Impact of different beer yeasts on wheat dough and bread quality parameters

In order to investigate the impact of different yeast strains from the species Saccharomyces cerevisiae on the dough and bread quality parameters, wheat flour was fermented using different beer yeasts. The results show that beer yeast strains could be included in the baking process since S. cerevisiae T-58 and S. cerevisiae s-23 provided adequate gas production and dough formation with superior structural properties like extensibility and stickiness to S. cerevisiae baker's yeast. The resulting breads show the highest specific volume with the highest slice area and the highest number of cells and the lowest hardness over time. The different yeasts had also an impact on the crust colour due to their abilities to ferment different sugars and on shelf life due to the production of a range of different metabolic by-products. According to this study it was possible to produce higher quality bread by using yeast coming from the brewing industry, instead of bread containing standard baker's yeast.     

Effect of wheat germ flour addition on wheat flour,dough and Chinese steamed bread properties

Wheat germ flour (WGF) has been developed as a functional food ingredient with high nutritional value. In this study, WGF was applied in steamed bread-making in order to improve the quality of Chinese steamed bread (CSB). Partial substitution of wheat flour with WGF at levels of 3%, 6%, 9% and 12% (w/w) was carried out to investigate physicochemical properties of blends and their steaming performance. Falling number (FN) values of composite flours ranged from 199 to 223 s. Viscosity analysis results showed that wheat flour mixed with WGF had higher pasting temperature and lower viscosities. Dough rheological properties were also investigated using farinograph and extensograph. The addition of WGF diluted the gluten protein in dough and formed weak and inextensible dough, which can be studied by scanning electron microscope (SEM) analysis. CSB made with WGF had significantly lower volume, specific volume and higher spread ratio. The sensory acceptability and physicochemical quality of CSB were improved with the application of a low level of WGF (3% and 6%). However, results showed that a high level of WGF over 9% is not recommended because of unsatisfactory taste. As a whole, addition of appropriate level of WGF in wheat flour could improve the quality of CSB.     

中麦175馒头和面条品质稳定性分析

为给优质小麦育种和生产提供参考依据,以优质小麦新品种中麦175于2010-2011年度在河北和北京14个地点的样品为材料,分析了磨粉品质、面粉和面片颜色、面团流变学和淀粉糊化特性、馒头和面条加工品质。结果表明,中麦175为馒头和面条兼用型优质品种,特点是软质、中偏弱的面筋强度、面粉颜色白,多数品质性状较稳定,籽粒硬度、PPO活性、面片a*值、稳定时间、拉伸面积、延展性和最大抗延阻力的变异系数较大,馒头加工品质地点间变异大于面条。磨粉品质和面团流变学参数对馒头加工品质有显著影响,籽粒硬度和出粉率对馒头表面颜色有显著负向影响,相关系数分别为-0.82(P<0.01)和-0.58(P<0.05);面粉L*值高,馒头加工品质好,二者相关系数为0.72(P<0.01);吸水率与馒头总分呈显著负相关(r=-0.84,P<0.01),稳定时间、拉伸面积、延展性和最大抗延阻力与馒头总分呈显著正相关,相关系数分别为0.85(P<0.01)、0.77(P<0.01)、0.62(P<0.05)和0.70(P<0.01)。降低PPO活性和吸水率,提高蛋白质含量、出粉率和黄色素含量可以改善面粉和面片颜色的亮白度,增加部分黄度,形成消费者可接受的奶白色。淀粉糊化特性对馒头和面条加工品质无显著影响。上述信息对改良小麦品质的稳定性有重要意义。     

杂粮馒头的生产工艺研究及鉴定评价

实验室试验与实际生产应该紧密结合,经发酵蒸制而成的杂粮馒头,具备色多、光亮、皮软、光润、膨松喧软、筋力适度、淡香微甜等的感官性状,其有宜于配菜,久食不厌的特点。而且,杂粮馒头还有经济、实惠、物美、价廉、易消化等优点。     

豆皮粉营养风味改良剂的制备及其应用

为改善国内豆皮资源大量浪费与研究深度不够的现状,寻求简便、低成本方法使豆皮高值化。通过焙烤制备豆皮粉风味改良剂,由正交试验优化工艺条件,并将豆皮粉添加到面包中,进行感官评定和持水性测定。通过正交试验,确定制备豆皮粉风味改良剂的最佳工艺条件为烘烤温度180℃,烘烤时间10 min,粉碎细度200目;通过感官评定和核磁共振CPMG实验发现,豆皮粉添加量为2%时的面包具有大豆特有的香味,弾柔性好,有嚼劲,同时持水性较好。制备的改良剂具有大豆特有豆香味,富含膳食纤维,颜色、细度与高筋面粉相近,适量添加可改善面包品质,可以作为营养风味改良剂添加到面包等食品中。     

添加玉米粉对馒头品质的影响

为了选择玉米淀粉的最佳添加工艺,使馒头品质得到改善,进行了三因素三水平实验。A因素为玉米淀粉添加量,三水平为15%,20%,25%;B因素为发酵时间,三水平为2.5,3.0,3.5 h;C因素为加水量,三水平为50%,53%,55%。正交分析显示三因素中对馒头感官评价的影响为A>B>C,即玉米淀粉添加量>发酵时间>加水量。所以在实际生产中,应控制好玉米淀粉添加量,确保馒头品质的显著提高。     

Glu-D1位点亚基缺失弱筋小麦新种质的创制及其品质分析

辐射诱变是一种重要的变异手段,为了丰富小麦的品质性状变异资源,通过采用60Co-?射线辐射普通小麦品种‘冀3235’幼胚愈伤组织的方法,获得辐射诱变处理的再生植株。对再生株后代种子进行麦谷蛋白亚基的SDS-PAGE分析,结果从中发现了不含Glu-D1位点编码的高分子量麦谷蛋白亚基的材料。经进一步的系谱选择,选育成了稳定遗传的7份材料。与对照‘冀3235’相比,这些株系的农艺性状无明显差异,醇溶蛋白A-PAGE电泳谱带也完全相同,仅在麦谷蛋白SDS-PAGE电泳图谱的Glu-D1位点上有差异（变异系缺少Glu-D1位点控制的亚基,对照‘冀3235’为2+12）。品质分析结果表明,Glu-D1位点缺失系的面粉品质发生了很大变化,其湿面筋没有检出,沉降值显著下降。这些变异系是培育弱筋小麦品种和评价Glu-D1位点功能的珍贵材料。     

豆渣高纤维面包的研制工艺

以豆渣为原料.探讨了豆渣纤维添加量对面包体积、弹柔性及风味的影响.结果表明:在不添加改良剂时.豆渣纤维最大添加量为5%;添加而包改良剂可提高豆渣纤维的添加量,并通过正交试验确定了在保证面包一定品质的前提下,面包改良剂为2%时,豆渣的最佳添加量为7%.     

Scouting the application of sourdough to frozen dough bread technology

The use of sourdough, even in combination with cryoprotectant (skim milk, sucrose and trehalose), conventional additives (guar gum, diacetyl tartaric acid esters of monoglycerides, ascorbic acid), honey or fructose and glucose, in frozen dough technology was investigated. After frozen storage, the leavening performance of doughs, and the hardness and texture of breads were compared to those of an unfrozen dough, and to those of a conventional frozen dough. All frozen doughs showed a longer fermentation time and a lower volume increase, with respect to unfrozen dough. When sourdough was combined with cryoprotectant, honey or both, the leavening performance improved compared to the use of sourdough alone. Compared to the conventional frozen dough, higher leavening performance was reached combining sourdough with cryoprotectant alone or together with honey. Sourdough combined with honey, fructose and glucose, honey and cryoprotectant, or conventional additives decreased bread hardness compared to the unfrozen dough bread and to the conventional frozen dough bread. Independently from the use of sourdough, conventional additives allowed to reach a specific volume not significantly different from that of unfrozen dough bread, and breads containing honey were characterized by low values of hardness and by high values of red index.     

Preparation of gluten-free bread using a meso-structured whey protein particle system

This article presents a novel method for making gluten-free bread using mesoscopically structured whey protein. The use of the meso-structured protein is based on the hypothesis that the gluten structure present in a developed wheat dough features a particle structure on a mesoscopic length scale (100 nm–100 μm). Whey protein particles were prepared by cold gelation of soluble whey protein aggregates during phase separation. The addition of a 2.4% whey protein particle suspension to wheat starch resulted in a dough that could be baked into a leavened bread with a specific volume up to 3.7 ml/g and a bubble size comparable with a normal bread. The relevance for structuring the whey protein into mesoscopic particles was confirmed by tests in which only a homogeneous whey protein gel or a whey protein solution was used. The protein particle system gave better results after proving and baking compared with these systems.