Quality changes of veal during freeze-thaw cycles determined by LF-NMR

The method of low field nuclear magnetic resonance(LF-NMR) was used to study the water distribution in veal during the process of freeze-thaw cycle. By analyzing transverse relaxation time,we found the correlations between LF-NMR parameters and meat quality changes. The results showed that with the increasing number of freeze-thaw time,the thawing loss changed significantly,the pressure loss and shear force showed a significant increase at the third time of freeze-thaw. The lightness value L increased first then decreased later,redness a* decreased gradually,yellowness b* increased gradually. The LF-NMR data indicated that three peaks of transverse relaxation times,T2 b,T21and T22,which represented three different groups of water in muscle as bound water,immobilized water and free water,respectively. Among them,the T21 had a significant correlation with the number of freeze-thaw time,thawing loss,pressure loss and lightness(p<0.05). As conclusion,the T21 might be used as a reference indicator to evaluate thawed veal quality.