抄録
Studies have been made on the effects of gamma radiation on microorganisms and the preservative effects on foodstuffs were reported by L. E. BROWNELL and his co-workers. But in Japan, there is no experiment on the sterilization of foods by gamma rays. So we tried the effects of gamma;-radiation on “Kamaboko” (a kind of fish cakes and one of the most perishable of foodstuffs) using cobalt-60 as a source of gamma;-rays.
First of all, the sample “Kamaboko” was cut to about 2.5 cm. square, 1.5 cm. in thickness, and strictly sealed in order to irradiate and to prevent the re-entery by other microorganisms. The cut sample was enclosed in vacuum, with airtight polyethylene bag (or vinyl-chloride bag) and successively resealed in vacuum with another airtight polyethylene bag (or vinyl-chloride, bag), and irradiated with Co60 source a definite interval, and definite distance from the source, at room temperature 10°±2°C.
Particularly, the other sample was covered with tin-leaf and enclosed with airtight polyethylene bag in the same manner as above mentioned.
Radiation with 3 me-Co60, the poor results were obtained, but with 21 curie-Co60 irradiated “Kamaboko” was maintained in good fresh conditions (colors, appearance, smells, pH value and acidity) for 7 day incubation at 25±0.5°C and after storage for 12 days at room temperature.
When the sample “Kamaboko” was covered with tin-leaf and enclosed with airtight polyethylene bag, the preservative effects of gamma-radiation was greatly accelerated.
These results were shown in tables and figures in text mentioned belows.
