Dice the mango pulp and puree with the raspberries. Mix well with the powdered sugar and lemon juice, pour into a flat metal bowl and freeze in the freezer for 2-3 hours, stirring occasionally. Place in the refrigerator an hour before use.
Peel the mango and papaya and cut into strips. Arrange in a star shape on a dessert plate, place a scoop of sorbet in the middle.