Relation Between Oxygen‐17 NMR and Rheological Characteristics of Wheat Flour Suspensions

Water binding has a significant influence on the rheological properties of wheat flour suspensions. Wheat flour‐water suspensions at concentrations from 60 ‐ 95% wet basis were subjected to rheological and NMR analyses in order to ascertain the relation between the two methods. The rheological data obtained by the Haake RV‐3 Rotoviscometer followed the Power Law, thus comparisons were based on consistency coefficient (a) and flow behavior (b) values. The NMR spectrometer measured oxygen‐17 relaxation rates (34 MHz in water and in deuterium oxide) as an indication of water mobility. The data showed a general inverse relationship between consistency coefficient and water mobility. However, the data indicated three distinct regions, each showing a linear relation with water mobility decreasing as apparent viscosity increased.