Abstract: Ovalipes punctatus meat was used to investigate the effects of electron beam (EB) irradiation on its nutritional and taste components in order to provide a basis for scientific application of EB irradiation. The results showed that the contents of total amino acids and non-essential amino acids in crab meat irradiated with doses equal to or greater than 7 kGy decreased obviously. Irradiation did not change the first or second limiting amino acids of crab meat. The ratio of essential amino acids to total amino acids (EAA/TAA) and the ratio of essential amino acids to non-essential amino acids (EAA/NEAA) in both unirradiated and irradiated groups exceeded 40% and 60%, respectively, indicating good protein quality. The results of fatty acid composition showed that EB irradiation had no significant effect on the content of saturated or unsaturated fatty acids. With the increase of irradiation dose, the total amount of free amino acids in crab meat showed a downward trend, whereas the contents of umami and sweet-umami free amino acid increased, which indicates that the appropriate irradiation dose could improve the taste of amino acids in crab meat. The main flavor nucleotide in crab meat was IMP. After EB irradiation, the contents of AMP and IMP while GMP content decreased thereby enhancing the umami taste of crab meat. Based on the synergistic effects of umami amino acids and flavor nucleotides, equivalent umami concentration (EUC) value in each irradiation group was higher than in the control group. The 1 kGy irradiation group had the highest EUC value of 17.92%. Collectively, EB irradiation at doses of 1–9 kGy had no obvious negative effect on the nutrition or taste of crab meat and it could be suitable for the pretreatment of crab meat.

Key words: Ovalipes punctatus, electron beam irradiation, amino acids, fatty acids, flavor nucleotides