The mangosteen is sometimes called the queen of fruits but, unlike the durian (which is considered the king), most people like the flavour immediately.
What is it? A small fruit with a thick, spongy, reddish-purple shell and a green cap. The flesh inside is soft, sweet and fragrant with a creamy texture.
What to look for: the shell should be firm but not too hard, which would indicate the fruit is under-ripe. If there are soft spots, the contents could be bruised or (worse) mouldy. If the fruit smells fermented, don't buy it.
How is it available? Fresh, frozen and canned - but fresh is best. Rich in antioxidants and said to improve the immune system, mangosteens are made into canned juice and nutritional supplements.
What else? The easiest way to open a mangosteen is to press firmly on either side of the shell with the palms of your hands - it will split open (the juice stains, so be careful). The base of the fruit has a small 'flower', with each petal representing a segment of fruit inside. The more petals the better because the smaller segments have smaller or no seeds. The leaves of the mangosteen sometimes harbour insects, so rinse the fruit thoroughly before peeling.
How to use: if you love the fruit, you'll enjoy them unadulterated and in large quantities. They taste best slightly chilled. Mangosteen sorbet is delicious because there's little to interfere with the flavour of the fruit. You'll need to make it quickly because the fruit darkens when exposed to air. Have ready a syrup solution made by dissolving two parts sugar into three parts hot water (by weight). Chill the syrup until it's very cold. Puree the peeled mangosteen, measure the puree and mix with two-thirds that amount of syrup plus enough fresh lemon juice so the flavour is pleasantly tart. Process in an ice-cream machine according to the manufacturer's directions then freeze to allow the flavours to ripen.
Make mangosteen jam by using proportions of about four parts fruit to three parts sugar - mix the ingredients together and allow to stand until the sugar dissolves. Cook, stirring constantly, until the mixture reaches the jelling point then stir in fresh lemon juice. Ladle into sterilised jars, cover with sterilised lids then boil in a water bath for 15 minutes (or store in the fridge).