Unlock ability when you eat

HI, Im sure its possible to make custom ability like place a block when u press a key, i already did that, but i try to make that if u eat a spesific item, u unlock the ability to place that a block when u press a key. example one piece: i have a fruit that allow me to use the power of fire, i want to make that when i eat the fruit, i can press i key like ehh: C. i press C and boom, fire appear, is that possible t od othat? if yes, than can u tell me how

Ro...

thx