Kluwak Seed (Pangium edule Reinw.)

Pangium edule Reinw. is a tropical tree that grows in Micronesia, Melanesia, and Southeast Asia, including Indonesia. The tree is highly poisonous, mostly because of the presence of cyanogenic glucoside (Burkill, 1935). The tree requires many years to mature and the seeds are therefore most frequently harvested from wild trees, as it is not economically feasible to cultivate (Anonymous, 2010). Although poisonous to humans, the seeds of the tree form part of the natural diet of the babirusa (Babyroussa babyrussa) (Leus, et.al., 2001).

In Indonesia, seed kernels are edible after some treatment following the removal of the cyanogenic glucoside (Andarwulan, et.al., 1999 a). The seeds are first boiled and then buried in ash, banana leaves and earth for forty days, during which time, they turn from a creamy white color to dark brown or black. The method relies on the fact that the hydrogen cyanide released by the boiling and fermentation is water soluble and easily (Anonymous, 2010). Fermented kluwak seeds become chocolate-brown, greasy and very slippery. Cooked seeds are used in a number of popular Malaysian and Indonesian dishes (i.e. rawon, brongkos, pindang, sambel kluwak, and sop konro) (Anonymous, 2009).

According to Andarwulan, et. al. (1999 b), the fermentation process starts by placing harvested fruits in the field for 10 days until the fruit is tainted. The seeds are then removed, washed, and boiled for 3 hours. The seeds are then cooled, placed in a hole in the ground (indoors) and covered by ash. After 40 days, the fermented seeds are cleaned and can be used as spices.