Suppressive Effect of Salts on Degradation of ATP-related Compounds in Fish Flesh during Cold Storage

Abstract

Suppression of degradation of ATP-related compounds in fish flesh during cold storage by several salts was demonstrated by using HPLC. Contents of the nucleotides such as ATP, ADP, AMP and IMP were 0.28, 0.27, 0.41 and 0.28μmol/g, respectively in the ground flesh of non-salted Alaska pollack frozen surimi, and those of inosine (HxR) and hypoxanthine (Hx) were 0.57 and 0.38μmol/g. The total nucleotides decreased during storage at 4°C, while HxR or Hx increased in return. An addition of 0.5M salts suppressed the degradation from IMP to HxR during storage, in the order of CaCl₂>MgCl₂>NaCl=KCl. On the other hand, the total nucleotide content in the ground flesh of sardine was 11.2μmol/g, in which IMP comprised 86%. The degradation of IMP during storage was also suppressed by 0.5M salts, in the order of NaCl =KCl>CaCl₂. It was presumed that these salts suppressed the degradation from HxR to Hx in addition to that from IMP to HxR, since HxR was considerably accumulated during storage in the presence of the salts.