Changes in Concentration of ATP-related Compounds in Various Tissues of Oyster during Ice Storage

Abstract

Changes in the levels of ATP-related compounds were investigated in the adductor muscle, mantle, gill, and body trunk of the oyster Crassostrea gigas during ice storage, in relation to fresh-ness. The determination was performed using an improved HPLC system with isocratic elution.
The level of ATP-related compounds in the adductor muscle was about twice that found in the other 3 tissues tested. In adductor muscle, ATP decreased rapidly, while AMP and IMP accu-mulated. Only adductor muscle contained AdR. The K value in the adductor muscle increased linearly but slowly during storage (about 22% at the initial decomposition stage), while the K' value increased rapidly and reached about 70% at the initial decomposition stage and thereafter remained constant. In mantle, gill, and body trunk, ATP levels decreased slowly, whereas ADP and AMP accumulated. IMP was present at low levels. The K values in the 3 tissues were low at the acceptable stage. The K' value increased slowly but linearly during storage. A. E. C. value decreased rapidly and continuously from 70-80% to 10-20% during the acceptable stage. Although K or K' values in the adductor muscle and K' or A. E. C. values in the other 3 tissues could be used as freshness indices, the K' value in the adductor muscle and the A. E. C. value in the other 3 tissues appeared to be most useful as freshness indices of oysters.