Game Object Drop

Hello,

I am making a game like burger time, check it out here. I am currently working on making adding it when the player walks over the entire piece of tomato that it will fall to the platform below. I am having troubles making this work. This is more of a theory question then provide the code question. How do you other developers think you would go about making the tomato fall to the next platform? I think i should add some type of points behind the game object that the character has to touch. After all touch it should then fall?