Rheological properties of wheat dough supplemented with functional by-products of food processing: Brewer’s spent grain and apple pomace

The physicochemical properties of brewer’s spent grain (BSG) and apple pomace (AP), and their effect on dough rheological properties were investigated. BSG had high protein content and both by-products were found to be high in dietary fibre. The rheological and the pasting properties of dough were significantly altered by the addition of by-products, with the main effects being due to the presence of dietary fibre. The biaxial extensional viscosity was significantly higher for the supplemented doughs; the strain hardening index decreased with increasing the levels of flour substitution. The replacement of wheat flour with the by-products significantly reduced the uniaxial extensibility, while the storage modulus, G″, was found to increase, indicating changes in the structural properties of dough. These changes were reflected in the ability of dough to rise during proofing.     

Effect of dietary fibre on dough rheology and bread quality

Dietary fibre is a common and important ingredient of a new generation of healthy food products demanded more each day by customers. Dietary fibre increases the nutritional value of bread but usually at the same time alters rheological properties of dough and, finally, the quality and sensorial properties of bread. The present work investigates the effect of some purified dietary fibres from different origins (orange, pea, cocoa, coffee, wheat and microcrystalline cellulose) on the rheological properties of wheat flour dough and the final quality of breads. The study of the rheological behaviour of the dough was performed by means of a consistograph and an alveograph. Bread quality was determined by means of texture, colour and specific volume measurements after baking under controlled conditions. The influence of fibre on bread sensory evaluation was established. Dietary fibre additions, in general, had pronounced effects on dough properties yielding higher water absorption, mixing tolerance and tenacity, and smaller extensibility in comparison with those obtained without fibre addition (in the control bread). Regarding the effect on bread properties, the fibre always enhanced the shelf life, as textural studies revealed. Sensory evaluations revealed that dietary fibres, with the exception of those from coffee and cocoa, can be added to flour at the level of 2% without deterioration of the bread palatability in comparison with white flour bread. Additions of 5% could imply the use of some additives to correct the rheological properties of dough.     

Effects of pineapple pomace fibre on physicochemical properties of composite flour and dough,and consumer acceptance of fibre‐enriched wheat bread

Pineapple pomace fibre (PF, containing 70.2% total dietary fibre) can be added to increase dietary fibre of wheat bread. This study was performed to evaluate effects of PF added at 0, 5 or 10% (wheat flour‐basis) on physicochemical properties of the composite flour (wheat flour as the control, CPF‐5 and CPF‐10, respectively) and its dough, to evaluate consumer acceptance of CPF breads and to identify factors affecting willingness to purchase of CPF breads. Incorporating PF affected rheological and pasting properties of CPF. Water‐ and oil‐holding capacity of CPF increased (P < 0.05) as PF levels increased. Bread made with CPF‐5 was more acceptable than that with CPF‐10; however, it was not significantly different from the control, having similar specific volume and texture, but having about three times higher total dietary fibre than the control (4.4% vs. 1.5%). Product label and health benefit information potentially affected consumers' willingness to purchase of fibre‐enriched bread.     

Apple pomace as a source of dietary fiber and polyphenols and its effect on the rheological characteristics and cake making

Apple pomace, a by-product of apple juice industry, is a rich source of fibre and polyphenols. Also in view of the antioxidant property of pomace, it would play an important role in prevention of diseases. Apple pomace procured from fruit juice industry, contained 10.8% moisture, 0.5% ash and 51.1% of dietary fibre. Finely ground apple pomace was incorporated in wheat flour at 5%, 10% and 15% levels and studied for rheological characteristics. Water absorption increased significantly from 60.1% to 70.6% with increase in pomace from 0% to 15%. Dough stability decreased and mixing tolerance index increased, indicating weakening of the dough. Resistance to extension values significantly increased from 336 to 742 BU whereas extensibility values decreased from 127 to 51 mm. Amylograph studies showed decrease in peak viscosity and cold paste viscosity from 950 to 730 BU and 1760 to 970 BU respectively. Cakes were prepared from blends of wheat flour containing 0–30% apple pomace. The volume of cakes decreased from 850 to 620 cc with increase in pomace content from 0% to 30%. Cakes prepared from 25% of apple pomace had a dietary fibre content of 14.2% The total phenol content in wheat flour and apple pomace was 1.19 and 7.16 mg/g respectively where as cakes prepared from 0% and 25% apple pomace blends had 2.07 and 3.15 mg/g indicating that apple pomace can serve as a good source of both polyphenols and dietary fibre.     

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。     

苹果渣膳食纤维面包的研制及其质构特性的测定

我国浓缩苹果汁每年产生约100万t苹果湿渣,苹果渣中膳食纤维非常丰富。为开发利用苹果渣,以其作为添加剂制得苹果渣膳食纤维面包。将苹果渣粉以0%、5%、10%和15%的量混合加入面粉制得苹果渣膳食纤维面包,通过测定苹果渣膳食纤维面包感官鉴评、比容、保水性、质构等,分析影响苹果渣膳食纤维面包品质的主要因素,确定苹果渣粉的最适添加量。结果表明:随着苹果渣粉含量的增加,面包的比容和硬度降低,保水性和弹性增加。其中,当苹果渣粉添加量为5%时,面包品质最好。     

Physicochemical properties of bread dough and finished bread with added pectin fiber and phenolic antioxidants

Comparative studies were conducted in this paper to investigate the effects of added dietary fiber (DF) and/or phenolic antioxidants on the properties of bread dough and finished bread. Breads were developed in the absence (control bread), or presence of apple pectin and/or fruit phenolic extracts (treated breads), and subjected to quality evaluation (attributes including color, weight, and volume) and characterization of chemical and rheological properties. Chemical analyses revealed that breads with added phenolic extracts had greater antioxidant activity and higher extractable phenolic content, than control bread and the treated breads with added apple pectin(s). The measured antioxidant activity was mainly derived from the phenolics present in bread. Storage modulus G' (elasticity) and loss modulus G″ (viscocity) of the treated bread dough with added pectin(s) only were higher than those of control dough. The G' or G″ of the treated breads incorporated with a combination of a pectin and fruit phenolic extract depended on the type of phenolic extract (that is, apple and blackcurrant extracts behaved differently from kiwifruit extract). The G' and G″ at the final baking step were higher than those of other stages, indicating an increase in cross-linking among polymeric molecules and bread particles of high molecular weight. We conclude that the added pectin and/or phenolic extract had influenced bread dough cross-linking microstructure and bread properties through being involved in the interactions with bread components such as wheat proteins during dough development and bread baking. PRACTICAL APPLICATION: Dietary fibers and phytochemicals (including phenolic antioxidants) have long been recognized as the active nutrients responsible for the health benefits of fruit and vegetables to humans. Interest in incorporating bioactive ingredients such as dietary fiber and phenolic antioxidants into popular foods like bread has grown rapidly, due to the increased consumer health awareness. The added bioactive ingredients may or may not promote the development of bread dough. This paper reports the findings associated with the properties of the functional breads enhanced with apple pectin and apple, blackcurrant, and kiwifruit phenolic extracts. Results of this paper indicate that the success of the development of such functional breads is ultimately determined by the interactions among added bioactive ingredients and other bread components.     

山药薏米芡实混合粉对小麦粉加工品质的影响

在小麦粉中加入山药、薏米、芡实混合粉,利用快速黏度分析仪、Mixolab混合实验仪和质构仪分析不同添加量的混合粉对小麦粉糊化特性、面团热机械学特性以及对馒头质构特性的影响.结果表明:随着混合粉添加量的增加,小麦粉的糊化黏度、崩解值、回生值、糊化温度、糊化时间、面团吸水率、形成时间和稳定时间逐渐降低,蒸煮稳定性和蛋白质弱...     

汽爆高粱全粉馒头的研制

目的:研究汽爆对高粱功能成分的影响以及汽爆高粱全粉添加量对面团和馒头质构特性的影响。方法:汽爆高粱以蒸汽为汽爆介质,研究0.8 MPa压力维压5 min的条件下高粱中功能成分的变化;将汽爆高粱全粉按不同比例添加到小麦面粉中制作馒头,用质构仪测定面团和馒头的质构特性,用白度仪测定馒头白度值,对馒头食用品质进行感官评价,并讨论了汽爆高粱全粉的适宜添加量。结果表明:高粱经汽爆处理后,高粱中的功能成分含量发生变化:不溶性膳食纤维和单宁含量明显下降,抗性淀粉、总多酚和总黄酮含量提高。添加适量的汽爆高粱全粉可改变小麦面团的特性及馒头的品质,在本实验中汽爆高粱全粉的适宜添加量为25%,此时硬化速率低,馒头的食用品质较好。结论:汽爆有利于降解不溶性膳食纤维和单宁含量,促进功能成分的溶出,抗性淀粉、总多酚和黄酮含量增加;汽爆高粱全粉可以添加到馒头中,可以为高粱的开发利用提供参考。     

Behaviour of Dietary Fibre Supplements During Bread Dough Development Evaluated Using Novel Farinograph Curve Analysis

A regression model composed of two sigmoid functions with variable asymptotes was developed and used to analyse the dietary fibre supplement behaviour during bread dough mixing. Using eight commercial dietary fibres of different botanical origin and model wheat starch-gluten flour, farinograph curves for fibre-flour blends and for the flour only were performed. After smoothing of the curves with the regression model, difference farinograms as the fibre supplementation effects were determined. The results showed that the difference farinograms had two peaks, whose shape was strongly differentiated by the studied supplements. The presence of both peaks allowed distinguishing two kinds of the rheological activity of each fibre supplement: weakening and strengthening of the consistency of bread dough during its development. The carrot, oat, cranberry, and cacao fibres exhibited dominance of strengthening over weakening action. While chokeberry, carob, apple, and flax fibres were characterised by dominance of weakening over strengthening action. The analysis of both position and height of the peaks in the difference farinogram can be also helpful for determination of hydration kinetics of the fibres used for bread supplementation.     

油橄榄果渣对面粉及面团理化特性的影响

将油橄榄果渣粉以不同比例与小麦粉混匀,得到4种混合粉,研究该4种混合粉的化学组成、糊化特性及其面团流变和质构特性。结果表明,随着油橄榄果渣粉添加量的增加,混合粉的糊化温度逐渐升高,峰值黏度、最低黏度、最终黏度和衰减值显著降低,面团的形成与稳定时间缩短,吸水率、评价值、最大抗延伸阻力、延伸度、拉伸能量、弹性和内聚性减小,其弱化度、硬度、黏附性、胶黏性和回复性增大。当混合粉中油橄榄果渣粉添加量不超过10%时,其具有较好的糊化特性和面团特性,可用于制作面条和面包等食品。     

Mechanisms Behind Distiller’s Grains Impact on Wheat Dough and Bread Quality

Distiller’s grains, by-product from ethanol production, can be a new source for nutritionally enriched bakery products, particularly because of its high amount of dietary fibre and protein. Ingredients rich in fibre provoke challenges to the dough and bread system; therefore, mechanisms behind dried distiller’s grains (DDGs) impact on wheat bread must be evaluated. So, dough and bread characteristics were analysed in bread containing 0–20 % DDG, and effects of pH, particle size and furfural as DDG metabolite were studied. As a result, wheat bread incorporating DDG provides smaller volume from 20 to 45 %, firmer crumb up to a factor of 6 and reduced springiness up to 10 %. However, pH adjustment balanced the negative influence, and the low pH of DDG was revealed as the most influential parameter. The variation of particle sizes could not influence dough or bread characteristics significantly. While the low pH of DDG and the high amount of dietary fibre do not completely explain the negative impacts, inhibiting effects on the activity of Saccharomyces cerevisiae were evaluated. DDGs contain 2.7 ppm furfural as a consequence of the drying process, so its role as inhibiting compound was investigated in a model suspension and dough. It was confirmed that furfural is contributing to structure weakening effects in dough.     

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.     

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。     

双乙酰酒石酸单双甘油酯对全麦面团特性及全麦馒头品质影响

为了改善全麦中麸皮带来的不利影响,本文尝试向全麦粉中添加双乙酰酒石酸单双甘油酯(DATEM,0~1.0%)改变全麦面团特性同时改善全麦食品品质。利用混合实验仪(Mixolab)、质构仪、动态流变仪、扫描电镜、激光共聚焦等研究了DATEM对全麦面团的混合特性、流变特性、拉伸特性和微观结构及其对全麦馒头比容、质构特性的影响。结果发现,DATEM使得全麦面团形成时间、稳定时间与回生值均升高,峰值粘度降低。DATEM添加增加了面团拉伸强度,弹性模量(G")和黏性模量(G"),但降低了面团延伸性。全麦面团微观结构显示,添加DATEM后面团内部断裂减少,结构均匀连续,面筋结构得到明显改善。DATEM使得全麦馒头硬度显著降低(p<0.05),由1546.70 g(对照)降低到680.56 g(DATEM 1.0%),当添加量为0.4%时,全麦馒头的比容比对照增加了1.2倍。     

Mixing properties of fibre-enriched wheat bread doughs: A response surface methodology study

Fibre-enriched baked goods have increasingly become a convenient carrier for dietary fibre. However, the detrimental effect of fibres on dough rheology and bread quality continuously encourages food technologists to look for new fibres. The effect of several fibres (Fibruline, Fibrex, Exafine and Swelite) from different sources (chicory roots, sugar beet and pea) on dough mixing properties when added singly or in combination has been investigated by applying a response surface methodology to a Draper-Lin small composite design of fibre-enriched wheat dough samples. Major effects were induced on water absorption by Fibrex that led to a significant increase of this parameter, accompanied by a softening effect on the dough, more noticeable when an excess of mixing was applied. Conversely, Exafine increased water absorption without affecting the consistency and stability of dough, which even improved when combined with Swelite. Fibruline showed little effect on dough mixing parameters, but showed synergistic effects with pea fibres. The overall result indicates that the use of an optimised combination of fibres in the formulation of fibre-enriched dough allow improving dough functionality during processing.     

百合粉添加量对面团特性及面包品质的影响

为拓宽百合的应用渠道,提高面包的营养价值,研究了百合粉添加量(0%,5%,10%,15%,20%)对面团的微观结构、糊化特性、流变学特性以及面包品质的影响。结果表明:随着百合粉添加量增大,混合粉的持油性先降低后增加,持水性显著增加(P<0.05)。添加了百合粉后,面团的糊化温度升高,回生值和峰值黏度下降,面团的弹性模量和黏性模量均呈上升趋势。百合粉的添加,破坏了面筋蛋白原本均匀致密的微观结构;使面包的硬度显著增大(P<0.05),弹性、内聚性、胶黏性、咀嚼性、回复性、比容和感官评分显著降低(P<0.05);改变了小麦面团的特性和面包的品质,在小麦粉中添加5%~10%的百合粉,能保证面包较高的感官品质。     

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.     

USE OF APPLE POMACE AS A SOURCE OF DIETARY FIBER IN WHEAT BREAD

Chemical analysis of apple pomace revealed that it contains 29.4% neutral detergent fiber and 13.0% pectin. Pomace-flour blends were prepared by incorporating 2, 5, 8 and 11% pomace in wheat flour. Blends were evaluated for their bread making quality. Water absorption increased with the increase of pomace in the blends. Neutralizing the acidity of pomace blended dough did not change the water absorption significantly. As the percentage of pomace in blends increased from 0 to 11, a reduction of 42.8% in loaf volume was observed but neutralization of pomace acidity in dough resulted in only 26.6% reduction in volume under similar conditions. On the other hand loaf weight of the breads, prepared from blends with 11% pomace under unneutralized and neutralized conditions, increased by 7.0 and 3.1%, respectively. With increase of pomace percentage in blends up to 11, the bread firmness increased from 3N in control to 12 and 10N respectively, in unneutralized and neutralized pomace blended dough. Blending of pomace (0–11%) increased baking time from 20 min for control to 33 min for unneutralized and 27 min for neutralized blends. Sensory evaluation of the product revealed that breads containing up to 5% pomace were acceptable.     

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.