These always result in failure if they are accidentally sliced by the player. If you struggle to get good scores because you are setting off bombs, you can play Zen mode to enjoy the game without them.
A bomb will always appear immediately after six fruits.
These are not as disastrous as Red Bombs, because they do not result in instant failure. If you strike one of the game's purple bombs, you lose 10 points, suffer the removal of all fruits on screen, without receiving any points, and lose the effects of any currently active Bonus Bananas.