8.3. Indonesia
Tempe kedele developed in Indonesia is a soybean fermentation. Soybeans are first soaked in water, generally overnight at ambient temperature, and they are then dehulled, partially cooked and inoculated with moulds of the genus Rhizopus. Tempeh, which contains over 40% protein, is a meat substitute and is used in soups or sliced, salted and deep fat fried in coconut oil. Lactic acid bacteria including Lb. casei and Lactococcus species dominate the fermentation,which may be initiated by the addition of a commercial culture or a small amount of a previous batch. Following fermentation, beans are bound together with the mycelia of Rhizopus oligosporus to form a compact ‘cake’. Tempe is being advocated as a protein-rich source of vitamin B12 in the Western vegetarian’s diet. The vitamin is thought to be produced by Klebsiella pneumoniae and Citrobacter freundii (Steinkraus, 1998) and is one of the most frequently cited examples of ‘bio-enrichment’. Tempeh bongkrek is a coconut press cake, which has led to deaths in its native central Indonesia. Toxicity is due to the production of toxoflavin and bongkrekic acid by the bacterium Burkholderia cocovenenans which can grow in the first few days of fermentation if Rhizopus growth is not favoured.