Tempeh

• Tempe is a widely consumed Indonesian traditional fermented food
• Tempe is principally made with soybeans, but can also be made from legumes and seeds
• Tempe is a staple food protein source for Indonesians, known for being inexpensive, affordable, and nutritious
• Soybean tempe was originally made by the Central Javanese and appeared in the 1700s
• In Indonesia, tempe is fermented with Rhizopus sp. Mould, especially R. oligosporus, R. oryzae, R. arhizus, R. stolonifer, R. microsporus
• Tempe has potential health benefits possibly due to biochemical changes during soybean fermentation
• During tempe processing, there are valuable changes in the increase of nutritional values of some nutrients in soybeans and the development of vitamins, phytochemicals, and antioxidants
• Microorganisms (bacteria and molds) ease the fermentation process in soybean products
• Tempe is the result of solid-state fermentation of soybean with the help of Rhizopus sp.
• The making of tempe goes through soaking, dehulling, washing, boiling, draining, cooling, inoculating with starter, and incubating at room temperature
• Soaking:

  • Allows the soybean to have full hydration
  • Supports the growth of Klebsiella pneumoniae to produce vitamin B12
  • Lactic acid fermentation occurs
  • pH of the soaked water is reduced to around 5.0
  • Inhibits (slows) the growth of spoilage microorganisms
  • Supports the growth of tempe starters
  • Softens the texture of soybean and makes it easy to remove the epidermis
• Dehulling:

  • Dehulled soybean is essential to have perfect fermentation by tempe starters
• Boiling:

  • Intended to kill unwanted microorganisms
  • Destroys the anti-nutrient constituents
  • Causes protein denaturation (bond weakening)
• Inoculating (introducing to) with microbia:

  • Soybean is inoculated with ragi (tempe starters) containing Rhizopus sp. (R. oligosporus, R. oryzae, R. chinensis, and R. arrhizus)
  • The inoculated soybean is packed into perforated plastic or banana leaf
• Incubating (keeping) at room temperature at 30 ±2◦C for 48 h:

  • Mold fermentation causes the hydrolysis of lipid and protein, increases the content of free fatty acids and amino acids, and decreases the carbohydrate content
  • Develops the flavors, antioxidant constituents, and improves the bioavailability of minerals
  • Indicated by the formation of a compact cake, where the beans are fully covered and bound together by the white mold Mycelia
• The results are limited air flow in the packaging: Rhizopus spp. sporangiospores will disperse and grow into a dense white mycelium that binds the soybean together to form a compact cake
• Fermenting soybeans with Rhizopus sp. mold is essential for improving the nutritional quality, flavor, texture, and shelf-life of tempe.
• Tempe is a more nutrient-dense food compared to soybeans, thanks to the fermentation process that enhances the bioavailability of nutrients and increases the overall nutritional content.
• Fermenting soybeans for tempe in banana leaves is a more traditional, environmentally friendly, and potentially safer option compared to using plastic.
• Rhizopus sp. mold plays a vital role in the fermentation of tempe by breaking down proteins and carbohydrates, improving the nutritional quality, texture, and flavor of the final product.