This really, I don't think, is the scientific name of the fruit because "ciruelas" technically means "plums". I guess these are tropical baby plums.
People sell bags of this fruit from wooden carts in the streets of santa marta. Buying a bag is like a guessing game, you never know what portion of the ciruelas are ripe and how many are still hard green and sour inside.
The perfectly ripe ones you can easily eat, skin and all. You just have to make sure to eat around the seed in the center which looks and feels like a tiny mango seed.
The ripe fruit tastes like a mix of a white grape and a mango. Yum.
But if you grab an un-ripe one, it is like biting into a lime. The sour ones taste better dropped in a beer.
Also, no one turns this street fruit into juice.