The effects of two irradiation doses (2.5 and 5 kGy) on nucleotide breakdown compounds in sea bass stored in ice were investigated. Nucleotide degradation was slower in sea bass irradiated at 2.5 and 5 kGy than untreated samples. Irradiated samples had lower hypoxanthine and inosine content than the control group. Significant differences (p < 0.05) in K and related values were found between control groups and irradiated samples (2.5 and 5 kGy). H and G values showed a good correlation with storage time (r(2) >= 0.98) while linear regressions of K and Ki ranged from 0.95 and 0.93 to 0.98 and 0.97, respectively. A dose of 5 kGy seemed to be more effective than that of 2.5 kGy to reduce nucleotide breakdown in sea bass. The best linear correlation was obtained from G and H values: thus, they might be used as freshness indicators for non-irradiated and irradiated sea bass. (C) 2010 Elsevier Ltd. All rights reserved.