Effect of defatted maize germ flour addition on the physical and sensory quality of wheat bread

Maize (Zea mays L.) processing produces large quantities of defatted maize germ (DMG) that is being used mainly for animal feed. The objective of this study was to exploit use of this nutrient-rich by-product in bread by replacing wheat flour at 5-20 g/100 g levels. Breads prepared with wheat-DMG flour blends were analyzed for loaf volume, density, instrumental dough hardness and bread firmness, Hunter color (“L”, “a”, “b”, chroma, and hue angle), and selected sensory attributes. Loaf volumes decreased significantly, from 318.8 ml to 216.3 ml, as the DMG flour supplementation was increased from 0 to 20 g/100 g; a similar effect was observed for bread specific volume. Increase in dough hardness (7.56-71.32 N) was directly related to increase in DMG flour levels. Instrumental firmness values were significantly higher for breads containing DMG flours, 61.58 N in 20 g/100 g DMG bread versus 32.84 N for the control bread, made with wheat flour only. The control bread was lighter in color, as shown by higher “L” values, than those having DMG flour, with chroma and hue angle values significantly higher in treatment breads. In general, no differences were observed for the sensory attributes of crumb color, cells uniformity, aroma, firmness, mouthfeel, and off-flavor in breads with up to 15 g/100 g DMG flour, while the overall acceptability scores showed a mixed pattern. The results of this study demonstrated that acceptable quality bread could be made with DMG flour addition at ≤15 g/100 g.     

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.     

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.     

Sensory and physical quality characteristics of bread fortified with apple pomace using fuzzy mathematical model

Apple pomace, after different processing procedures, was added into wheat flour in bread production to improve the dietary fibre content of breads. A fuzzy mathematical model was used in the sensory assessment of bread to improve the reliability of final conclusion. The addition of both apple pomace (AP) and skimmed apple pomace (SAP) reduced the extensibility and improved the resistance of wheat dough compared to the control sample. Wheat dough fortified with apple pomace of differing particle sizes did not have significant effects on either farinograph properties or extensograph properties. Sensory assessment of bread based on fuzzy mathematical model indicated that optimum concentration of apple pomace, both AP and SAP, added into wheat dough was 3%. Such results may be of importance when considering the use of apple pomace in bread production so as to enhance the dietary fibre intake, and also improve the sensory properties of bread.     

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.     

Influence of extrusion condition and hemp addition on wheat dough and bread properties

This study was to evaluate the influence of hemp addition and extrusion conditions on properties of dough and bread. The extruded and non-extruded hemp/ rice flours with different hemp/rice ratio were mixed with wheat flour at 15% ratio. In those flour assays, extrusion greatly decreased the paste viscosities, while the addition of hemp inhibited the decrease of peak viscosity on the extrusion condition. The onset gelatinization temperature was extended due to the hemp addition. The test on dough properties showed that extrusion increased water absorption, arrival time, weakness, extensibility, and the volume after 105 min fermentation, and decreased the stability time and elasticity of dough, while hemp addition mainly increased the weakness and extensibility. For bread properties, extrusion decreased the specific volume, crust and crumb L value, and uniformed air cells, when the hemp addition increased the bread specific volume and decreased the hardness during storage time.     

Effect of extruded wheat bran on dough rheology and bread quality

Bran extrusion is mainly under study and works should be performed to know the effect on dough and bread. This study was designed to investigate the effect of bran extrusion (addition of 2.5 g/100 g to 20 g/100g bran) on the rheological characteristics of bread dough, behaviour during fermentation, and bread quality. Extruded bran increased dough development time and tenacity to a greater extent than non-extruded bran, and minimized the loss of stability if over-mixing occurred. Extruded bran, due to its greater gas production, also reduced loss of dough height during fermentation to a greater extent than untreated bran. However, breads with extruded bran showed a higher volume and lower initial firmness than breads with normal bran if improver was added. However, no differences were found in the organoleptic evaluation. Bran extrusion therefore modified dough rheology but did not negatively affect bread quality. It could even improve the quality of breads with bran when improvers are added.     

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     

面粉中胚芽含量对面团流变学特性及馒头品质的影响研究

在小麦面粉中添加同种小麦提取的胚芽所制成的胚芽粉,测定其面团流变学特性及降落数值,并做馒头感官评价试验。实验表明,拉伸面积、最大拉伸阻力、拉伸阻力、拉伸比例、稳定时间和粉质质量指数与胚芽添加量呈显著线性负相关;弱化度与胚芽添加量呈显著的线性正相关;降落数值、形成时间与胚芽添加量线的相关性不显著。在一定添加范围内(0～2%)馒头总评分随胚芽粉添加量增大而增大,超过此数值则馒头总评分随添加量增加而减小;馒头的麦香味也有此趋势。     

糯麦粉对冷冻面团发酵流变特性和面包烘焙特性的影响

采用发酵流变测定仪和质构分析仪研究不同比例的糯麦粉对冷冻面团发酵流变学特性和面包烘焙特性的影响。结果表明：无论面团冷冻与否,随着糯麦比例增加,面团发展的最大高度(Hm)和持气率(R)逐渐下降,而气体释放曲线最大高度(H＇m)和CO2产气量(Vco2)在一定程度上增加。随着冻藏时间的延长,面团各种参数(Hm、H＇m、R等)逐渐降低,但是下降的幅度随糯麦粉添加量的增加而减小,如与冻藏7d相比,添加质量分数0%、10%、20%和30%的糯麦面团经冻藏60d后Hm分别下降了12.9%、9.6%、7.7%和7.5%,而R则分别下降了2.8%、2.1%、1.6%和1.7%。在冷冻贮藏过程中,面包品质虽有一定程度的下降,但添加糯麦粉的面包品质下降程度较慢,抗老化效果好,且由感官评定可知,冻藏不同天数后,添加10%糯麦粉的面包最易受人们喜爱。     

Dough properties and breadmaking qualities of whole waxy wheat flour and effects of additional enzymes

BACKGROUND: Waxy wheat, a new kind of genetically back‐crossed wheat, was applied to make whole bread in this study. Dough properties and bread quality of the whole waxy wheat flour, which was milled from 100% whole grains containing bran and germ, were determined. RESULTS: Whole waxy wheat had lower protein and lipid contents but higher dietary fiber content than whole regular wheat flour. Pasting temperature and viscosity of the whole waxy wheat flour were significantly lower than those of the whole regular wheat. However, the white wheat flour milled from wheat grains with 48% recovery had significantly higher peak viscosity than the whole waxy wheat. Bread made from the whole waxy wheat flour was significantly softer than that from the whole regular wheat flour during storage. However, bread made from whole waxy wheat had significantly lower specific volume than that from the white waxy flour because of the high amount of dietary fiber. Addition of cellulase increased paste viscosity, lowered dough mixing properties and reduced the firmness of the bread. The addition of pentosanase also increased paste viscosity, lowered dough mixing properties, improved loaf volume of bread but increased the firmness of breadcrumbs, while the addition of α‐amylase only increased final viscosity of flour and did not affect dough properties and bread qualities of whole waxy wheat flour. CONCLUSION: As a result, waxy wheat shows superior properties for making whole breads. Additional enzymes are also necessary to improve bread quality and nutritive values of whole waxy bread. Copyright © 2007 Society of Chemical Industry     

薏米全粉的添加对小麦粉加工品质的影响

研究不同添加量（5%、10%、15%、20%和25%）的薏米全粉对小麦粉的粉质特性,拉伸特性、糊化特性以及对馒头的质构和感官评价的影响。结果表明：薏米全粉的添加增加了小麦粉中蛋白质、油脂和灰分的含量。与小麦粉面团相比,薏米全粉不影响小麦粉的形成时间和稳定时间,但在添加量高于15%时弱化度增加显著;添加薏米全粉的面团拉伸能量,延伸性总体上降低,最大拉伸阻力在45?min和135?min差异不显著,拉伸比增加显著。薏米粉的添加显著提高了馒头的硬度、弹性和咀嚼性,显著降低了回复性和内聚性,感官评定与质构硬度和咀嚼性结果一致。随着薏米全粉的添加,口感各个指标总体上降低,但是5%～10%的薏米全粉添加量对馒头感官评价影响不大,并且少量薏米所产生的气味更受人喜爱。结合上述因素,考虑到对面团流变特性、糊化特性和馒头品质的影响,小麦粉中添加10%的薏米全粉较为合适。     

INSTRUMENTAL TEXTURE and BAKING QUALITY of HIGH-FIBER TOAST BREAD AS AFFECTED BY ADDED WHEAT MILL FRACTIONS

The effect of bran type, level of addition, particle size, addition of wheat germ, as well as other additives like improvers and dough conditioners, on the instrumental texture and baking quality of high-fiber toast bread (white pan bread) has been investigated. the specific loaf volume decreased significantly (3.45 cc/g) when the bran level was raised to 30%, but at 20% bran addition, the specific loaf volume was superior to that of the control bread. the specific loaf volume of test breads remained higher than the control bread up to a level of 7.5% wheat germ addition. Additives like ascorbic acid (50 ppm) and sodium stearoyl-2-lactylate (0.5%) further improved the baking quality of test bread samples. the objective texture values (measured as compression force, kg) indicated that the test bread with bran addition up to 20% and germ up to 7.5% possessed a softer texture (0.80 kg) than the control bread (1.02 kg). In comparison with control bread, the panelists gave higher sensory scores for all attributes of test bread samples containing up to 20% red coarse bran or up to 30% red fine bran. A similar trend in sensory quality of test samples containing up to 7.5% wheat germ was also observed. High-fiber toast bread made from white flour, equal proportions of coarse and fine bran at 20%, wheat germ at 7.5%, plus sodium stearoyl-2-lactylate at 0.5% levels, was found to possess softer texture and improved sensory quality than the whole wheat flour bread.     

Functional effects of xanthan gum on composite cassava-wheat dough and bread

The use of composite flour for bread making is gradually gaining prominence worldwide due to some economic and nutritional reasons. However, studies on the application of functional ingredients purposely to improve composite bread quality are very few. This paper examines the functional role of xanthan gum (XG) on the properties of dough and bread from composite cassava-wheat flour. The viscoelastic properties of dough and gas retention characteristics of batter as well as the fresh and storage properties of bread from the composite flour (90% wheat plus 10% cassava) were studied. The crumb cell structure was also studied using digital image analysis technique. Inclusion of XG had significant effects on the dough tenacity and extensibility and sensory acceptability of fresh composite bread. The oven spring, specific volumes of bread loaf and crumb softness were higher at 1% XG content. Also, addition of XG made the composite bread samples had more open crumb structure and better sensory acceptability. However, moisture loss and crumb firming during bread storage were best reduced when 1% XG was added to bread formulation.     

麦麸膳食纤维对面团流变学特性及馒头品质的影响

研究了麦麸膳食纤维的加工技术并制备了微细化活性麦麸膳食纤维;分别添加5％、8％、10％、12％和15％的麦麸膳食纤维素到面粉并调制成面团,记录并测定其粉质特性参数与拉伸特性参数。结果表明：麦麸膳食纤维的添加使面团的吸水率增大、形成时间与稳定时间显著延长、弱化度下降,面团的粉质特性得到明显改善,但其面团的弹性逐渐下降;麦麸膳食纤维的添加使面团的抗拉伸阻力和拉力比数增大．而使面团拉伸能量和延伸性变小。按传统工艺技术制备了不同麦麸膳食纤维添加量的馒头样品,并进行了感官评价．麦麸膳食纤维的添加使馒头的体积及馒头感官指标评价得分均呈下降的趋势,当其添加量为8％时,馒头的总体品质评价得分高于80％。是可以为消费者所接受。     

EFFECT OF EMULSIFIERS AND FUNGAL α-AMYLASE ON RHEOLOGICAL CHARACTERISTICS OF WHEAT DOUGH AND QUALITY OF FLAT BREAD

Teftoon, a flat bread made of whole wheat flour, is prepared by hand sheeting of dough, followed by baking. Different emulsifiers, like lecithin, E471 (distilled monoglyceride) and E472 (diacetylated tartaric acid esters of mono- and digelycerid of fatty acids), were added to the flour at various levels ranging between 0.25 and 1.0% w/w, and it was observed that they improved the dough characteristics. Improvement in bread quality parameters, such as force to tear and sensory acceptability, were monitored. Fungal α -amylase was also incorporated into the flour at 5–20 g/100 kg flour basis alone and in combination with the emulsifier. The force required to tear the fresh bread was decreased with emulsifier and enzyme addition; however, E472 addition at 0.75% w/w of whole wheat flour gave the softest bread. The tear force of stored bread significantly increased with storage; however, bread containing E472 showed a less increase in tear force up to a period of 3 days. The sensory acceptability was found to be higher than that of the control bread for emulsifiers, and lower for enzyme at a concentration higher than 10 g/kg flour.

PRACTICAL APPLICATIONS

Flat bread is normally consumed fresh, but the staling phenomenon starts immediately after baking this kind of bread. Today, large-scale production and increased consumer demands for high-quality bread with long shelf life have created the need for functional food additives such as emulsifiers and α -amylase enzyme. Incorporation of emulsifiers and enzyme decreased the hardness of Taftoon bread. Emulsifiers and α -amylase enzyme enhanced the flat bread dough quality. The sensory acceptability also improved with the addition of emulsifiers. Optimizing the amount of emulsifiers and enzyme required for reduction of bread hardness is vital because the quality and price of the final product depend on this parameter.     

BAKING PERFORMANCE AND CONSUMER ACCEPTABILITY OF RAW AND EXTRUDED COWPEA FLOUR BREADS

Cowpea flour was used to partially replace wheat flour in yeast bread, using automatic household‐type bread machines for mixing, proofing and baking. Loaves containing 15 or 30% extruded cowpea flour weighed more (683.4 g) than loaves from other treatments (641.1–652.6 g). The 100% wheat had the highest loaf volume (2.58 L) and the 30% extruded cowpea the lowest (1.64 L). Cowpea flour breads contained more protein (13.9–15.4%) than the 100% wheat (4.1% fat, 12.5% protein). Bread made with 15% extruded cowpea flour was not different (P < 0.05) from the all‐wheat control in sensory quality and acceptability. Hedonic ratings for the control and 15% extruded cowpea flour ranged from 6.6 (like slightly) to 7.4 (like moderately) for all sensory attributes. The least liked samples contained either 30% raw or 30% extruded cowpea flour, receiving ratings for all attributes ranging from 4.8 (disliked slightly) to 6.2 (liked slightly). Overall, 15% extruded cowpea flour demonstrated successful bread making performance without compromising sensory quality.     

Effects of two barley β-glucan isolates on wheat flour dough and bread properties

The effects of wheat flour fortification with two different molecular weight barley β-glucan isolates (1.00 × 10⁵, BG-100 and 2.03 × 10⁵, BG-200) on the rheological properties of dough and bread characteristics, using flours from two wheat cultivars that differ in their breadmaking quality, have been examined. The farinograph water absorption of doughs and the moisture content and water activity of the breads increased with increasing β-glucan content; the β-glucan isolate with the higher molecular weight (BG-200) exerted a greater effect than did BG-100. The addition of β-glucans to the dough formula increased the development time, the stability, the resistance to deformation and the extensibility of the poor breadmaking quality doughs, as well as the specific volumes of the respective breads, exceeding even that of the good breadmaking cultivar. Furthermore, the colour of the bread crumbs got darker and their structure became coarser, whereas the bread crumb firmness decreased with increasing level of β-glucan addition. Generally, the BG-200 was more effective in increasing the specific bread volume and reducing the crumb firmness, especially when used to fortify the poor breadmaking quality flour. The results further indicate a requirement for optimisation of the fortified doughs (level and molecular size of the β-glucan) to maximise bread quality attributes (loaf volume, texture, and staling events).     

Soybean Flour Lipoxygenase Isozymes Effects on Wheat Flour Dough Rheological and Breadmaking Properties

The effects of soy flour from LOX null mutant isolines and purified LOX isozymes on the rheological and breadmaking properties of a commercial hard wheat flour were investigated. Wheat flours were fortified with either 3% soy mutant flours alone, or in the presence of 0.2% and 1% linoleic acid. Purified LOX 2 isozyme had the greatest effect among LOX isozymes on dough extensibility and strength. Linoleic acid substrate addition reduced dough extensibility and strength. The L2L3 null isoline mutant for L1 resulted in the largest increase in bread volume. A reduction in bread firmness occurred after 5 day storage for all three single null mutant-containing samples in the presence of 1.0% linoleic acid substrate.     

Effect of Lipid Extraction Process on Performance of Texturized Soy Flour Added Wheat Bread

ABSTRACT: Wheat breads were prepared to contain 0%, 2%, 6%, or 12% non-solvent extracted texturized soy flour (NSETSF) or solvent extracted texturized soy flour (SETSF) to evaluate their effects on instrumental and sensory characteristics. To compare the effects of added dough enhancers versus those contained in lip id-extracted soy flour, a sucrose ester was included in some formulations. Both soy flours produced comparable loaves relative to percent inclusion. Texture analysis and trained sensory panel evaluation indicated that SETSF loaves were softer than NSETSF loaves. The consumer panel found bread with 12% NSETSF similar to the control. Texturized, lipid-extracted soy flours added to wheat breads produced a "sucrose ester"-like property.