Slice each banana in half lengthwise; slice in half crosswise.
Cut 4 (10-inch) circles of parchment paper. Fold each circle in half; open each.
Place 4 pieces of banana near fold; top with 1 tablespoon juice mixture. Fold paper over filling; seal edges with narrow folds. Repeat procedure with remaining ingredients.
Place packets on baking sheets.
Bake at 350 for 5 minutes or until packets are slightly puffy and contents are thoroughly heated.