The Change of Moisture in Cherry by Low-field NMR

The change and migration law of moisture in cherry stored at room temperature was researched by low-field nuclear magnetic resonance(NMR) technology. Free induction exponential decay curve was measured by using CPMG pulse sequences,transverse relaxation time T2was obtained by inversion operation. The experimental results showed that cherry's internal moisture mainly existed three states: free water,immobilized water and bound water,the content of free water reduced continuously with the storage time,a part of free water evaporated to the outside,and other part of free water changed into immobilized water and bound water,in order to maintain the normal metabolism of pulp cells. At the later storage period,part of free water migrated to the core for enough moisture and activity. The NMR imaging results showed that peel and flesh of cherry layered,and moisture migrated in cherry from surface to the inner with the extension of storage time,analysis results were consistent with the T2spectra.