The changes in content of ATP related compounds, polyamines, volatile basic nitrogen (VBN), and lactic acid were investigated in the kuruma prawn muscle during storage at 5°C, 0°C, and -1°C in relation to freshness
During storage at low temperatures, ATP decreased rapidly, while AMP and IMP accumulated. Although the levels of inosine (HxR) and hypoxanthine (Hx) were low at the acceptable stage, Hx increased remarkably as decomposition progressed. The increase in K values was considerably slow and reached around 20% at the stage of initial decomposition. As for polyamines, putrescine (Put) was absent at the acceptable stage, detected in a small amount at the stage of initial decom-position, and then increased markedly at the stage of advanced decomposition. VBN increased linearly with storage time and reached 20 to 26mg/100g at the stage of initial decomposition. Lactic acid increased to the level of about 50mg/100g during storage at low temperatures and decreased as the decomposition progressed. K value, VBN, and lactic acid contents appeared to be useful as potential indices for the freshness of kuruma prawn. Furthermore, Put and Hx con-tents seemed to be useful as decomposition indices for kuruma prawn.