaletunc Gonul , Lesher Larry
Published: June 2007

The effectiveness of a dough conditioner containing an amylase enzyme, surfactants, and a reducing compound on preserving the textural stability of shelf‐stable bread was compared with that of sucrose ester. Military‐specification Meal, Ready‐to‐Eat bread was formulated to contain sucrose ester alone, the dough conditioner alone, both in combination, or neither additive. Samples were also stored at 4, 21, and 38°C for 12 weeks. Instrumental texture, as determined by uniaxial compression and mathematically fitted stress‐strain relationships, and sensory texture, as determined by a trained texture panel, were assessed periodically between 0 and 12 weeks. Both sucrose ester and the dough conditioner yielded stored samples that were softer than the control; sucrose ester was slightly more effective than the dough conditioner in preserving instrumental texture, and the additive combination yielded the lowest firmness parameters. Thermal analysis results were consistent with mechanical and sensory evaluations in showing slightly increased recrystallization of starch in the noadditive formulation. Panelists perceived the samples containing sucrose ester to be much closer to an “ideal” texture compared with those containing the dough conditioner. A partial substitution of the lower cost dough conditioner for higher cost sucrose ester may be possible.
Pasting Property Differences of Commercial and Isolated Rice Starch with Added Lipids and β‐Cyclodextrin
Authors: Liang Xiaoming , King Joan M. , Shih Fred F.
Published: June 2007

Lipids are known to generally affect starch properties but the effects of lipid structure and β‐cyclodextrin (β‐CD) on different starches has not been investigated. This study compared the effects of lipids and β‐CD on pasting properties of isolated rice starch with commercial rice starch. Flour was defatted by Soxhlet extraction and deproteinated by alkaline protease digestion. Fatty acids, monopalmitin (MP), tripalmitin, lysophosphatidylcholine (LC), lysophophatidylethanolamine (LE), each added at 0.2 and 0.6% (starch db), and β‐CD added at 2 and 6% (starch db) were tested. Pasting temperature (PT) increased with added phospholipid, particularly in the commercial starch, while all lipids except tripalmitin increased final viscosity (FV) and total setback (TSB). Breakdown (BKD) was mainly affected and increased by up to 39 RVU for fatty acids while decreasing by up to 80 RVU for other lipids in both starches. TSB doubled by the addition of 0.6% MP but decreased to onethird by 0.6% LE or LC. Addition of β‐CD decreased minimum viscosity (MV) and FV while increasing BKD in isolate but decreased TSB in commercial starch.
Effects of Different Salts on Mixing and Extension Parameters on a Diverse Group of Wheat Cultivars Using 2‐g Mixograph and Extensigraph Methods
Authors: Butow B. J. , Gras P. W. , Haraszi R. , Bekes F.
Published: June 2007

Cations of differing chaotropic capacities (LiCl, NaCl, and KCl) were used in small‐scale mixing and extensigraph studies to assess functional changes in dough behavior of wheat cultivars varying in total protein content and HMW glutenin composition. Salt addition, regardless of cationic type, caused an increase in dough strength and stability. The smaller (hydrated) and least chaotrophic cations (Li+<Na+<K+) effected the greatest increase in mixing time (MT) and resistance to extension (Rmax) and produced the most stable resistance breakdown (RBD). The effects of different cations on mixing and extensions indicated strong intercultivar variation; differential responses to salt addition were further shown when the cultivars were grouped according to protein content and Glu‐1D or Glu‐1B genome composition. Increases in dough strength parameters due to the addition of salt were consistently more significant for cultivars showing an overexpression of Bx7 (>12% protein). In the absence of genotypic variation, a significant interactive effect of cultivar type, protein amount, and salt addition was found for all functional dough parameters except extensibility. During mixing, there was a decrease in the amount of apparent unextractable polymeric protein (%UPP) in the dough. This phenomenon was ameliorated by the presence of salt in doughs formed from weaker flours and was most pronounced early on in the mixing process (t = 100–200 sec). Results show the importance of refining 2‐g mixograph studies to include salt in the “flour and water” dough formula.