Stew the apples in very little water, a few squirts of juice from a lemon and a tiny bit of sugar. Strain through a fine sieve. If necessary, dilute with a little apple juice and leave to cool.
Steam the black currants in very little water, a few squirts of lemon juice and a little bit of sugar. Cool, crush and strain through a fine sieve. If necessary, dilute with a little mineral water and chill in the refrigerator.
Separately crush kiwis, mango, papaya and raspberries. Now strain through a fine sieve. If necessary, dilute the individual purees with a small amount of mineral water and refrigerate.
Pour one tablespoon of each puree into chilled soup plates. Gently push the plates to distribute the purees evenly. Place a teaspoon of yogurt in the center of each plate and run a wooden skewer through the purees in a spiral pattern to create a pretty pattern.
Garnish the plates with a few raspberries and mint leaves and dust the rim with a little powdered sugar, if desired.
Tip: Use creamy natural yogurt for an even finer result!