Besides fresh consumption, mangosteen pulp can be commercially processed into various products such as jams, candies, bars and pastilles, frozen mangosteen, spray dried mangosteen pulp powder and mangosteen in heavy syrup.

Canning: Canned fruits command high prices in Japan and other countries. Mangosteen fruits have been canned for export marketing. The fruit required for canning is of a small size, about 40g per fruit or 23-25 fruits per kg, and the fruit colour should be of maturity stage 3, 4 or 5. Fruits can either be canned as whole or separated segments. The drained weight is about 280 to 340g. The steps involved in the process of canning of mangosteen are shown in the following flowchart.

A flowchart showing the steps involved in the process of canning of mangosteen

[Source: Kanchanapom and Kanchanapom (1998)]

Crystallisation: Crystallized mangosteen is very popular in Thailand. It is prepared from fruits collected at the blood-line stage, peeled under water, crystallized and then skewered onto wooden sticks.

Freezing: Quick freezing of mangosteen maintains fruit quality. Freezing can also maintain flavour and volatile substances in the product at nearly the same level as for the fresh fruit. Deep-freezing at -18 to -27 °C can extend the storage life of mangosteen up to six months. In Thailand, half-rind frozen mangosteen is more acceptable than whole rind. Polystyrene (PS) foam tray wrapped with stick film is found to be the most suitable package for whole rind frozen fruits for retail markets. Frozen mangosteen is now commercially available.

Mangosteen jam and preserve: To make jam (Malaysian style), heat the sugar (equals to the weight of mangosteen pulp) with half a cup of water until dissolved and filter the syrup through a fine cloth. Mix the mangosteen pulp (seedless) with 1 cup of water with a few cloves and heat for 15 to 20 minutes. Stir while heating until soft. Add syrup and lime juice and stir until the mangosteen turns clear and thickened. Prepare a jar for keeping the jam by immersing in boiling water for 5 minutes and then placing upside down over low heat until dry. Pour in the jam while still hot and close the lid tightly. In the Philippines, a preserve is made by simply boiling the segments in brown sugar, and the seeds may be included to enrich the flavor.

Mangosteen jelly: The rind is rich in pectin. After treatment with 6% sodium chloride to eliminate astringency, the rind is made into a purplish jelly.

Preserved mangosteen

Ingredients:

50 mangosteen fruits
2 cups of granulated sugar

Directions: Mix the mangosteen pulp into the sugar and place in a brass frying pan. Using low heat, stir until liquid issues from the fruit. Gradually increase the heat and continue mixing until the seeds become brittle. Keep in a tightly sealed container. Preserved mangosteen can be kept for a long time before eating .

Compressed mangosteen:

Directions: Pare mangosteen fruit and remove the pulp from the peel using a stainless steel or wooden fork, so that the fruit flavour is not tainted by metal.

Take care not to separate the segments. Place in a jar. Prepare syrup from 1 cup of granulated sugar and 1 cup of water and pour onto the mangosteen. Place the jar in a pan of water and boil gently as follows:

Large jar - 20 minutes
Medium-sized jar - 15 minutes
Small jar - 10 minutes

Roasted/ boiled seeds: The seeds are sometimes eaten alone after boiling or roasting.