Correlation of Proton T ₁ with Polymer and Solute Waters in Starch‐Sucrose Mixtures

Proton pulsed NMR methodology was applied to correlate the observed spin‐lattice (T 1 ) and spin‐spin (T 2 ) relaxation times with the amount of water associated to sucrose (SOL) and that to starch (POL) in a sucrose‐starch model system containing both. Sucrose, starch and four mixtures were equilibrated to four water activities (a w , 0.86‐0.97). Calculations for T 2 were invalid due to an undeterminable amount of molecular diffusion caused by field inhomogeneity in the magnet. Model equations were developed for calculating SOL and POL from T 1 and a w ; These values showed high correlations (R 2 >0.97) with SOL and POL as determined from sorption data for sucrose and starch. This validated the use of this instrument with the mathematical models developed.