These are called mangosteens and are a type of seasonal tropical fruit. We were told to eat mangosteens after eating durians (another local fruit) to balance off the heatiness. Every time the mangosteens season arrives, I am reminded of the days when we were kids and living in an estate where there are many mangosteen trees. After school, we would armed ourselves with long bamboo poles and head off to the trees in search of ripe mangosteens to pluck. Of course we were told not to climb the trees for obvious reasons, but kids being kids, we naturally disobeyed and happily climbed from branch to branch searching for ripening fruits. Before we know it, we have reached the top of the tree and whoa! what a view! What a feeling... sitting on the branch, swaying in the breeze, with nary a care for the danger that we were putting ourselves in should we slip! Sigh! The joy of childhood days.... never to be experienced again...oh well, there is always the golden years to look forward to? hmmmmm..... doesn't sound right. lol!
Anyway, I have digressed...below are some pictures of how mangosteens look like in case you do not know already. Mangosteens are ripe when their skin have turned from green to light red then to dark red and eventually black, though I would not recommend that you keep them till they are black because they will be too ripe at this stage. Even the one in the picture below is considered too ripe for my liking but at least the stem is still green.
Be sure to choose those with skin without cracks or you will end up with inedible fruits as injured skin of mangosteens oxidises pretty fast, resulting in harden skin and brownish flesh too.
Aahhh....sweet and juicy!