Guanábanas in Colombian Market
The guanábana is a large tropical fruit with white flesh and large black seeds. It has a sour flavor, hence the English name "sour sop". The fruit is used to prepare a beverage. In Colombia I often found the juice prepared with milk, but the canned guanabana juice that I find in the US is prepared with water.
The fruits are surprisingly large. Some of the fruits in this photo were a foot long (30 cm).
The botanical name for the guanábana is Annona muricata, in the family Annonaceae. While in Colombia I also ate two related fruits, called "cherimoya" and "anon" -- both of which are smaller (fist sized), sweet instead of tart, and are typcally eaten fresh.