Effects of γ-irradiation on β-pinene content and germination in grapefruit were investigated in order to develop a method to identify γ-irradiated grapefruit.
β-Pinene is a component of essential oil in grapefruit and was reported to be susceptible to γ-irradiation. However, it was not degraded by irradiation (30 to 200krad) in this experiment. When grapefruit irradiated at 50krad were stored at 10°C for 2 months, no change of β-pinene content was found. β-Pinene itself was also stable to γ-irradiation at 1Mrad. Thus, identification of irradiated grapefruit from the amount of β-pinene was impossible.
On the other hand, the effect of γ-irradiation on radicle elongation was small but that on plumule expansion was so large as to prevent shooting in grapefruit irradiated even at 30krad. Therefore it should be possible to identify γ-irradiatd grapefruit by a germination method.