Extra-strong dough properties associated with over-expression of HMW glutenin subunit GLU-B1 7X

Abstract

The rheological properties of flour dough are predominantly determined by high molecular weight glutenin subunits (HMW-GS). When water is added to flour and mixed to form a dough these large polymeric proteins form a three dimensional network called gluten. Different HMW-GS make varying contributions to dough strength or resistance to stretching. As higher dough strength generally results in greater bread volume, there has been a trend in many countries to select for glutenin subunits, which increase dough strength. The selection of the 5+10 over the 2+12 glutenin subunits has made a major improvement to bread quality in many countries including the UK. It has been found that not only the types of subunits but also the amount of a particular subunit, affects the dough strength. The Glu-B1 7x subunit has been found to “over-express” or produce a greater than normal percentage of the Glu-B1x subunit. Wheat varieties with over-expressed Glu-B1 7x subunit are found to produce strong flour dough properties. When both the over-expressed 7x subunit and the 5+10 subunits are present, extra strong dough properties result.