NMR state diagram concept

The objective of this presentation is to introduce a new concept, "NMR State Diagram. " The spinspin relaxation times (T2) of low moisture content food ingredients at different temperatures were determined using an NMR spectrometer. The obtained relaxation times were plotted against the corresponding temperatures. Our research showed that the shapes of temperature urves fell into distinct patterns. There are three significant features of these curves. The first important feature is the transition point with a corresponding transition temperature of T_Tran- The second and third important features of these curves are the slopes of the near-linear portions before and after the transition point, respectively. The occurrence and position of the transition point and levels of the slopes were found to highly correlate to the physiochemical characteristics of the samples. Therefore the temperatnre-T2 curves can be treated as a state diagram. The potential applications of this NMR State Diagram concept may include: (1) ingredients screening, useful for product formula development, (2) prediction of physiochemical changes (texture, viscosity, caking, water and fat migration, etc), chemical degradation of nutrients and microbiological activity, which are associated with mobility of water and polymers, (3) Combined with MRI (magnetic resonance imaging) techniques, the concept would greatly improve our understanding of quality and safety of food products, especially intermediate moist foods (IMF).