Location: Grain Quality and Structure ResearchTitle: Implications of non-covalent interactions in zein-starch dough and bread quality Author
|Tilley, Michael - Mike|
|Yan, Shuping - Kansas State University|
|Aramouni, Fadi - Kansas State University|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 9/17/2012
Publication Date: 9/30/2012
Citation: Smith, B.M., Bean, S., Tilley, M., Yan, S., Aramouni, F. 2012. Implications of non-covalent interactions in zein-starch dough and bread quality. AACC International Annual Meeting. Abstract. 61-P.
Technical Abstract: A major limitation in the production of wheat-free breads is the lack of protein functionality in non-wheat cereals. Breads made from non-wheat flours such as rice, maize, and sorghum must be made from thick batters and are of lower quality than wheat bread. The development of visco-elastic dough from non-wheat proteins would allow a wider range of gluten-free products to be made and improve the quality of such foods. Zein has been shown to form wheat-like dough, however the mechanism is unknown. To identify the factors responsible for dough development in zein-starch mixtures and their influence on zein bread quality, a mixture of 20% zein-80% maize starch was mixed with water and different reagents known to alter zein protein-protein interactions. The salts, NaSCN, NaCl, and Na2SO4 were evaluated at concentrations from 0 – 2M for their influence on the properties of zein-starch dough systems. The use of NaSCN at low concentrations made softer more wheat-like dough. Urea and ethanol had similar affects on the zein-starch dough and produced softer more workable dough. With increasing concentrations of NaCl and Na2SO4 there was a coalescing of the proteins and no dough was formed. The use of the reducing agent beta-ME had little effect on the mixing properties of zein-starch dough. As NaCl content in the bread formula was increased from 0 to 2M the specific volume of bread decreased from 3.5 to 1 mL/g. Likewise, including 5% ethanol (v/v) in the bread formula was found to slightly increase specific volume and prevented crumb failure. This research demonstrated that unlike wheat, zein proteins are capable of forming visco-elastic dough due to non-covalent interactions rather than disulfide linked high Mw proteins and that dough formation with zein was very sensitive to the presence of kosmotropic salts such as NaCl.