Final answer:
Irradiation of meat primarily causes the killing of most harmful bacteria without making the food radioactive or significantly changing its nutritional value. Some changes in flavor may occur, especially in high-fat foods.
Step-by-step explanation:
Irradiation of meat causes most harmful bacteria to be killed. This process involves exposing food to ionizing radiation, such as from cobalt-60 or cesium-137, which disrupts the DNA-RNA-protein synthesis cycle necessary for bacterial reproduction. The food does not become radioactive and it does not lose significant nutritive value. However, irradiation can cause a change in flavor, particularly in foods with high fat content, though this can be minimized with lower doses and colder temperatures. It's important to note that irradiation does not cook food to a safe temperature, which is a separate process entirely.