Techno‐functional properties of wheat flour‐resistant starch mixtures applied to breadmaking

Resistant starch can be used to reduce the availability of carbohydrates in baked products. In this study, the effect of type 4 resistant wheat starch (RS₄) on wheat flour dough and breads was evaluated. Wheat flour was substituted by RS₄ at 10%, 20% and 30% w/w (RS10, RS20 and RS30, respectively). Rheological and thermal behaviours of dough were evaluated. Besides, bread quality, starch digestibility and bread staling were analysed. All substituted dough exhibited viscoelastic behaviour but lower elastic and viscous moduli. Regarding to bread quality, specific volume and crumb texture were negatively affected in samples with RS₄. However, all samples were technologically acceptable. During storage, crumb hardening was observed in breads without and with RS₄ but amylopectin retrogradation was not particularly affected. The in vitro digestibility of bread with RS showed a lower release of reducing sugars and a lower estimated glycaemic index, suggesting a healthier profile for these breads.     

Dough properties and baking characteristics of white bread,as affected by addition of raw,germinated and toasted pea flour

Thermal and non-thermal processing may alter the structure and improve the techno-functional properties of pulses and pulse flours, increasing their range of applications in protein-enhanced foods. The effects of germination and toasting of yellow peas (Pisum sativum) on flour and dough characteristics were investigated. Wheat flour was substituted with raw, germinated and toasted pea flour (30%). The resulting bread-baking properties were assessed. Toasting increased dough water absorption and improved dough stability compared with germinated and raw pea flour (p < 0.05). This resulted in bread loaves with comparable specific volume and loaf density to that of a wheat flour control. Significant correlations between dough rheological properties and loaf characteristics were observed. Addition of pea flours increased the protein content of the breads from 8.4% in the control white bread, to 10.1–10.8% (p < 0.001). Toasting demonstrated the potential to improve the techno-functional properties of pea flour. Results highlight the potential application of pea flour in bread-making to increase the protein content.     

The effect of enzymic modification on the foaming, water absorption and baking quality of defatted soya flour

Defatted soya flour slurries were treated for 0,5,10,15 and 30 min with papain at 50°C and tested for whipability, water absorption and baking quality at replacement levels in wheat flour of 10,20 and 30% (w/w). When whipped, all modified suspensions showed volume increases exceeding 250% with lower stability ratings than the unmodified samples. The 30 min enzyme treated product exhibited excellent water absorption. Use in bread resulted in a depression of loaf volume, development of a granular texture, off-colour and flavour. As was expected, all favourable characteristics decreased upon increasing the percentage of soya product in the dough formulation. Loaf volumes of breads containing 10% modified soya flour (MSF) ranged from 444 to 527 cc; with 20% MSF between 374 and 428 cc, and with 30% MSF between 383 and 409 cc. Loaf volume of all wheat flour bread was 861cc. Hunter colour difference meter readings indicated samples at all replacement levels, regardless of the enzyme modification time, exhibited higher levels of visual lightness than all wheat flour bread. All experimental breads exhibited a higher level of yellow tones and lower level of green tones compared to the all wheat flour bread.     

大麦全粉对面团特性及面包焙烤品质的影响

本文以不同比例的大麦全粉(以下简称大麦粉)替代高筋小麦粉,研究添加10%~60%(m/m)大麦粉对面团特性及面包焙烤品质的影响。结果表明,随着大麦添加量的增加,大麦-小麦混合粉的湿面筋含量降低,从36.43%(对照组)降至11.43%(添加60%大麦粉);面团吸水率增加,形成时间、稳定时间及C2(弱化值)值显著降低,延伸性与最大抗延伸阻力也显著下降;面团微观结构也随之发生变化,添加大麦粉的面团组织变得粗糙,在20%~60%添加范围内,气孔壁出现断裂,且几乎观察不到完整的气孔结构;对于面包品质而言,添加大麦粉的面包比容降低、硬度增加、弹性减小、感官品质下降,同时面包内部气孔所占面积减少、孔洞所占面积增加、面包片亮度变暗。大麦粉添加量为10%~20%时,但其整体感官品质仍可被接受;而添加过多的大麦粉(30%~60%)时,面包的焙烤品质显著降低,面包特有海绵状的纹理结构逐渐消失。     

Effect of Flour Extraction Rate and Baking on Thiamine and Riboflavin Content and Antioxidant Capacity of Traditional Rye Bread

ABSTRACT:  The effect of rye flour extraction rates and baking on thiamine and riboflavin content, and antioxidant capacity of traditional rye bread were studied and compared with white wheat flour. The content of thiamine was higher (10.9%) in rye dough formulated with dark rye flour (F-100%; extraction rate of 100%) than in rye dough formulated with brown rye flour (F-92%; extraction rate of 92%) that was similar to dough made with wheat flour. The riboflavin content in rye dough made from flour F-100% was also higher (16%) than in dough formulated with flour F-92%, and both provided larger riboflavin content than wheat dough. Baking led to reductions in thiamine of 56% for wheat bread and of 20% for both rye breads; however, this process caused only a 10% decrease in riboflavin for wheat bread and a 30% decrease for rye breads. Trolox equivalent antioxidant capacity, peroxyl radical scavenging capacity, DPPH radical scavenging activity, and Folin–Ciocalteu reducing capacity were higher in rye than in wheat dough and bread. Baking process produced slight changes in antioxidant activity, except for Superoxide Dismutase-like activity where a sharp decrease was observed. Our findings showed that rye breads are an important source of B vitamins and rye breads formulated with dark and brown flours showed better antioxidant properties than wheat bread. Therefore, rye breads should be more widely recommended in human nutrition.     

Effect of Rice, Corn and Soy Flour Addition on Characteristics of Bread Produced from Different Wheat Cultivars

Preparation and consumption of bread enriched with flours that contain appreciable amounts of protein, lysine, dietary fiber, and minerals will provide a healthy alternative to consumers and also a lowering of bread making cost in countries where wheat is not a major domestic crop. Addition of rice, corn, and soy flour to bread and durum wheat flours at 10, 20, 30, 40, 50% levels was carried out to examine the effects on the baking (specific volume, color, firmness) and sensory characteristics of bread. Dough rheological properties were also studied using Brabender Farinograph and Extensograph. Results of the present study suggest that incorporation of rice, corn, and soy in bread wheat flour up to a level of 10% (flour basis) and in durum wheat flour up to 20% produces bread without any negative effect in quality attributes such as color, hardness, and flavor and reasonable acceptance offering promising nutritious and healthy alternative to consumers. Increasing levels of substitution (30 and 50%) resulted in decreasing dough strength, extensibility, and loaf volume, due to the replacement of gluten by the added protein. Overall acceptability scores of these breads were found to be very low. The durum flour can be substituted with nongluten flours up to 10% more than the bread wheat flour because of its stronger gluten matrix and better dough rheological characteristics.     

Effects of flour from different barley varieties on barley sour dough bread

Twenty flours from 16 different barley varieties cultivated in 1990 and 1992, and a Swedish reference flour, were fermented by Lactobacillus plantarum A1 to sour doughs. Barley breads (40% barley/60% wheat flour) from each flour type were baked with and without an admixture of barley sour dough in order to investigate how the sour dough admixture would affect the baking properties. A trained panel carried out sensory evaluation by conventional profiling on breads made from three of the barley varieties and the Swedish reference flour, made with and without sour dough admixture.

The barley varieties influenced both the sour dough properties and the properties of the barley bread. The pH of bread with sour dough ranged from 4.6 to 4.8 as compared to 5.4 to 5.6 in bread without sour dough. The acidity of the breads with sour dough ranged from 4.1 to 5.0 ml NaOH/ 10 g bread crumb as compared to 2.4 to 3.6 in breads without sour dough. In 14 of the twenty bread types an addition of sour dough lowered the bread volume. Breads with a sour dough admixture scored higher for total taste and acidulous taste than breads without sour dough. The β-glucan content of the flours had no significant influence on the sour dough or the sensory characteristics of the bread, except for the breadcrumb colour.     

Dough and bread qualities of flours with whole waxy wheat flour substitution

Whole wheat flour has been developed as fiber-rich food for healthy bowel function. In this study, whole waxy wheat flour (WWF) was characterized and applied for breadmaking with the hope that breads made from WWF would improve the quality based on the superior properties of the waxy flour in retardation of bread staling. WWF had significantly higher protein, ash and dietary fiber contents (13.5%, 1.6% and 15.3%, respectively), but lower lipid content (0.8%) than commercial white flour (CWF). Amounts of soluble and insoluble dietary fiber in WWF were 4.1% and 11.2% (% total weight), respectively. WWF had lower pasting temperature and viscosities than CWF. Dough made from WWF increased water absorption and showed lower stability during mixing than that from CWF. The high amount of dietary fiber diluted the gluten protein in dough during mixing to form weak and inextensible dough. Bread made from whole waxy wheat flour had significantly low specific volume and big gal cell distribution as compared to that from CWF. Also, dark-brown color and bitter taste are weak points of whole waxy wheat bread. However, the WWF bread was significantly softer than CWF bread during storage. The qualities of breads were also improved using partial WWF substitution (10%, 30% or 50%) for CWF. As a result, whole waxy wheat flour can be used for breadmaking to improve nutritious quality of bread for health benefits.     

IMPROVEMENT OF THE WHEAT AND CORN BRAN BREAD QUALITY BY USING GLUCOSE OXIDASE AND HEXOSE OXIDASE

The effects of addition of wheat (10, 20 and 30%) and corn bran (10 and 20%) on rheological and bread making properties of flour were examined. To improve dough and bread properties, glucose oxidase (GO) and hexose oxidase (HO) (15–30 and 45 mg/kg) were used separately in each bran-wheat flour formula with L-ascorbic acid at 75 mg/kg, glucose at 0.5% and vital gluten at 9.2%. Water absorption and development time increased as the amount of wheat and corn bran increased, while dough stability, maximum resistance to extension, extensibility, energy and loaf volume decreased. Corn bran was found to be more detrimental to dough rheology and bread characteristics than wheat bran. Corn bran and wheat bran could be used at bread making up to levels of 10 and 20%, respectively. Addition of 30 mg/kg of HO in combination with constant additives was most effective in improving dough and bread characteristics and GO with its 15 mg/kg usage level followed it. Further increasing of enzyme levels led to over oxidizing of doughs and breads.

PRACTICAL APPLICATIONS

Corn bran up to 10% and wheat bran up to 20% levels can be used in bread making. To improve dough and bread quality, besides L-ascorbic acid (75 mg/kg) and vital gluten (as a percentage of added bran weight), GO (15 mg/kg) or HO (30 mg/kg) could be incorporated into wheat flour-bran mixtures. However, the amount of enzyme should be carefully chosen because when they are used above the mentioned levels, they cause overoxidation of doughs and small loaf volumes are obtained. As a conclusion; by using the corn bran, which is a by-product of the starch industry, not only could it be possible to offer healthy alternative breads which contain high amounts of dietary fiber to consumers, but it could also be possible to obtain economical value by evaluating such a by-product in the bread industry.     

Effect of Sodium Stearoyl-2-Lactylate on the Rheological and Baking Properties of Wheat Bread Fortified with Defatted Soybean and Sesame Meal

Wheat flour was fortified with 8% DSBM (defatted soybean meal), 12% DSBM and 8% DSBM/4% DSM (defatted sesame meal) to increase the protein content and amino acid profile, and to upgrade the overall nutritional value of the bread. SSL (sodium stearoyl-2-lacty-late), at 0.5 and 1% levels, was incorporated into the three bread systems to overcome the deleterious effect of fortification on bread quality. Amylograph peak viscosity, dough elasticity, dough stability and bread volume improved when SSL was used. Addition of 1% SSL improved rheological properties and bread volume to a greater extent than 0.5% SSL. The control (100% wheat) bread had the best flavor, texture and color scores, followed by the 8% DSBM, 8% DSBM/4% DSM and 12% DSBM breads.     

Effect of Extruded Wheat Germ on Dough Rheology and Bread Quality

Wheat germ, a by-product of the milling industry, has interesting nutritional properties. However, it has limited use due to a high risk of rancidity, which could be reduced by using certain thermal treatments such as extrusion. The aim of this study was to investigate how wheat germ extrusion affects the changes induced by its addition to bread dough. For this purpose, different quantities of extruded or raw wheat germ (2.5, 5, 7.5, 10, and 20?g/100?g flour) were added to bread dough. Rheological characteristics of the dough and final quality characteristics of the bread were analysed from both the physical and the sensory points of view. Wheat germ addition increased water absorption and development time but decreased stability after over-kneading, dough tenacity, extensibility, and dough alveographic strength. The addition of extruded wheat dough improved stability and decreased extensibility and strength. Bread made from dough with added wheat germ presented decreased volume, cohesiveness, and elasticity and increased firmness. However, extrusion increased the volume of breads with added wheat germ and improver and decreased firmness. All breads obtained positive acceptability scores in sensory analysis, although wheat germ addition (10?g/100?g flour) slightly decreased texture, appearance, and overall acceptability scores of breads. Germ extrusion therefore improves dough rheology and bread quality and constitutes a suitable treatment to stabilise wheat germ in bread dough.     

Effect of flaxseed and wheat flour blends on dough rheology and bread quality

The rheological and baking properties of flaxseed/wheat composite flours were studied. Flaxseed flour was used to replace 50, 100, 150 and 200 g kg^?1 of wheat flour in bread. Farinographic studies showed that water absorption, dough development time and mixing tolerance index increased as the amount of flaxseed flour increased, while dough stability decreased at 100, 150 and 200 g kg^?1 of flaxseed flour substitution. The extensographic energy of dough also decreased at 150 and 200 g kg^?1 flaxseed levels. The addition of increasing amounts of flaxseed flour caused a decrease in extensibility. Doughs containing 100, 150 and 200 g kg^?1 flaxseed flour showed resistance to extension comparable to that of control dough. The specific volume of flaxseed flour breads was similar to that of control bread. Crust L, a, b values of breads with flaxseed flour were lower than those of control bread. Breads with flaxseed flour gave lower crumb L and b values and higher a values than control bread. The sensory properties showed that an acceptable bread could be produced using flaxseed flour up to a level of 200 g kg^?1. Copyright © 2007 Society of Chemical Industry     

Effect of fungal α-amylase on the dough properties and bread quality of wheat flour substituted with polished flours

Whole grains of a hard-type wheat cultivar ‘1CW’ (No. 1 Canada Western Red Spring) were polished from the outer layer to the inner layer by 10% of the total grain weight using a modified rice-polisher. The polished flours of three fractions; C-1, C-5, and C-8 corresponding to 100–90%, 60–50% and 30–0% layer of the 1CW grain, respectively were used in this study. Effects of fungal α-amylase on polished flour substitution for the common wheat flour CW of 1CW on rheological or physicochemical dough properties and bread qualities were studied. When the polished flours were substituted for CW without fungal α-amylase, the mixing tolerance index of dough in a farinograph and all parameters of viscoelastic properties significantly increased rather than those of CW alone. As a result, baking qualities of breads made from the substituted flours were significantly inferior. But, the polished flours increased the total gas generation significantly during fermentation, as compared with CW alone. The addition of fungal α-amylase to polished flour substituted CW distinctly developed gluten matrix in the SEM images and produced large amounts of the generated gas during fermentation. Therefore, the loaf volume and firmness of breads were improved by the combined additions of polished flours and fungal α-amylase. Especially, the C-8 of the innermost fraction was more susceptible to affection of fungal α-amylase among all polished flours, and resulted in improvement of gas cell distribution and softness of breadcrumbs without lowering the loaf volume as compared with CW bread.     

Wheat Germ Lipoxygenase: Its Effect on Dough Rheology,Microstructure, and Bread Making Quality

Extracted lipoxygenase from defatted wheat germ of commercial bread wheat along with raw and defatted germ were used to study their effect on rheological characteristics of wheat flour dough and bread making quality. The addition of 500 U and 1000 U of lipoxygenase increased the water absorption from 59.5 to 62.3 and 66.7%, respectively. The dough stability increased to 10.5 min, whereas mixing tolerance index values marginally decreased, and the addition of raw or defatted germ did not affect the mixing profile of the wheat flour dough. Breads with lipoxygenase were softer with a lower firmness value of 546 g when compared to the control (594 g) and had brighter crumb as seen in the reduction in ΔE values from 22.34 (control) to 19.04. The addition of gluten along with the lipoxygenase showed a synergistic effect. The specific volume of breads increased to 3.95 cc/g and the firmness values decreased to 538 g. Scanning electron micrographs at different stages of bread processing have shown improvement in the gluten network.     

小麦粉储存湿度对面粉品质及其制作馒头品质的影响

研究通用中筋粉在常温(25℃),不同湿度(50%、65%、80%)条件下储存过程中面粉中水分含量、粗蛋白质含量、湿面筋含量、脂肪酸值等指标及其制作面团的酸度和馒头的感官品质的变化。实验结果表明,在湿度80%条件下,随着储存时间的延长面粉水分含量变化显著(p<0.05)。同一储藏时间,湿度越高,面筋含量越低。不同湿度(50%、65%、80%)条件下,面粉中的脂肪酸值都随储存时间的增加而增加(p<0.05)。不同湿度(50%、65%、80%)储存过程的面粉制作的发酵面团的酸度都呈现先降低后增加的趋势,制作馒头的感官评分呈现下降的趋势(p<0.05)。面粉在不同湿度(50%、65%、80%)储存过程中,储存30 d的面粉,醒发后面团酸度都显著下降(p<0.05);继续延长储存期,在湿度50%下的面粉制作的面团酸度有回升,但不超过原始的面团酸度,随储存湿度提高面团酸度增加明显;感官评分表明,储存环境湿度越高,面粉制作的馒头品质下降越快,湿度80%储存60 d后的面粉制成的馒头口感差。湿度50%存放120 d仍可用于加工馒头。结论:面粉储存过程中,湿度越大,面粉品质下降越快,进而影响到所制作的馒头品质。     

Baking Studies and Nutritional Value of Bread Supplemented with Full-Fat Sweet Lupine Flour (L. albus cv Multolupa)

Full-fat sweet lupine flour (FFLF) was used to replace 3, 6, 9 and 12% of the wheat flour (WF) in bread. Physical characteristics of the dough, and the chemical composition and biological quality of the breads were investigated. Farinological studies showed that water absorption increased gradually from 60% for WF to 77% for a blend with 12% FFLF. Developing time, weakening of dough and valorimeter value were adversely modified by addition of FFLF. Different levels of FFLF increased in water absorption, loaf volume and loaf weight as compared to all wheat bread. However, specific loaf volume remained constant (3.72) up to 6% FFLF, then decreased. Protein content of wheat bread increased from 10.3% for the control to 11.7% for 9% FFLF bread. PER increased from 1.72 for the control bread to 2.00 for 9% lupine-bread (p<0.01). Bread with 9% FFLF is a possibility for using this legume in human feeding.     

Hard Red Spring wheat/C-TRIM 20 bread: Formulation,processing and texture analysis

C-TRIM, a β-glucan-rich fraction, was added to Hard Red Spring wheat (HRSW) flour to increase soluble fiber content of bread, and to obtain a minimum of 0.75 g/bread serving (0.75 g/30 g or 2.5%) required by FDA for health claim. Three treatments or blends FGT0 (100% wheat flour – control), FGT1 (58% flour, 25% gluten and 17% C-TRIM) and FGT2 (60% flour, 22.5% gluten, and 17% C-TRIM) were used in the study. The total amount of soluble fiber from C-TRIM in FGT1 and FGT2 was 4.07–4.17% which was more than the amount required by FDA. The presence of C-TRIM increased both, the Farinograph water absorption and the arrival time. The dough mixing tolerance index (MTI) was also increased by C-TRIM. The FGT1 had higher stability than FGT2, whereas, the loaf volume of FGT1-B was also significantly higher than FGT0-B control and FGT2-B bread. The DSC results indicated that the amount of freezable-water in C-TRIM treated bread (FGT1-B and FGT2-B) was significantly higher than the control wheat flour bread (FGT0-B). This may be attributed to the higher amount of water absorbed by C-TRIM during bread dough (FGT1-D and FGT2-D) preparation and trapped or bound within the bread matrix after baking as compared to the control. After storage of FGT0-B, FGT1-B, and FGT2-B breads 2, 5, and 7 days storage at 25 °C, 4 °C, and −20 °C, the texture of bread were measured with a Texture Analyzer and the data analyzed statistically. The FTG0-B control bread firmness was significantly higher than FGT1-B and FGT2-B C-TRIM treated breads after 7 days storage at 25 °C. The amount of 0.1 M acetic acid-extractable protein was lower in FGT1-B than the control wheat flour (FGT0-B) sample. In addition, more protein was extracted at pH 7.0 than pH 4.5 because of less charges at neutral pH than pH 4.5. The free zone capillary electrophoresis analysis showed obvious differences in the protein charge and size between the dough and bread.     

Enzymes Action on Wheat–Soy Dough Properties and Bread Quality

High levels of soy flour added to wheat bread produce negative effects on gluten network formation, dough properties, and on bread final quality. The objective of this study was to assess the influence of three enzymes, transglutaminase (TG), glucose oxidase (GOX), and endoxylanase (XYL), on dough properties and final quality of high-protein breads. The addition of TG and GOX increased the mixing stability and maximum resistance of dough, decreased its extensibility, and produced stronger and more consistent dough samples. XYL incorporation produced opposite results. XYL addition and the lowest GOX dose increased bread volume significantly and decreased initial crumb firmness, while high doses of TG (0.3%) produced detrimental effects on bread volume and crumb firmness. In conclusion, XYL and GOX 0.001% addition improved the final quality of soy-fortified breads, but XYL was the best additive to improve dough properties, bread volume, and quality.     

YEAST BREAD CONTAINING DISTILLERS' DRIED GRAIN: DOUGH DEVELOPMENT AND BREAD QUALITY

A commercially available distillers' dried grain (DDG) was chemically and physically characterized and used in yeast bread. Total dietary fiber (51.1%) and protein (25.8%) were the principal constituents of the DDG. Compared with bread flour and whole-wheat flour, the DDG was more acidic and absorbed more water and oil. The effect of substituting 0, 5, 10, 15, and 20% DDG for bread flour on dough development was examined. As the DDG level increased, mixogram peak heights and development angles decreased, and peak times increased. Quality of breads containing 5, 10, and 15% DDG was compared with that of a control bread containing 50% whole-wheat flour. As the DDG level increased, loaf volume decreased. Experienced sensory panelists found that the intensity of the characteristics of breads containing DDG deviated more from those of the “ideal” multigrain bread than from those of the control.     

Influence of sorghum flour addition on flat bread in vitro starch digestibility,antioxidant capacity and consumer acceptability

Wheat flour (WF) flat bread was prepared with varying levels of wholegrain “white” sorghum flour (WSF) or “red” sorghum flour (RSF). Farinograph dough rheology indicated reduced water absorption and stability time and increased breakdown with increased sorghum flour addition. The total phenolic content and antioxidant capacity of the 40% RSF flat bread >40% WSF flat bread > control (100% WF) flat bread. The rapidly digestible starch (RDS) level was lower in the 40% WSF and 40% RSF flat breads than the control (100% WF). Hedonic sensory evaluation indicated that sorghum addition did not reduce the sensory preference for the flat breads. Human clinical studies are now required to determine if the lower levels of RDS and higher antioxidants observed in the sorghum containing flat breads translate into beneficial low glycemic index and reduced oxidative stress in vivo.