Changes in Polyamines and Amino Acids in Ascidian Halocynthia roretzi Muscle during Storage.

The changes in contents of polyamines and free amino acids (FFA) were investigated in the ascidian muscle during storage at -3°C, 2°C, and 20°C. Agmatine (Agm), tryptamine (Tpm), and spermidine were distributed in the live ascidian muscle. Agm and Tpm increased as the decomposition of muscle progressed, reaching the levels of approximately 1.20 and 0.90mg/100g at the stage of initial decomposition, respectively. From these results, it was concluded that Agm and Tpm could be useful as freshness indices for ascidian muscle. As dominant amino acids, taurine (Tau), proline, glutamic acid, and glycine accounted for 66% of the total FAA in the ascidian muscle, especially Tau alone 26%. The total FAA in-creased in the early stages and then decreased before the stage of initial decomposition, irrespective of storage temperature. An increase in Tau content was observed while hypotaurine (Hypotau) decreased during storage. The ratio of Tau: Hypotau became greater during storage regardless of storage temperature. Thus, Hypotau appeared to be a precursor of Tau.