Effect of surfactant gels on dough rheological characteristics and quality of bread

Sodium stearoyl-2-lactylate (SSL), diacetyl tartaric acid esters of monoglyceride (DATEM), glycerol monostearate (GMS), and distilled glycerol monostearate (DGMS) surfactant gels were made with water and varying shortening contents. The effect of these gels on dough rheological characteristics and quality of bread was investigated. Overall, the surfactant gels improved the farinograph and extensograph characteristics of wheat flour, but the improvement reduced to some extent with the presence of shortening in the gels. Alveograph data indicated that dough properties improved with the addition of surfactant gels. Shortening in gels showed varying influence on the dough alveograph properties of wheat flour. The results indicated that the surfactant gels changed the rapid visco analyzer characteristics of wheat flour, and the presence of shortening in gels further altered the characteristics. All surfactant gels improved the volume, specific volume, texture, and overall quality scores of bread, but the improvement varied for different surfactants. By increasing the addition of shortening in gels, though the quality characteristics further improved, the response to surfactants reduced by increasing shortening content.     

EFFECT OF SURFACTANT GEL AND GUM COMBINATIONS ON DOUGH RHEOLOGICAL CHARACTERISTICS AND QUALITY OF BREAD

Sodium stearoyl‐2‐lactylate (SSL), diacetyl tartaric acid esters of monoglyceride (DATEM), glycerol monostearate (GMS) and distilled glycerol monostearate (DGMS) surfactant gels were made with water. Addition of surfactant gels decreased water absorption by the bread while xanthan, karaya, guar and locust bean gums increased the same. Only DGMS or GMS and gum combinations further improved water absorption. All the gums except for guar along with surfactant gels improved dough stability. Both surfactant gels and gums improved the extensograph dough properties of wheat flour to varying degrees. Alveograph characteristics of wheat flour improved to varying extents with surfactant gels while the gums influenced the viscoelastic properties in differing ways. Different combinations of surfactant gels and gums showed varied influences on rapid visco analyzer characteristics of wheat flour. Both surfactant gels and gums improved the bread making quality. Among surfactants, SSL in combination with gums, and among gums locust bean in combination with surfactant gels improved the bread making quality of wheat flour to a maximum extent.     

Effect of storage of surfactant gels on the bread making quality of wheat flour

Sodium stearoyl-2-lactylate (SSL), diacetyl tartaric acid esters of monoglyceride (DATEM), glycerol monostearate (GMS) and distilled glycerol monostearate (DGMS) surfactant gels were made with water and varying shortening contents. The SSL, DGMS, GMS and DATEM gels, with and without shortening in them, were stored for 3, 6, 9 and 15 days and their effects on bread-making quality were studied. All the gels improved the bread-making quality, to varying extents depending on the surfactant. On storage of gels, the improving effect was gradually reduced with increasing time, for all the gels made, with or without shortening. The adverse effect of storage on gels with shortening on bread-making quality was greater than that on gels without shortening and it varied from surfactant to surfactant. The results brought to light the adverse effect of storage of gels in improving the quality of bread.     

Comparison of uniaxial/biaxial extensional rheological properties of mixed dough with traditional rheological test results: relationship with the quality of steamed bread

The formula and preparation of steamed bread are different from those of western bread. The extensional rheological behaviour plays a key role in the development of steamed bread dough. However, there are inadequate studies on the rheological properties of mixed dough with yeast. In this study, the relationship between properties of dough in the presence or absence of yeast was elucidated. Besides, the flour characteristics and quality of steamed bread prepared from different wheat varieties were evaluated. The uniaxial/biaxial extensional rheological properties of wheat dough were compared with traditional rheological test results. Large deformations in the extensional properties were measured by Extensograph and the Kieffer extensibility rig, while the biaxial extension was quantified using uniaxial compression. These characteristics of dough and flour correlated with each other in different ways. Correlation analysis illustrated that the uniaxial extensional rheological properties of dough with yeast better indicated the quality of the steamed bread. Moreover, the total work for breakage of the dough with yeast was the best predictor for specific volume of steamed bread. The texture-based properties of steamed bread showed correlation with biaxial extension viscosity. The rheological tests provide useful information for evaluating wheat flour and steamed bread quality.     

Dough rheology and baking performance of wheat flour–lupin protein isolate blends

The impact of addition of two lupin protein isolates (LPI), enriched either in proteins belonging to globulin (LPI G) or to albumin (LPI A) fraction, on wheat flour dough and bread characteristics was investigated. LPI addition increased the dough development time and stability plus the resistance to deformation and the extensibility of the dough. The presence of LPI proteins in dough affected bread quality in terms of volume, internal structure and texture, while extra gluten addition to the blends to compensate for wheat gluten dilution, resulting from LPI addition, led to an improvement of bread quality characteristics. Generally, the incorporation of LP isolates to wheat flour delayed bread firming. The results obtained are discussed in terms of a possible action of LPI particles as a filler of the gluten network and partly in terms of possible interactions that take place between the gluten protein constituents and those of lupin.     

Effect of heat-moisture treated maize starch on the properties of dough and bread

Twenty percent of wheat flour was substituted with heat-moisture treated maize starch (HMT-M) or native maize starch (N-M), and the dough properties and the bread qualities were studied. Bread was baked with optimum (farinogram water absorption (63.0–66.4%)), 70% and 75% of water at the presence or absence of shortening. Elasticity of the dough with HMT-M decreased as compared with that of N-M and the control (without any maize starches) as measured by farinograph. Differential scanning calorimetry (DSC) and viscograph results showed that HMT-M hardly swelled and gelatinized in the dough. Specific volume of bread and softness of crumb baked with optimum water absorption decreased by the substitution of HMT-M. Bread quality containing HMT-M was improved at 70% water absorption as compared with optimum water absorption. By the addition of shortening, the specific volume of bread baked with HMT-M increased and the grain structure became finer. However, the firmness of crumb baked with HMT-M at the presence or absence of shortening was the same. As a result, HMT-M is still needed to study further for its application in breadmaking.     

谷朊粉对高含量荞麦面团的影响及其作用机理

本文全面研究了不同添加量谷朊粉(5%、10%和15%)对高含量(50%小麦粉替代率)荞麦面团流变学特性及馒头品质的影响,并以添加10%谷朊粉的混合面团和参照组(纯小麦粉)面团为基础,通过扫描电镜,红外光谱及分析面团中的化学作用力等分析手段,进一步探讨了谷朊粉对改善混合面团流变学性质及馒头品质方面的作用机理。结果表明,添加10%的谷朊粉能够增加荞麦-小麦混合面团中二硫键的含量,改变面团中的化学作用力(离子键、氢键含量和疏水作用力),进而改变面团中面筋蛋白的构象,改善面团的微观结构,从而改善混合粉的糊化特性及面团的粉质和拉伸特性,提高馒头的比容和弹性,改善馒头芯的孔隙结构,但仍达不到参照组馒头的品质,表明添加高含量荞麦全粉不仅仅是稀释面筋蛋白。     

不同全麦粉替代率对冷冻馒头品质的影响研究

目的 探讨不同全麦粉替代率对冷冻馒头品质影响的变化规律.方法 采用不同比例全麦粉(0、10％、20％、30％、40％、50％、60％、70％、80％、90％、100％)替代小麦粉,测定了混合粉的湿面筋含量和流变学特性,对比新鲜馒头,评价全麦粉替代率对冷冻馒头外观、质构和感官品质的影响.结果 随全麦粉替代率增加,面团湿面...     

Effect of emulsifiers,fat level and type on the rheological characteristics of biscuit dough and quality of biscuits

The effect of level and type of fat as well as emulsifiers on the rheological characteristics of biscuit dough and quality of biscuits has been studied. Increasing the level of fat from 150 to 250 g kg⁻¹ softened the dough, as indicated by a reduction in extrusion time from 108 to 18 s and an increase in compliance from 31.9 to 49.9%, while it reduced the development of gluten, as shown by a reduction in elastic recovery from 0.485 to 0.365 mm. Among the different types of fats used, hydrogenated fat produced the stiffest dough. Addition of any of the emulsifiers glycerol monostearate, lecithin or sodium stearoyl lactylate lowered the elastic recovery value, indicating their contribution to the shortening effect on gluten, and also resulted in a reduction in consistency and hardness and made the dough more cohesive. The maximum change was observed with sodium stearoyl lactylate. The density, breaking strength and compression strength of biscuits decreased, indicating an improvement in crispness, with increasing fat level. The thickness of biscuits was significantly higher when hydrogenated fat or oil was used in the formulation. Biscuits made with bakery shortening had better surface characteristics and higher crispness. Glycerol monostearate and lecithin brought about a greater improvement in the quality of biscuits when compared with sodium stearoyl lactylate. Studies indicated that emulsifiers in general had a greater beneficial effect, particularly in the case of biscuits made from medium hard wheat flour. © 1999 Society of Chemical Industry     

Influence of additives on the rheological characteristics and baking quality of wheat flours

 The response of Indian commercially milled flour to different additives was studied. The incorporation of reducing agents, such as l-cysteine hydrochloride (l-cysteine HCl), reduced the water absorption capacity (WAC) and stability of medium-strong wheat flour as well as weak wheat flour. This effect was also shown by other reducing agents or enzymes; however, the extent of change was found to be greater in medium-strong wheat flour. Surfactants/emulsifiers, such as glycerol monostearate, sodium stearoyl lactylate, and diacetyl tartaric esters of monoglycerides (DATEM), did not alter the WAC significantly, but marginally improved the stability of the dough. The change observed in the extensograph was greater with reducing agents and enzymes. In general, use of l-cysteine HCl or α-amylase or protease reduced the resistance to extension and increased the extensibility, depending on the level of addition. l-cysteine HCl, however, gave a greater reduction in the resistance to extension in medium-strong than in weak flour. On the other hand, use of surfactants/emulsifiers increased the resistance to extension and decreased the extensibility, and the effect was greater with DATEM. The bread volume improved considerably on incorporation of l-cysteine HCl, while DATEM also increased the loaf volume considerably at a 1% level in weak flour. Maximum improvement in loaf volume was found for DATEM in the case of weak flour, indicating that the responses of flour to different additives were different. Received: 10 February 1999 / Revised version: 27 April 1999     

脱脂大豆粉对小麦粉及馒头品质影响研究

将脱脂大豆粉添加到小麦粉中,研究其对小麦粉理化特性和馒头制作品质的影响。研究结果表明,在小麦粉中添加低于2%的脱脂大豆粉时,可以明显地改善小麦粉的品质,具体体现在可以增加面粉的白度,增加面团的吸水量、稳定时间以及拉伸曲线面积和拉伸比数,还可以改善馒头的品质;当在小麦粉中添加高于2%的脱脂大豆粉时,其对面粉的品质具有不好的影响,具体体现在降低小麦粉的白度以及面团的筋力,对馒头的品质也具有不良的影响,表现为馒头体积变小,颜色发暗。     

BREAD MAKING OF DURUM WHEAT WITH CHICKPEA SOURDOUGH OR COMPRESSED BAKER'S YEAST

Two ways of improving durum wheat bread-making quality were evaluated.
First, durum wheat (cultivar "Papadakis") was blended with bread wheat flour of good (A-flour) or medium (B-flour) quality (70% durum and 30% bread wheat flour). Durum wheat flour displayed the γ-gliadin 45 electrophoretic band and acceptable bread-making quality. Breads from flour blends had better volume, particularly the durum and A-flour blend. The addition of ascorbic and citric acid and malt flour improved dough rheological properties and thus bread volume, as well as staling rate and sensory characteristics. These were more pronounced in the blend of durum with B-flour.
Second, durum wheat flour alone was used to prepare chickpea sourdough-leavened bread, as flavor is important for consumer acceptance. With the addition only of salt, the chickpea sourdough-leavened durum wheat bread displayed acceptable loaf volume, distinguished flavor and longer shelf life compared with bread prepared with compressed baker's yeast.

PRACTICAL APPLICATIONS

One of the practical applications of this study is the possibility of using a common durum wheat cultivar instead of local varieties as is the case with traditional breads. Results of this work may be useful for promoting greater acceptance of durum wheat breads as well as expansion of the use of a traditional Mediterranean chickpea sourdough-leavened durum wheat bread with distinguished flavor and taste.
This work may serve as a guide for determining the quality of flours suitable for production of "home made" or "village" bread (which has high market value as specialty bread) by blending durum and bread wheat flours. Best results are obtained with good-quality bread wheat flour, regardless of the good quality of durum wheat cultivar used, together with the use of the dough improvers implemented in this work.     

食品添加剂对面团流变学特性影响的初步实验研究

面团的流变学特性会对面制品的质量产生重要影响,而食品添加剂的种类和添加量将显著改变面团的流变学特性。本研究利用质构仪考察了若干种食品添加剂对面团拉伸特性的影响。结果表明:面团中添加NaCl、单甘酯、明胶、抗坏血酸、面粉强筋剂、海藻糖等都对面团的拉伸性能有一定的影响,不同的添加剂影响各异。相对而言,1.5%～2%的NaCl、0.5%的单甘酯、0.4%的明胶、0.4%的面粉强筋剂等都对面团的抗拉伸性能和稳定性有明显改善。而总体上,抗坏血酸和海藻糖对面团拉伸性能的作用主要是增加其抗拉伸应力,但会使面团的拉伸时间显著缩短,本研究的结果为面制品生产中正确选择适当的食品添加剂及添加量提供了基础数据。     

小麦粉吸水速率对面团特性及馒头品质的影响

该文以不同吸水速率的小麦粉为基础,研究在相同的揉混条件下,其面团特性及馒头品质的变化。使用粉质仪将面团稠度达到最高时所用的加水量与消耗的时间的比值定义为吸水速率,测定不同吸水速率小麦粉其粉质特性、湿面筋含量、面筋指数、游离巯基与二硫键含量、面团质构特性、馒头比容与高径比、馒头的质构特性。研究结果表明,当小麦粉吸水速率从0.17 g/s增大到3.87 g/s时,面团的稳定时间及粉质质量指数显著下降。其湿面筋含量从38.81%下降到19.19%,二硫键含量从13.31μmol/g下降到9.05μmol/g。面团的质构特性在发酵0 min时呈先升高后降低趋势、在醒发45 min后整体呈下降趋势。馒头的比容从2.67 mL/g降低到2.27 mL/g、高径比从0.68降低到0.56,其硬度、胶着性、咀嚼性均成下降趋势。整体而言,吸水速率低的小麦粉其面团相对较硬且馒头较为筋道有嚼劲;吸水速率较高的小麦粉其面团硬度稍弱且馒头较为松软。     

质构仪在面团和面包品质评定中的应用研究(英文)

以八种品牌面粉为试验材料,采用英国 CNS-FARNELL 公司制造的质构仪测试了面团的硬度、弹性、粘力、粘着性、断裂力、断裂能量、断裂回复形变程度、回复能量、回复形变程度等九种指标,并通过相关分析研究了这些指标与面包品质(面包体积和弹性变化率)以及与小麦面粉的品质性状的相互关系。研究结果表明:面团的硬度、粘力与面包的体积呈正相关,相关系数分别为 0.546、0.568,弹性与面包的体积呈负相关,相关系数为-0.606;粘力与24h后室温下弹性变化率呈显著的正相关,相关系数为0.707。面团的质构特性与面粉的品质指标的相关性也非常明显。     

The application of dextran compared to other hydrocolloids as a novel food ingredient to compensate for low protein in biscuit and wholemeal wheat flour

Wheat is primarily used for bread-making. However, fungal diseases, grain moisture at harvest and low-protein contents strongly influence the quality of the wheat flour, thus creating challenges for traders, millers and commercial bakers who struggle to produce consistently high-quality products. This paper address the replacement of low-protein/wholemeal flour functionality for bread-making purposes. Three hydrocolloids, xanthan gum, dextran and hydroxypropyl methylcellulose, were incorporated into bread recipes based on high-protein flours, low-protein flours and coarse wholemeal flour. Hydrocolloid levels of 0–5 % (flour basis) were used in bread recipes to test the water absorption. The quality parameters of dough (farinograph, extensograph, rheofermentometre) and bread (specific volume, crumb structure and staling profile) were determined. Results showed that xanthan had negative impact on the dough and bread quality characteristics. HPMC and dextran generally improved dough and bread quality and showed dosage dependence. Volume of low-protein flour breads were significantly improved by incorporation of 0.5 % of the latter two hydrocolloids. However, dextran outperformed HPMC regarding initial bread hardness and staling shelf life regardless the flour applied in the formulation.     

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.     

Combined effects of wheat gluten and carboxymethylcellulose on dough rheological behaviours and gluten network of potato–wheat flour-based bread

Incorporating high level of potato flour into wheat flour enhances nutritional values of bread but induces a series of problems that lead to the decline of the bread quality. To overcome the barrier, wheat gluten and carboxymethylcellulose (CMC) were added into potato–wheat composite flour to improve dough machinability and bread quality. The rheological properties, thermo-mechanical properties and microstructures of dough were investigated. The results showed that the interaction between gluten and CMC mitigated the discontinuity of gluten matrix and gluten protein aggregation caused by the addition of potato flour, which yielded a more branched and compact gluten network. The compact three-dimensional viscoelastic structure induced improvements of gas retention capacity and dough stability, making it mimic the machinability properties of wheat flour dough. Bread qualities were apparently improved with the combined use of 4% gluten and 6% CMC, of which specific volume increased by 42.86%, and simultaneously, hardness reduced by 75.93%.     

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。     

Identification and effect of ethyl galactoside on the properties and baking quality of dough

One of the reaction products of lactose and lactase in the presence of ethanol was isolated and identified as ethyl galactoside (EG) using gas-liquid chromatography, fast atom bombardment–mass spectrometry and ¹H and ¹³C Nuclear Magnetic Resonance Spectroscopies. Dough and bread qualities were studied by adding three different levels of EG (0.033, 0.067 and 0.134 mmol per kg of wheat flour) to the bread ingredients. Addition of 0.067 mmol EG per kg of wheat flour indicated significantly large loaf volume of the bread, and retarded the firmness of bread during storage when compared to the control. The small level of EG significantly improved the bread qualities as compared with lactose or a combination of lactose and lactase. And also, the wheat flour dough containing EG (0.067 mmol) significantly reduced the modulus of elasticity and viscosity coefficient. The addition of EG (0.067 mmol) to the bread ingredients slightly tended to lower the gelatinisation temperature of starch. The scanning electron microscopic observations indicated that the gluten portion of dough containing EG was developed well, and this caused the large loaf volume and good appearance from cross view of bread.