Effect of Carob Flour Addition on the Rheological Properties of Gluten-Free Breads

In this study, the rheological properties of gluten-free doughs from rice flour containing different amounts of carob flour were investigated. Water added changed in response to the carob amount. Dynamic oscillatory and creep tests were performed in order to gain knowledge on the rheological behaviour of doughs, which is essential for the control of the bread-making procedure and the production of high-quality bread. Simple power law mathematical models were developed in order to evaluate the effect of carob and water added in dough rheological behaviour. Creep data evaluation demonstrates that an increase in water content decreased the resistance of dough to deformation and, therefore, dough strength, whereas carob flour increased the elastic character and structure strength of the dough. This was also found in dynamic oscillatory tests. Increased amounts of carob flour led to an increase in bread dough elastic character since fibre addition elastifies and strengthens the dough structure. Moreover, doughs exhibited a solid-like viscoelastic character, with the storage modulus (G′) predominant over the loss modulus (G″). Dough rheological properties have an important effect on baking characteristics. Rheological experiments and applied mathematical models can provide us with good knowledge of rheological behaviour and dough viscoelasticity prediction. Therefore, dough samples containing carob-to-water ratios of 10:110 and 15:130 can be considered to possess a balance between the viscous and elastic properties compared to the other samples.     

Influence of Flour Particle Size on Quality of Gluten-Free Rice Cakes

There is a growing interest in developing gluten-free bakery products in recent time. In cake making, gluten network formation is not essential, but hardly any information exists about the influence of the gluten-free flour characteristics affecting the final cake product. This study analyses the influence of two different rice cultivars (short and long) with different flour particle size in batter characteristics (specific volume, viscosity and internal structure) and in sponge and layer cake formulas (volume, shape, texture and colour). During starch gelatinization, the finest flours (median particle size finer than 100 μm) increased their viscosity and reached the peak viscosity (RVA) later than the coarsest flours. Moreover, the finest flours gave batters with lower specific volumes but with an air distribution in smaller and uniform bubbles in both formulas. These flours also produced higher volume and lower firmness in sponge cakes and greater symmetry index both in sponge and layer cakes. The rice type also influenced batter and cakes characteristics but in a lesser extent. The different results obtained depending on the rice flour particle size, type flour and cake formulation indicate the need to define them both in industrial specifications and in research studies.     

制粉车间设备操作与改进

前言 良好的设备、完善的工艺流程、准确的电气控制,是小麦制粉过程中的3大要素,是相对独立、相互依存的统一体.电气控制的准确动作是设备正常运转的前提.设备的完好与正常运转是工艺实现的基础,工艺的有效实现才能生产出符合市场需求的合格产品.所以,如何对这三者进行正确操作与管理,并根据实际进行相应改造,使之有机统一、协同作用,是解决实际生产问题,提高市场竞争能力的最直接最有效方法.     

不同实验磨研磨的小麦粉的粒度分布

采用4种不同型号的实验磨研磨不同硬度的小麦,通过激光粒度仪测试小麦粉的粒度。结果表明,不同小麦粉的粒度差异较大,尤其是细小粉粒的分布很不均衡。采用光辊心磨的实验磨磨制的小麦粉,其细粉比例高于齿辊实验磨,但低于生产线小麦粉的细粉比例。小麦硬度越高其细粉比例越低。     

Particle Size Fractionation of High-Amylose Rice (Goami 2) Flour as an Oil Barrier in a Batter-Coated Fried System

The particle size effects of high-amylose rice (Goami 2) flour on quality attributes of frying batters were characterized in terms of physicochemical, rheological, and oil-resisting properties. High-amylose rice flours were fractionated into four fractions (70, 198, 256, and 415 μm) of which morphology was also analyzed by scanning electron microscopy. Rice flour with smaller particle size exhibited a higher degree of starch gelatinization, giving rise to increased pasting parameters. When the rice flours were incorporated into frying batters, higher steady shear viscosity was observed in the batters with finer rice flour, which could be well characterized by the power law model. In addition, the dynamic viscoelastic properties of the batters were enhanced by the use of rice flour with smaller particle size, which also caused an increase in batter pickup. When subjected to deep fat frying, the batters with finer rice flour exhibited reduced moisture loss. Furthermore, the oil uptake was found to have a positive correlation with the particle size of rice flour (R ²?=?0.88), even showing the reduction of oil uptake by 15%. It could be synergistically attributed to the formation of outer starch granular layers, high batter viscosity/pickup, and reduced moisture loss by finer rice flour.     

小麦粉粒度变化与淀粉损伤程度

从小麦淀粉的原生态(粒径大小与分布)出发,首先拿等级粉的粗细度与之比较,分辨淀粉损伤的综合程度和倾向,进而对工艺中各研磨部位的面粉粒度、淀粉损伤程度进行分析研讨,以化验的量化结果,揭示淀粉损伤的真实面貌。紧紧抓住面粉粒度变化和淀粉损伤程度的同步因素,逐渐深入,诠释不被重视的等级粉淀粉损伤原因和专用粉能适应不同面制品要求的理论基础,提出了研究淀粉损伤和面粉粒度是制粉工艺研究的当务之急。     

粒度与小麦粉品质关系的研究

采用粉筛将1M₃、2M₁系统粉筛分成4种不同粒度区间小麦粉(A区间：粒度>118μm、B区间：100μm<粒度≤118μm、C区间：85μm<粒度≤100μm、D区间：粒度≤85μm),研究粒度与小麦粉品质之间的关系。结果表明：随筛分粒度减小,白度增大,破损淀粉增多,面团形成时间和稳定时间、粉质质量指数呈先增后减趋势,弱化度则先减后增,吸水率在大粒度区间最高;1M₃系统粉黏度和回生值降低,2M₁系统粉黏度先增后减,衰减值和回生值无明显变化趋势;糊化温度明显升高。C粒度区间小麦粉淀粉含量低、蛋白含量高、面筋品质较好;B、C粒度区间小麦粉水溶剂保持力和乳酸溶剂保持力较高、蔗糖溶剂保持力较低,其面团延伸性、弹韧性及面团筋力也较好。因此,B、C粒度区间小麦粉品质较好。     

Water Binding of Wheat Flour Doughs and Breads as Studied by Deuteron Relaxation

Water mobility in wheat flour doughs and breads was investigated by deuteron relaxation using pulsed NMR. Water was replaced by deuterium oxide in dough and bread at different concentrations. Mixograms indicated that wheat flour associated more strongly with D₂O than it did with H₂O. Varying the D₂O:H₂O ratio of flour doughs had no effect on the longitudinal (T₁) or transverse (T₂) relaxation times of deuteron. Hard wheat and soft wheat flour doughs showed similar increases in T₁ and T₂ with increasing moisture content. Staling of bread crumb was accompanied by decreased T₁ and T₂, indicating an overall decrease in water mobility and increase in water binding. The decrease in water mobility of bread crumb with storage time was shown to be independent of reduction in moisture content.     

Precooked Corn Flour for Venezuelan Arepa Preparation: Characterization of Particle Size Fractions

Commercial precooked corn flour (used for Venezuelan arepa preparation) was sieved into fractions using a Ro-tap shaker. Particles 297 μm thick had the highest consistency. Particles 354 μm thick had the longest stability, their yellow color value (Hunter) was the smallest, and arepas made from them had the highest elasticity. Sedimented volumes were greater for particles 297 μm thick and coarser. Functional properties, evaluated by trained judges, were better for fractions with sizes between 297 and 420 μm. Regression analysis showed that particles between these sizes are the best suited for Venezuelan arepa preparation.     

粉路的解读与分析

从皮磨、重筛、渣磨、清粉及心磨和尾磨系统对粉路进行了解读,并对皮磨、渣磨、心磨和清粉系统的操作要点进行分析。     

Influence of Buckwheat Flour and Carboxymethyl Cellulose on Rheological Behaviour and Baking Performance of Gluten-Free Cookie Dough

In the present study, the influence of buckwheat flour and carboxymethyl cellulose (CMC) on the production of sheetable gluten-free cookie dough of acceptable rheological properties and subsequently their effect on the quality of gluten-free cookies was studied. The buckwheat flour was used to replace 10, 20 and 30 % of rice flour in gluten-free formulations. Cookie doughs of 100 % rice flour and 100 % wheat flour served as control samples. The impact of CMC addition was examined on formulation containing 20 % of buckwheat flour. Oscillatory and creep measurements were applied to test the effect of buckwheat flour and CMC on the viscoelasticity of gluten-free cookie dough. Frequency sweep results showed that all samples had solid elastic-like characteristics. An increase in the buckwheat flour addition led to a decrease in storage modulus and zero shear viscosity and an increase in tan δ and maximum creep compliance, while the addition of CMC led to an increase in dough tenacity and resistance to deformation. Cookie dough containing 30 % of buckwheat flour expressed the highest viscous properties, as revealed by relative viscous compliance value. The gluten-free dough containing CMC and buckwheat flour between 20 and 30 % replacement level showed similar strength and extensibility as wheat cookie dough. The results of the physical and sensory evaluation of gluten-free cookies showed that buckwheat addition led to a decrease in cookie hardness and fracturability and an increase in eccentricity (deformation from regular shape) as well as the overall acceptability, as evaluated by untrained panellists.     

Gluten-Free Bread Making Trials from Cassava (Manihot Esculenta Crantz) Flour and Sensory Evaluation of the Final Product

The aim of this work was to evaluate the effectiveness of the use of cassava flour in bread making, and the sensory acceptability of the final product. Different baking trials were carried out by using egg white and extra-virgin olive oil, in consideration of their high nutritional value with respect to other food additives (i.e., hydrocolloids). Significant (p < 0.05) improvements of loaf specific volume (from 2.24 to 3.93 mL/g) and crumb firmness (from 9.14 to 4.67 N) were achieved by contemporarily including egg white and extra-virgin olive oil in the formulation. Cassava breads containing both these ingredients obtained the best scores from panelists for all the test breads examined and resulted attractive as the wheat bread prepared as reference.     

秋冬季节面粉生产过程中应注意的问题

秋冬季节由于气候变化,给面粉生产带来一些诸如增白剂起速和白度以及制粉技术方面的影响,根据多年的实践总结低温下面粉使用添加剂应注意的问题及其添加剂的选择和品质鉴定方法.     

小麦粒度硬度水分调节和制粉性能

阐述了小麦粒度范围和分离方法；小麦硬度和检测方法；小麦水分调节的理论、加水量、吸水率和渗透速度；不同粒度小麦的水分调节试验和不同粒度小麦的制粉性能试验：包括制粉结果、破碎磨剥刮率和中间货料出率、灰分曲线、蛋白质和面筋出率、粉质仪曲线数据，以及方案比较和建议。     

Rapid Separation and Measurement of Particle Size Distribution of Starch Granules by Sedimentation/Steric Field-Flow Fractionation

Sedimentation/steric field-flow fractionation (Sd/StFFF) is introduced as a new technique for the size analysis of starch granules. Sd/StFFF provides both high speed and high resolution, and narrow size fractions of starch granules can be collected from the eluting stream for further characterization by microscopy or other techniques. The sedimentation FFF instrument was calibrated and applications were made to 12 starch samples derived from wheat, durum wheat, corn, oat, tapioca, and potato. The instrument response curve (the fractogram) and the size distribution curves for several of these samples were recorded. The mode or bimodal diameters and the percentages of A-and B-granules were compiled.     

Navy Bean Flour Particle Size and Protein Content Affect Cake Baking and Batter Quality1

Whole navy bean flour and its fine and coarse particle size fractions were used to completely replace wheat flour in cakes. Replacement of wheat flour with whole bean flour significantly increased the protein content. The protein content was adjusted to 3 levels with navy bean starch. The effect of navy bean flour and its fractions at 3 levels of protein on cake batter rheology and cake quality was studied and compared with wheat flour samples. Batters prepared from navy bean flour and its fractions had higher viscosity than the cake flour. Reducing the protein content by addition of starch significantly lowered the viscosity of cake batters. The whole navy bean flour and coarse bean fraction cakes were softer than cakes made with wheat flour but had reduced springiness. Principal component analysis showed a clear discrimination of cakes according to protein. It also showed that low protein navy bean flour cakes were similar to wheat flour cakes. Navy bean flour with protein content adjusted to the level of cake (wheat) flour has potential as a healthy alternative in gluten‐free cakes.     

麦麸添加量和粒度对小麦淀粉糊化特性的影响

以强筋和中筋小麦粉为试验材料,添加2个强筋小麦和2个中筋小麦麸皮,并采用5个添加量(5%,10%,15%,20%,25%)、4个粒度(0.16～0.43 mm,0.43～1.0 mm,1.5～2 mm,2.5～3.0 mm)处理,分析麦麸添加量、粒度对小麦粉糊化特性的影响。随着麦麸添加量的增加,峰值黏度、低谷黏度、最终黏度、黏度面积、反弹值和峰值时间都呈现显著下降趋势,而淀粉糊化起始时间和糊化温度均呈现的Y=AX2-BX+C二次曲线增加趋势。峰值黏度、低谷黏度、最终黏度、黏度面积、反弹值平均值随着麸皮粒度的增大,均呈现升高趋势,而麦麸粒度对糊化温度和糊化起始时间没有影响。中筋小麦麸皮粒度在0.16～2 mm之间对峰值黏度和黏度面积的影响没有显著的差异,而超过1.5 mm的强筋小麦麸皮粒度对峰值黏度、低谷黏度、最终黏度和黏度面积的影响差异显著;小于2 mm的麸皮粒度对稀懈值的影响差异不显著,小于1 mm的麸皮粒度对反弹值的影响差异不显著。     

小麦粉加工技术与装备发展趋势

1前言 粮油加工业作为粮食再生产过程的重要环节和食品工业的基础性行业,与人民生活密切相关,与农业、农村和农民问题密切相关.我国是小麦最大的生产国,也是最大的消费国,小麦产量占世界总产量的16%～18%.小麦粉是我国居民主要的食物来源,也是加工部分食品的基础原料,它具有其他粮食作物不可替代的优势.因此,小麦不仅是我国重要的粮食作物之一,也是维护国家粮食安全的重要物资,在国家粮食安全中占有重要的战略地位,以小麦为主要品种的粮食生产更是十分重要和政府迫切关心的大事.     

Hard Winter Wheat and Flour Properties in Relation to Breadmaking Quality of Straight-dough Bread： Flour Particle Size and Bread Crumb Grain

Samples of 12 hard winter wheats and their flours that produced breads varying in crumb grain scores were studied for 38 quality parameters including： wheat physical and chemical characteristics; flour ash and protein contents, starch damage, swelling power, pasting characteristics, and flour particle size distribution; dough properties determined by a mixograph; and breadmaking properties for pup loaves （100g flour）. Only two parameters, the protein content of wheat and the granulation of flour, showed significant correlations with bread crumb grain scores. Protein content of wheat ranging 12.9%- 14.5% determined by an NIR method showed a weak inverse relationship （r =-0.61, p〈0.05） with bread crumb grain score. Flour particle size distribution measured by both Alpine Air Jet Sieve and NIR methods revealed that the weight wt % of particles less than 38 μ m in size and representing 9.6% - 19.3 % of the flour weights was correlated positively （r =0.78, p 〈 0.01） with crumb grain score, whereas wt % of flour particles larger than 125μm had an inverse relationship （r =-0.60, p〈0.05） with crumb grain score.     

玉米干法提胚制糁制粉生产工艺与设备

本文介绍了玉米清理—水汽调节—脱皮—脱胚—分离等主要工序组成的玉米干法提胚制糁生产工艺及提胚制粉的生产工艺。阐述了玉米干法提胚制糁制粉的技术关键、主要设备及技术参数。