Effect of Physical States of Nonpolar Lipids on Rheology,Ultracentrifugation, and Microstructure of Wheat Flour Dough     

Akihiro Watanabe  Kazuhisa Yokomizo  Ann‐Charlotte Eliasson 《Cereal Chemistry》2003,80(3):281-284

In the previous study, we investigated effect of physical state of nonpolar lipids of gluten‐starch model dough. This experiment examined a real wheat flour dough system to assess the role of fat crystals in the breadmaking processes. These experiments were performed with a baking test and an investigation of wheat flour dough through rheological measurements (both large and small deformations), scanning electron microscopy, and ultracentrifugation. As a result, we found that the added oil was absorbed in the gluten structure, causing the aggregation of the gluten, which gave rise to more elastic behavior. In contrast, solid fat seemed to be distributed uniformly between the starch granules in the dough, reducing the friction between the starch granules and facilitating thin gluten gel layers. These properties lead to the lower G′ value and the increased viscous behavior, which yields an increase in loaf volume. In addition, the supposed mechanism behind the large loaf volume described in the previous study was that fat provides a uniform distribution of the dough components, and that the dough can thus expand easily, resulting in a larger loaf volume, which was supported in the wheat flour dough system. In conclusion, we found that thin, expandable gluten films and the uniform dispersion of gluten and starch granules in the dough are prerequisites for attaining better baking performance.  相似文献   

Transgenic Enhancement of High‐Molecular‐Weight Glutenin Subunit 1Dy10 Concentration: Effects in Wheat Flour Blends and Sponge and Dough Baking     

Robert A. Graybosch  Bradford Seabourn  Yuanhong R. Chen  Ann E. Blechl 《Cereal Chemistry》2013,90(2):164-168

Dough strength is needed for efficient breadmaking quality. This property is strongly influenced in wheat (Triticum aestivum L.) by gluten seed storage proteins and, in particular, by high‐molecular‐weight (HMW) glutenin subunit composition. Experiments were designed to elevate expression of a key native HMW glutenin subunit (1Dy10) via genetic engineering and to determine whether resultant flours can be used in sponge and dough applications, the most common commercial bread‐baking procedure. Both unblended and blended samples from transgenic and nontransgenic sister lines were tested, with blended samples being formed by addition to a control sample. Dough properties, as determined by farinograph evaluation, were improved by the transgene‐encoded increases in 1Dy10 in both undiluted and blended flours. Mean farinograph stability of transgenic samples was twice that of the control, and blends with transgenic samples demonstrated increases in stabilities proportional to the amount of transgenic flour included. Mean farinograph quality numbers of transgenic samples, and of all blends containing transgenic flour, were significantly higher than both the control and all nontransgenic treatments. In the sponge and dough bake procedure, undiluted transgenic samples induced lower scores, relative to both control and undiluted nontransgenic samples, for water absorption, crumb body firmness, and loaf volume. In blends, however, the transgenic samples resulted in improvements in some sponge and dough loaf attributes, including loaf symmetry and crumb color score, without any concomitant loss of loaf volume in transgenic blends. These improved variables relate to finished product appearance and to consumer selection in markets. The use of transgenic flours with increased 1Dy10 glutenin content in commercial blends could provide advantages in sponge and dough bake applications.  相似文献