Directions: Prepare the pineapple by cutting the bottom and spiky top off the fruit. Stand upright and cut off the skin, removing all the spikes and as little of the flash as possible.
Lay the pineapple on its side and cut into a bite-size chunks. Place the pineapple, oranges, lemon juice and grapefruit in a food processor or blender and process for a few minutes until all the ingredients are combined. Press the fruit juice through a sieve to remove any pith or membrances. Serve chilled with breakfast or a snack.