CHEMICAL INDEXES FOR ASSESSING FRESHNESS OF SHELLFISH DURING STORAGE

The changes in content of AT-P and related compounds were investigated in the muscle of oyster, hard clam, ark-shell, and abalone during sto rage at 5-degrees-C. We evaluated the efficacy of the K, K', and A.E.C . values calculated from the content of ATP and related compounds as f reshness indices. The degradation patterns of ATP and related compound s were different among the 4 species. ATP decreased rapidly in the oys ter and hard clam, but gradually in the ark-shell and abalone. AMP acc umulated in all 4 species, while further degradation to IMP and/or HxR occurred markedly in the oyster and ark-shell. Although the K values on the hard clam, ark-shell, and abalone were low at the acceptable st age, the K' value on the hard clam increased slowly but linearly and i ncreased rapidly and linearly for the oyster and ark-shell from the be ginning of storage. For the ark-shell and abalone, the A.E.C. value de creased rapidly and linearly during the acceptable stage. The K' and A .E.C. values appeared to be useful as freshness indices for shellfishe s.