DamageValue help

I made a plugin called CakeDrops and i have an issue.
I cannot for the life of me figure out how to store the damage value of the cake.
Say someone took a bite of a cake then they picked it up and put it back down.
The way the plugin stands right now it would give them a full cake.
The way i see fixing this is by storing the damage value of the picked up cake and then using an if statement to see if the cake has been eaten. if it hasnt then it will call the damage value of the cake and place a cake with the same value but if it is then it will place a full cake.