变性淀粉对非发酵面团冻融品质的影响

为了探究变性淀粉对非发酵面团冻融品质的影响,本研究比较了在添加马铃薯羟丙基二淀粉磷酸酯、木薯醋酸酯淀粉、木薯羟丙基淀粉与马铃薯醋酸酯淀粉后非发酵面团冻融品质的变化。结果表明：变性淀粉未能有效控制冻融面团的失水率,但冻融面团深层结合水相对含量均有所增加,凝胶能力下降,且不受变性淀粉添加量与种类的影响。冻融面团剪切力均随着变性淀粉添加量增加呈现“下降-上升”的趋势,且均低于对照组。变性淀粉添加量较少时基本能较好地改善熟面坯的质构特性,高添加量反而不利于熟面坯的质构特性。添加木薯醋酸酯淀粉不利于面团流变性的改善,而其余3 种变性淀粉在添加量较低（＜5%）时,有利于改善面团的流变特性。因此,变性淀粉在添加量较少时对非发酵面团冻融品质有一定的改良作用。     

变性淀粉对冷冻面团面包品质的影响

以木薯淀粉为原料,主要研究了预糊化淀粉、羟丙基二淀粉磷酸酯和乙酰化二淀粉磷酸酯三种变性淀粉的物化特性与冻融稳定性,以及它们对冷冻面团面包比容及面包全质构的影响。实验结果表明:木薯淀粉经过不同方式的变性后,物化特性差异很大,其中,羟丙基二淀粉磷酸酯的冻融稳定性最好,预糊化淀粉的冻融稳定性最差;添加5%三种变性淀粉后均能显著延缓冷冻面团的下降趋势,并对冷冻面团面包的品质具有良好的改善作用。这一结果与变性淀粉冻融稳定性及冷冻面团面包比容变化趋势一致,进一步表明变性淀粉,尤其是羟丙基二淀粉磷酸酯可以有效抑制冷冻面团内部水分的迁移,降低冻藏过程中冰晶和重结晶的形成,从而改善冷冻面团面包的内部质构。     

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。     

酶制剂对面团流变学特性和面包品质的影响

探讨不同添加量的酶制剂对面团流变学特性和面包品质的影响。结果表明:真菌淀粉酶和木聚糖酶可弱化面团的流变学特性,葡萄糖氧化酶、谷氨酰胺转氨酶和脂肪酶可不同程度地改善面团的流变学特性;真菌淀粉酶、木聚糖酶、葡萄糖氧化酶和脂肪酶能有效改善面包焙烤品质,增大面包的比容,改善面包的硬度和弹性,而谷氨酰胺转氨酶对面包品质的影响不明显。真菌淀粉酶、木聚糖酶、葡萄糖氧化酶和脂肪酶的最适添加量分别是5μL/kg、20mg/kg、30μL/kg、50mg/kg。     

不同变性淀粉对冷冻面团热力学特性的影响

采用差示扫描量热法(DSC)研究4种不同种类变性淀粉对冷冻面团热力学特性(玻璃化转变温度、冰晶融化特性和可冻结水含量)的影响。结果表明,冷冻面团的玻璃化转变温度在-30℃左右,不同变性淀粉对冷冻面团玻璃化转变基本无明显影响;添加5%马铃薯羟丙基淀粉、木薯羟丙基淀粉和木薯醋酸酯淀粉可以显著降低冷冻面团冰晶融化范围,面团中形成的冰晶大小更加均匀;冷冻面团可冻结水含量随着马铃薯醋酸酯淀粉和马铃薯羟丙基淀粉添加量的增加呈降低趋势,添加10%木薯羟丙基淀粉时,面团可冻结水含量显著低于空白组,而木薯醋酸酯淀粉对面团可冻结水含量无显著影响。     

马铃薯生浆对面团特性和面包品质的影响

以小麦粉和马铃薯生浆为主要原料制备面团及面包,研究不同马铃薯生浆添加量对面团的拉伸特性、流变学特性及面包品质的影响。结果表明：随着马铃薯生浆添加量的增加,面团的抗延伸阻力和延伸性均降低;随着马铃薯生浆添加量的增加,面包的硬度和咀嚼性上升,烘焙损失率下降,面包芯亮度降低,面包形态、色泽、口感、组织的感官评分降低,但气味的感官评分先升高后降低。不同马铃薯生浆添加量面团的储能模量(G′)均大于损耗模量(G″),当马铃薯生浆添加量为10%时,面团的G′和G″均最低。     

麦芽糖淀粉酶对面包品质及面团特性的影响

研究枯草芽孢杆菌来源的麦芽糖淀粉酶对面包品质及面团特性的影响,为深入了解酶制剂在烘焙产品中的作用提供理论依据。本实验主要研究了麦芽糖淀粉酶(添加量0%、0.02%、0.04%和0.06%)对面包比容、质构、贮藏期间面包保水性、质构、感官品质及面团流变学特性的影响。结果表明:面包保水性随麦芽糖淀粉酶添加量的增加而显著提高(P<0.05),而且麦芽糖淀粉酶能显著延缓面团黏度和回生值的增加(P<0.05),改善面团品质。当面包贮藏天数的增加,麦芽糖淀粉酶还能延缓面包硬度和咀嚼性的增加,减缓贮藏期面包品质下降(P<0.05)。其中,添加0.04%的麦芽糖淀粉酶能够明显延缓面包老化,对面团淀粉糊化特性影响较小。面包贮藏第7 d时,能减少水分损失36.92%,保持面包弹性。因此,麦芽糖淀粉酶能够延缓面包老化和面包品质下降。     

T0098变性淀粉在面包中应用效果研究

采用改良二次发酵法制作面包,将T0098变性淀粉以不同比例添加到面包基本配方中,考察变性淀粉对面包加工过程及面包品质的影响,通过贮存实验、扫描电子显微镜观察并分析变性淀粉对面包内部组织结构的影响。结果表明,T0098变性淀粉可明显改善面包感官品质,其最适添加量为2%(面粉为基准),并可有效延长面包保鲜期。     

变性淀粉对冷冻面团面包焙烤特性的影响

探讨了醋酸酯马铃薯淀粉对冷冻面团面包焙烤特性的影响。面团中分别添加不同质量分数(0%、5%、7.5%、10%、12.5%、15%)的醋酸酯马铃薯淀粉,在冷冻不同天数后,解冻进行焙烤,并对比容和全质构等参数进行测定。结果表明:醋酸酯马铃薯淀粉增大了面包的比容,减缓了面包在冻藏过程中比容的下降趋势,改善了面包的品质。     

菊糖对面团流变学特性及面包品质的影响

添加不同比例的菊糖于面包粉中,对面包面团特性及面包品质变化进行研究。结果表明,添加菊糖能够明显影响面包粉的粉质和拉伸等流变特性。随着菊糖添加量的增加,面团吸水率显著下降,面团形成时间和面团稳定时间延长,弱化度减小;添加菊糖可增加面团的延伸度、拉伸面积和拉伸阻力;面粉的峰值黏度、最终黏度、衰减值和回生值也显著降低,其淀粉老化速度得到延缓;弹性模量和黏性模量显著增加,面团的网络结构得到改善;但面团发酵体积显著减小,使得面包的比容减少,面包初始硬度显著性增加,在面包贮藏过程中,添加2.5%、5%、7.5%的菊糖面包硬度明显低于未添加菊糖的面包硬度,说明适宜添加量的菊糖能够改善面包内部结构,降低其贮藏过程中的硬度和老化速率,延长面包货架期。     

Overall and Local Bread Expansion,Mechanical Properties,and Molecular Structure During Bread Baking: Effect of Emulsifying Starches

In order to determine the relationship between molecular structure of wheat bread dough, its mechanical properties, total and local bread expansion during baking and final bread quality, different methods (rheological, nuclear magnetic resonance, magnetic resonance imaging and general bread characterisation) were employed. The study was extended on wheat dough with starch modified by octenyl succinic anhydride (OSA) in order to generalise the results. The interest of investigating multi-scale changes occurring in dough at different phases of baking process by considering overall results was demonstrated. It was found that OSA starch improved the baking performance during the first phase of baking. This feature was due to a higher absorption of water by OSA starch granules occurring at temperatures below that of starch gelatinization, as confirmed by NMR, and consecutive higher resistance to deformation for OSA dough in this temperature range (20–60 °C). This was explained by a delayed collapse of cell walls in the bottom of the OSA dough. In the second phase of baking (60–80 °C), the mechanism of shrinkage reduced the volume gained by OSA dough during the first phase of baking due to higher rigidity of OSA dough and its higher resistance to deformation. MRI monitoring of the inflation during baking made it possible to distinguish the qualities and defaults coming from the addition of OSA starch as well as to suggest the possible mechanisms at the origin of such dough behaviour.     

Wheat dough rheology and bread quality effected by Lactobacillus brevis preferment,dry sourdough and lactic acid addition

The influence of chemical and biological acidification on dough rheological properties and bread quality has been investigated. Two different flour types were used. Dough was chemically acidified with lactic acid. Two types of biologically acidified dough were prepared: dough with dry sourdough and with a Lactobacillus brevis preferment. Wheat dough rheological properties were investigated using the Farinograph, Extensograph and Amylograph. The baking response was also determined using standard baking tests. Addition of acidifiers resulted in firmer doughs with less stability, decreased extensibility and decreased gelatinisation maximum. The biological acidifiers increased the bread specific volume. Lactic acid addition had no influence on bread specific volume. In general, biological and chemical acidification decreased bread hardness. The addition of dry sourdough significantly decreased the lightness and increased the yellowness and redness of the bread crumb. The crust chroma, hue angle and brownness index were significantly changed by addition of acidifiers.     

专用油脂对冷冻面团焙烤品质的影响

将以棕榈油和大豆油为原料制备的专用油脂应用于冷冻面团中,研究专用油脂对冷冻面团流变学特性影响及对冷冻面团焙烤面包品质的影响。结果表明：添加专用油脂制备的冷冻面团面包比容大、纹理细腻、口感柔和、品质良好;专用油脂可以有效地提高冷冻面团的筋力和延伸性,并能延缓冷冻面团因冻藏导致的焙烤品质下降,对延缓面包老化效果良好;确定专用油脂在冷冻面团中的添加量为配方中面粉质量的6%。     

氧化酶在全麦面包制作中的应用研究

将一种多酚氧化酶漆酶(Laccase,简称LAC)应用于全麦面包的制作,比较其与2种常用的氧化酶对面团的流变性质和面包品质的影响,旨在开发一种新型的烘焙用酶制剂。通过面团流变性质的测定及面包品质的综合评价研究氧化酶对面团和面包质量的影响,结果表明LAC可提高普通面团和全麦面团的黏弹性,对全麦面团的作用更强。全麦面包中加入LOX和LAC能显著增加全麦面包的比容,并以LAC提高比容最为明显。LAC对全麦面包质构的改善作用最明显,且能改善全麦面包的风味。质构测定结果表明LAC对全麦面包质构的改善作用最强。LAC可明显延长面包的老化时间。     

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%.     

海藻酸丙二醇酯对全麦冷冻面团冻藏稳定性和烘焙特性的影响

本文研究了海藻酸丙二醇酯（Propylene glycol alginate,PGA）对全麦冷冻面团冻藏期间稳定性的影响,并探究了冷冻面团烘焙面包品质的变化。将0.3%的PGA加入全麦面团,通过测定冷冻面团冻藏1、2、3、4和5周后发酵特性、流变特性、蛋白质二级结构、微观结构以及面包的比容、质构特性、内部纹理结构和老化程度等,研究冷冻面团冻藏期间的稳定性。结果表明,随着冻藏时间的延长,添加PGA的冷冻面团在冻藏5周后具有较好的保水性,其发酵特性及流变特性相对于对照组均有所改善。冻藏5周后,对照组与PGA组其面包比容分别下降了19.872%和14.153%;面包硬度分别升高了64.186%和36.386%;气孔表面积分率分别下降了3.497%和2.300%;老化焓值分别上升了65.142%和42.416%。添加PGA能延缓冷冻面团冻藏期间β-折叠含量的上升和β-转角相对含量的下降。电镜扫描图（SEM）显示,随着冻藏时间的延长,PGA组的冷冻面团孔洞数目相比对照组明显减少且大小均匀,面筋网络结构完整性和连续性提高。研究结果表明PGA可以有效地延缓冷冻面团在冻藏期间的品质劣变,维持冷冻面团的稳定性并提高面包的烘焙特性。     

Quality characteristics improvement of low‐phenylalanine toast bread

This study was designed to prepare and evaluate low‐phenylalanine toast bread made from gliadin‐free wheat flour and hydrocolloids. Wheat protein fraction (gliadin) rich in phenylalanine was extracted using aqueous alcohol solution for the production of low‐phenylalanine wheat flour. Pectin, gum arabic and carboxymethylcellulose (CMC) were used separately to improve the quality of bread at levels of 1, 2 and 3%. Chemical, rheological, organoleptic, baking, staling and microstructure of bread were studied. Phenylalanine content of gliadin‐free bread samples reduced by 43.2% compared with control. Separation of gliadin negatively affected the rheological properties of dough and baking quality of bread, while rheological properties, baking quality and staling were improved upon hydrocolloids addition. Microscopic examination of crumb structure revealed remarkable differences in control and treated breads. It was found that acceptable bread could be produced using gliadin‐free wheat flour with the addition of pectin or CMC up to 2 and 3%, respectively.     

谷朊粉对面包基础粉品质特性的影响

探讨不同添加量的谷朊粉对面包基础粉蛋白质的品质、流变特性及面包烘焙品质的影响。结果表明:谷朊粉可以明显增加面包基础粉的湿面筋含量、沉淀值和蛋白质含量,强化其流变学特性,有效改善面包烘焙品质,增大面包比容和高径比并改善其弹性和硬度。当谷朊粉添加量为10%时,面包烘焙品质最好。     

麦麸细粉营养成分分析及在面包烘焙中的应用

采用喷雾调质、研磨和筛选分离出小麦麸皮中的麦麸细粉,分析其营养成分,并通过流变特性测试及烘焙应用试验,研究其对面粉营养成分及面团烘焙特性的影响。结果表明,分离所得麦麸细粉的蛋白质和膳食纤维含量高达15.8%和33.6%,且富含钾、钙、铁等多种矿物质。随着麦麸细粉在面包专用粉中添加比例的增加,面包专用粉的灰分和湿面筋含量呈递增趋势;面筋指数、糊化黏度逐渐降低,面团吸水率、弱化度逐渐增加;稳定时间、延展性呈减小趋势;面包的搅拌时间、发酵时间延长,比容和品质评分降低。添加10%麦麸细粉的面包烘焙性能和感官品质较好,且营养价值得到了显著改善。