Determination of the Phase Change in the ¹H-NMR Relaxation Behavior of Dehydrating Soybean Seed Using the AIC Method

The physical state of water in dehydrating soybean seeds determined by the NMR relaxation times (T₁) was analyzed using AIC and a three phase regression model was the most appropriate. The first transition occurred at a 44% water content and the second at 18%. In the first phase, the water content 60% at the "physiological maturity" stage, at which time developmental processes in the majority of seeds either cease or slow down. In the second phase, the seeds quickly lost loosely bound water from the cytoplasm during a very short period. In the third phase, a glassy state could represent a useful mechanism to trap residual water molecules and to prevent damaging interactions between cell components and thus T₁ might increase at the glass transition point. The three phases demonstrating cytoplasmic water might thus correspond to desiccation tolerance with a different dehydration process.