Tempeh is a fermented soybean product originating from Indonesia. It is made by fermenting cooked soybeans with Rhizopus moulds, resulting in a firm, compressed cake with a mild flavor. The traditional production process involves soaking, dehulling, cooking, and mixing soybeans with tempeh starter before wrapping and incubating to allow mould growth. Fermentation increases nutrients and breaks down compounds causing flatulence. Tempeh production is still predominantly small-scale in Indonesia and Malaysia, but it has spread to other countries and can now be produced industrially using stainless steel equipment and pure mould cultures.

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Tempeh production
Dr. Esther Shoba R
Assistant Professor
Kristu Jayanti College
Bangalore

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INTRODUCTION
Tempeh is a fermented soybean product of Indonesian origin.
It consists of cooked, dehulled whole soybeans which have been fermented by
Rhizopus moulds.
It is a moist solid cake with a mild, pleasant taste .
It is usually sliced, dipped into a salt solution and deep-fried in oil.
The traditional product is highly perishable and is usually consumed the day it is
made.
In industrial production, it can be preserved by drying or freezing (after blanching to
inactivate the mould and its enzymes.)

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 Tempeh is still, predominantly a home-made or cottage-industry product in
Indonesia and Malaysia.
 It is practically unknown in Japan.
 However , it has been introduced to the U.S.A. and to Europe, mainly for the
population of Indonesian origin and for the rapidly expanding Indonesian
restaurant trade.
 It is made in modern, sanitary plants, using stainless steel equipment and
sometimes, pure cultures of mould.

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 Production methods vary as with most traditional foods. In a typical process,
soybeans are soaked in water, dehulled and then cooked in boiling water for one
hour.
 After draining the soybeans are spread out for air-drying of the superficial moisture.
 Tempeh from the previous day is used as a starter.
 The prepared soybeans are thoroughly mixed with the starter, wrapped in banana
leaves and left to ferment for one to two days.
 Mould growth is vigorous and the whole mass is soon covered and bound together
by Rhizopus mycelium.
 The traditional banana leave is replaced by suitable plastic materials or foil,
perforated to provide the moderate aeration necessary for mould growth without
excessive sporulation.
 Commercial dehulled full-fat grits can be used instead of whole soybeans.

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FLOW CHART

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 1. Beans are soaked overnight in what is known as the prefermentation.
 2. Early the next morning the beans are dehulled and split, using anything from mills to hands and feet.
 3. Beans are cooked in open kettles where more dehulling takes place.
 4. Cooked beans are placed in a large woven colander about 3 feet across and placed in front of fans to
dry.
 5. Cooled beans are inoculated with the culture.
 6. Incubate at around 30 °C for 48 hr.

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 7. Inoculated beans are now scooped into perforated plastic bags or banana
leaves.
 8. Whereas the perforated plastic bags were the most common way of incubating
tempeh, most cooks preferred tempeh incubated in banana leaves.
 9. Incubation takes place in a room or closet where inoculated beans sit out at
room temperature on wooden slats.
 10. After 2 days the tempeh is sold in its perforated incubation bag or banana leaf
in the marketplace.

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CHANGES DURING FERMENTATION
 A. Changes in Lipids
 Free fatty acids increased from 0.5% in the unfermented control to 21.0% in the
dehydrated tempeh (with the same moisture content). During fatty acid
synthesis, Rhizopus sp. produced only gamma-linolenic acid (GLA) instead of
alpha-linoleic acid. GLA is a prostaglandin and leukotriene precursor. It is used
therapeutically to decrease the cholesterol and triglyceride content in blood. It is
not found in soybean.
 B. Changes in Carbohydrates
 During fermentation, the principal changes in carbohydrates are the rapid
decrease of hex-oses and the slow hydrolysis of stachyose, the flatulence factor
in beans. This makes tempeh a more socially acceptable soybean product.

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 C. Changes in vitamins
 Riboflavin increased by 2-47 times, niacin increased by 2-7 times, and vitamin
B12 by 33 times. Thiamin, unfortunately, decreased.
 Panthothenic acid has been reported to stay the same or increased by 2-4 times.
 Pyridoxine increased by 4-14 times.
 Biotin and total folate compounds were respectively 2.3 and 4-5 times higher in
tempeh than in unfermented soybeans.

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D. Presence of Antioxidants and Antibiotic in Tempeh
 An isoflavone identified as 6,7,4'-trihydroxy isoflavone (called Factor 2) has been
reported The antioxidative effect of factor 2 on retinol was about the same as
DL-alpha-tocopherol, and three times that of genistein.
 In Indonesia, tempeh is widely used to ween babies off mother's milk and to help
patients recover strength from dysentery and other ailments of the intestinal tract.
 R. oligosporus NRRL 2710 was reported to produce an antibiotic active
compound against a number of gram-positive bacteria including S. aureus and B.
subtilis, as well as the gram negative K. pneumoniae.
 This may help explain why tempeh is provided to patients with dysentery and
other ailments of the intestinal tract.

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NUTRITIVE VALUE
 Tempeh is very nutritive and contains many health promoting phytochemicals
such as isoflavones and saponins.
 Tempeh fermentation produces natural antibiotic
 Tempeh is a complete protein food that contains all the essential amino acids.
 Isoflavones (reduce risk of coronary hearth disease and some cancers.)
 Protein High quality Nutritional loss Very low during process
 Rich in P, K, Fe Good source Of vitamin B(thiamine) and vitamin K

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 (1)An excellent source of protein, contains all the essential amino acids; same
quality protein as meat or poultry.
 (2) Excellent source of calcium.
 (3) Low in saturated fat
 (4)High in essential fatty acids & vitamins , Cholesterol free.
 (5)High in soluble dietary fiber.
 (6) Easy to digest because the fermentation process breaks down the complex
proteins found in soybeans, making tempeh more easily digested than non-
fermented soy foods or whole soybeans.
 (7) High in isoflavones. (Cancer Preventing)
 (8) A good source of folic acid.
 (9) low in sodium.

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