H-1 AND NA-23 NMR RELAXATION-TIMES STUDY OF PECTIN SOLUTIONS AND GELS

H-1 and Na-23 longitudinal and transverse relaxation times have been m easured to examine the concentration dependence of the dynamic behavio ur of pectin solutions and gels. T1 and T2 relaxation times were measu red in HDE pectin solutions and gels prepared with different cosolutes . A lowering of T1 and T2 values was observed in relation to a better efficiency of the intermolecular forces between polymer molecules and/ or the formation of more extended junction zones. The T1/T2 ratio was also exploited indicating that even bulk water experiences anisotropic motions due to the gel formation. A correspondence of NMR results wit h previous reported data of rheological measurements of pectin gels pr epared with the same cosolutes was found.