Investigation on Variation of Water State and Quality of Dried Shrimp during Rehydrated Process by LF-NMR and MRI

KeyWord:LF-NMR  MRI  dried shrimp meat  rehydration  water state  quality

Abstract:

      The water distribution and state change of dried shrimp meat during rehydrated process at 25 ¡æ were investigated by LF-NMR and MRI,and the correlation between NMR parameters and texture,rehydration ration was analyzed to construct the predicted mode by linear regression analysis.Three water components,i.e.bound water,immobilized water and free water were observed in dried shrimp meat during the rehydrated process.The contents and mobility of immobilized water and free water increased as the extension of the rehydration time,while that of bound water did not change obviously.The results of MRI indicated that the water absorbed by the dried shrimp mainly was components with short relaxation time,and permeated from head to body and tail.Good linear correlation was observed between the NMR parameters (T22£¬T23£¬A22£¬A23 and ATotal) and texture profile analysis parameters including the hardness,chewiness,springiness,cohesiveness and rehydration ratio of dried shrimp meat(R2¡Ý0.613),which could provide a rapid and non-destructive method to predict the quality of dried shrimp meat during rehydrated process.