Effect of mixing method on the rheological characteristics of biscuit dough and the quality of biscuits

 The effect of different mixing methods on the rheological characteristics of biscuit dough and the quality of biscuits was studied. The amount of water required to prepare the desired consistency of dough varied considerably depending on the mixing method: 16% for the creaming method (CM) and the sugar solution method (SSM), 20% for the blending method (BM), 24% for the all-in-one method (AOM), and 25% for the creaming followed by water and flour addition method (CWFM). Although the extrusion time, compliance, apparent biaxial extensional viscosity and hardness values of doughs made by different mixing methods were similar, the other rheological characteristics differed significantly. Elastic recovery, which is indicative of gluten development, was lower in the case of doughs mixed by the CM and the SSM and higher for the AOM and the CWFM. The CM produced dough with lower cohesiveness and adhesiveness, while the AOM produced dough with higher cohesiveness and adhesiveness. Biscuits produced by the CM and the SSM had lower thickness, higher spread and crisper texture. However, biscuits made by the other mixing methods had excessively higher thickness, porous crumb and hard texture. Received: 21 December 1998     

Compositional and varietal influence of finger millet flour on rheological properties of dough and quality of biscuit

Biscuits prepared from flour composites containing 60:40 and 70:30 (w/w) finger millet:wheat flour were evaluated for its dough characteristics and biscuit quality. Hardness of biscuit dough measured by textural profile analysis was more in 60:40 combination than in 70:30 level. The dough became more adhesive with higher level of wheat flour and it varied across varieties. Extensograph data also showed that resistance of biscuit dough increased with the increasing levels of wheat flour. However, very little difference was observed between addition of 30 and 40 g/100 g wheat flour in terms of resistance to extension. Wheat composite flour (40 g/100 g) had higher water absorption capacity than in 30 g/100 g composite flour. Bandwidth of composite flour was narrower in 40 g/100 g wheat flour composite. Expansion of biscuit and breaking strength after baking was more in 70:30 composite than in 60:40. Among the varieties used, VL-324 brought about the positive changes of composite flour in rheological characteristics in terms of adhesiveness, extensibility and resistance to extension, which in turn improves biscuit quality. It provided better physical quality biscuit dough and biscuit in terms of its spread ratio, density and breaking strength. Studies indicated that composite of finger millet and wheat flour (60:40) was found better, particularly in case of biscuit quality. Out of six varieties, VL-324 was found best in terms of biscuit quality as well as acceptability.     

Influence of fibre from different cereals on the rheological characteristics of wheat flour dough and on biscuit quality

Demand for health oriented products such as sugar-free, low calorie and high fibre products is increasing. One such recent trend is to increase the fibre content in food products to overcome health problems such as hypertension, diabetes, and colon cancer, among others. Consumption of high fibre products consisting of indigestible cellulose, hemicellulose, lignin and gums have several health benefits. Apart from these benefits, β-glucan-rich fibres have the benefit of reducing the absorption of glucose. Fibre sources from wheat, rice, oat and barley were used to study their influence on rheological characteristics of wheat flour dough and biscuit making quality. Ash, total protein and dietary fibre content of bran samples ranged between 4% and 10%, 12% and 14% and 20.4% and 49.5%, respectively. Farinograph characteristics of the wheat flour-bran blends showed increase in water absorption from 60.3% to 76.3% with increase in the level of bran from 0% to 40%. The resistance to extension values as well as extensibility of the dough decreased with increase in the bran level. The spread ratio of the biscuits prepared from wheat, rice and oat bran blends decreased from 8.38 to 7.52, whereas the same increased to 9.3 for biscuits prepared from barley bran blends. The breaking strength values of biscuits ranged between 1.34 and 3.83 kg. Highly acceptable biscuits could be obtained by incorporating 30% of oat bran or 20% of barley bran in the formulation.     

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     

Impact of dairy protein powders on biscuit quality

The effects of whey protein concentrate and sodium caseinate (NaCas) on a short dough biscuit formulation were investigated with respect to dough characteristics and final product quality. Dairy powders were added at levels of 5, 10 and 15% of flour weight. Addition of 5 and 10% dairy protein powders reduced dough hardness. Doughs containing 10 and 15% NaCas had significantly higher springiness and cohesiveness values compared with the values of the control (p<0.05). Addition of both protein powders increased surface brownness, indicated by an increase in L* value. Whey protein concentrate resulted in biscuit shrinkage during baking, whereas biscuits containing NaCas powders were significantly larger than the control (p<0.05). In general, biscuits containing protein powders were harder than the control and hardness increased as the level of protein powder was increased. Confocal laser microscopy showed that doughs with NaCas had an extensive protein network and NaCas appears to interact with the flour proteins.     

亚麻籽饼粕粉对面团流变学特性以及饼干品质的影响

本文将亚麻籽饼粕粉以0%～40%的比例取代低筋小麦粉,研究亚麻籽饼粕-小麦混合粉的粉质特性、糊化特性以及面团的动态流变学特性、质构特性,同时研究亚麻籽饼粕粉添加量对饼干延展比、颜色、质构及感官品质的影响,结果表明,随着亚麻籽饼粕粉含量增加,面团的吸水率从56.8%增加到80%、形成时间从1.1 min增加到13.5 min、稳定时间增加约1倍,弱化度从89降低到5,粉质质量指数增加约4.2倍,硬度从297.9增加到1438.8,同时饼干的脆性略有下降,颜色变暗。亚麻籽饼粕粉含量超过30%后,可以抑制淀粉的短期回生。添加20%及以下含量亚麻籽饼粕粉的饼干总体可接受度高、风味好、质构佳。     

Interrelationship between rheological characteristics of dough and quality of biscuits; use of elastic recovery of dough to predict biscuit quality

Rheological characteristics of biscuit doughs as influenced by ingredients, processing conditions and additives were related to the quality of biscuits. Extrusion time (r=−0.54, P<0.01), elastic recovery (r=−0.84, P<0.01), apparent biaxial extensional viscosity (r=−0.62, P<0.01), consistency (r=−0.73, P<0.01) and hardness (r=−0.68, P<0.01) of the dough were significantly correlated to the spread of the biscuits. Elastic recovery (r=−0.64, P<0.01) and cohesiveness (r=0.67, P<0.01) of dough mainly influenced the thickness of biscuits. Extrusion time (r=0.53, P<0.01), elastic recovery (r=0.78, P<0.01), apparent biaxial extensional viscosity (r=0.59, P<0.01), consistency (r=0.62, P<0.01) and hardness (r=0.60, P<0.01) were positively correlated to density of biscuits. The density of biscuits was found to be well correlated to sensory texture (r=−0.49, P<0.01). The studies have clearly shown that among the various rheological characteristics, elastic recovery was found to be the best index in predicting the textural quality of biscuits.     

Effect of steaming on the rheological characteristics of wheat flour dough

 The effect of steaming on the various rheological characteristics of wheat flour dough was studied. Steaming of flours at atmospheric pressure for 15 min completely denatured the gluten and reduced the water absorption capacity from 58.4% to 45.0%. Even steaming for just 5 min increased the resistance to extension considerably from 500 BU (Brabender Units) to 1000 BU and the ratio figure (resistance to extension/extensibility) from 4.2 to 27.4, indicating stiffening of the dough. The dough made from steamed flour had a higher hardness value of 91.1 N than the dough made from raw wheat flour which had a value of 51.1 N. The pasting characteristics of flour steamed for 15 min measured in a Rapid Visco Analyser showed increased peak viscosity from 218 rapid visco units (RVU) to 257 RVU as well as increased cold paste viscosity from 175 RVU to 200 RVU and increased hot paste viscosity from 94 RVU to 108 RVU for flour steamed for 15 min. Received: 4 August 1998 / Revised version: 23 October 1998     

Influence of yeast and frozen storage on rheological, structural and microbial quality of frozen sweet dough

The aim of the present study was to investigate the effect of yeast content and frozen storage (9 weeks at −40 °C) on the structural and rheological parameters, and fermentative activity of frozen sweet dough. Two types of dough were studied (to estimate dough shelf life): simple yeasted dough (SY) and double yeasted dough (DY). Fermentative activity (yeast viability, gassing power, and dough volume), rheological and textural parameters were assessed for frozen sweet doughs.These effects were explored by different and complementary methods: Fourier transform infrared (FTIR), dynamic rheology, texture profile analysis (TPA) and differential scanning calorimetry (DSC).The data showed that the longer the frozen storage time at −40 °C, the higher the decreased of frozen sweet dough quality. The rheological attributes such as hardness, ΔS, springiness, tan δ and yeast activity declined significantly during frozen storage. This modification led to lower specific volume of frozen sweet dough during proofing.The observed changes of the frozen sweet doughs rheological properties after thawing may be attributed to the damage on the gluten cross-linking, mainly produced by the ice crystallization during frozen storage. The storage effect was particularly concentrated in the first 27 days of storage.     

Effect of blending of raw and steamed wheat flour on the rheological characteristics of dough

 The blended dough made from raw wheat flour and wheat flour steamed for 15 min at a ratio of 1 : 1, along with minor ingredients (salt, oil) showed reduced farinograph water absorption capacity. The stability of the blended dough with oil was reduced while the mixing tolerance index increased. The inclusion of salt in the blend increased the resistance to extension and also the area under the curve. The hardness and cohesiveness measured by means of texture profile analysis decreased with the inclusion of oil in the blend, while increasing with the addition of salt. The Rapid Visco Analyser used to measure pasting characteristics showed a peak viscosity which increased for the blend with salt, but decreased for that with oil. Similarly, the hot paste viscosity, cold paste viscosity and area under the curve increased for the blend with salt, but decreased for the blend with oil. Received: 5 February 1999 / Revised version: 21 April 1999     

大黄鱼鱼卵磷脂对面团流变学和面包感官品质的影响

目的 探究大黄鱼鱼卵磷脂对面团流变学和面包感官品质的影响。方法 以小麦面包为对象,面团动态流变性及面包比容、色泽和质构为评价指标,分析不同大黄鱼鱼卵磷脂添加量（0%、0.2%、0.6和1.0%）对面包外观、感官品质和质构的影响,将添加大豆磷脂（0.6%）的面团和面包作为对照组。结果 随着提高大黄鱼鱼卵磷脂的添加量,面包的硬度、咀嚼性持续增大,弹性、粘聚性逐渐降低。 当鱼卵磷脂添加量为0.2%时,能够显著改善面包的质构,而且能够增大面包的比容,生产出的磷脂-小麦面包口感较好,入口软糯。与普通小麦面包相比,其面包蓬松稳定,具有较好黏弹性。结论 添加大黄鱼鱼卵磷脂比大豆磷脂更能显著改善面包感官品质。     

Effects of freezing and frozen storage conditions on the rheological properties of different formulations of non-yeasted wheat and gluten-free bread dough

Empirical and fundamental rheological measurements were made on fresh and frozen dough to study the effects of freezing and frozen storage conditions. Frozen dough was stored at two different temperatures, −18 °C and −30 °C, and for 1, 7 and 28 days. Four dough formulations were tested: a standard wheat dough, a fibre-enriched wheat dough, a standard gluten-free dough and a gluten-free dough containing amaranth flour. No yeast was used in any formulation. The wheat dough is more affected by freezing and by the first days of storage whereas the gluten-free dough is more affected by a longer storage time. A storage temperature of −30 °C alters dough rheological properties more than a storage temperature of −18 °C. The addition of dietary fibres to the wheat dough increases its resistance to freezing and frozen storage. The addition of amaranth flour to gluten-free dough also increases its resistance to freezing but decreases its resistance to storage conditions.     

天然菊粉对面团流变学及面条品质的影响

为了获得膳食纤维含量高的面条,探讨了天然菊粉对面粉糊化、面团流变学和面条品质的影响。结果表明,天然菊粉能够显著(p<0.05)降低面粉糊化过程中的峰值黏度、峰谷黏度、最终黏度和破损值,显著提高糊化温度(p<0.05)。天然菊粉能够改善面条面粉的粉质和拉伸特性。添加天然菊粉能使面团吸水率和弱化度降低,而使面团的形成时间、稳定时间和粉质质量指数增加。随天然菊粉添加量的增加,面团的拉伸阻力和拉伸比例逐渐增大,而拉伸曲线面积和延伸度呈先增大后减小的趋势。当天然菊粉添加量为7.5%时,面条的干物质吸水率高达180.66%。在天然菊粉1.25%~15%添加量实验范围内,天然菊粉的添加对面条的弹性和咀嚼性没有显著影响(p>0.05)。综合考虑,天然菊粉的最适添加量为7.5%。     

小麦粉改良剂对面团流变学特性的影响

采用粉质仪和拉伸仪研究不同面团改良剂单体(酶制剂、氧化剂、磷酸盐)对小麦粉面团流变学特性的影响。结果表明:α-淀粉酶、木聚糖酶和ADA对面团粉质特性有显著影响;木聚糖酶、ADA和Vc对面团拉伸特性有显著影响,且ADA的影响程度较大。随着α-淀粉酶、木聚糖酶和ADA添加量的增加,面团的稳定时间和评价值呈下降趋势,弱化度呈上升趋势。随着木聚糖酶添加量的增加,延伸性呈增大趋势,拉伸比值和最大抗拉伸阻力均呈下降趋势,且变化幅度较大;随着ADA和Vc添加量的增加,延伸性、拉伸比值和最大抗拉伸阻力与添加木聚糖酶时变化趋势相反。焦磷酸钠和三聚磷酸钠对拉伸特性无明显作用,在一定添加量时对面团粉质特性有明显影响。脂肪酶对粉质和拉伸特性影响不明显。     

不同水对面团性质影响

通过在等量面粉中分别加入5种不同的水制成面团,测定其形成湿面筋含量、色泽及质构性质并进行比较。结果表明:去离子水不适于制作面团;加农夫山泉(矿物质水)和自来水制作面团性质略有改善,但色泽变差;加盐水制作面团粘性小,面团形成湿面筋含量增加、延伸性好、色泽好;加碱水可加速和面进程,产生淡黄色外观,但不能添加过量,否则会恶化面团品质。     

米粉对面团流变特性及酥性饼干品质的影响

目的 探究了米粉的添加对面团流变学特性以及酥性饼干品质的影响。方法 选取了3种米粉(粳糯米粉、籼糯米粉、普通粳米粉)分别以0%、10%、20%、30%的比例替代中筋小麦粉，研究分析了米粉-中筋小麦粉混合粉的糊化特性，面团的粉质拉伸特性，动态流变以及酥性饼干的理化性质，质构特性及感官品质。结果 随着两种糯米粉添加量增加，混合粉的糊化特征值均呈下降趋势，而添加普通粳米粉后则趋势相反；添加米粉后混合面团的吸水率和弱化度随着三种米粉的添加量的增加显著升高，分别可达65.7%和160.50，而面团形成时间和稳定时间则显著降低(P<0.05)；混合面团的弹性模量（G''），黏性模量（G"）和损耗角正切值（tanδ）随着米粉添加量的增加而逐渐减小，表明米粉的添加减弱了面筋网络的形成；与低筋粉酥性饼干相比，混合粉酥性饼干的延展比较低，且三种米粉的添加可显著提升酥性饼干的脆性，经感官评价及综合比较后得出添加20% 籼糯米粉的混合粉饼干整体品质较佳。结论 通过在中筋面粉中加入米粉后可以有效改变面团的特性，以替代低筋面粉应用于酥性饼干的加工 ，本研究也为米粉在酥性饼干专用粉的制备奠定了理论基础。     

挤压膨化小扁豆粉对面团特性及面条品质的影响

将质量分数0%、5%、10%、15%、20%、25%和100%的挤压膨化小扁豆粉添加到小麦粉中,研究了挤压膨化小扁豆粉对面团特性及面条品质的影响。结果表明,随着挤压膨化小扁豆粉添加量的增大,混合粉中蛋白质和灰分含量增大,水分和脂肪含量减小。混合粉面团形成时间和稳定时间显著减小,弱化度增大。当挤压膨化小扁豆粉添加量超过10%后,淀粉的糊化热稳定性和蒸煮稳定性均变差,淀粉酶解速率增大。挤压膨化小扁豆粉添加量10%～15%组面团黏弹性与对照面团最为接近,且在该范围添加量下,面条硬度和咀嚼性大小适宜,弹性良好。添加量0%～15%时挤压膨化扁豆粉的添加不影响面条的断条率和蒸煮损失率,综合考虑,推荐面条中挤压膨化小扁豆粉的添加量为10%。