We're in Panama, and frequently see hand-lettered signs for 'frutas duras' at at fruit/vegetable stands. We assume 'frutas' means fruits. But 'duras'? Un-ripe? That doesn't seem right, as who would buy un-ripe fruit?
La significa refresco congelado
So I suppose that could mean a cold/frosty fruit beverage,
but more likely they're advertising cold, refreshing fruit.
By the way, you will likely only see this use of duras in and around Panama.