O-17 NUCLEAR-MAGNETIC-RESONANCE STUDIES OF WATER MOBILITY DURING BREAD STALING

The O-17 signal from bread treated with enriched water was observed during staling. Bread samples containing various humectants and surfactants (as well as a control sample containing neither) were used. Both the transverse relaxation time (T2) and the integrated signal intensity were monitored. During staling T2 decreased by 20-30%, and the intensity decreased by 0-22% depending on the nature of the additives. The NMR data do not correlate with the inhibition of amylopectin crystallization by surfactants. We conclude that the high-resolution NMR experiment is sensitive to only that fraction of water which is present in the amorphous region. The changes in T2 and intensity were due to changes which took place in that region.