When food is irradiated with gamma rays, the duration of the radiation effect depends on the type of radiation used and the specific requirements of the process. Gamma rays are a form of ionizing radiation and can penetrate deep into the food.
In general, the radiation does not linger in the food after the irradiation process is complete. Once the food has been exposed to the gamma rays, the radiation source is turned off, and the food no longer receives any additional radiation. The gamma rays themselves are not persistent and do not remain in the food.
However, it's important to note that the process of food irradiation can induce chemical changes in the food. These changes are a result of the interaction between the radiation and the molecules within the food. The extent and nature of these chemical changes depend on various factors, including the dose of radiation applied and the composition of the food.
After irradiation, the food does not become radioactive. It does not retain any residual radioactivity from the gamma rays. However, the chemical changes induced by irradiation can affect the quality, shelf life, and nutritional content of the food. Therefore, regulatory bodies in different countries set specific limits and guidelines for the maximum allowable radiation doses for various types of food to ensure food safety.
It's worth noting that irradiation is a well-studied process, and its effects on food are carefully evaluated to ensure that the benefits, such as improved food safety and extended shelf life, outweigh any potential negative impacts.