They're more common to find at Asian markets, where they often come in mesh bags of a half dozen, but my experience is they're often overripe and their fruit has become slightly translucent and mushy.
You can identify a ripe mangosteen by a rich reddish purple exterior that gives slightly when pressed. If it's darkened to a blackish purple and is very hard to the touch, it is probably over-ripened.
They are very rare at farmer's markets though. Growing them in the USA in most places requires a greenhouse as they need a tropical climate: year round high humidity and a minimum temperature of ~55-60F.
IIRC pinha the fruit is not native to Brasil, but to the Indian sub-continent like so many other amazing tropical fruits.
I would suggest for anyone looking for novel fruits in the northeast of Brasil, check out "Ingá", the variety that has the nickname "ice cream bean"[1]
I just popped in to ask the same question! I’ve been trying to find fresh lingonberries every Thanksgiving for years. You’d think that one could find anything in a city of this size, but >99% of it is just bodega bodega bodega
In the same vein -- is there any website that catalogues all the fruits you can buy around the world? That documents all the varieties, together with which countries/states/cities you can find them in?
When I travel, discovering new fruits is one of my favorite parts. Like when I discovered the custard apple [1] in Brazil, it blew my mind.
And it would be really cool to have a list of all the fruits you could buy when you travel to make sure you don't miss any. Or the fact that the article says tejocotes are sold in NYC -- when I've never come across them -- makes me wonder what other fruits are here that I also had no idea?
[1] https://en.wikipedia.org/wiki/Annona_squamosa