Visualized Radiation

Potassium-40 contained in foods emits β-particles and γ-rays.

The distribution of potassium can be found by using an imaging plate¹ and detecting β-particles from Potassium-40.

The above image was obtained by placing pieces of pork meat, banana and ginger on an imaging plate and exposing for 25 days while blocking shielding external radiation. The protein part of the pork meat, the peel of the banana, and the buds of the ginger contain relatively large amounts of potassium. It can be seen that the fat portion of the pork meat contains little potassium.

1. An imaging plate is a support medium, such as a plastic sheet, coated with a fluorescent substance that reacts to radiation.
   By placing a sample containing radioactive materials on a plate for a defined period of time, two-dimensional distribution of radioactivity in the sample can be examined.

• Included in this reference material on March 31, 2013
• Updated on March 31, 2019