抗性淀粉与小麦粉共混体系黏弹性的研究

采用微波湿热-循环冷冻制备小麦抗性淀粉粗品,以酶解纯化后得到的抗性淀粉纯品添加小麦粉中,研究其在不同替代比例(5%、10%、15%、20%)条件下对面团流变特性的影响。研究表明:不同比例的抗性淀粉与面粉共混体系其表观黏度均随着剪切速率的增大而减小,呈现出"剪切稀化"现象,表现出假塑性流体特性;随着替代比例的增加,面团的储能模量以及损失模量也显著升高,损耗角正切值tanδ逐渐降低,面团弹性增加。与对照组相比,实验组替代比为5%和10%时,面团的最大蠕变柔量(J_(max))、瞬时蠕变柔量(J_0)和迟滞蠕变柔量(J_1)呈现出明显降低的趋势,继续增大替代比,变化不显著。研究结果表明小麦粉中添加抗性淀粉显著改变了共混体系的黏弹性,使面团的硬度随着替代比的增加而增大。     

外源添加面筋蛋白对小麦面团热机械学和动态流变学特性的影响研究

通过向小麦粉中添加面筋蛋白粉,替代比分别为0%、5%、10%、15%、20%、25%、30%,利用混合实验仪(Mixolab),快速粘度仪(RVA)和动态流变仪,研究添加不同比例面筋蛋白粉对小麦面团热机械学及动态流变学特性的影响。结果表明:面筋蛋白的添加使得面团的吸水率显著地从53.3%增加到67%,形成时间从1.41 min增加到9.31 min,而稳定时间随着替代比的增大,呈现先上升后显著下降的趋势,替代比为5%时达到最大值10.02 min。面筋蛋白的添加使小麦面团的峰值扭矩显著地从2.06 Nm降低到1.37Nm,回生值从1.68 Nm降低到1.06 Nm。动态流变学试验表明:面筋蛋白的添加使得小麦面团的粘弹性特性发生明显变化,随着面筋蛋白粉比例的增加,储能模量(G′)与损失模量(G〞)呈先升高后降低的趋势;损耗角正切值tanδ则呈逐渐升高的趋势。只有在面筋蛋白粉比例为5%时的低频扫描范围内,tanδ小于对照,此时混合体系中分子交联聚合程度升高,面筋网络强度增加。     

小麦淀粉对面团微观结构及冷冻面团馒头品质的影响

淀粉作为小麦粉的主要成分在决定面团特性以及冷冻面团馒头品质中发挥着重要的作用。采用分离重组的方法,探究淀粉添加比例分别为0%（对照组）、10%、15%、20%、25%、30%、35%、40%、45%、50%时,混合粉糊化特性、面团微观结构、游离巯基含量和冷冻面团馒头品质的变化。结果表明：不同比例淀粉的添加量改变了混合粉的糊化特性和粉质特性,分别与淀粉添加比例呈线性相关关系。随着淀粉添加比例的增加,混合粉面团弱化度和面团中游离巯基含量逐渐增加,从微观结构的变化发现面团中面筋蛋白网络的连续性逐渐降低。当淀粉添加比例达到20%时,冷冻面团馒头的硬度和咀嚼性达到最小值,分别为2 833 g 和2 567 g。适当增加小麦粉中的淀粉含量改善面团的加工适应性,更利于冷冻面团馒头的制备。     

瓜尔豆胶对马铃薯-小麦混合粉面团质构和流变特性的影响

本文探究了添加量为0(对照组)、0.3%、0.6%、0.9%、1.2%和1.5%的瓜尔豆胶对马铃薯含量为35%的混合面团质构特性和流变特性的影响。结果表明:改良面团属于假塑性流体,具有剪切稀化特性。添加瓜尔豆胶能减小面团的硬度,改善拉伸特性,增大弹性模量和黏性模量,降低损耗角正切值、应变值和蠕变柔量,使面团高聚物含量增大,聚合度提高。其中,瓜尔豆胶添加量为0.9%的混合面团硬度适中,拉伸距离最大;弹性模量和黏性模量与对照组接近,黏弹性好;应变值、蠕变速率和蠕变柔量最小,表明面团内部强度大,在外力作用下,面团抗变形能力强;面团蠕变回复率和可回复性柔量最大,面团在撤去外力后,回复能力强。所以瓜尔豆胶添加量为0.9%的混合面团,适合用于制作马铃薯主食产品。     

南瓜粉对小麦粉粉质特性及面团品质的影响

以南瓜粉和小麦粉为原料,考察南瓜粉添加量对小麦粉粉质特性、糊化特性及面团的晶型与结晶度、水分分布、流变学特性的影响。结果表明：随着南瓜粉添加量的增大,面团的稳定时间、公差指数、带宽及糊化特性均显著性下降（P＜0.01）;储能模量和损耗模量先下降后上升,面团弹性先升高后降低;弱结合水含量逐渐增大;当南瓜粉添加量为15%时,面团中淀粉结晶度出现最大值,为23.9%。综上,适量添加南瓜粉可降低面筋蛋白浓度,抑制淀粉的糊化特性,提高面团弹性,从而改善面粉粉质及品质特性。     

竹笋膳食纤维对面粉粉质特征及面团质构特性的影响

本文研究了不同竹笋膳食纤维添加量对小麦粉粉质特性、生面团拉伸和流变学特性以及熟面团质构特性的影响。结果表明,随着竹笋膳食纤维添加量的增加,面团稳定时间、粉质质量指数呈先上升后下降趋势,而拉伸阻力和拉伸比例呈上升趋势。竹笋膳食纤维添加量为3.0%时,稳定时间最长为7 min 32 s,粉质质量指数最大为95,弱化度最低为64。随着扫描频率增大,面团弹性模量和黏性模量增大,损耗角正切减小;频率相同时,添加量小于3.0%时,面团的弹性模量、黏性模量增加;质构特性研究发现,随着竹笋膳食纤维添加量的增大(0.5%~5.0%),面团的硬度、弹性、粘附性、咀嚼性均呈现先增加后降低的趋势。结果表明:适量添加竹笋膳食纤维可改善面粉的粉质及质构特性,有助于提高面粉的食用品质。     

香菇粉对小麦面团热机械学和动态流变学特性的影响研究

本试验通过测定不同比例的香菇粉和小麦粉混合粉的热机械学和动态流变学特性,研究香菇粉对小麦面团特性的影响。结果表明,香菇粉的添加使小麦面团的吸水率增大,面团的形成时间和稳定时间先下降后上升,相应的蛋白质弱化度先升高后降低。香菇粉的添加使小麦面团的峰值黏度和回生值均显著降低。动态流变学试验显示:香菇粉的添加使得小麦面团的黏弹特性发生了显著的变化,储能模量(G')与损失模量(G")均呈现先降低后升高的趋势。而tanδ随香菇粉比例的增大呈现了先略微升高后明显降低的趋势,表明了混合体系中分子交联的程度有所增加,弹性比例增大。     

玉米微孔淀粉对冷冻面团品质特性的影响

该文以冷冻面团为研究对象，探究玉米微孔淀粉添加量对面团冻结后品质特性的影响。通过对面粉糊化特性、冷冻面团失水率、色度、质构及面团流变学特性测定，结果表明，添加适量的微孔淀粉有利于保持冷冻面团的品质特性。在0%～5%的添加范围内，随着微孔淀粉添加量的增加，面粉峰值黏度、衰减值、终值黏度和回生值总体上呈现下降趋势(P<0.05),冷冻面团的色度、硬度、胶着性则显著增加，储能模量(G′)、损耗模量(G″)均随着微孔淀粉添加量的增加逐渐上升。添加量为3%时，冷冻面团的失水率与流变学特性中损耗角正切值最低、弹性最大；内聚性、咀嚼性与玉米微孔淀粉添加量无显著相关。综上所述，添加玉米微孔淀粉使面粉糊化特性各指标均呈现出下降趋势，有利于面团稳定；适量的微孔淀粉添加有利于提高冷冻面团的质构特性和流变学特性，改善冷冻面团品质。     

高粱粉与小麦粉共混体系黏度和糊化特性

为探索高粱粉对小麦粉黏度和糊化特性的影响,以高粱粉和小麦粉共混体系为对象,采用单因素试验方法,以期拓展高粱在食品加工中的应用。结果表明,不同高粱粉添加量均可提高小麦粉共混体系的峰值黏度、保持黏度和最终黏度, 10%的高粱淀粉添加量提升效果最佳。相对于纯小麦粉, 5%～20%高粱粉添加可提升共混体系的回生值,但无显著性差异(p0.05)。较高量的高粱粉添加则可极显著提高共混体系的衰减值(p0.01), 5%的高粱粉添加和纯高粱粉衰减值高于纯小麦粉,但差异不显著(p0.05)。纯高粱粉的糊化峰值时间短,且极显著低于共混体系和小麦粉组(p0.01),而纯小麦粉与共混体系组间糊化峰值时间差异不显著(p0.05)。共混体系的淀粉糊化温度没有显著性差异(p0.05)。高粱粉与小麦粉共混体系黏度和糊化特性的变化结果,可为高粱在辅食食品的加工和改性提供数据参考。     

抗性淀粉对面团流变学特性的影响、应用及改良

主要研究小麦粉中加入不同比例的抗性淀粉(RS)后,对面团流变学特性以及焙烤食品(面包)品质的影响。结果表明,添加RS会影响面团的流变学特性,降低面包品质。为此,通过加入谷朊粉对混合粉(小麦粉+抗性淀粉)进行品质改良,研究表明,谷朊粉对混合粉面团流变学特性有明显改善作用。RS添加量控制在10%,只需添加3%的谷朊粉,面包品质就能明显改善。     

稻米-高筋小麦混合粉面团的静态和动态流变学特性

本实验研究了6 种稻米-高筋混合粉面团的静态和动态流变学特性。结果表明,随着稻米粉添加量的增加,在动态流变频率扫描中,混合面团的储存模量（G’）和损耗模量（G’’）整体呈上升趋势,损耗角正切（tan δ）整体呈规律性下降趋势;在静态流变的蠕变松弛实验中,最大蠕变应变量、最大蠕变柔量和瞬时恢复柔量逐渐减小,零剪切黏度和瞬间恢复比率逐渐增加,表明加入稻米粉后面筋蛋白有所稀释,但稻米粉中的淀粉吸水膨胀相互黏附,且与米蛋白相互作用赋予面团更高的弹性模量和更复杂的内部结构。在动态流变的温度扫描中,糊化温度前后混合面团的黏弹性变化明显,G’和G’’曲线类似淀粉糊化曲线,说明生面团加热的过程中,影响其流变学特性的主要成分为淀粉;降温过程中,稻米粉添加量的影响较小,高温区G’和G’’呈规律性增加,温度低于60 ℃后各项流变指标规律性差;在整个降温的过程中样品均具有类固体的性质。     

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.     

Impact of the addition of resistant starch from modified pea starch on dough and bread performance

The interest in the use of resistant starch (RS) for the development of new bakery products has significantly increased due to its ascribed physiological effects with proven health benefits. The objective of the present work was to analyse the effects of the wheat flour substitution by modified pea starch with high level of RS (PeaP) on breadmaking performance. The effects of PeaP on wheat dough functionality were evaluated by mixing/overmixing properties, texture profile analysis, viscometric profile and thermal properties. Bread quality was evaluated by physico-chemical parameters, crumb texture profile, digital image analysis, nutritional parameters and sensory evaluation. Flour substitution by PeaP up to 20% allowed keeping mechanical, extensional and viscometric parameters without significant hindering of dough machinability. Overdose of modified pea starch (30%) negatively affects dough mixing and overmixing behaviour. As a functional/prebiotic fibre, PeaP addition up to 10–20% of flour replacement entitles the formulation of wheat bread allowing a significant increase in the RS level (from 0.70 to 5.10%), delay/decrease in amylopectin retrogradation, with acceptable changes in bread quality up to 10–20% of flour replacement.     

转谷氨酰胺酶对玉米面团加工特性的影响

考察不同转谷氨酰胺酶(TGase)添加量对玉米面团(玉米粉添加量质量分数为30%)的流变特性、微观结构、保水力和质构性质的影响,并对所制面条的烹调损失率进行分析。结果表明,当酶的添加量为50~150 U/g面粉时,玉米面团的弹性模量和黏性模量显著增加;保水力增加了32.6%~46.4%;质构分析结果表明,玉米鲜湿面条的硬度、弹性和咀嚼性显著增加,咀嚼性增加了1.56~6.11倍。扫描电镜分析结果表明,玉米面团的微观结构发生了变化,表现为蛋白质发生了交联的同时,淀粉的分布状态也发生了改变。蒸煮得率从194%提高到206%。可以看出,添加TGase有利于改善玉米面团及所制面条的品质。     

谷朊粉和小麦淀粉添加量对重组面团冻藏品质的影响

面团的冷冻保存品质无法满足鲜湿面条工业化生产的要求。为了研究面团主要组分（面筋蛋白和淀粉）对面团冷冻品质的影响,以高筋小麦面粉（50%）、谷朊粉和小麦淀粉（不同比例）为原料进行面团重组,-18℃冻藏20 d分析其水分分布、流变特性、糊化特性、凝胶强度、微观结构以及氢键强度,以100%原小麦面粉作为对照组。结果表明,随着谷朊粉:小麦淀粉比例从4:1减小至1:4,冷冻重组面团中的水分分布逐渐由结合水向自由水迁移,弹性模量从125900 Pa降低至73020 Pa;样品的各项糊化参数增大,凝胶硬度也由114.30 g增大到181.39 g。扫描电镜观察发现,谷朊粉:小麦淀粉比例越低越不利于面筋蛋白网络结构的均匀性。添加了谷朊粉和小麦淀粉后,重组面团中的氢键强度均大于对照组,且随着谷朊粉:小麦淀粉比例的减小不断增大。当谷朊粉:小麦淀粉为4:1时,冻藏20 d的重组面团的弹性模量值比对照组高49.95%,有效延缓了面团在冻藏过程中的品质劣变。将淀粉与面筋蛋白进行面团重组可以提高面团的黏弹性,进而有利于其冷冻保存品质。     

The impact of resistant starch on characteristics of gluten-free dough and bread

The study focused on partial replacement in gluten-free breads of corn starch with tapioca and corn resistant starch preparations. The use of resistant starch resulted in the increase of storage and loss moduli of the dough, and the lowering of loss tangent, which indicates its more elastic character. The incorporation of resistant starch reduced creep and recovery compliance and elevated zero shear viscosity. Modified doughs displayed higher starch gelatinization temperatures and lower viscosities that were proportional to the share of RS. It was found that the loaves baked with the share of resistant starch had less hard crumb than bread without RS addition. The crumb hardness diminished with the increasing amount of applied RS preparation. The addition of resistant starch raised total dietary fibre, by up to 89%, as compared to control (bread without RS addition). The most pronounced change was observed for insoluble dietary fibre (increase 137%), while only slight increase was found for its soluble fraction (18%).     

Interpretation of mechanical spectra of carob fibre and oat wholemeal-enriched wheat dough using non-linear regression models

Oscillation and creep shear tests were applied to test the effect of fibre-rich additions - carob fibre (0-5%) and black oat wholemeal (0-20%) - on the rheological properties of wheat flour dough. Interpretation of changes in the values of the storage modulus (G′) and loss modulus (G″) and the tangent of the phase angle (tan δ) in the function of oscillation frequency (f) was performed on the basis of proposed 3-parameter non-linear regression models. The results of creep measurements were analysed using the 6-parameter Burgers model. Increase in the share of the fibre-rich additions caused the G′(f) and G″(f) curves to shift towards higher values, and steeper slope and stronger bending of the shapes of the curves, while the tan δ(f) curve tended to shift towards lower values. The application of carob fibre and oat wholemeal at rates of 2% and 10%, respectively, caused that the ratio of viscous to elastic properties of wheat flour dough was the least dependent on the shear rate (f). The result of creep tests showed an increase in the instantaneous and retarded moduli of elasticity and the Newtonian viscosity of wheat flour dough with increase in the share of the additions.     

Effect of native and germinated finger millet flour on rheological and sensory characteristics of biscuits

Wheat flour was replaced with native finger millet flour (NFMF) and germinated finger millet flour (GFMF) at 30–50% levels to make soft dough biscuits. Dough rheological properties and baking characteristics of the blends were evaluated. Farinograph data of wheat flour replaced with NFMF and GFMF showed a decrease in water absorption, dough stability and an increase in mixing tolerance index as the level of replacement increased. Extensibility of dough decreased for both NFMF and GFMF as the levels increased. The hardness of biscuit dough measured by texture profile analysis increased from 125 to 234 N for NFMF and 118 to 126 N for GFMF. Scanning electron microscopic studies on the biscuit dough showed polygonal finger millet starch granules adhering to wheat starch granules and protein matrix. The results of the study indicated that the replacement level of 40% with either NFMF or GFMF produced biscuits with acceptable sensory attributes. Addition of sodium stearoyl‐2‐lactylate (SSL) showed further improvement in terms of spread ratio, surface characteristics and texture.     

Study on Resistant Starch Functionality in Short Dough Biscuits by Oscillatory and Creep and Recovery Tests

The effect of wheat flour replacement by a resistant starch-rich ingredient (RSRI) on the structure of short dough biscuits was studied by oscillatory and creep and recovery tests to determine linear viscoelastic properties. The RSRI was substituted for the flour at three different levels, 20%, 40% and 60% (w/w). The use of RSRI increased the elastic and the viscous moduli but did not influence tan δ. The compliance values during the creep test were adjusted successfully to the Burger model. The creep and recovery test revealed an increase in elasticity and resistance to flow and a decrease in deformability with RSRI, but the differences were only significant at the 40% and 60% levels. The RSRI did not affect relative recovery, thus no effect on the type of structure is expected. Deformability was positively correlated with biscuit spread during baking.     

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...