Rheological Properties Of Wheat Dough Using A Novel Compression Recovery Technique

ABSRACT Ranking wheat flour quality by class or grade does not reveal functional quality attributes relevant to the end user. This has resulted in a continuous effort to find more effective ways to measure quality across the wheat value chain. In line with these efforts, a novel rheology instrument, the CORE, was introduced as a simple and rapid quality test for gluten. The instrument applies a biaxial compression force followed by a free recovery, to measure the elastic behavior of gluten samples. Although designed for gluten, the instrument exhibits potential to reveal valuable data using dough as a more realistic test material. The CORE was optimized for dough, resulting in new test parameters where dough is compressed at 1 Newton (N) for 5 seconds, followed by a 55-second free recovery. To gain a deeper understanding of its characterization abilities, this test was applied on three large sample sets of flour. It showed a wide range of degrees of elasticity (DE) across different wheat classes and within two sets of Hard Red Winter (HRW) wheat. In addition, the test revealed a new measureable material property, firmness, represented by a sample‟s resistance to the applied compression force (RC). This new value was strongly negatively correlated with DE, at r2=0.89, indicating that samples which are highly elastic are also difficult to compress. Values for DE and RC showed inconsistent correlations with some physicochemical data, but strong agreement with rheological data of the farinograph and alveograph, where multivariate correlations exceeded 0.80. The CORE was capable of detecting a significant increase in DE and RC upon treatment of flour with dough-enhancing enzyme transglutaminase. However, the enzyme‟s effect varied among cultivars. Similarly, the CORE was successful in detecting improved elasticity upon blending strong flour with weaker flour. Yet, the extent of elasticity imparted by the donor flour was cultivar-specific, and not mathematically predictable