Characterization of Polymer and Solute Bound Water by Pulsed NMR

Pulsed NMR signals from water in combination with two polymers and two solutes, individually and in mixtures, was measured over a w range 0.75–0.95. Both spin‐lattice (T 1 ) and spin‐spin (T 2 ) relaxation curves showed negligible slopes for water with starch and casein (polymer water) and large for water with sucrose and salt (solute water). Mixtures of polymer and solute waters showed intermediate slopes. Dilution of a sucrose solution gave T 1 and T 2 responses approaching that of pure water. T 2 from NaCl indicated less and from sucrose more water structure than pure water. NMR data coincided with sorption isotherms. It was concluded that polymer and solute waters show different NMR responses and can coexist in a food.