Carbohydrate Digestibility and Resistant Starch of Steamed Bread

Sixteen Australian hard and soft wheats and two U.S. hard wheats were milled into flours (break and reduction) for preparation of steamed breads. Chemical composition and rheological properties of the flour were determined. Steamed breads were analyzed for carbohydrate digestibility and resistant starch. There was no relationship between flour type, protein content and specific volume of steamed breads. Carbohydrate digestibility of steamed breads from soft wheat flour was higher than that of breads from hard wheat flour. Reduction flours produced steamed breads with higher carbohydrate digestibility than break flours. Resistant starch was higher in steamed breads from soft wheat flours than in those from hard wheat flours. Reduction flour produced higher resistant starch levels than break flours. Commercial white bread had resistant starch levels similar to those of steamed breads from soft wheat flour and hard wheat reduction flour.     

Effect of solvents and supercritical-CO2 extraction of lipids on physico-chemical,functional, pasting and rheological properties of hard,medium hard and soft wheat varieties

This study was conducted to compare the effect of lipids removal using supercrital-CO₂ extraction and organic solvents (hexane and isopropanol) from hard and soft wheat flour varieties. Flours were evaluated for physicochemical properties (protein, ash, hunter colour), sodium dodecyl sulphate-polyacrylamide gel electrophoresis, foaming properties, water and oil absorption capacity, pasting, farinographic and dynamic rheology. Protein content of flours increased after defatting and supercritical fluid extracted (SCE) wheat flours showed the highest increase. SCE flours showed higher peak viscosity than native and hexane extracted (HE) and isopropyl alcohol extracted (IPAE) flours. Functional properties improved upon defatting and the highest increase in functional properties was observed for SCE flours. Empirical and fundamental rheological measurements were affected by defatting and SCE flours showed the highest change in visco-elasticity. SC-CO2 was proved better alternative technique over conventional organic solvent methods to remove lipids from flours that brought desirable changes in some functional properties.     

Wheat washing with ozonated water: effects on selected flour properties

Soft and hard wheat samples were washed using ozonated water (1.5 mg L⁻¹). Milling (rate of extraction), rheological (farinograph and extensograph characteristics), chemical (protein, falling number, sedimentation volume), colour (Hunter Laboratory values) and microbiological (total bacterial and yeast/moulds) properties of flours milled from the washed wheat were evaluated. Results indicated that washing with ozonated water did not significantly alter the chemical, physical or rheological properties of the flours from hard wheat samples. However, small but statistically significant ( P =0.05) differences were observed on extensograph values of flours milled from the soft wheat washed with ozonated water. A significant reduction ( P =0.05) in the total bacterial and yeast/mould counts was obtained after washing with ozonated water for both soft and hard wheat samples. Results suggest that ozonated water can be successfully used to wash hard wheat without affecting flour quality.     

A Comparative Study of the Inter-Relationships Between Mixograph Parameters and Bread- Making Qualities of Wheat Flours and Glutens

The mixing characteristics and bread-making qualities of flours, reconstituted flours and glutens from a diverse range of wheat cultivars obtained from Canada, France and the UK, were investigated. Simple correlations were calcu-lated among Mixograph parameters, loaf volume, Glu - 1 quality scores, protein content, SDS-sedimentation volume and baking absorption. The results indicate that the mixing properties of flours from cultivars in the medium–strong range are significantly influenced by their protein contents. On the other hand, the mixing properties of ‘extra strong’ or weak flours are relatively less affected by their protein contents, and it appears that the protein quality primarily controls their behaviour during mixing. Gluten samples, other than weak glutens from cvs Riband and Corin, required a longer time to mix to peak dough resistance (PDR) than their corresponding flour or reconstituted flour samples. However, the differences in mixing time were more pronounced between ‘extra strong’ glutens and their corresponding flours or reconstituted flours. The Mixograph parameter PDR showed highly significant ( P< 0·001) correlations with loaf volume for flour, reconstituted flour and gluten samples. In each case, variation in PDR explained more than 65% of the variation in loaf volume, reaching about 83% for glutens. PDR was also significantly correlated with Glu - 1 quality scores. However, the mixing times for flours, reconstituted flours and glutens demonstrated no simple correlations with loaf volume. On the basis of the results, it appears that the 2 g Mixograph PDR value for flour or gluten may be used to assess flour or gluten bread-making quality. It may be used as a viable alternative to the baking test for the evaluation of the baking potential of flour or gluten, as well as an alternative to currently used ‘gel protein’-based pro-cedures for differentiating between ‘strong’ and ‘extra strong’ wheats.     

Phytic acid content in milled cereal products and breads

Phytic acid was determined in cereal (brans, flours and milled wheat-products) and breads. The method was based on complexometric titration of residual iron (III) after phytic acid precipitation. The cereal flours showed values ranged between 3–4 mg/g for soft wheats, 9 mg/g for hard wheat and 22 mg/g for whole wheat. Corn, millet and sorghum flours reported a mean of 10 mg/g and oat, rice, rye and barley between 4 and 7 mg/g. Wheat brans had wide ranges (25–58 mg/g). The phytic acid for oat brans was half that of wheat bran (20 mg/g) and higher value (58 mg/g) than that for rice bran. The milling products (semolinas) from hard wheat exhibited 10 mg/g and soft wheat a mean of 23 mg/g. The breads made with single or mixture cereal flours exhibited ranges between 1.5 and 7.5 mg/g. The loss of phytic acid relative to unprocessed flours was between 20% for oat bread and 50% for white bread.     

Functional Characteristics of Sprout-Damaged Soft White Wheat Flours

Soft white wheat was sprouted in the laboratory for 1, 2 and 4 days, respectively, before milling the wheat into flours. The flours were used to bake cakes and cookies and to determine thickening powers. The flours milled from wheat which had been sprouted for 2 or 4 days were slightly higher in ash and protein and darker in color than the flour from the sound wheat. Sprouting of the grain for longer than 1 day resulted in flours of poor cake baking quality. The cakes were low in volume, had a dip in the center, a coarse grain and a firm texture. Cookie spreads increased and cookie top grain score improved with longer times of sprouting of the grain, but the crust color of the cookies darkened. The flavor was not affected by sprouting. The thickening power of the sprout-damaged soft wheat flours decreased with time of sprouting of the soft wheat before milling into a flour. Generally, laboratory sprouting of soft white wheat had an adverse effect on the functionality of flours in soft wheat applications. Effects of field sprouting on soft wheat flour performance are expected to be similar to those observed with laboratory sprouted soft wheat.     

The Effect of Pin and Attrition Milling on Starch Damage in Hard Wheat Flours

Starch damage of 10.9 and 15.7%, respectively, in break and reduction flours of commercial hard wheats was increased to 16.0 and 28.6%, respectively, by pin milling. Attrition milling and cryofreezing prior to pin milling resulted in less pronounced starch damage, apparently due to reduced heat evolution and mechanical stresses as evidenced by the intensities of the X-ray diffraction patterns. Pin-milled flours exhibited chipping and splitting of starch granules as compared to surface abrasions and deep pitting on the granules from attrition-milled flours. It appeared that the latter flours would be more suitable for air classification of hard wheat flours into protein concentrates and starch fractions.     

Quality Characteristics of Wholemeal Flour and Bread from Durum Wheat (Triticum turgidum L subsp. durum Desf.) after Field Treatment with Plant Water Extracts

The use of selected plant water extracts to control pests and weeds is gaining growing attention in organic and sustainable agriculture, but the effects that such extracts may exert on the quality aspects of durum wheat are still unexplored. In 2014, 5 plant water extracts (Artemisia arborescens, Euphorbia characias, Rhus coriaria, Thymus vulgaris, Lantana camara) were prepared and distributed on durum wheat cv Valbelice to evaluate their potential herbicidal effects. After crop harvesting, the major physicochemical and technological parameters of wholemeal flours obtained from each treatment were measured and compared with those from chemical weeding and untreated controls. A baking test was also performed to evaluate the breadmaking quality. In wholemeal flours obtained after the treatment with plant extracts protein and dry gluten content were higher than in control and chemical weeding. Wholemeal flours obtained after chemical weeding reached the highest Mixograph parameters, and that from durum wheat treated with R. coriaria extract demonstrated a very high α‐amylase activity. We concluded that the treatments with plant water extracts may influence many quality traits of durum wheat. This occurrence must be taken into account in overall decisions concerning the use of plant extracts in pest and weed management practice.     

Ver?nderungen an Kleber verschiedener Weizensorten durch Oxidation

Zusammenfassung Mehle aus den Weizensorten Monopol, Schirokko, Clement und Maris Huntsman wurden sofort nach der Vermahlung mit Stickstoff (M_N) bzw. Luft (M_O) überblasen. Die Isolierung der Kleber erfolgte ebenfalls unter Stickstoff (K_N) bzw. Luft (K_O). Der unter anaeroben Bedingungen erhaltene Kleber (K_N) wurde im gefriergetrockneten Zustand durch Überblasen mit Luft oxidiert (K_N/O). Die verschiedenen Kleber wurden succinyliert. Bei der Gelpermeationschromatographie der succinylierten Kleber an Sepharose 6B-Cl zeigte sich, daß die Oxidation mit Luft bei den starken Sorten Monopol und Schirokko eine Zunahme der sehr hochmolekularen Fraktion 1(> 800 kD) bewirkt. Die Änderung der Aminosäurezusammensetzung dieser Fraktion deutet darauf, daß prolamin-ähnliche Proteine von der Molekulargewichtserhöhung betroffen sind. Bei den schwachen Sorten Clement und Maris Huntsman ändert sich die Molekulargewichtsverteilung des succinylierten Klebers durch Oxidation dagegen kaum. Der durch Oxidation bedingten Molekulargewichtsverteilung entspricht die in Zugversuchen mit Kleber beobachtete Zunahme des Dehnwiderstandes und Abnahme der Dehnbarkeit, die ebenfalls nur bei den starken Sorten auftritt. Die am oxidierten Mehl isolierten Kleber (K_O) zeigten dabei das gleiche Verhalten wie die nachträglich oxidierten Kleber (K_N/O). Backversuche mit oxidierten und nicht-oxidierten Mehlen sowie mit rekombinierten Mehlen, die verschiedene Kleber enthielten, hatten die aufgrund der Zugversuche mit den jeweiligen Klebern zu erwartenden Ergebnisse. Die Oxidation hatte auch hier durchweg nur bei den starken Sorten einen Einfluß. Die Ergebnisse zeigen, daß die bekannten Veränderungen bei der Alterung von Mehlen und das unterschiedliche Verhalten verschiedener Mehle gegenüber Oxidationsmitteln auf Reaktionen von Proteinkomponenten des Klebers zurückzuführen sind, die sortenspezifisch sind und die auch nicht oder zumindest nur teilweise von niedermolekularen Bestandteiles des Mehls abhängen.

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Changes in the gluten of different wheat varieties due to oxidation

Summary Flours from the wheat varieties Monopol, Schirokko, Clement and Maris Huntsman were treated with nitrogen (M_N) or air (M_O) immediately after milling. The glutens were isolated from these flours under nitrogen (K_N) or air (K_O). The glutens obtained under nitrogen (K_N) were oxidized after lyophilization by treatment with air in a dry state (K_N/O). All the different gluten samples obtained were succinylated. Gel permeation chromatography of the succinylated glutens on Sepharose 6B-Cl shows that oxidation by treatment with air causes an increase in the high-molecular-weight protein fractions I (> 800 kD) of the strong wheat varieties Monopol and Schirokko. The changes in the amino acid composition of these fractions indicate that prolamin-like proteins are involved in this increase of the high-molecular-weight proteins. The succinylated glutens of the wheat varieties Clement and Maris Huntsman show no significant changes of their protein patterns on oxidation. The mentioned changes in the protein patterns of the succinylated glutens are in accordance with the extensigrams obtained with the corresponding glutens: Only the hard varieties exhibit an increase of the resistance and a decrease of the extensibility. Glutens isolated from oxidized flours (K_O) and glutens oxidized subsequently (K_N/O) yield identical extensigrams. Baking tests with oxidized, non-oxidized and recombined flours, which contain differently treated glutens also show that the influence of oxidation is restricted to the hard varieties. The results show that the known changes during aging of flours and the different behaviour of flours towards oxidizing agents are related to reactions of specific protein components of the gluten, which are typical for hard varieties. These reactions are obviously not dependent an low molecular weight components of the flour.

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Die Arbeit wurde durch die AIF über den Forschungskreis der Ernährungsindustrie e. V. gefördert     

Antioxidant properties of commercial soft and hard winter wheats (Triticum aestivum L.) and their milling fractions

The total phenolic content (TPC), total antioxidant activity (TAA), 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) scavenging capacity, inhibition of coupled oxidation in a β‐carotene–linoleate model system, iron(II) chelation activity and inhibition of copper‐induced oxidation of human low‐density lipoprotein (hLDL) cholesterol of 80% ethanolic extracts of soft and hard winter wheat samples and their milling fractions, namely flour, germ, bran and shorts, were investigated. Soft wheat extracts examined demonstrated higher TPC and TAA compared to those of hard wheat extracts. The germ fraction possessed the highest TPC, followed by bran, shorts, whole grain and flour for both wheat types examined. The TAA of both wheat types showed similar results except that shorts performed better than bran in this assay. Free radical scavenging properties of whole grain and milling fractions of both soft and hard wheat samples were examined against DPPH radical. The germ and flour fractions demonstrated the highest and lowest DPPH radical scavenging activity, respectively, among wheat fractions. Wheat extracts were also efficient in preventing bleaching of β‐carotene, which is also known to be free radical mediated. In the iron(II) chelation assay the flour extracts demonstrated excellent activity, while the germ extracts showed a weak activity. The trends were similar in both soft and hard wheat for the iron(II) chelation assay. Wheat extracts also inhibited copper‐induced oxidation of hLDL. In LDL oxidation assay, wheat extracts performed better than the reference antioxidant, ferulic acid. Thus wheat phenolics may serve as effective antioxidative components as measured by in vitro techniques. Copyright © 2005 Society of Chemical Industry     

Fining of red wines with gluten or yeast extract protein

Due to a growing interest in alternatives to substitute gelatin as clarifying agent, this work investigates the use of yeast extracts and glutens. Physico‐chemical characteristics of proteins were analysed. Fining experiments were carried out on young red wines. Turbidity reduction, lees volume and effects on polyphenolic content and colour characteristics were determined. The results indicated that glutens and yeast extracts turbidity reduction is comparable to gelatin. Lees production was considerably reduced by non‐animal proteins: yeast extracts produced 44%, wheat glutens 60% and maize gluten 92% less than gelatin. Lees volume is highly correlated (R = ?0.720) with the absolute superficial charge density value (SCD) and with the pI (0.936) when clarifier was used in combination with bentonite. Treatments with glutens reduced less the polyphenolic content (between 0.6 and 8.7 units) than gelatin did. There were slight differences on the modification of colour intensity.     

Sodium Dodecyl Sulfate and Sulfite Improve Some Functional Properties of Soy Protein Concentrates

The effects of sodium dodecyl sulfate (SDS) and sodium sulfite were studied on dispersibility, water and oil absorption of soy protein concentrates from toasted soy flours. Dispersibility was improved from 6.2% to 65% by 0.5% SDS, 0.25% sodium sulfite at pH6, and 60°C. Water absorption was improved from 5.5 to 7 mL water/g concentrate by 0.5% SDS at pH 6 at 20°C. Oil absorption was improved from 4.1 to 5.9 mL oil/g concentrate by 0.5% SDS, 0.25% sodium sulfite at pH 6 and 20°C.     

A critical examination of the sodium dodecyl sulfate (SDS) sedimentation test for wheat meals

Sedimentation tests have long been used to characterise wheat flours and meals with the aim of predicting processing and end‐product qualities. However, the use of the sodium dodecyl sulfate (SDS) sedimentation test for durum wheat (AACC International Approved Method 56–70) has not been characterised for hexaploid wheat varieties with a diverse range of protein quality and quantity. This paper reports the variation associated with important method parameters: sample weight, SDS concentration, technician, grinder and screen aperture (particle size). Sedimentation volumes were recorded every 5 min for 30 min and expressed as specific volume, i.e. sediment volume in mL g^?1 meal. Ten diverse hexaploid wheat samples of markedly different protein quality and quantity were examined. The SDS sedimentation assay was shown to be highly robust and reproducible, with ANOVA (analysis of variance) model R² values greater than 0.98 (individual time points). The procedure delineated soft and hard hexaploid wheat samples based on a combination of protein quantity and quality. Sample weight (if corrected to unit weight basis), recording time of at least 10 min, SDS stock concentration of at least 10 g L^?1 (final), grinder type and screen aperture were minor sources of variation in SDS sedimentation volume relative to the effects due to differences among wheat samples. Interactions among ANOVA model terms were of relatively minor importance. Published in 2007 by This article is a US Government work and is in the public domain in the USA.     

Antioxidant Activity of Methanolic Extracts of Various Oilseed Protein Ingredients

Antioxidant activity (AA) of methanolic extracts of defatted flours, concentrates, and isolates produced from glandless cottonseed, peanut, and soybean was determined against linoleate oxidation catalyzed by metmyoglobin (MetMb), Fe⁺⁺-EDTA (1:l molar ratio) and fresh beef homogenates and against autoxidation of safflower oil. Total phenolic content of the extracts was also determined. Methanolic extracts of glandless cottonseed protein ingredients showed uniquely and consistently higher AA than those of peanut and soy protein ingredients. Total phenolic content was also markedly higher for the cottonseed protein extracts. Methanol-soluble AA was significantly correlated with total phenolic content for the extracts of defatted flours and concentrates but not for the extracts of isolates. The comparative methanol-soluble AA values of these oilseed protein ingredients were indicative of their antioxidation potential in cooked meat products.     

Phytochemical compositions, and antioxidant properties, and antiproliferative activities of wheat flour

Ten soft wheat varieties grown in Maryland were compared for their phytochemical compositions, antioxidant properties and antiproliferative activities. Free radical scavenging capacities were examined against DPPH(·), oxygen, hydroxyl and ABTS(·+) radicals. Significant radical scavenging capacities were detected in all wheat flour extracts. Total phenolic content ranged from 1.66 to 2.01 mg of GAE/g wheat flour. The wheat flours contained 172.91-297.55 μg/g insoluble bound ferulic acid, contributing 89.74-94.29% of total ferulic acid on a per weight basis. The concentrations of lutein and zeaxanthin were 0.27-0.46 and 0.08-0.13 μg/g, respectively. In addition, the wheat flours had 0.30-0.59 and 0.07-0.29 μg/g α- and δ-tocopherols, respectively. Four wheat flour extracts were further examined for their antiproliferative activities. The Jamestown wheat flour showed significant antiproliferative activity against both HT-29 and Caco-2 colon cancer cells at the initial treatment concentration of 50 mg flour equivalents/ml, while USG3555 flour showed inhibitive effect only in HT-29 cancer cells, suggesting the different and possible selective antiproliferative property of the wheat flours. These results may be used to direct the breeding effects to produce soft winter wheat varieties with improved health properties.     

Superficial Charge Density of Fining Agents: Influence of pH,Dose, and Temperature

The effects of pH, dose, and temperature on the superficial charge density of fining agents were determined in a model solution. This study included three gelatines and one egg's albumin, all of which are common fining agents, as well as three wheat glutens (one native and two hydrolyzed). Wheat glutens have been allowed to be used as fining agents only since 2005, and there are no preliminary studies examining them. The results of this study showed that the superficial charge density was mainly pH-dependent (p < 0.01), and that pH showed a greater effect at a higher degree of protein hydrolysis. For Gel 3, albumin and the wheat glutens, a larger protein concentration, decreased the superficial charge density. Gel 2, which was soluble in hot water, had the highest superficial charge density (>0.831 meq g^?1), which indicated that it would be more reactive than the other fining agents. Between pH 3.4 and 4.0, Gluten 1 and Gel 3 were more highly charged (superficial charge density >0.3 meq g^?1) than Gel 1 or the hydrolysed glutens. These data are useful for wine producers.     

Chemical composition and functional properties of raw and roasted Nigerian benniseed (Sesamum indicum) and bambara groundnut (Vigna subterranean)

Benniseed and bambara groundnut seeds were roasted at 80 and 120 °C for 10–60 min. For both flours, the effects of roasting temperature and time on selected functional properties and chemical composition were determined, as were the effects of pH on the emulsification capacity and nitrogen solubility. The chemical constituents of the raw flours were present at higher concentrations than those of the roasted flours except for fat and ash. Protein concentrates of both flours contained 80.5–81.5% crude protein as the major constituent. Nitrogen solubility was lowest at pH 4.0 for raw and roasted benniseed flour and pH 5.0 for raw and roasted bambara groundnut flour. Roasting generally lowered the nitrogen solubility and increased the water and oil absorption capacities while decreasing the foaming capacity and emulsification capacity of both flours.     

Quality parameters and baking performance of commercial gluten flours

Commercial gluten which is labeled in different ways, i.e., gluten, gluten flour, glutinated flour, is sold without any specifications. Breadmaking potential of commercial gluten was assessed by adding them in different concentration levels (6 and 50 g/100 g) to wheat flour. This evaluation was done by physicochemical analyses and subjective characterization. Protein content of commercial glutens ranged from 15.2 g/100 g to 75.2 g/100 g. Diastatic activity of glutinated flours was around 30% lower than the values of wheat flour, while this activity in gluten flours was 24 - 79% lower than wheat flour values. Direct correlation was observed between protein content of blends and loaf volumes: breads volume value increased with the percentage of protein in blends (r_s=1). Furthermore as the percentage of protein in flour blends increased (up to 17.5 g/100 g) scores for smell, crumb color, crumb grain, crumb texture and eatability improved. Breads obtained by incorporating 6 g/100 g of gluten flour or 50 g/100 g of glutinated flour to a wheat flour had the best scores. Breads containing the highest protein content (50 g/100 g gluten flour) were refused by taste panelists, however, after being sliced and toasted they were rated acceptable.     

新收获小麦后熟过程中蛋白质和氨基酸含量的变化

分析了储存在4℃和室温条件下新收获的软麦和硬麦在后熟过程中的生理生化变化。新收获小麦在20℃的发芽率超过80%,在收获后3~4个月中呼吸有2次高峰,尤其第1个呼吸峰非常明显,室温条件较4℃提高第1个呼吸峰值。当呼吸速率趋于不变时,软麦硬度增大在第4个月,硬麦在第5个月。水溶蛋白、盐溶蛋白及谷蛋白各有2次合成高峰。硬麦醇溶蛋白在第60天有一个积累高峰,软麦至少有2个积累高峰,分别在第30天和60天。谷蛋白合成最高峰在第90天,与水溶蛋白类似,而醇溶蛋白合成最高峰在第60天,与盐溶蛋白类似。随着醇溶蛋白和游离巯基含量减少,谷蛋白迅速积累。常温条件下谷蛋白的氧化聚合较低温条件下迅速,积累量大。软麦谷蛋白氧化聚合过程较硬麦早。谷蛋白积累之前,绝大部分氨基酸急剧积累,在室温条件较4℃下积累明显。半胱氨酸含量在90~120天时增加到最大,之后迅速减少。     

Hard Winter Wheat and Flour Properties in Relation to Breadmaking Quality of Straight-dough Bread： Flour Particle Size and Bread Crumb Grain

Samples of 12 hard winter wheats and their flours that produced breads varying in crumb grain scores were studied for 38 quality parameters including： wheat physical and chemical characteristics; flour ash and protein contents, starch damage, swelling power, pasting characteristics, and flour particle size distribution; dough properties determined by a mixograph; and breadmaking properties for pup loaves （100g flour）. Only two parameters, the protein content of wheat and the granulation of flour, showed significant correlations with bread crumb grain scores. Protein content of wheat ranging 12.9%- 14.5% determined by an NIR method showed a weak inverse relationship （r =-0.61, p〈0.05） with bread crumb grain score. Flour particle size distribution measured by both Alpine Air Jet Sieve and NIR methods revealed that the weight wt % of particles less than 38 μ m in size and representing 9.6% - 19.3 % of the flour weights was correlated positively （r =0.78, p 〈 0.01） with crumb grain score, whereas wt % of flour particles larger than 125μm had an inverse relationship （r =-0.60, p〈0.05） with crumb grain score.