抗性淀粉对小麦粉凝胶质构特性的影响

以3种不同筋力小麦粉为原料,研究了抗性淀粉(Resistant Starch,RS)对小麦粉凝胶质构特性的影响。结果表明:抗性淀粉不能形成凝胶,添加5%～20%抗性淀粉的小麦粉配粉可形成凝胶。抗性淀粉RS3和RS2对强筋、中筋和弱筋小麦粉凝胶的影响趋势相同,随着配粉中抗性淀粉的比例逐渐增加,各凝胶的硬度、黏着性和胶着性显著降低,中筋粉的硬度、黏着性和胶着性值最高,弱筋粉次之,强筋粉最低;3种筋力小麦粉及其抗性淀粉配粉的弹性和凝聚性差异很小。     

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%.     

Understanding high pressure-induced changes in wheat flour–water suspensions using starch–gluten mixtures as model systems

The effect of high pressure (HP) on wheat flour–water suspensions was investigated. Suspensions were treated for 10 min at 200–600 MPa. HP-treatment significantly increased the consistency of the flour suspensions, as studied by frequency sweep tests. Temperature sweeps revealed that HP-induced starch gelatinisation, with a sigmoidal-shaped correlation between degree of gelatinisation and treatment pressure. Analysis of protein solubility in different buffers indicated the HP-induced formation of urea-insoluble complexes and/or disulphide bonds. Furthermore, the effects of HP on the isolated components wheat starch and gluten were studied, and starch–gluten mixtures were used as a model system for flour. A negative effect of gluten on the consistency increase of starch suspension was observed. Comparing the rheological parameters of HP-treated wheat flour suspensions to those of starch suspensions, confirmed the weakening effect of gluten. However, the presence of gluten in flour could not fully explain the differences between starch and flour suspension.     

黑小麦全粉的流变学特性及复配混粉馒头的品质研究

通过对黑小麦全粉、与对照样特精粉复配混粉的面筋数量与质量测定,对黑小麦全粉占10%、15%、20%、25%、30%、40%、50%复配混粉进行流变学特性指标的测定及制作馒头成品以评价。结果表明:不同复配比例的混粉湿面筋数量表现比例越大含量越高;黑小麦全粉的流变学特性较差;复配混粉也都低于对照样特精粉的流变学指标;黑小麦全粉单独并不适合制作馒头,当复配比例在10%~15%时,馒头评价总分在80以上。     

小麦膳食纤维对面粉流变学特性的影响

小麦膳食纤维分为不溶性膳食纤维和可溶性膳食纤维两类,在面制品中具有重要的应用价值。应用粉质拉伸仪研究了不溶性和可溶性小麦膳食纤维对面粉流变学特性的影响。结果表明,不溶性小麦膳食纤维对面团面筋具有恶化作用;可溶性小麦膳食纤维对面团面筋具有改良作用,可根据制作面食品的种类来决定添加小麦膳食纤维的种类和添加量。     

蒸汽爆破甘薯渣粉对小麦粉粉质及饼干品质特性的影响

研究蒸汽爆破甘薯渣粉对小麦粉粉质及混合粉制作饼干品质特性的影响。将蒸汽爆破甘薯渣粉添加到小麦粉中,测定不同比例蒸汽爆破甘薯渣粉与小麦粉混合后的沉淀指数、糊化特性、粉质特性以及混合粉饼干质构性质。结果表明：小麦粉中添加不同量的蒸汽爆破甘薯渣粉后,小麦混合粉的沉淀指数、峰值黏度、低谷黏度、稀懈值、最终黏度和反弹值均降低;蒸汽爆破甘薯渣粉添加到小麦粉中,面筋蛋白被稀释,吸水能力随可溶性膳食纤维质量分数的增加而增加,而面团的形成时间和稳定时间缩短,弱化度升高,粉质质量指数降低;混合粉焙烤出的饼干质构特性发生变化。根据饼干的质构特性和感官评定结果,在低筋面粉中添加质量分数6%的蒸汽爆破甘薯渣粉时,混合粉制作的饼干品质最佳。     

Rheological properties of wheat flour substitutes/alternative crops assessed by Mixolab

Wheat is one of the most common cereals used in the world. However, due to greater public awareness of celiac disease and gluten intolerance as well as consumers demands for healthy food and variety in food products, in many widely consumed staples, such as bread, wheat flour is fully or partially replaced with flour from other cereals, pseudocereals or legumes. Although wheat flour alternatives are readily available in the market, these products are often of inferior quality. The aim of this paper was to predict the suitability of alternative crops such as rice, corn, buckwheat, amaranth and soya for the production of quality bread. Their rheological properties were studied, and compared to the properties of wheat flour which served as a benchmark. The tested alternative cereals, pseudocereals and legumes were selected in order to represent the widely used ones in gluten-free products as well as the ones found to be nutritionally improved according to recent publications. Moreover, the differences between wheat and buckwheat flour, and their wholegrain counterparts were also studied. The determination of rheological properties of wheat flour dough as well as the dough from other raw materials (rice, corn, buckwheat, amaranth and soya) was performed by Mixolab. According to results obtained by Mixolab measurements, flours from different raw materials exhibited Mixolab profiles which greatly differ from wheat flour profile. Samples of rice and both types of buckwheat flour expressed the most similar rheological behaviour to wheat flour. However, since, there was no tested material which exactly mimic wheat flour dough properties, it was concluded that their mixtures would give the optimal rheological profile. Although it is a very challenging task to mimic wheat flour unique breadmaking properties, it is possible to create products having similar rheological behaviour to wheat flour dough, but improved functional properties.     

茶多酚对两种类型面团流变特性的影响

本实验分别将茶多酚按照0%、0.9%、1.8%、2.7%的比例添加到低筋面粉和高筋面粉中,采用粉质仪和拉伸仪法,研究茶多酚添加对面团流变特性的影响。结果表明,随着茶多酚添加量的增加,面团吸水率均降低,低筋面粉面团形成时间变化不明显,而高筋面粉面团形成时间缩短;添加0.9%茶多酚的面团,稳定时间均显著延长,抗拉伸阻力增加,弱化度下降,低筋面粉面团延展度降低,而高筋面粉面团延展度变化不大;而添加1.8%和2.7%茶多酚的面团稳定时间显著降低,弱化度显著增加,抗拉伸阻力和延展度均降低。综上所述,面粉中添加少量的茶多酚(0.9%),面团的耐揉性、筋力增强,低筋面粉面团可塑性变差,高筋面粉面团可塑性变化不大;而茶多酚添加量较大(1.8%、2.7%)时,两种类型面粉面团的耐揉性、筋力及可塑性均变差。      

Effect of proteins on the formation of starch–lipid complexes during extrusion cooking of wheat flour with the addition of oleic acid

The formation of starch–lipid complexes plays an important role in extruded products. The effect of gluten proteins on thermal conditions at which the starch–lipid complexes formed during extrusion cooking of wheat flour with the addition of oleic acid was evaluated, considering wheat starch as a reference. The presence of gluten proteins in wheat flour extrudates brought about a reduction of the formation of starch–lipid complexes compared to blend of wheat starch and oleic acid extruded at the same operating conditions (melting enthalpy: 0.4 vs. 1.6 kJ kg^?1). Moreover, the lubricant effect of oleic acid observed during extrusion of wheat starch (low values of specific mechanical energy and residence time) was not found during extrusion of wheat flour with addition of oleic acid because of the interaction between gluten proteins and oleic acid. This research points out the importance of proteins on biopolymer modifications and their effect on extrudate quality.     

发芽小麦粉复配谷朊粉工艺优化及其粉质特性

通过将发芽小麦粉碎回添的方式制备混合小麦粉。探讨了不同添加量的不同阶段发芽小麦粉对面粉质量及面包烘焙品质的影响,同时为了改善混合小麦粉的面团特性及烘焙品质,在混合小麦粉中添加了谷朊粉,研究了谷朊粉添加量对面团流变学特性及面包感官品质的影响,并采用正交实验优化了发芽小麦复配谷朊粉面包制作工艺参数。实验结果表明,当露白阶段(发芽18 h)、芽长1/4(发芽41 h)及1/2阶段(发芽65 h)的发芽小麦粉的添加量分别不大于30%、20%及15%时,其混合小麦粉的烘焙品质与正常小麦粉处于同一水平;面包的最佳生产工艺:发芽小麦(露白阶段)含量为15%,谷朊粉含量为3%,酵母添加量为1.2%,加水量为30%,其感官评价分值为91.4;发芽小麦可以粉碎回添的方式用于全麦面包的制备,扩展了收割与贮藏过程中发芽导致不适于制粉的小麦的实际使用价值。      

麦麸膳食纤维对小麦粉糊化及凝胶质构特性的影响

为研究膳食纤维对淀粉糊化及凝胶质构的影响,本实验以2种不同筋力小麦粉为原料,添加麦麸膳食纤维,5个添加量处理,分析其小麦粉糊化特性、凝胶质构及其微观结构。结果表明:随麦麸膳食纤维添加量的增加,峰值粘度、低谷粘度、稀懈值、最终粘度和回生值等糊化特征参数均呈显著下降趋势,糊化时间和糊化温度的变化不明显,且没有规律性;添加膳食纤维显著降低了糊化凝胶的硬度、粘附性和咀嚼度(p<0.05),而弹性、内聚性和胶粘性未见显著变化;膳食纤维对2种不同筋力小麦粉糊化和凝胶质构特性的影响趋势基本一致;膳食纤维改变了面团和糊化凝胶体系的微观结构,可增加面团的紧致性,但会降低凝胶结构的致密性和均匀性。     

不同粒度小麦粉的蛋白质性质研究

选用75~123μm的筛网将小麦粉进行筛理分级后,得到7种不同粒度的小麦粉颗粒,并将其分为大中小3种颗粒。通过对其总蛋白质含量、蛋白质组分含量、湿面筋含量、面筋指数、巯基二硫键及蛋白质二级结构的分析,探究不同粒度小麦粉的蛋白质性质。结果表明,不同粒度区间小麦粉的蛋白质性质存在显著差异。与中小颗粒粉相比,大颗粒小麦粉中蛋白质含量、面筋含量、二硫键含量较高,面筋质量较好,蛋白质的二级结构较为稳定,且大颗粒小麦粉的蛋白性质与原粉较相似,其中3号粉的蛋白质品质高于原粉,这表明当小麦粉粒度在95~112μm时,小麦粉蛋白质性质得到提升。而中小颗粒小麦粉的蛋白质性质差异性不显著。整体而言,大颗粒小麦粉的蛋白质质量及结构稳定性相对较好。     

Protein Characteristics that Affect the Quality of Vital Wheat Gluten to be Used in Baking: A Review

The use of vital wheat gluten in the baking industry and wheat flour mills aims to improve the rheological characteristics of flour considered unsuitable to obtain products such as sliced bread, French bread, high‐fiber breads, and other products that require strong flours. To improve characteristics such as flour strength, dough mixing tolerance, and bread volume, vital wheat gluten is added to flour at levels that can vary from 2% to 10% (flour basis), with 5% being a commonly used dosage. However, the vital wheat gluten commercialized in the market has few quality specifications, especially related to the characteristics of the proteins that constitute it and are responsible for the formation of the viscoelastic gluten network. Information on protein quality is important, because variations are observed in the technological quality of vital wheat gluten obtained from different sources, which could be associated to damage caused to proteins during the obtainment process. Several tests, either physical–chemical analyses, or rheological tests, are carried out to establish gluten quality; however, they are sometimes time‐consuming and costly. Although these tests give good answers to specify gluten quality, flour mills, and the baking industries require fast and simple tests to evaluate the uses and/or dosage of vital gluten addition to wheat flour. This review covers the concepts, uses, obtainment processes, and quality analysis of vital wheat gluten, as well as simple tests to help identify details about protein quality of commercial vital wheat gluten.     

轻碾脱皮对全麦粉及其馒头品质的影响

以强筋、中强筋、中筋小麦为原料,采用干法轻碾脱皮,研究了不同轻碾脱皮比例对小麦籽粒、全麦粉及其馒头品质的影响。结果表明:随着轻碾脱皮比例的增加,小麦籽粒的灰分含量、硬度指数、千粒质量分别降低了0.17%、1.0~1.5、1.74~1.82 g,容重增加了22.0~23.4 g/L;全麦粉的灰分和损伤淀粉含量分别降低了0.12%~0.14%、1.0~2.1 UCDc;不溶性膳食纤维、总膳食纤维含量分别降低了0.38%~0.49%、0.13%~0.17%,而可溶性膳食纤维含量增加了0.22%~0.33%;全麦粉的糊化指标呈上升趋势,稳定时间延长了0.3~0.7 min,而弱化度降低了9~25 FU;全麦粉馒头的硬度、胶着性、咀嚼度分别降低了732~1 114 g、335~549、147~346,而弹性和回复性分别增加了0.030~0.031、0.049~0.066,另外亮度L*值及感官评价总分增加,从而表明轻碾脱皮处理能有效改善全麦粉的流变学特性及其馒头品质。     

麦麸粒径对全麦面团流变学特性的影响

麦麸经不同强度超微粉碎后得到4种不同平均粒径(分别为327、209、144、45μm),将麦麸按照出粉率进行回添得到全麦面粉,以探讨不同粒度组成的麦麸对全麦面团流变学特性的影响。糊化特性分析结果显示随着麦麸粒径的逐渐减小,全麦面粉的峰值黏度、最低黏度、最终黏度和回生值等显著增大。粉质特征显示全麦面粉的吸水率随麦麸粒径的减小逐渐增大,但稳定时间减小、弱化度增大。拉伸仪结果表明醒发时间会影响麦麸粒径对面团面筋网络结构的作用,在面筋网络的逐步扩展和形成阶段(45~90、90~135 min),较小粒径的麦麸会促进面筋网络结构变得密实但降低了其延展性。动态流变学特征显示全麦面团的弹性模量和黏性模量随麦麸粒径的减小而减小,但在扫描范围内高于普通面团。由本研究结果可推测,麦麸粒径的减小会促进淀粉颗粒与麦麸层细胞的分离及麦麸纤维在面团中的分布,但增加了面团形成过程中的物理空间阻碍,干扰了蛋白质分子间的交联和面筋网络结构与淀粉颗粒的结合。      

小麦粉品质特性与挂糊油炸猪肉片外壳品质的相关性分析

本文以12个品种小麦粉为研究对象,研究了小麦粉的蛋白质、粉质和拉伸特性等品质指标,及其挂糊油炸猪肉片外壳品质,并分析了小麦粉的品质特性与挂糊油炸猪肉片外壳（CDBPS）品质指标间的相关关系。结果表明,参试小麦粉蛋白及其组分含量在不同品种间存在较大差异,其中总蛋白和湿面筋含量变异系数分别为15.14%和16.56%,球蛋白变异系数高达62.81%。粉质参数中形成时间、稳定时间、弱化度和粉质质量指数变异系数等均较大,拉伸特性各指标变异系数均大于20%。挂糊油炸猪肉片外壳含油量与总蛋白含量、面筋指数、麦醇溶蛋白含量,粉质参数的吸水率,拉伸特性的拉伸曲线面积、拉伸阻力和延伸度均具有极显著负相关关系（P<0.01）,相关系数分别为?0.739、?0.833、?0.833、?0.797、?0.736、?0.709、?0.722。外壳硬度和易碎性均与总蛋白、麦醇溶蛋白、吸水率、拉伸曲线面积和拉伸阻力呈极显著正相关（P<0.01）。此外,外壳色度与湿面筋、面筋指数、麦醇溶蛋白和拉伸曲线面积也存在多种相关性。本研究可为挂糊油炸肉品糊粉小麦专用粉选择提供一定的科学依据。     

“哈师”黑粒小麦全麦粉的品质评价

对“哈师”黑粒小麦的千粒质量与制粉进行测试,研究其全麦粉的理化指标、面筋含量及特性、流变学特性。结果表明：“哈师”黑粒小麦的千粒质量为30.11g,出粉率达75%,其全麦粉的蛋白质含量为18.56%,干、湿面筋含量分别为28.79%和64.55%,远远高于普通小麦粉,但面筋弹性一般。面团吸水率为67.6%,面团形成为3.0min,稳定时间2.1min,弱化度119FU,粉质评价值40。面团流变性低于普通小麦粉。综合判断,“哈师”黑粒小麦适宜加工成面条。     

不同溶剂分离重组游离脂对面粉品质的影响

本文采用氯仿、石油醚和正己烷三种溶剂,分别使用快速抽提和索氏抽提两种方法分离面粉中的游离脂,比较原面粉和游离脂重组面粉的品质差异。结果表明:在三种溶剂中,氯仿的提油率最高(0.94%,1.18%),正己烷其次,石油醚最低(0.71%,0.77%)。与原面粉相比,氯仿索氏抽提分离重组面粉的面筋指数和粉质特性变化最大(形成时间和稳定时间分别由5.65 min和9 min增大到13 min和18.8 min);使用石油醚索氏抽提法分离重组面粉中的游离脂,对面粉的面筋指数、形成时间、稳定时间和粘度特性(回生值除外)影响不显著。与原面粉制作的面条相比,石油醚索氏抽提重组粉制作面条的黏聚性和弹性无显著变化。因此,采用石油醚索氏抽提分离重组面粉中的游离脂,是一种理想的不破坏面粉性质的游离脂分离方法。     

Description of Microstructural Changes in Wheat Flour and Flour Components during Hydration by using Environmental Scanning Electron Microscopy

The initial microstructures of two wheat flours (hard wheat flour and soft wheat flour) and flour components (starch, gluten, soluble pentosans and insoluble pentosans) were observed by scanning electron microscopy (SEM) and the changes in microstructure during hydration were described using environmental SEM (ESEM). SEM images permitted observation of the classical microstructure of wheat flour particles and starch granules. The initial microstructure of the purified fractions of flour components (gluten, soluble pentosans and insoluble pentosans) seemed largely dependent on the purification techniques, and could not thus directly be used to describe their in situ behavior during flour processing. ESEM observations of wheat flours and flour components during hydration first demonstrated slight changes in surface of particles that we associated to apparent swelling effects. The formation of a continuous aqueous phase between particles was observed for long hydration times.     

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。