乳化剂影响新鲜及冷冻面团面包品质的研究

研究了硬酯酰乳酸钠(SSL)、卵磷脂、单甘酯、蔗糖酯、双乙酰酒石酸甘油酯(DATEM)等几种面包加工常用乳化剂对新鲜面团及冷冻面团的力学特性及面包的质构和感官品质的影响。结果表明,乳化剂的添加会显著提高新鲜面团的力学特性和新鲜面团面包的感官品质,卵磷脂为最适乳化剂,适宜添加量为0.45%(面粉为基数);乳化剂对冷冻面团的力学特性的影响不显著,但可以显著改善冷冻面团面包感官品质,SSL为最适乳化剂,适宜添加量为0.30%(面粉为基数)。     

乳化剂对冷冻面团水分状态和玻璃化转变温度的影响

乳化剂能通过改变面团中的水分状态来改变面团的玻璃化转变温度(Tg)和低温贮藏后的微观结构。利用低场核磁共振技术(LF-NMR)研究乳化剂对面团中水分状态的影响,并利用差示扫描量热法(DSC)和扫描电子显微镜(SEM)研究乳化剂对面团的Tg和低温贮存后面团微观结构的影响。结果表明：乳化剂能不同程度地降低面团中自由水含量,当加入0.15%双乙酰酒石酸单(双)甘油酯(DATEM)时,面团中自由水含量相对空白面团减少了5.78%;乳化剂也改变了面团的Tg,空白面团的Tg为－31.3℃,当加入0.50%的单甘酯时,面团的Tg为－17.3℃,提高了14℃,而山梨醇酐单硬脂酸酯(SP60)和卵磷脂在本实验的添加量范围内,未能将面团的Tg显著提高;乳化剂能不同程度的改善低温贮藏后面团的微观结构,尤其是加入0.50%单甘酯或0.15% DATEM后,面团实现玻璃化贮存,其微观结构得到了很好的保护。     

乳化剂对冷冻面团(高筋粉)拉伸特性的影响

采用质构仪研究添加硬脂酰乳酸钙(CSL)、硬脂酰乳酸钠(SSL)、单干酯、大豆磷脂、双乙酰酒石酸单(双)甘油酯(DATEM)乳化剂对冷冻面团拉伸特性的影响,通过单因素试验,选出对拉伸面积影响较大的4种乳化剂进行响应面分析。结果显示:当SSL添加量为0.11%,单干酯添加量为0.62%,大豆磷脂添加量为0.27%,DATEM添加量为0.28%时,拉伸面积最大,对冷冻面团品质有很好的改良作用。     

食品添加剂对面团流变学特性影响的初步实验研究

面团的流变学特性会对面制品的质量产生重要影响,而食品添加剂的种类和添加量将显著改变面团的流变学特性。本研究利用质构仪考察了若干种食品添加剂对面团拉伸特性的影响。结果表明:面团中添加NaCl、单甘酯、明胶、抗坏血酸、面粉强筋剂、海藻糖等都对面团的拉伸性能有一定的影响,不同的添加剂影响各异。相对而言,1.5%～2%的NaCl、0.5%的单甘酯、0.4%的明胶、0.4%的面粉强筋剂等都对面团的抗拉伸性能和稳定性有明显改善。而总体上,抗坏血酸和海藻糖对面团拉伸性能的作用主要是增加其抗拉伸应力,但会使面团的拉伸时间显著缩短,本研究的结果为面制品生产中正确选择适当的食品添加剂及添加量提供了基础数据。     

不同特性乳化剂对面团流变学性质的影响

对添加硬脂酰乳酸钠(SSL)、甘油单硬脂酸酯(DMG)、聚氧乙烯(20)失水山梨醇单硬脂酸酯(polysorbate60)的面团流变学特性进行研究,结果显示,虽然基本脂肪酸组成相同,但3种乳化剂对面团形成时间、面团稳定性、面团弱化度、抗拉伸强度等基本性质的影响有很大差异.高质量分数的DMG对面团有弱化倾向,添加polysorbate60可以得到面团形成的时间最长和最好的面团稳定性;添加SSL和polysorbate60对面团抗拉伸强度有不同程度的提高,而且SSL在较长的面团混揉时间能起到最好作用.不同剂量的乳化剂对面团流变学性质的影响也不相同.     

常用食品乳化剂对复合骨汤乳化稳定效果的影响

以稳定系数R值、平均粒径D_[4,3]及粒径分布系数PDI、Zeta电位和乳液黏度为指标,探究了不同食品乳化剂(蔗糖酯、单甘酯、吐温80、大豆卵磷脂和酪蛋白酸钠)及其添加量对复合骨汤乳化稳定效果的影响。研究结果表明,与原复合骨汤相比,添加乳化剂后复合骨汤乳液的稳定性都得到显著提高(P<0.05);5种乳化剂的最佳乳化效果添加浓度分别为蔗糖酯2.5%、单甘酯2.5%、吐温80 0.5%、大豆卵磷脂2.5%、酪蛋白酸钠2.0%;不同乳化剂对复合骨汤乳液的乳化、稳定效果和机制不同,优劣次序为吐温80>大豆卵磷脂>蔗糖酯>单甘酯>酪蛋白酸钠;结合乳液稳定性及感官评价结果,复合骨汤中分别添加2.5%蔗糖酯和1.5%大豆卵磷脂时稳定性和感官品质最好。     

两种乳化剂对冷冻麻薯坯及其烘烤品质的影响

为分别探究蔗糖脂肪酸酯及单硬脂酸甘油酯单独使用时对冷冻麻薯坯及其烘烤品质的影响,对添加不同乳化剂品种及用量的混粉进行糊化特性检测;对冷冻麻薯坯进行动态流变学特性以及水分分布检测;对冷冻麻薯坯烘烤后进行质构、比容测定和感官评价。结果表明：两种乳化剂均使混粉的衰减值与回生值降低,最大下降量分别为279.00 cP和173.50 cP;适量添加乳化剂可以改善冷冻麻薯坯的弹性模量、黏性模量以及水分分布状态,延缓水分迁移;烘烤品质中,加入两种乳化剂使麻薯面包硬度与对照组相比均降低;比容有所改善;当蔗糖酯添加量为0.40%、单甘酯添加量为0.15%时,综合感官评分分别为84.5和81.0,风味较好。因此,蔗糖酯添加量为0.40%和单甘酯添加量为0.15%对冷冻麻薯坯及其烘烤品质均有较好改善效果。     

水分含量及添加剂对面团流变学性能的影响

利用质构仪分析了水分含量和单甘酯、明胶、食盐、海藻糖、抗坏血酸等五种添加剂对面团流变学特性的影响.结果表明:水分的多少直接影响到面筋网络的形成.水分含量在40%～42%时,面团的综合流变学性能比较好.单甘酯和明胶对面团的抗穿刺能力提高比较明显,且明胶优于单甘脂,二者最佳添加量约为3%.NaCl、海藻糖、抗坏血酸能明显提高面团的抗拉伸能力,抗坏血酸的最佳添加量约为0.2%,海藻糖的最佳添加量约为1.5%.     

双乙酰酒石酸单甘酯对馒头品质改良作用的研究

研究双乙酰酒石酸单甘酯(Diacetyltartaric acid ester of monoglycerides,DATEM)对馒头品质的影响,以及DATEM与单甘酯(GMS),脂肪酶复配后对馒头品质的作用.研究结果表明,DATEM在馒头制作中的最佳添加量为0.10%(以面粉质量计,下同).在DATEM与单甘酯的复配中,0.10% DATEM与0.20%单甘酯复配后馒头的感官评分最高,0.10?TEM与10哦脂肪酶复配后总分最高.DATEM添加量为0.10%,单甘酯添加量为0.05%且脂肪酶添加量为10 mg/dg时馒头能获得最好品质.     

冷冻面团的组分配比对其拉伸性能的影响

实验借助英国CNSFARNELL公司的QTSTextureAnalyser质构分析仪对影响冷面团稳定性的若干因素进行了深入研究。这些影响因素包括:冷冻面团中水分、盐、糖、单甘酯、SSL、磷酸二氢钙的添加量。根据所得到的图表和数据,得出结论:制作冷冻面团时各种原料和添加剂的添加量分虽为:水62%、食盐2%、糖15%、单甘酯0.3%、SSL0.3%、磷酸二氢钙0.3%时面团的拉伸性最佳。     

不同乳化剂对油酸和亚油酸乳状液稳定性的影响

本文以粒径、稳定性和流变为考察指标,利用激光粒度仪、食品稳定性分析仪、流变仪等研究不同种类和添加量的食品乳化剂(阿拉伯胶、酪蛋白酸钠、吐温20)对不饱和脂肪酸(油酸和亚油酸)乳状液的制备及其稳定性的影响。结果表明,三种乳化剂均可制备出稳定性较好的乳状液,不同乳化剂的质量分数不同得到乳状液的稳定性不同。较高质量分数的阿拉伯胶(4%,w/v)乳状液,具有最低的澄清指数并且具有最大粘度(0.30~0.40 Pa·s)。当酪蛋白酸钠的质量分数为2%时,制备出的乳状液较稳定,但粒径较大,贮藏稳定性较差。较低质量分数的吐温20(1%,w/v)的乳状液具有最小粒径(0.20~0.21 μm),经过贮藏后变化程度也最小。本文研究了不同食品乳化剂制备的不饱和脂肪酸乳状液及其稳定性,可为不饱和脂肪酸乳状液的制备和应用提供参考。     

食品添加剂对面团动态流变学及冷冻面团烘焙特性的影响研究

应用动态流变仪,研究了食品添加剂硬脂酰-2-乳酸钠(SSL)、刺槐豆胶(LBG)、葡萄糖氧化酶(GOD)、木聚糖酶(XY)及葡萄糖氧化酶和木聚糖酶(GOD+XY)复合对面团动态流变学特性以及对冷冻面团烘焙特性的影响。结果表明,在频率0.1～40Hz扫描过程中,与未添加任何添加剂的面团(空白面团)相比,添加SSL的面团弹性模量、粘性模量和损耗角正切都减小;添加LBG的面团弹性模量和粘性模量增大,损耗角正切减小;添加GOD的面团弹性模量增大,粘性模量和损耗角正切减小;含有XY的面团弹性模量和粘性模量减小,损耗角正切增大;而含有GOD+XY的面团弹性模量和粘性模量增大,损耗角正切减小。升温扫描过程中,在低于55℃时弹性模量和粘性模量变化较小。随温度的升高,大约从55℃开始弹性模量和粘性模量迅速增加到最大值,然后又快速降低。采用6个配方研究了不同添加剂及其不同配比对冷冻面团烘焙特性的影响,实验发现酶制剂、乳化剂及胶体复合明显提高了冷冻面团的烘焙特性,缩短了醒发时间、增大了面包比容和降低了面包瓤硬度,这表明酶制剂、乳化剂和胶体在面团体系中存在协同增效的作用。     

The Effects of Vital Wheat Gluten and Transglutaminase on the Thermomechanical and Dynamic Rheological Properties of Buckwheat Dough

The improvement of the processing properties of gluten-free cereals is a challenging issue for cereal technologists. Vital wheat gluten (VWG), transglutaminase (TGase), or combinations of the two have been successfully used to improve the processing properties of food materials. In this study, a Mixolab system and a rheometer were used to investigate the effects of TGase on the thermomechanical and dynamic rheological properties of buckwheat flour dough (BF dough) and a buckwheat flour dough containing 15% VWG (BF-VWG dough). The results indicated that the addition of 1.0% TGase decreased the water absorption and significantly increased the stability, storage modulus (G′), and complex modulus (|G*|) of the BF dough. The presence of 15% VWG had a synergistic effect, enhancing the effectiveness of the TGase in improving the thermomechanical and dynamic rheological properties of the BF-VWG dough. Quantification of the free amino groups showed that the amino groups were more effectively bonded in the BF-VWG dough than in the BF dough when the TGase level exceeded 1.0%. Confocal laser scanning microscopy (CLSM) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis confirmed that the TGase promoted the formation of protein complexes. These data indicate that the combination of VWG and TGase can be used to improve the properties of buckwheat flour for buckwheat-based food production.     

EFFECT OF EMULSIFIERS AND FUNGAL α-AMYLASE ON RHEOLOGICAL CHARACTERISTICS OF WHEAT DOUGH AND QUALITY OF FLAT BREAD

Teftoon, a flat bread made of whole wheat flour, is prepared by hand sheeting of dough, followed by baking. Different emulsifiers, like lecithin, E471 (distilled monoglyceride) and E472 (diacetylated tartaric acid esters of mono- and digelycerid of fatty acids), were added to the flour at various levels ranging between 0.25 and 1.0% w/w, and it was observed that they improved the dough characteristics. Improvement in bread quality parameters, such as force to tear and sensory acceptability, were monitored. Fungal α -amylase was also incorporated into the flour at 5–20 g/100 kg flour basis alone and in combination with the emulsifier. The force required to tear the fresh bread was decreased with emulsifier and enzyme addition; however, E472 addition at 0.75% w/w of whole wheat flour gave the softest bread. The tear force of stored bread significantly increased with storage; however, bread containing E472 showed a less increase in tear force up to a period of 3 days. The sensory acceptability was found to be higher than that of the control bread for emulsifiers, and lower for enzyme at a concentration higher than 10 g/kg flour.

PRACTICAL APPLICATIONS

Flat bread is normally consumed fresh, but the staling phenomenon starts immediately after baking this kind of bread. Today, large-scale production and increased consumer demands for high-quality bread with long shelf life have created the need for functional food additives such as emulsifiers and α -amylase enzyme. Incorporation of emulsifiers and enzyme decreased the hardness of Taftoon bread. Emulsifiers and α -amylase enzyme enhanced the flat bread dough quality. The sensory acceptability also improved with the addition of emulsifiers. Optimizing the amount of emulsifiers and enzyme required for reduction of bread hardness is vital because the quality and price of the final product depend on this parameter.     

Incorporation of several additives into gluten free breads: Effect on dough properties and bread quality

The objective of this work was to assess the effect of emulsifiers, hydrocolloids and enzymes on gluten-free dough rheology and thermal properties and bread quality, while relating dough properties parameters to bread technological quality. Breads were based on rice flour, cassava starch and full-fat active soy flour, with 65% or 75% (flour-starch basis) of water incorporation. Additives used were emulsifiers (diacetyl tartaric acid ester of monoglycerides – DATEM and sodium stearoyl lactylate – SSL), enzymes (glucose oxidase and α-amylase) and hydrocolloids (xanthan gum, carboxymethylcellulose, alginate and carrageenan). Results showed that additive incorporation modified dough behavior, evidenced by different calorimetric and rheological properties. Besides, the electrophoretic pattern of dough extracted proteins changed with glucose oxidase addition. These modifications resulted in breads with different characteristics, such as specific volume, firmness and firming rate, and crumb structure. Nonetheless, they did not necessarily show better quality parameters than the control bread. The control dough displayed good performance for obtaining gluten-free breads of acceptable volume, crumb structure and, principally, with lower hardening rate during storage. Contrary to widespread opinion, this work shows that the presence of additives is not essential for gluten-free bread production. This fact provides new perspectives to the gluten free market at the moment of selecting raw materials and technological parameters, reducing production costs and facilitating gluten free products development.     

发芽糯玉米粉对面包面团结构和特性的影响

本文研究了添加0%、10%、20%和30%（发芽糯玉米粉的含量）的发芽糯玉米粉到面包面粉中后,面团的淀粉颗粒结构、流变性、老化性和持水性的变化。结果表明：面团的结构和性质与添加发芽糯玉米粉的量有关,发芽糯玉米粉的添加引起面团结构的明显变化。其中B型淀粉含量增加,A型淀粉表面的凹陷越来越多。流变性和老化性变化在20%以上添加量时变化最明显,面团持水力、面团形成时间、稳定性和粉质指数随着发芽糯玉米粉的添加量的增加而降低,软化度和公差指数呈上升趋势。延伸度、拉伸阻力和能量值是呈总体下降趋势。老化性显著高于小麦面团,持水能力要比全部小麦粉的低。这些研究表明发芽糯玉米粉添加比例能够显著影响面团的结构和特性。     

Antistaling Additives, Flour Type and Sourdough Process Effects on Functionality of Wheat Doughs

Antistaling additives—distilled monoglycerides (MGL), diacetyl tartaric ester of monodiglycerides (DATEM), sodium stearoyl lactylate (SSL), carboxymethylcellulose (CMC), hydroxypropylmethylcellulose (HPMC) and fungal α-amylase—were studied for effects on rheological and fer- mentative properties of white/whole wheat bread doughs, made following straight/sour dough processes. A fractionated factorial design (L³²) was used to evaluate single additive effects and interactions. Single addition of DATEM, followed by SSL, α-amylase and hydrocolloids improved oven rise and final volume. In presence of DATEM, synergistic (MGL) and antagonistic (SSL) effects of additional emulsifiers were found on gassing power. SSL was the only effective conditioner for enhancement of mixing properties. Dough plasticity was negatively affected by MGL addition and by CMC/HPMC in white/whole flours respectively. Some combinations resulted in detrimental dough handling properties.     

品质改良剂及燕麦酸面团对燕麦面团黏弹特性的改善

采用动态流变仪初步探讨添加不同量的羟甲基丙基纤维素（hydroxy propyl methyl cellulose,HPMC）、黄原胶、乳清粉、大豆分离蛋白、燕麦酸面团对燕麦面团动态流变学特性的影响。结果表明：在频率0.01～10 Hz扫描过程中,与未添加任何配料的燕麦面团相比,添加不同量HPMC或燕麦酸面团的燕麦面团弹性模量、黏性模量均增加,且添加HPMC的燕麦面团损耗因子也有所增加,其中添加0.5% HPMC和30%燕麦酸面团对燕麦面团黏弹特性的改善作用最佳;添加0.2%黄原胶、5%乳清粉、5%和10%大豆分离蛋白对燕麦面团的动态流变学特性无明显影响,而添加10%、15%乳清粉或15%大豆分离蛋白时,燕麦面团弹性模量、黏性模量反而降低。