Abstract:

The effects of electron beam and gamma ray irradiation on microorganism inactivation and oxidation in steamed
tofu rolls were studied in order to investigate the difference between both irradiations, which might be helpful for guiding the
application of electron beam irradiation in food processing and preservation. Plate count method was used to measure irradiated
samples for the total number of colonies as D10 values. 2-Thiobarbituric acid (TBARs) value was determined to show
the inductive oxidation effects of irradiation. Results showed that D10 values of electron beam and gamma ray irradiation
were 0.48 kGy and 0.43 kGy, respectively. There was no significant (P ≥ 0.05) difference between two irradiation methods
according to ANOVA analysis. The TBARs values of irradiated steamed tofu rolls increased significantly during storage (P ＜
0.05). Gamma ray irradiation led to a significant increase in TBARs value during storage whereas electron beam irradiation did
not show any effect. Electron beam irradiation had poorer oxidation effect on steamed tofu rolls when applied at the same dose
as gamma ray irradiation. In conclusion, electron beam irradiation showed a similar efficacy of microorganism inactivation but
less powerful oxidation effect than gamma ray irradiation.

Key words: irradiation, electron beam, gamma ray, microorganism inactivation, oxidation