Peel the clementines, separate into segments, and halve them. Squeeze juice from the lemons. Wash apples and dice finely without peeling; toss in a bowl with lemon juice to prevent browning. Add clementines.
Peel oranges and grapefruit, supreme by removing segments from membranes with a sharp knife. Halve orange segments and cut grapefruit into thirds. Add to bowl. Pick mint leaves and incorporate.
Drizzle with grenadine syrup, sprinkle brown sugar, and mix gently. Chill until serving. Thirty minutes prior, cube bananas and fold in for peak freshness.
