牡丹花蕊蛋白对面团和面筋蛋白特性的影响

为实现牡丹花蕊资源化利用,以大豆分离蛋白为参照,研究牡丹花蕊蛋白对面团和面筋蛋白质构、动态流变学特性、二硫键、表面微观结构和二级结构的影响。结果表明,牡丹花蕊蛋白能够明显提高面团的硬度、黏着性和咀嚼性,添加量低于6%时效果优于大豆分离蛋白。添加花蕊蛋白提高了面团的储能模量与损耗模量,使得面团黏弹性增加。牡丹花蕊蛋白对面筋蛋白网络结构形成的影响与大豆分离蛋白基本一致,添加量为6%时,扫描电镜显示面筋蛋白气孔数量多且孔洞深,网络结构致密;面筋蛋白二级结构中,相对稳定的α-螺旋+β-折叠占比达到最大值59.32%,与空白组相比二硫键含量提高了89%。牡丹花蕊蛋白能够有效促进面筋蛋白网络结构的形成,提高面团的品质,可用于对黏弹性要求较高的面制品生产。     

深度发酵过程面团面筋蛋白的变化

面团在深度发酵过程中面团面筋蛋白的变化对面团的持气性具有显著影响。运用排水法测定分析面团发酵情况,并且检测酵母发酵过程中面团的可洗出面筋含量、面筋指数、二硫键含量等的变化。酵母产气量和面团持气性在开始阶段均较好,随后持气性出现明显的下降趋势;面团面筋含量和面筋指数随着发酵时间的增加均明显下降;面筋蛋白中二硫键含量呈先下降后稳定的趋势;在酵母面团的发酵过程中,由于二硫键的破坏,面筋含量及面筋质量都有所下降,从而影响面团的持气性。     

发酵面团气室结构稳定性调控理论研究进展

均一且细腻的气室结构是衡量发酵面制品品质优劣的关键因素。过去常认为发酵面制品的质构特性,尤其是产品内部气室结构主要与面筋蛋白网络的流变学性质相关。但近年来的研究成果表明发酵面团气体分散相与面筋蛋白网络半固态连续相基质之间存在粘弹性薄层液膜结构,它对面团调质时气体的渗透、发酵和醒发期间气泡的膨胀、以及面团焙烤过程中气泡粘弹性具有不同程度的影响。本文综述了影响发酵面团气室稳定性的两种理论机制,即面筋蛋白网络稳定理论和薄层液膜稳定理论,同时详述了影响面团气室稳定性的关键因素和调控手段,以期为发酵面制品品质改良提供新思路,并为多相食品体系功能特性改善提供理论支撑。     

添加金针菇粉、茶树菇粉对面团流变学特性的影响

研究添加金针菇粉、茶树菇粉对面团流变学特性的影响,为食用菌作为功能基料开发新型的功能性食品提供理论依据。以金针菇和茶树菇两种食用菌粉为原料,利用混合实验仪（Mixolab）研究添加金针菇粉和茶树菇粉对面团的吸水率指数、揉混指数、面筋筋力指数、黏度指数、淀粉酶活性指数和回生指数等揉混特性的影响,并利用快速黏度仪和质构仪分别测定面团的峰值黏度、衰减值、最终黏度和回生值等糊化特性和硬度、弹性、黏附性等质构特性的变化。结果表明：添加2.5%～10%的金针菇粉和茶树菇粉能够延长面团的形成时间,破坏面筋蛋白的网络结构,降低面团的稳定性、面筋筋力、抑制老化回生,使形成的面团硬度增加,糊化黏度、黏附性和弹性下降。综合分析两种食用菌粉对面团特性的影响,发现5%的添加量为金针菇粉、茶树菇粉的最佳预测值,以在满足产品加工特性的基础上较大程度地丰富面制品的营养品质。     

阿拉伯木聚糖对面团及面制品品质影响的研究进展

阿拉伯木聚糖(arabinoxylan, AX)作为一种膳食纤维,在面团加工过程中会与其主要组分发生相互作用,从而影响面团特性和面制品品质。文章分析了AX与面团中面筋蛋白和小麦淀粉间的相互作用,总结归纳了其对面团持水性、流变性和发酵特性等方面的影响规律,概述了近年来国内外关于AX在应用于蒸煮类、焙烤类、油炸类面制品等方面所取得的研究成果,指出了目前在AX的精细结构、链构象特征、量效关系等方面需要解决的一些重要问题,并针对这些问题提出了今后的研究建议,以期推动AX在面制品行业中的理论研究和实际应用。     

蛋白质和淀粉对面团流变学特性和淀粉糊化特性的影响

以3个筋力不同的小麦粉为材料,利用分离重组方法,在保持小麦粉其他成分不变的情况下,组成不同面筋蛋白和淀粉含量的配粉,研究面筋蛋白和淀粉添加量对面团流变学特性和面粉糊化特性的影响。结果表明：随着面筋蛋白添加量的增加,3种筋力小麦粉配粉的面团稳定时间和粉质质量指数均呈升高趋势,峰值黏度、低谷黏度、最终黏度、稀懈值、回生值等总体呈下降趋势。小麦粉添加淀粉后,面团稳定时间和粉质质量指数均呈下降趋势,峰值黏度、低谷黏度、最终黏度、稀懈值、回生值等总体呈升高趋势。面筋蛋白和淀粉对小麦面团吸水率和面粉糊化温度的影响均较小。不同筋力小麦粉配粉各品质指标总体变化趋势一致,但变化幅度有一定差异。     

燕麦麸皮添加量对面团流变特性及面筋蛋白结构的影响

将燕麦麸皮以0%、10%、15%、20%、25%(w/w)的比例添加到小麦粉中,研究燕麦麸皮添加量对面团及面筋品质的影响。实验结果表明,随着燕麦麸皮添加量的增加,面团吸水率、形成时间、粘度崩解值显著(p<0.05)增加,稳定时间、回生值显著(p<0.05)降低,面团的热机械学性质下降;面筋蛋白的弹性模量、粘性模量增大,tan δ值降低,面筋蛋白固体特性增强,机械强度增大;面筋蛋白的热降解温度下降、600 ℃时的质量损失率显著(p<0.05)增大,面筋蛋白热稳定性降低;面筋蛋白二硫键含量显著(p<0.05)下降了25.74%~37.59%;扫描电镜的结果表明,添加燕麦麸皮后面筋蛋白原本均匀、致密的网络网络结构遭到破坏,面筋蛋白网络结构变得脆弱、呈蜂窝状。综上所述,添加燕麦麸皮会破坏面筋蛋白均匀致密的网络结构,这可能是导致面团流变性质劣变的原因。     

复配品质改良剂对南方馒头冷冻面团冻藏品质的影响

为提升和改善冷冻面团南方馒头的品质,分析冻藏过程中复配品质改良剂(海藻糖添加量4%、磷酸二氢钠添加量0.15%、黄原胶添加量0.05%、羧甲基纤维素钠添加量0.04%)对冷冻面团南方馒头比容、硬度、感官品质的影响,并从面团拉伸特性、动态流变特性、微观结构、蛋白质二级结构等方面探究复配品质改良剂在南方馒头冷冻面团中的作用机理。结果表明:冻藏过程中,冰晶会对淀粉颗粒、面筋蛋白及网络结构造成伤害,导致面团品质下降。复配品质改良剂可以保护面团中的面筋结构,减少面筋蛋白二级结构的变化,进而延缓弹性模量和黏性模量的降低速度,改善面团最大拉伸阻力和延伸度劣变,提升南方馒头硬度、比容和感官品质等品质,保持南方馒头松软的风味。     

冻藏对面团中面筋蛋白分子结构及功能特性影响的研究进展

冷冻面团具有降低生产成本、提高产品质量和方便消费者优点,可用于加工生产面包、蛋糕和馒头等面制品。面团品质劣变是导致冷冻面团货架期缩短的主要原因,而冷冻面团品质下降的主要诱因是小麦面筋蛋白的品质劣变。本文综述了冷冻面团中面筋蛋白的分子组成、空间结构及功能特性等的变化,并对冷冻面团的未来发展方向进行了展望。     

不同谷物麸皮对面团流变学特性及面筋蛋白结构的影响

本实验选用小麦麸皮、黑小麦麸皮、燕麦麸皮为原材料,探究在高添加量(质量分数30%)情况下不同谷物麸皮对面团流变学特性、面筋蛋白组成及结构的影响。结果表明,谷物麸皮含有丰富的膳食纤维,麸皮的加入使面团的吸水率、黏度崩解值显著增加,回生值显著降低,面团的形成时间、稳定时间虽与麸皮种类有关,但整体均呈上升趋势;添加麸皮的面筋蛋白中麦谷蛋白与麦醇溶蛋白比例增加了24.7%~73.0%、二硫键含量显著下降了26.0%~35.5%;面筋蛋白中的二级结构以β-折叠为主,小麦麸皮和黑小麦麸皮的加入使得面筋蛋白中的β-转角结构向β-折叠结构转化;扫描电子显微镜图显示麸皮的加入破坏了面筋蛋白原本均匀致密的微观结构。综上所述,谷物麸皮的加入改变了面筋蛋白的组成及二级结构,这些变化可能是导致面团流变学特性及面制品品质下降的原因。     

苦荞粉添加量对面团性质及馒头品质的影响

通过添加不同量的苦荞粉配成苦荞-小麦混粉,研究混粉揉混特性、面团微观结构的变化以及苦荞馒头的感官品质。结果表明,当添加量在5%~15%时,揉混结果中的和面时间和峰值面积变化不大,微观结构中蛋白质面筋网络结构略微减弱,但当添加量达到20%后,和面时间和峰值面积都有大幅度降低,微观面筋网络结构也出现明显的下降。同时,苦荞粉添加量为15%时馒头感官品质较好。综合分析可知,添加量为15%时苦荞馒头仍具有较好的品质。     

Improvements of Modified Wheat Protein Disulfide Isomerases with Chaperone Activity Only on the Processing Quality of Flour

Wheat protein disulfide isomerase (wPDI) with oxidoreductase activity, isomerase activity, and chaperone activity catalyzes the formation of disulfide bonds in gluten in vitro; the addition of wild-type wPDI weakened yet the flour processing quality. To develop the potential flour improvers from wPDI, the modified wPDIs were prepared by the biological or chemical method, and their effects on the processing quality of flour in connection with bread making were investigated by farinograph, texture profile analysis, electrophoresis, size exclusion chromatography, and scanning electron microscopy. A truncated protein of wPDI, fragment AB with oxidoreductase, and isomerase activities only was firstly confirmed to exert deteriorative effects similar to wPDI on the dough and bread quality. Then other two modified wPDIs, mPDI and aPDI, were prepared by site-directed mutagenesis and alkylation, respectively. Both mPDI and aPDI considerably retained the chaperone activity of wPDI but completely lost oxidoreductase and isomerase activities. After adding the appropriate amount of mPDI or aPDI, the stability time of dough was significantly prolonged from 3.60 to 4.15 or 4.13 min, respectively. The enhanced gluten network matrix and decreased hardness and chewiness of bread further suggested that dough was strengthened by the treatment of mPDI or aPDI. Moreover, the formation of gluten network was facilitated by the modified wPDIs with chaperone activity only for the increase amount of gluten macropolymer and the decrease content of SDS-soluble gluten. Consequently, mPDI and aPDI are valid candidates of flour improvers in food industry.     

小麦粉吸水速率对面团特性及馒头品质的影响

该文以不同吸水速率的小麦粉为基础,研究在相同的揉混条件下,其面团特性及馒头品质的变化。使用粉质仪将面团稠度达到最高时所用的加水量与消耗的时间的比值定义为吸水速率,测定不同吸水速率小麦粉其粉质特性、湿面筋含量、面筋指数、游离巯基与二硫键含量、面团质构特性、馒头比容与高径比、馒头的质构特性。研究结果表明,当小麦粉吸水速率从0.17 g/s增大到3.87 g/s时,面团的稳定时间及粉质质量指数显著下降。其湿面筋含量从38.81%下降到19.19%,二硫键含量从13.31μmol/g下降到9.05μmol/g。面团的质构特性在发酵0 min时呈先升高后降低趋势、在醒发45 min后整体呈下降趋势。馒头的比容从2.67 mL/g降低到2.27 mL/g、高径比从0.68降低到0.56,其硬度、胶着性、咀嚼性均成下降趋势。整体而言,吸水速率低的小麦粉其面团相对较硬且馒头较为筋道有嚼劲;吸水速率较高的小麦粉其面团硬度稍弱且馒头较为松软。     

Mechanistic study of the impact of germinated brown rice flour on gluten network formation,dough properties and bread quality

The objective of the study was to investigate the impact of germinated brown rice flour (GBRF) on the mechanism of high gluten wheat flour (HGWF) network formation and dough properties. Therefore, dough properties, microstructures, stability mechanism and bread quality were evaluated. Results showed that HGWF+10%GBRF exhibited a higher dough stability time (DST), pasting temperature, storage modulus (G′) and loss modulus (G′′), as well as a lower compliance value. The microstructure of dough showed that GBRF interfered with the self-organization of gluten protein molecules and affected the formation of gluten network structure. The disulfide bonds and β-sheet structure were proved to play an important role in facilitating the formation of a stable three-dimensional network structure, which revealed the regulatory mechanism of GBRF in maintaining the dough stability and strength. Furthermore, the dough mixing properties and texture parameters (i.e., hardness and fracturability) of breads were significantly correlated. Overall, GBRF can be used as a potential ingredient for whole grain products and its realistic role in bread-making has been demonstrated.     

Effects of tannic acid on gluten protein structure,dough properties and bread quality of Chinese wheat

BACKGROUND: The effects of tannic acid, which is present in many plants, on the structure of gluten proteins and the properties of dough and bread were studied. Tannic acid was added at levels of 0.01, 0.02 and 0.03 g kg^?1 during the dough‐making process. RESULTS: The added tannic acid acted negatively on disulfide bond formation but interacted with gluten proteins via other covalent bonds, as detected by UV spectroscopy and dynamic rheometry. Rheological properties and texture of the bread were measured by farinograph, extensograph and texture profile analyser. Texture analysis indicated little change in adhesiveness and resilience of the bread at all three levels of tannic acid compared with the control, but changes in hardness and chewiness of the bread made with added tannic acid indicated that tannic acid could delay bread staling. CONCLUSION: The effect of tannic acid on flour and dough is different from that of other flour redox agents. It breaks down disulfide bonds but also has positive effects on dough properties and bread quality. Disulfide bonds are commonly considered to be the most important factor affecting changes in the quality of bread. However, this study presents the new concept that other covalent bonds can also improve the quality of flour and bread and uses this property to investigate new, safe and efficient flour additives. Copyright © 2010 Society of Chemical Industry     

SPI与SPH及其复配产物对面团特性和面条品质的影响机制

为提高面制品的营养品质,研究并比较了添加大豆分离蛋白(soy protein isolate,SPI)、大豆水解蛋白(soy protein hydrolyzates,SPH,水解度为4.54%)以及SPI和SPH复配产物(SPI-SPH)的混合粉的面筋特性和粉质特性,面团的动态流变学特性、蛋白质组分、二硫键和非共价键变化,以及面条的品质变化。添加SPI后面粉的湿面筋含量升高,干面筋含量下降,面筋指数降低,粉质特性评价值升高;面团的醇溶蛋白和麦谷蛋白含量增加,黏弹性增大,弹性比例增加。添加SPI-SPH的面粉面筋特性和面团特性变化趋势与添加SPI的面粉一致,其粉质特性评价值增大。添加SPH的面粉中无面筋洗出,粉质特性评价值升高;面团盐溶蛋白含量显著增加(P<0.05),弹性比例降低。添加大豆蛋白的面团中二硫键含量均增加,疏水相互作用减弱,氢键增强。与原面粉面条相比,SPI面条的硬度增大10.82%,SPI-SPH和SPH面条的弹性分别减小7.23%和6.02%,且添加SPH后面条的蛋白质保留率由93.02%降至87.31%。研究表明,大豆蛋白与面筋蛋白通过二硫键交联以及非共价键相互作用,阻碍面筋网络形成,破坏了面筋网络的连续性。并且,SPI和SPH复配在一定程度上减弱了SPH对面筋的弱化作用。     

棕榈油添加量对面团质量的影响

目的:探寻棕榈油在生产馕、面包、馒头、苏打饼干及冷冻面制品等发酵面团中的应用工艺。方法:利用旋转流变仪测定棕榈油添加量对发酵面团流变特性的影响,并通过扫描电镜观察面团微观结构分析棕榈油添加量对面团组分的作用机理。结果:在小麦粉中分别添加4%,6%,8%,10%,12%(以小麦粉的总质量为100%计)的棕榈油,面团的发酵特性和流变特性发生显著变化。当棕榈油添加量为4%~10%时,有效地改善了面团发酵特性,延缓了面团老化速度。但当棕榈油添加量为12%时,会稀释面筋蛋白,降低面筋网络结构的稳定性,增大发酵面团的硬度和黏性。随着棕榈油添加量的增加,面团的发酵体积、持水性和黏弹性先递增后递减。结论:添加适量棕榈油有利于面筋网络结构的形成和稳定,改善面团的发酵及流变特性,棕榈油添加量为6%~8%时面团发酵效果较好。     

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。     

小麦粉破损淀粉含量对面团发酵性能的影响

以中、高筋小麦粉为研究对象,分析破损淀粉含量对面团流变发酵特性和馒头品质的影响。结果表明,随着破损淀粉含量增加,面团流变发酵性能、馒头比容、亮度及感官评分均先上升后降低;中、高筋小麦粉破损淀粉含量分别为25.11,25.60时,面团发酵高度、总产气量和持气率最大;制作的馒头比容、亮度大,感官评分最高,外形挺立、表面光滑、内部结构均匀细密、口感好。因此,中、高筋小麦粉破损淀粉含量分别为21.65~25.11,23.56~25.60时,馒头品质较好。     

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%.