In a nonreactive medium saucepan, simmer the pineapple juice, strawberry juice, orange juice, lime juice, apple, and star anise over low heat until the apple is just tender, about 12 minutes. Transfer to a large bowl and refrigerate until chilled. Discard the star anise and stir in the berries. Divide the soup among 6 bowls. Add a scoop of lemon sorbet and about 2 tablespoons of Champagne to each bowl and garnish with the basil.