Only on the surface of meat like beef will you find the bacteria that can give you food poisoning - ensuring it is seared on all sides, it doesn't matter what the middle is like. Obviously, if the thing is green then it is too past it anyway.
However, don't take this to mean it is the same for all meats such as pork and chicken; pork in particular can have worms that travel and nest in your eye, and the worm eggs are deeply embedded in the muscles and needs to be cooked through (by cooking through, it means the very deepest centre of whatever meat your are cooking needs to reach 70 Celci. for at least two minutes).
However, don't take this to mean it is the same for all meats such as pork and chicken; pork in particular can have worms that travel and nest in your eye, and the worm eggs are deeply embedded in the muscles and needs to be cooked through (by cooking through, it means the very deepest centre of whatever meat your are cooking needs to reach 70 Celci. for at least two minutes).


