The pineapple-guava ring can be frozen for up to 3 days.
To make fresh pineapple juice, peel and core a pineapple, cut it into small chunks and puree in a blender. Work the puree through a fine-mesh strainer. Let the juice stand for about 30 minutes. Skim off any foam and use the clear juice. One pineapple yields about 2 cups of juice.