Pulsed Nuclear Magnetic Resonance Study of Water Mobility in Flour Doughs

Transverse relaxation time (T 2 ) of water protons in wheat flour doughs, an indication of molecular mobility of water, was determined by pulsed nuclear magnetic resonance. The relaxation curves consist of two components with a long and a short T 2 , corresponding to a more mobile and a less mobile fraction, respectively. The less mobile fraction has a T 2 of about 20 msec and accounts for about 0.62g water per g dry solid. These values seem to be independent of flour strength and mixing time. The more mobile fraction increased with moisture content and showed T, value of about 60 msec for most samples. Mixing and addition of salt to the dough resulted in reduced T 2 .